The relationship between dysphagia and the localisation of brain lesion in stroke: is the involvement of the pons and medulla important?

OBJECTIVES

The presence of dysphagia in stroke is associated with mortality and morbidity. The aim of this retrospective study is to present the relationship between dysphagia and the demographic characteristics of the patient, and the type and localisation of brain lesion in the acute period in stroke patients with dysphagia.

MATERIALS AND METHODS

The data of 284 patients who had stroke-related dysphagia, had a disease duration 1-3 months, had no history of swallowing dysfunction before the event, and had their brain MRI/CT reports in the hospital were included.

RESULTS

The rate of tube-dependent oral areas was higher in the lesions located in the pons and the medulla than in the lesions located in the MCA cortex, the basal ganglia, and the cerebellum (p ˂ 0.001, p = 0.032 and p = 0.011, respectively) and the percentage of those fed with NG + TPN + PEG was statistically significantly higher (p = 0.002, p = 0.032 and p = 0.011, respectively). History of pneumonia was found to be statistically significantly higher in the lesions located in the pons and the medulla than in the lesions located in the MCA cortex, ACA cortex, PCA cortex, the basal ganglia, periventricular white matter, the thalamus, the cerebellum, and the midbrain (p ˂ 0.001, p = 0.005, p = 0.023, p ˂ 0.001, p = 0.023, p = 0.001, p = 0.011 and p = 0.023, respectively).

CONCLUSION

In conclusion, although lesion localisation in the acute period in patients with dysphagia varied in terms of clinical swallowing evaluation findings, weight loss, pneumonia history, the rate of tube-dependent intake, were shown to be higher in patients who had lesions in the pons and the medulla, which is a finding that should be considered in the clinical follow-up of acute stroke patients with lesions in the pons and the medulla.

Diagnostic delay of multiple sclerosis: prevalence, determinants and consequences

BACKGROUND

Early diagnosis and treatment of patients with multiple sclerosis (MS) are associated with better outcomes; however, diagnostic delays remain a major problem.

OBJECTIVE

Describe the prevalence, determinants and consequences of delayed diagnoses.

METHODS

This single-centre ambispective study analysed 146 adult relapsing-remitting MS patients (2016-2021) for frequency and determinants of diagnostic delays and their associations with clinical, cognitive, imaging and biochemical measures.

RESULTS

Diagnostic delays were identified in 77 patients (52.7%), including 42 (28.7%) physician-dependent cases and 35 (24.0%) patient-dependent cases. Diagnosis was delayed in 22 (15.1%) patients because of misdiagnosis by a neurologist. A longer diagnostic delay was associated with trends towards greater Expanded Disability Status Scale (EDSS) scores (B = 0.03; p = 0.034) and greater z-score of the blood neurofilament light chain (B = 0.35; p = 0.031) at the time of diagnosis. Compared with patients diagnosed at their first clinical relapse, patients with a history of >1 relapse at diagnosis (n = 63; 43.2%) had a trend towards greater EDSS scores (B = 0.06; p = 0.006) and number of total (B = 0.13; p = 0.040) and periventricular (B = 0.06; p = 0.039) brain lesions.

CONCLUSION

Diagnostic delays in MS are common, often determined by early misdiagnosis and associated with greater disease burden.

Cerebral Neuroschistosomiasis Presenting as a Brain Mass

Neuroschistosomiasis is a rare manifestation of schistosomal infections presenting with cerebral and spinal cord involvement. We reported a case of a 31-year-old woman who presented with a history of headache, dizziness, and nausea. Brain MRI with contrast showed features suggestive of brain lesion with edema, and a serology test for Schistosoma was positive. She was diagnosed with neuroschistosomiasis and treated with intravenous steroids followed by praziquantel resulting in a significant regression of the brain mass. Cerebral neuroschistosomiasis is a rare complication of Schistosoma infection, and clinicians should consider it among the differential diagnosis of unexplained brain lesions.

Human Neural Larva Migrans Caused by Ophidascaris robertsi Ascarid

We describe a case in Australia of human neural larva migrans caused by the ascarid Ophidascaris robertsi, for which Australian carpet pythons are definitive hosts. We made the diagnosis after a live nematode was removed from the brain of a 64-year-old woman who was immunosuppressed for a hypereosinophilic syndrome diagnosed 12 months earlier.

An HIV-positive woman with massive brain lesion due to toxoplasmosis: A case report

Key Clinical Message

Toxoplasmosis-related huge brain lesions may require decompressive craniectomy and lesion excision to avoid brain damage. In this situation, injectable cotrimoxazole is a better choice for treatment.

Abstract

Toxoplasma gondii is a worldly distributed obligate intracellular protozoa. Toxoplasmosis is a prevalent opportunistic infection in HIV-infected people, but it was rarely recorded prior to the identification of HIV infection. Here, we report a toxoplasmosis brain lesion in an Iranian HIV-positive patient. A 45-year-old woman with a complaint of malaise was referred to the Valiasr Hospital in Arak city. In her past clinical history, the patient had a history of anemia, deep vein thrombosis (DVT), and positive HIV. The patient was informed of the diagnosis of massive brain toxoplasmosis as a definite diagnosis. The patient was then taken to the operating room for a left decompressive craniectomy, during which the ensuing brain lesion was excised. After a few days, she was discharged from the hospital in good condition and without any complications.

The low dimensionality of post-stroke cognitive deficits: it's the lesion anatomy!

For years, dissociation studies on neurological single-case patients with brain lesions were the dominant method to infer fundamental cognitive functions in neuropsychology. In contrast, the association between deficits was considered to be of less epistemological value. Still, associational computational methods for dimensionality reduction-such as principal component analysis or factor analysis-became popular for the identification of fundamental cognitive functions and to understand human cognitive brain architecture from post-stroke neuropsychological profiles. In the present in silico study with lesion imaging of 300 stroke patients, we investigated the dimensionality of artificial simulated neuropsychological profiles that exclusively contained independent fundamental cognitive functions without any underlying low-dimensional cognitive architecture. Still, the anatomy of stroke lesions alone was sufficient to create a dependence between variables that allowed a low-dimensional description of the data with principal component analysis. All criteria that we used to estimate the dimensionality of data, including the Kaiser criterion, were strongly affected by lesion anatomy, while the Joliffe criterion provided the least affected estimates. The dimensionality of profiles was reduced by 62-70% for the Kaiser criterion, up to the degree that is commonly found in neuropsychological studies on actual cognitive measures. The interpretability of such low-dimensional factors as deficits of fundamental cognitive functions and their provided insights into human cognitive architecture thus seem to be severely limited, and the heavy focus of current cognitive neuroscience on group studies and associations calls for improvements. We suggest that qualitative criteria and dissociation patterns could be used to refine estimates for the dimensionality of the cognitive architecture behind post-stroke deficits. Further, given the strong impact of lesion anatomy on the associational structure of data, we see the need for further optimization of interpretation strategies of computational factors in post-stroke lesion studies of cognitive deficits.

Changes in Local and Network Brain Activity After Stereotactic Thermocoagulation in Patients with Drug-Resistant Epilepsy

OBJECTIVE

Stereoelectroencephalography-guided radiofrequency thermocoagulation (SEEG-guided RF-TC) aims to reduce seizure frequency by modifying epileptogenic networks through local thermocoagulative lesions. Although RF-TC is hypothesized to functionally modify brain networks, reports of changes in functional connectivity (FC) following the procedure are missing. We evaluated, by means of SEEG recordings, whether variation in brain activity after RF-TC is related to clinical outcome.

METHODS

Interictal SEEG recordings from 33 DRE patients were analyzed. Therapeutic response was defined as more than 50% reduction in seizure frequency for at least one month following RF-TC. Local (power spectral density, PSD) and FC changes were evaluated in three-minute segments recorded shortly before (baseline), shortly after and 15 minutes after RF-TC. The PSD and FC strength values after thermocoagulation were compared with baseline as well as between the responder and non-responder groups.

RESULTS

In responders, we found a significant reduction in PSD after RF-TC in channels that were thermocoagulated (TC) for all frequency bands (p-value =0.007 for broad, delta and theta, p-value <0.001 for alpha and beta bands). However, we did not observe such PSD decrease in non-responders. At the network level, non-responders displayed a significant FC increase in all frequency bands except theta (broad, delta, beta band: p-value < 0.001; alpha band: p-value < 0.01), while responders showed a significant FC decrease in delta (p-value<0.001) and alpha bands (p-value<0.05). Non-responders showed stronger FC changes with respect to responders exclusively in TC channels (broad, alpha, theta, beta: p-value>0.05; delta: p= 0.001).

SIGNIFICANCE

Thermocoagulation induces both local and network-related (FC) changes in electrical brain activity of patients with DRE lasting for at least 15 minutes. This study demonstrates that the observed short-term modifications in brain network and local activity significantly differ between responders and non-responders and opens new perspectives for studying the longer-lasting functional connectivity changes after RF-TC.

A robust role for motor cortex

The role of motor cortex in non-primate mammals remains unclear. More than a century of stimulation, anatomical and electrophysiological studies has implicated neural activity in this region with all kinds of movement. However, following the removal of motor cortex, rats retain most of their adaptive behaviors, including previously learned skilled movements. Here we revisit these two conflicting views of motor cortex and present a new behavior assay, challenging animals to respond to unexpected situations while navigating a dynamic obstacle course. Surprisingly, rats with motor cortical lesions show clear impairments facing an unexpected collapse of the obstacles, while showing no impairment with repeated trials in many motor and cognitive metrics of performance. We propose a new role for motor cortex: extending the robustness of sub-cortical movement systems, specifically to unexpected situations demanding rapid motor responses adapted to environmental context. The implications of this idea for current and future research are discussed.

Compliance and effect of thickener use in dysphagia patients with brain lesions: An observational pilot study

The study aimed to investigate the status of thickener use in dysphagia patients with brain lesions and incidence of adverse events based on fluid viscosity. Twenty dysphagia patients with brain lesions who were recommended to use thickeners following a videofluoroscopic swallowing study were enrolled in this observational pilot study. Patients were educated to use thickener as level 2 or 3 based on the International Dysphagia Diet Standardization Initiative flow test. We evaluated the viscosity of the fluid that patients drank once a week for 2 weeks, and reviewed medical records regarding adverse events. Patients were divided into 2 groups based on the average value obtained from the viscosity evaluations as thin (Levels 0-2) and thick fluid groups (Levels 3-4). Adverse events were compared between the groups. The number of patients who did not follow the recommendations increased from 35.0 to 45.0% during the 1-week follow-up period. No patient developed pneumonia or urinary tract infection. Constipation (P = 0.338) and dehydration status (P = 0.202) were not significantly different between the 2 groups. In 2 evaluations for 20 patients, 40.0% of the cases did not follow the educated viscosity, and the number gradually increased in the follow-up evaluation. Considering that there were no significant differences in the incidence of adverse effects including pneumonia according to the fluid viscosity, a further study is necessary to establish detailed criteria for thickener use in dysphagia patients with brain lesions.

Breakdown of utilitarian moral judgement after basolateral amygdala damage

Most of us would regard killing another person as morally wrong, but when the death of one saves multiple others, it can be morally permitted. According to a prominent computational dual-systems framework, in these life-and-death dilemmas, deontological (nonsacrificial) moral judgments stem from a model-free algorithm that emphasizes the intrinsic value of the sacrificial action, while utilitarian (sacrificial) moral judgments are derived from a model-based algorithm that emphasizes the outcome of the sacrificial action. Rodent decision-making research suggests that the model-based algorithm depends on the basolateral amygdala (BLA), but these findings have not yet been translated to human moral decision-making. Here, in five humans with selective, bilateral BLA damage, we show a breakdown of utilitarian sacrificial moral judgments, pointing at deficient model-based moral decision-making. Across an established set of moral dilemmas, healthy controls frequently sacrifice one person to save numerous others, but BLA-damaged humans withhold such sacrificial judgments even at the cost of thousands of lives. Our translational research confirms a neurocomputational hypothesis drawn from rodent decision-making research by indicating that the model-based algorithm which underlies outcome-based, utilitarian moral judgements in humans critically depends on the BLA.

Small Brain Lesion Enhancement and Gadolinium Deposition in the Rat Brain: Comparison Between Gadopiclenol and Gadobenate Dimeglumine

OBJECTIVES

The aim of the set of studies was to compare gadopiclenol, a new high relaxivity gadolinium (Gd)-based contrast agent (GBCA) to gadobenate dimeglumine in terms of small brain lesion enhancement and Gd retention, including T1 enhancement in the cerebellum.

MATERIALS AND METHODS

In a first study, T1 enhancement at 0.1 mmol/kg body weight (bw) of gadopiclenol or gadobenate dimeglumine was evaluated in a small brain lesions rat model at 2.35 T. The 2 GBCAs were injected in an alternated and cross-over manner separated by an interval of 4.4 ± 1.0 hours (minimum, 3.5 hours; maximum, 6.1 hours; n = 6). In a second study, the passage of the GBCAs into cerebrospinal fluid (CSF) was evaluated by measuring the fourth ventricle T1 enhancement in healthy rats at 4.7 T over 23 minutes after a single intravenous (IV) injection of 1.2 mmol/kg bw of gadopiclenol or gadobenate dimeglumine (n = 6/group). In a third study, Gd retention at 1 month was evaluated in healthy rats who had received 20 IV injections of 1 of the 2 GBCAs (0.6 mmol/kg bw) or a similar volume of saline (n = 10/group) over 5 weeks. T1 enhancement of the deep cerebellar nuclei (DCN) was assessed by T1-weighted magnetic resonance imaging at 2.35 T, performed before the injection and thereafter once a week up to 1 month after the last injection. Elemental Gd levels in central nervous system structures, in muscle and in plasma were determined by inductively coupled plasma mass spectrometry (ICP-MS) 1 month after the last injection.

RESULTS

The first study in a small brain lesion rat model showed a ≈2-fold higher number of enhanced voxels in lesions with gadopiclenol compared with gadobenate dimeglumine. T1 enhancement of the fourth ventricle was observed in the first minutes after a single IV injection of gadopiclenol or gadobenate dimeglumine (study 2), resulting, in the case of gadopiclenol, in transient enhancement during the injection period of the repeated administrations study (study 3). In terms of Gd retention, T1 enhancement of the DCN was noted in the gadobenate dimeglumine group during the month after the injection period. No such enhancement of the DCN was observed in the gadopiclenol group. Gadolinium concentrations 1 month after the injection period in the gadopiclenol group were slightly increased in plasma and lower by a factor of 2 to 3 in the CNS structures and muscles, compared with gadobenate dimeglumine.

CONCLUSIONS

In the small brain lesion rat model, gadopiclenol provides significantly higher enhancement of brain lesions compared with gadobentate dimeglumine at the same dose. After repeated IV injections, as expected for a macrocyclic GBCA, Gd retention is minimalized in the case of gadopiclenol compared with gadobenate dimeglumine, resulting in no T1 hypersignal in the DCN.

High Precision Bone Cutting by Er: YAG Lasers Might Minimize the Invasiveness of Navigated Brain Biopsies

Biopsies of brain tissue are sampled and examined to establish a diagnosis and to plan further treatment, e.g. for brain tumors. The neurosurgical procedure of sampling brain tissue for histologic examination is still a relatively invasive procedure that carries several disadvantages. The “proof of concept”-objective of this study is to answer the question if laser technology might be a potential tool to make brain biopsies less invasive, faster and safer. Laser technology might carry the opportunity to miniaturize the necessary burr hole and also to angulate the burr hole much more tangential in relation to the bone surface in order to take biopsies from brain regions that are usually only difficult and hazardous to access. We examined if it is possible to miniaturize the hole in the skull bone to such a high extent that potentially the laser-created canal itself may guide the biopsy needle with sufficient accuracy. The 2-dimensional, i.e. radial tolerance of the tip of biopsy needles inserted in these canals was measured under defined lateral loads which mimic mechanical forces applied by a surgeon. The canals through the skull bones were planned in angles of 90° (perpendicular) and 45° relative to the bone surface. We created a total of 33 holes with an Er : YAG laser in human skull bones. We could demonstrate that the achievable radial tolerance concerning the guidance of a biopsy needle by a laser created bone canal is within the range of the actual accuracy of a usual navigated device if the canal is at least 4 mm in length. Lateral mechanical loads applied to the biopsy needle had only minor impact on the measurable radial tolerance. Furthermore, in contrast to mechanical drilling systems, laser technology enables the creation of bone canals in pointed angles to the skull bone surface. The latter opens the perspective to sample biopsies in brain areas that are usually not or only hazardous to access.

Retinal ganglion cell complex thickness at school-age, prematurity and neonatal stressors

PURPOSE

To investigate the association between the ganglion cell complex (GCC) thickness at early school-age and prematurity and other neonatal factors.

METHODS

Cross-sectional study. The sample included very preterm children with gestational age (GA) below 32 weeks or birthweight below 1500 g enrolled in a follow-up program (n = 101) and a comparison group of term-born children (n = 49). Ganglion cell complex (GCC) thickness was measured at 4-8 years using high-quality optical coherence tomography (OCT) images. Data on neonatal and postnatal features were extracted from clinical records; analyses included mixed linear models.

RESULTS

Ganglion cell layer (GCL) and retinal nerve fiber layer (mRNFL) were thicker in term than in preterm born children (2.9 μm and 2.4 μm respectively, p < 0.001). Within the preterm group, lower GA was associated with a decrease in total GCL (0.7 μm per week, p < 0.001). Being small for GA was associated with further thinning in both layers (1.4 and 2.8 µm). Postnatal corticosteroids therapy and severe brain lesion were associated with thinning in the total GCL of 6 µm (p < 0.001) and 4.1 µm (p = 0.002), respectively, and shock was associated with thinning in total mRNFL of 6 µm (p < 0.001).

CONCLUSIONS

Lower GA or birthweight are associated with thinning of GCC layers. When performing an OCT examination at school-age and a decrease in GCC thickness is observed, it may be relevant to ask about a history of prematurity, and further enquire about neonatal shock, postnatal corticosteroids therapy or severe brain lesion that are related to additional decrease in GCC thickness.

Cortical Thickness of Brain Areas Beyond Stroke Lesions and Sensory-Motor Recovery: A Systematic Review

Background: The clinical outcome of patients suffering from stroke is dependent on multiple factors. The features of the lesion itself play an important role but clinical recovery is remarkably influenced by the plasticity mechanisms triggered by the stroke and occurring at a distance from the lesion. The latter translate into functional and structural changes of which cortical thickness might be easy to quantify one of the main players. However, studies on the changes of cortical thickness in brain areas beyond stroke lesion and their relationship to sensory-motor recovery are sparse. Objectives: To evaluate the effects of cerebral stroke on cortical thickness (CT) beyond the stroke lesion and its association with sensory-motor recovery. Materials and Methods: Five electronic databases (PubMed, Embase, Web of Science, Scopus and the Cochrane Library) were searched. Methodological quality of the included studies was assessed with the Newcastle-Ottawa Scale for non-randomized controlled trials and the Risk of Bias Cochrane tool for randomized controlled trials. Results: The search strategy retrieved 821 records, 12 studies were included and risk of bias assessed. In most of the included studies, cortical thinning was seen at the ipsilesional motor area (M1). Cortical thinning can occur beyond the stroke lesion, typically in regions anatomically connected because of anterograde degeneration. Nonetheless, studies also reported cortical thickening of regions of the unaffected hemisphere, likely related to compensatory plasticity. Some studies revealed a significant correlation between changes in cortical thickness of M1 or somatosensory (S1) cortical areas and motor function recovery. Discussion and Conclusions: Following a stroke, changes in cortical thickness occur both in regions directly connected to the stroke lesion and in contralateral hemisphere areas as well as in the cerebellum. The underlying mechanisms leading to these changes in cortical thickness are still to be fully understood and further research in the field is needed. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020200539; PROSPERO 2020, identifier: CRD42020200539.

Lesions and reduced working memory impair emotion recognition in self and others

ABSTRACTEmotion recognition (ER) can be conceived of as an integration of affective cues in working memory. We examined whether reduced working memory capacity and brain lesions in neural networks involved in emotion processing interactively impair ER of both one's own and another person's emotions. To assess the recognition of one's own and other's emotions, pictures from the International Affective Picture System (IAPS) and facial expressions from the Karolinska Directed Emotional Faces (KDEF) database representing fear, anger, disgust, and sadness were presented to 40 lesioned patients and 40 healthy students. To manipulate working memory, a math task was imposed between exposure to the stimuli and collection of responses. Participants indicated the intensity of each of the four emotions for each picture. ER was computed as the difference between trials where the elicited emotion matched the requested emotion and trials where the elicited and requested emotions did not match. Whereas lesions impaired ER in both self and others, working memory load exclusively decreased recognition of other persons' emotions.

Musical hallucinations in cerebrovascular disease

Purpose

Musical hallucinations (MH) are a subset of complex auditory hallucinations in which individuals perceive music in the absence of an external auditory stimulus. It is a rare phenomenon, first described by Ballinger in 1846, with diverse presentations from familiar childhood melodies to a simple pitch which evolved into the harmonies Robert Schumann incorporated in his sole Violin Concerto.

Views

This uncommon phenomenon has diverse etiologies, including psychiatric and neurological backgrounds, which guide its classification and methods of treatment. The pathophysiological basis of MH remains understood incompletely, potentially resulting from lesions anywhere along the auditory pathway, from the external auditory canal to the auditory cortex. The strong association between MH and hearing impairment has led researchers to hypothesize that MH represent a "release phenomenon," in which sensory deprivation, eliminating the afferent input to the auditory sensory network, instigates spontaneous activity within a system - comparable to the Charles Bonnet syndrome, in which visual impairment precipitates the development of visual hallucinations (so called auditory Charles Bonnet syndrome), and phantom limb syndrome, in which amputees experience sensations in a limb that is not no longer there. In this paper, we report on six cases of MH in patients with cerebrovascular disease, who presented to the neurology department at the Poznan University of Medical Sciences from 2015 to 2018.

Conclusions

We discuss the findings of computed tomography and magnetic resonance imaging of six cases of MH in patients with cerebrovascular disease, and the treatment leading to its resolution. We briefly review the literature on MH in patients with cerebrovascular diseases, discussing their suggested pathophysiology, clinical presentations and response to medical treatment.

Efficacy of a Training on Executive Functions in Potentiating Rehabilitation Effects in Stroke Patients

Cognitive impairment after a stroke has a direct impact on patients' disability. In particular, impairment of Executive Functions (EFs) interferes with re-adaptation to daily life. The aim of this study was to explore whether adding a computer-based training on EFs to an ordinary rehabilitation program, regardless of the specific brain damage and clinical impairment (motor, language, or cognitive), could improve rehabilitation outcomes in patients with stroke. An EF training was designed to have minimal motor and expressive language demands and to be applied to a wide range of clinical conditions. A total of 37 stroke patients were randomly assigned to two groups: a training group, which performed the EF training in addition to the ordinary rehabilitation program (treatment as usual), and a control group, which performed the ordinary rehabilitation exclusively. Both groups were assessed before and after the rehabilitation program on neuropsychological tests covering multiple cognitive domains, and on functional scales (Barthel index, Functional Independence Measure). The results showed that only patients who received the training improved their scores on the Attentional Matrices and Phonemic Fluency tests after the rehabilitation program. Moreover, they showed a greater functional improvement in the Barthel scale as well. These results suggest that combining an EF training with an ordinary rehabilitation program potentiates beneficial effects of the latter, especially in promoting independence in activities of daily living.

Encapsulated Intracerebral Hematoma Presenting as Cerebral Abscess

Chronic encapsulated intracerebral hematoma is a rare pathology which may present after spontaneous intracerebral hemorrhage (ICH) or radiosurgery for arteriovenous malformations. A 66-year-old male presented with recent diagnosis of cerebrovascular accident (CVA) status post-treatment with tissue plasminogen activator and mechanical thrombectomy. His recent diagnoses included infective endocarditis, septic bacteremia, meningitis, and aspiration pneumonia. One month following his CVA, the patient presented with delayed altered mental status. In the setting of increasing lethargy, computed tomography and magnetic resonance imaging of the brain were performed, which suggested a brain abscess, septic emboli, and ventriculitis. The patient was taken to surgery emergently. Intraoperatively, the patient was found to have an encapsulated mass of liquid consistency. Tissue pathology demonstrated ischemic cortical tissue and hemorrhage. Multiple cultures were negative for growth. The patient was ultimately determined to have an encapsulated intracerebral hematoma. Encapsulated intracerebral hematoma should be a part of the differential diagnosis when presented with a brain abscess in the setting of a patient who is at risk of ICH.

Obstructive and Central Sleep Apnea in First Ever Ischemic Stroke are Associated with Different Time Course and Autonomic Activation

INTRODUCTION

Sleep-related breathing disorders are highly prevalent in patients with ischemic stroke. Among sleep-disordered breathing disorders, obstructive sleep apnea is the most represented one, but central sleep apnea, isolated or in the context of a periodic breathing/Cheyne-Stokes respiration, is frequently reported in these patients. Altered baroreflex responses have been reported in the acute phases of a cerebral event.

METHODS

We conducted, in a group of patients with ischemic stroke (n=60), a prospective 3-month follow-up physiological study to describe the breathing pattern during sleep and baroreflex sensitivity in the acute phase and in the recovery phase.

RESULTS

In the acute phase, within 10 days from the onset of symptoms, 22.4% of patients had a normal breathing pattern, 40.3% had an obstructive pattern, 16.4% had a central pattern, and 29.9% showed a mixed pattern. Smaller variations in the Apnea-Hypopnea Index were found in normal breathing and obstructive groups (ΔAHI 2.1±4.1 and -2.8±11.6, respectively) in comparison with central and mixed patterns (ΔAHI -6.9±15.1 and -12.5±13.1, respectively; ANOVA p=0.01). The obstructive pattern became the most frequent pattern, in 38.3% of patients at baseline and 61.7% of patients at follow-up. Modification of baroreflex sensitivity over time was influenced by the site of the lesion and by the sleep disorder pattern in the acute phase (MANOVA p=0.005).

CONCLUSION

We suggest that a down-regulation of autonomic activity, possibly related to reduced vagal modulation, may help the recovery after stroke, or a transitory disconnection from the cortical node that participates in the regulation of sympathetic outflow.

The Clinical and Imaging Characteristics Associated With Neurological Sequelae of Pediatric Patients With Acute Necrotizing Encephalopathy

Background: Acute necrotizing encephalopathy of childhood (ANE) is a rare but rapidly progressing encephalopathy. Importantly, the exact pathogenesis and evidence-based treatment is scarce. Thus, we aimed to identify the clinical, imaging, and therapeutic characteristics that associated with prognosis of pediatric ANE patients. Methods: A retrospective study was conducted on pediatric patients with ANE who were admitted to Wuhan Children's Hospital between January 2014 and September 2019. All cases met the diagnostic criteria for ANE proposed by Mizuguchi in 1997. The clinical information and follow-up data were collected. The prognostic factors were analyzed by trend chi-square test and Goodman-Kruskal gamma test. Results: A total of 41 ANE patients ranging in age from 8.9 to 142 months were included in this study. Seven cases (17%) died, and the other 34 survivors had different degrees of neurological sequelae. Factors tested to be significantly correlated with the severity of neurological sequelae were the intervals from prodromal infection to acute encephalopathy (G = -0.553), conscious disturbance (r = 0.58), endotracheal intubation (r = 0.423), elevation of alanine aminotransferase (r = 0.345), aspartate aminotransferase (r = 0.393), and cerebrospinal fluid protein (r = 0.490). In addition, dynamic magnetic resonance imaging (MRI) evaluation on follow-up revealed that the total numbers of brain lesion location (χ² = 6.29, P < 0.05), hemorrhage (r = 0.580), cavitation (r = 0.410), and atrophy (r = 0.602) status were significantly correlated with the severity of neurological sequelae, while early steroid therapy (r = -0.127 and 0.212, respectively) and intravenous immunoglobulin (IVIG) (r = 0.111 and -0.023, respectively) within 24 h or within 72 h after onset showed no association. Conclusions: Intervals from prodromal infection to acute encephalopathy (≤1 day), total numbers of brain lesion location (≥3), the recovery duration of hemorrhage and atrophy (>3 months), and the presence of cavitation predict severe neurological sequelae in pediatric patients with ANE. Early treatments, including steroid therapy and IVIG, had no correlation with better outcomes. Further studies are needed to establish a consensus guideline for the management of ANE.

Common and Distinct Features of Adult Neurogenesis and Regeneration in the Telencephalon of Zebrafish and Mammals

In contrast to mammals, the adult zebrafish brain shows neurogenic activity in a multitude of niches present in almost all brain subdivisions. Irrespectively, constitutive neurogenesis in the adult zebrafish and mouse telencephalon share many similarities at the cellular and molecular level. However, upon injury during tissue repair, the situation is entirely different. In zebrafish, inflammation caused by traumatic brain injury or by induced neurodegeneration initiates specific and distinct neurogenic programs that, in combination with signaling pathways implicated in constitutive neurogenesis, quickly, and efficiently overcome the loss of neurons. In the mouse brain, injury-induced inflammation promotes gliosis leading to glial scar formation and inhibition of regeneration. A better understanding of the regenerative mechanisms occurring in the zebrafish brain could help to develop new therapies to combat the debilitating consequences of brain injury, stroke, and neurodegeneration. The aim of this review is to compare the properties of neural progenitors and the signaling pathways, which control adult neurogenesis and regeneration in the zebrafish and mammalian telencephalon.

Combined Brain-Heart Magnetic Resonance Imaging in Autoimmune Rheumatic Disease Patients with Cardiac Symptoms: Hypothesis Generating Insights from a Cross-sectional Study

BACKGROUND

Autoimmune rheumatic diseases (ARDs) may affect both the heart and the brain. However, little is known about the interaction between these organs in ARD patients. We asked whether brain lesions are more frequent in ARD patients with cardiac symptoms compared with non-ARD patients with cardiovascular disease (CVD).

METHODS

57 ARD patients with mean age of 48 ± 13 years presenting with shortness of breath, chest pain, and/or palpitations, and 30 age-matched disease-controls with non-autoimmune CVD, were evaluated using combined brain-heart magnetic resonance imaging (MRI) in a 1.5T system.

RESULTS

52 (91%) ARD patients and 16 (53%) controls had white matter hyperintensities (p < 0.001) in at least one brain area (subcortical/deep/periventricular white matter, basal ganglia, pons, brainstem, or mesial temporal lobe). Only the frequency and number of subcortical and deep white matter lesions were significantly greater in ARD patients (p < 0.001 and 0.014, respectively). ARD vs. control status was the only independent predictor of having any brain lesion. Specifically for deep white matter lesions, each increase in ECV independently predicted a higher number of lesions [odds ratio (95% confidence interval): 1.16 (1.01-1.33), p = 0.031] in ordered logistic regression. Penalized logistic regression selected only ARD vs. control status as the most important feature for predicting whether brain lesions were present on brain MRI (odds ratio: 5.46, marginal false discovery rate = 0.011).

CONCLUSIONS

Subclinical brain involvement was highly prevalent in this cohort of ARD patients and was mostly independent of the severity of cardiac involvement. However, further research is required to determine the clinical relevance of these findings.

Diagnosing gaze and arrow cueing effects in unilateral spatial neglect

Individuals with left unilateral spatial neglect (USN) following a right hemisphere lesion show difficulty in orienting their attention toward stimuli presented on the left. In normal cognition, others' gaze direction and a pointing arrow naturally guide visual attention. Here, we explore a method to identify patients who may benefit from these skills as a base for compensation during rehabilitation. We tested gaze and arrow cueing effects in 26 healthy participants and in 13 patients with USN. Our data show that brain injuries causing USN do not affect gaze and arrow cueing in a consistent manner from one patient to another.

Laser interstitial thermal therapy for an eloquent region supratentorial brain lesion

Laser interstitial thermal therapy (LITT) is a minimally invasive stereotactic technique that causes tumor ablation using thermal energy. LITT has shown to be efficacious for the treatment of deep-seated brain lesions, including those near eloquent areas. In this video, the authors present the case of a 62-year-old man with a history of metastatic melanoma who presented with worsening right-sided hemiparesis. MRI revealed a contrast-enhancing lesion in left centrum semiovale in close proximity to corticospinal tracts, consistent with radiation necrosis. The authors review their stepwise technique of LITT with special attention to details for a lesion located near eloquent area. The video can be found here: https://youtu.be/ndrTgi6MXqE .

A Comparison of Shallow and Deep Learning Methods for Predicting Cognitive Performance of Stroke Patients From MRI Lesion Images

Stroke causes behavioral deficits in multiple cognitive domains and there is a growing interest in predicting patient performance from neuroimaging data using machine learning techniques. Here, we investigated a deep learning approach based on convolutional neural networks (CNNs) for predicting the severity of language disorder from 3D lesion images from magnetic resonance imaging (MRI) in a heterogeneous sample of stroke patients. CNN performance was compared to that of conventional (shallow) machine learning methods, including ridge regression (RR) on the images' principal components and support vector regression. We also devised a hybrid method based on re-using CNN's high-level features as additional input to the RR model. Predictive accuracy of the four different methods was further investigated in relation to the size of the training set and the level of redundancy across lesion images in the dataset, which was evaluated in terms of location and topological properties of the lesions. The Hybrid model achieved the best performance in most cases, thereby suggesting that the high-level features extracted by CNNs are complementary to principal component analysis features and improve the model's predictive accuracy. Moreover, our analyses indicate that both the size of training data and image redundancy are critical factors in determining the accuracy of a computational model in predicting behavioral outcome from the structural brain imaging data of stroke patients.

Ganglion cyst of the temporomandibular joint with intradural extension: case report

Intracranial extension of temporomandibular joint (TMJ) ganglion cysts is very rare. Two previously reported cases presented clinically due to effects on cranial nerves and had obvious association with the TMJ on imaging. To the authors' knowledge, intracranial extension of a TMJ ganglion cyst presenting with seizures and mimicking a primary brain tumor has not been previously reported. The patient underwent resection of a presumptive primary cystic temporal lobe tumor, but the lesion had histopathological features of a nonneoplastic cyst with a myxoid content. He was followed with serial imaging for 5 years before regrowth of the lesion caused new episodes of seizures requiring a repeat operation, during which the transdural defect was repaired after the adjacent segment of the TMJ was curetted. A thorough review of all imaging studies and the histopathological findings from the repeat operation led to the correct diagnosis of a TMJ ganglion cyst. This case highlights an unusual presentation of this rare lesion, as well as its potential for recurrence. TMJ ganglion cysts should be included in the differential diagnosis of cystic tumors involving the anterior temporal lobe, presenting with or without seizures. Focused imaging evaluation of the TMJ can be helpful to rule out the possible role of associated TMJ lesions.

Venture in 101 Cranial Punctures: A Comparative Study between Frame-based versus Frameless Biopsy of 101 Intracranial Space Occupying Lesion

Background:

Presumptive diagnosis based solely on the clinical picture and imaging is not sufficient to provide appropriate treatment with certainty and hence histopathological confirmation of intracranial space occupying lesion (ICSOL) is essential. Needle biopsy via stereotactic frame-based or frameless neuronavigation technique is efficient procedure. The objective of this study is to compare their accuracy and efficacy and safety.

Methods:

This is a retrospective comparative study conducted among 101 biopsies of ICSOL. Patients data were retrieved from medical record. Data were analyzed in SPSS ver. 20. P value of <0.05 was considered significant.

Results:

Out of 101 patients, Frame-based stereotactic biopsy was done among 55 patients (54.4%) while 46 patients (45.6%) underwent frameless stealth neuronavigation guided biopsy. Male to female ration was 2.1:1. Age ranged from 5 to 82 years. 54.5% (55 patients) have deeper location of tumor while 45.5% (46 patients) have lobar location of tumor. Frontal (16.8%) and Thalamic (13.8%) were the common site. Mean size of tumor was 3.09±0.85cms. There was statistically significant difference in operative duration among study groups. Overall Diagnostic yield was 89.1%. Glioma was the most common (50.5%) diagnosis. Glioblastoma WHO Grade IV was 37.6% followed by lymphoma (12.8%).

Conclusion:

Needle biopsy via stereotactic frame-based or neuronavigation frameless technique is a safe and efficient procedure having high diagnostic yield. Reasons for negative biopsy could be missed target or retrieval of gliotic tissue.

Brain Lesions as a Predictor of Therapeutic Outcomes of Hand Function in Infants With Unilateral Cerebral Palsy

AIM

The present study aimed to investigate whether the response variability of infants to modified constraint-induced movement therapy and bimanual therapy are associated with different types of brain lesions.

METHOD

Infants with unilateral cerebral palsy (N = 22) ages 8-15 months (mean = 10.95, standard deviation = 2.15 months) were grouped according to having either a periventricular brain lesion or a middle cerebral artery infarct lesion. Improvement in hand function was analyzed based on the mini-Assistive Hand Assessment results.

RESULTS

Infants with periventricular brain lesion displayed greater positive response to upper limb treatment compared to those with middle cerebral artery infarct ( P = .02). A significant difference in improvement according to type of treatment was found in the middle cerebral artery infarct group but not in the periventricular brain lesion.

CONCLUSION

The present study showed an association between the type of brain lesion and the efficacy of upper limb treatment in infants. Infants with periventricular brain lesions displayed greater positive responses than those with middle cerebral artery infarct.

Early Amplitude-Integrated Electroencephalogram as a Predictor of Brain Injury in Newborns With Very Low Birth Weight: A Cohort Study

PURPOSE

To evaluate the relationship between abnormal early amplitude integrated electroencephalography (EEG) and severe lesions in imaging tests performed during the neonatal period in very low birth weight infants.

METHODS

An amplitude-integrated EEG was performed in 70 patients with a mean birth weight of 1226 g during the first 48 hours of life. Severe lesions on magnetic resonance imaging (MRI) or ultrasonography (US) during the neonatal period were considered as adverse conditions. Variables were compared using the χ² test or analysis of variance. Sensitivity, specificity, and positive likelihood ratio were calculated.

RESULTS

Adverse outcomes were observed in 6 patients. There was a significant relationship ( P < .001) between abnormal amplitude-integrated EEG background and severe lesions on MRI and US. Sensitivity and specificity were 100% and 89%, respectively.

CONCLUSION

Early amplitude-integrated EEG with moderate/severe abnormalities in the background is associated with severe structural lesions detected in imaging studies and should be considered as an auxiliary screening tool for the detection of neonatal brain lesions in very low birth weight infants.

Long-term follow up of 3 T MRI-detected brain lesions after percutaneous catheter-based left atrial appendage closure

BACKGROUND

Left atrial appendage closure (LAAC) for stroke prevention is an increasingly performed intervention.

AIMS

This prospective study aims to evaluate the incidence of long-term magnetic resonance imaging (MRI)-detected brain lesions as well as potential changes of neurocognitive function after percutaneous LAAC.

METHODS

Brain MRI at 3 T was performed within 24 hr before and after LAAC. A follow-up MRI was carried out after three months. Neuro-cognitive examination using the National Institutes of Health Stroke Scale (NIHSS) score and the Montreal Cognitive Assessment (MoCA) Test was performed.

RESULTS

Successful device implantation was achieved in all 25 patients (age 74.6 ± 10.2 years, male = 17) using the Amulet (n = 20), Occlutech (n = 3), or a Lambre (n = 2) device. In 12/25 (48%) patients, acute brain lesions (ABL) were detected after LAAC. A three-month follow-up MRI was performed in seven patients, and no new ABLs were seen. In 5/7 (71%) patients, there were no residual changes from the ABLs detectable. However, the FLAIR sequence was still positive in two patients. After LAAC, there were no significant differences in the MoCA-test (mean 24.3 ± 4.5 vs. 23.5 ± 4.5; P = 0.1) and the NIHSS-score (mean 0.9 ± 1.6 vs. 1.2 ± 1.8; P = 0.1). This was the same at the three-month follow-up (MoCA-test 23.5 ± 4.5 vs. 23.8 ± 2.7; P = 0.3; NIHSS-score 1.2 ± 1.8 vs. 1.0 ± 0.8; P = 0.4).

CONCLUSION

While new MRI-detected brain lesions are commonly observed after percutaneous LAAC, ABLs were no longer detectable in 71% of the patients at the three-month follow-up. There were no significant changes in neurocognitive function after LAAC and at the three-month follow-up.

Semisupervised learning using denoising autoencoders for brain lesion detection and segmentation

The work explores the use of denoising autoencoders (DAEs) for brain lesion detection, segmentation, and false-positive reduction. Stacked denoising autoencoders (SDAEs) were pretrained using a large number of unlabeled patient volumes and fine-tuned with patches drawn from a limited number of patients ([Formula: see text], 40, 65). The results show negligible loss in performance even when SDAE was fine-tuned using 20 labeled patients. Low grade glioma (LGG) segmentation was achieved using a transfer learning approach in which a network pretrained with high grade glioma data was fine-tuned using LGG image patches. The networks were also shown to generalize well and provide good segmentation on unseen BraTS 2013 and BraTS 2015 test data. The manuscript also includes the use of a single layer DAE, referred to as novelty detector (ND). ND was trained to accurately reconstruct nonlesion patches. The reconstruction error maps of test data were used to localize lesions. The error maps were shown to assign unique error distributions to various constituents of the glioma, enabling localization. The ND learns the nonlesion brain accurately as it was also shown to provide good segmentation performance on ischemic brain lesions in images from a different database.

Brain lesions affecting gait recovery in stroke patients

OBJECTIVES

Gait recovery is an important goal in stroke patients. Several studies have sought to uncover relationships between specific brain lesions and the recovery of gait, but the effects of specific brain lesions on gait remain unclear. Thus, we investigated the effects of stroke lesions on gait recovery in stroke patients.

MATERIALS AND METHODS

In total, 30 subjects with stroke were assessed in a retrograde longitudinal observational study. To assess gait function, the functional ambulation category (FAC) was tested four times: initially (within 2 weeks) and 1, 3, and 6 months after the onset of the stroke. Brain lesions were analyzed via overlap, subtraction, and voxel-based lesion symptom mapping (VLSM).

RESULTS

Ambulation with FAC improved significantly with time. Subtraction analysis showed that involvement of the corona radiata, internal capsule, globus pallidus, and putamen were associated with poor recovery of gait throughout 6 months after onset. The caudate nucleus did influence poor recovery of gait at 6 months after onset. VLSM revealed that corona radiata, internal capsule, globus pallidus, putamen and cingulum were related with poor recovery of gait at 3 months after onset. Corona radiata, internal capsule, globus pallidus, putamen, primary motor cortex, and caudate nucleus were related with poor recovery of gait at 6 months after onset.

CONCLUSION

Results identified several important brain lesions for gait recovery in patients with stroke. These results may be useful for planning rehabilitation strategies for gait and understanding the prognosis of gait in stroke patients.

The Face-Processing Network Is Resilient to Focal Resection of Human Visual Cortex

Human face perception requires a network of brain regions distributed throughout the occipital and temporal lobes with a right hemisphere advantage. Present theories consider this network as either a processing hierarchy beginning with the inferior occipital gyrus (occipital face area; IOG-faces/OFA) or a multiple-route network with nonhierarchical components. The former predicts that removing IOG-faces/OFA will detrimentally affect downstream stages, whereas the latter does not. We tested this prediction in a human patient (Patient S.P.) requiring removal of the right inferior occipital cortex, including IOG-faces/OFA. We acquired multiple fMRI measurements in Patient S.P. before and after a preplanned surgery and multiple measurements in typical controls, enabling both within-subject/across-session comparisons (Patient S.P. before resection vs Patient S.P. after resection) and between-subject/across-session comparisons (Patient S.P. vs controls). We found that the spatial topology and selectivity of downstream ipsilateral face-selective regions were stable 1 and 8 month(s) after surgery. Additionally, the reliability of distributed patterns of face selectivity in Patient S.P. before versus after resection was not different from across-session reliability in controls. Nevertheless, postoperatively, representations of visual space were typical in dorsal face-selective regions but atypical in ventral face-selective regions and V1 of the resected hemisphere. Diffusion weighted imaging in Patient S.P. and controls identifies white matter tracts connecting retinotopic areas to downstream face-selective regions, which may contribute to the stable and plastic features of the face network in Patient S.P. after surgery. Together, our results support a multiple-route network of face processing with nonhierarchical components and shed light on stable and plastic features of high-level visual cortex following focal brain damage.

SIGNIFICANCE STATEMENT

Brain networks consist of interconnected functional regions commonly organized in processing hierarchies. Prevailing theories predict that damage to the input of the hierarchy will detrimentally affect later stages. We tested this prediction with multiple brain measurements in a rare human patient requiring surgical removal of the putative input to a network processing faces. Surprisingly, the spatial topology and selectivity of downstream face-selective regions are stable after surgery. Nevertheless, representations of visual space were typical in dorsal face-selective regions but atypical in ventral face-selective regions and V1. White matter connections from outside the face network may support these stable and plastic features. As processing hierarchies are ubiquitous in biological and nonbiological systems, our results have pervasive implications for understanding the construction of resilient networks.

Neuropsychology of Aesthetic Judgment of Ambiguous and Non-Ambiguous Artworks

Several affective and cognitive processes have been found to be pivotal in affecting aesthetic experience of artworks and both neuropsychological as well as psychiatric symptoms have been found to affect artistic production. However, there is a paucity of studies directly investigating effects of brain lesions on aesthetic judgment. Here, we assessed the effects of unilateral brain damage on aesthetic judgment of artworks showing part/whole ambiguity. We asked 19 unilaterally brain-damaged patients (10 left and 9 right brain damaged patients, respectively LBDP and RBDP) and 20 age- and education-matched healthy individuals (controls, C) to rate 10 Arcimboldo's ambiguous portraits (AP), 10 realistic Renaissance portraits (RP), 10 still life paintings (SL), and 10 Arcimboldo's modified portraits where only objects/parts are detectable (AO). They were also administered a Navon task, a facial recognition test, and evaluated on visuo-perceptual and visuo-constructional abilities. Patients included in the study did not show any deficits that could affect the capability to explore and enjoy artworks. SL and RP was not affected by brain damage regardless of its laterality. On the other hand, we found that RBDP liked AP more than the C participants. Furthermore, we found a positive correlation between aesthetic judgment of AP and visuo-perceptual skills even if the single case analyses failed to find a systematic association between neuropsychological deficits and aesthetic judgment of AP. On the whole, the present data suggest that a right hemisphere lesion may affect aesthetic judgment of ambiguous artworks, even in the absence of exploration or constructional deficits.

Symmetry of the arcuate fasciculus and its impact on language performance of patients with brain tumors in the language-dominant hemisphere

OBJECTIVE Cerebral damage in frontal, parietal, and temporal brain areas and, probably more importantly, their interconnections can lead to deficits in language. However, neural plasticity and repair allow the brain to partly compensate for neural injury, mediated by both functional and structural changes. In this study, the authors sought to systematically investigate the relationship between language performance in brain tumor patients and structural perisylvian pathways (i.e., the arcuate fasciculus [AF]) using probabilistic fiber tracking on diffusion tensor imaging. The authors used a previously proposed model in which the AF is divided into anterior, long, and posterior segments. The authors hypothesized that right-handed patients with gliomas in the language-dominant (left) hemisphere would benefit from a more symmetrical or right-lateralized language pathway in terms of better preservation of language abilities. Furthermore, they investigated to what extent specific tumor characteristics, including proximity to the AF, affect language outcome in such patients. METHODS Twenty-seven right-handed patients (12 males and 15 females; mean age 52 ± 16 years) with 11 low-grade and 16 high-grade gliomas of the left hemisphere underwent 3-T diffusion-weighted MRI (30 directions) and language assessment as part of presurgical planning. For a systematic quantitative evaluation of the AF, probabilistic fiber tracking with a 2 regions of interest approach was carried out. Volumes of the 3 segments of both hemispheric AFs were evaluated by quantifying normalized and thresholded pathways. Resulting values served to generate the laterality index of the AFs. RESULTS Patients without language deficits tended to have an AF that was symmetric or lateralized to the right, whereas patients with deficits in language significantly more often demonstrated a left-lateralized posterior segment of the AF. Patients with high-grade gliomas had more severe language deficits than those with low-grade gliomas. Backward logistic regression revealed the laterality index of the posterior AF segment and tumor grade as the only independent statistically significant predictors for language deficits in this cohort. CONCLUSIONS In addition to the well-known fact that tumor entity influences behavioral outcome, the authors' findings suggest that the right homologs of structural language-associated pathways could be supportive for language function and facilitate compensation mechanisms after brain damage in functionally eloquent areas. This further indicates that knowledge about preoperative functional redistribution (identified by neurofunctional imaging) increases the chance for total or near-total resections of tumors in eloquent areas. In the future, longitudinal studies with larger groups are mandatory to overcome the methodological limitations of this cross-sectional study and to map neuroplastic changes associated with language performance and rehabilitation in brain tumor patients.

Anger and stroke: a potential association that deserves serious consideration

OBJECTIVE

To assess the relationship between states of anger and stroke.

METHODS

Systematic review of the literature.

RESULTS

In total, 21 papers were selected for the systematic review of data published on the subject of anger and stroke. A state of anger may be a risk factor for stroke, as well as a consequence of brain lesions affecting specific areas that are caused by a stroke. Scales to assess anger varied among authors. There was no consensus regarding the area of brain lesions that might lead to a state of anger. Although some authors agreed that lesions on the right side led to angrier behaviour, others found that lesions on the left side were more relevant to anger. Likewise, there was no consensus regarding the prevalence of anger pre or post-stroke. Some authors did not even find that these two conditions were related.

CONCLUSION

Although most authors have accepted that there is a relationship between anger and stroke, studies with uniform methodology need to be conducted if this association is to be properly evaluated and understood.

Long term motor function after neonatal stroke: Lesion localization above all

Motor outcome is variable following neonatal arterial ischemic stroke (NAIS). We analyzed the relationship between lesion characteristics on brain MRI and motor function in children who had suffered from NAIS. Thirty eight full term born children with unilateral NAIS were investigated at the age of seven. 3D T1- and 3D FLAIR-weighted MR images were acquired on a 3T MRI scanner. Lesion characteristics were compared between patients with and without cerebral palsy (CP) using the following approaches: lesion localization either using a category-based analysis, lesion mapping as well as voxel-based lesion-symptom mapping (VLSM). Using diffusion-weighted imaging the microstructure of the cortico-spinal tract (CST) was related to the status of CP by measuring DTI parameters. Whereas children with lesions sparing the primary motor system did not develop CP, CP was always present when extensive lesions damaged at least two brain structures involving the motor system. The VLSM approach provided a statistical map that confirmed the cortical lesions in the primary motor system and revealed that CP was highly correlated with lesions in close proximity to the CST. In children with CP, diffusion parameters indicated microstructural changes in the CST at the level of internal capsule and the centrum semiovale. White matter damage of the CST in centrum semiovale was a highly reproducible marker of CP. This is the first description of the implication of this latter region in motor impairment after NAIS. In conclusion, CP in childhood was closely linked to the location of the infarct in the motor system.

From Phineas Gage and Monsieur Leborgne to H.M.: Revisiting Disconnection Syndromes

On the 50th anniversary of Norman Geschwind's seminal paper entitled ‘Disconnexion syndrome in animal and man’, we pay tribute to his ideas by applying contemporary tractography methods to understand white matter disconnection in 3 classic cases that made history in behavioral neurology. We first documented the locus and extent of the brain lesion from the computerized tomography of Phineas Gage's skull and the magnetic resonance images of Louis Victor Leborgne's brain, Broca's first patient, and Henry Gustave Molaison. We then applied the reconstructed lesions to an atlas of white matter connections obtained from diffusion tractography of 129 healthy adults. Our results showed that in all 3 patients, disruption extended to connections projecting to areas distant from the lesion. We confirmed that the damaged tracts link areas that in contemporary neuroscience are considered functionally engaged for tasks related to emotion and decision-making (Gage), language production (Leborgne), and declarative memory (Molaison). Our findings suggest that even historic cases should be reappraised within a disconnection framework whose principles were plainly established by the associationist schools in the last 2 centuries.

Navigation strategies as revealed by error patterns on the Magic Carpet test in children with cerebral palsy

Introduction: Short-term memory develops differently in navigation vs. manual space. The Magic Carpet (MC) is a novel navigation test derived from the Walking Corsi Test and the manual Corsi Block-tapping Task (CBT). The MC requires mental rotations and executive function. In Cerebral Palsy (CP), CBT, and MC scores relate differently to clinical and lesional factors. Hypotheses of this study are: that frontal lesion specifically affect navigation in CP; that brain lesions affect MC cognitive strategies.

Materials and Methods: Twenty-two children with spastic CP, aged 5 to 14 years, 14 with a unilateral and 8 with a bilateral form, underwent the CBT and the MC. Errors were classified into seven patterns by a recently described algorithm. Brain lesions were quantified according to a novel semi-quantitative MRI scale. Control data were partially drawn from a previous study on 91 typically developing children.

Results: Children with CP performed worse than controls on both tests. Right hemispheric impairment correlated with spatial memory. MC span was reduced less than CBT span and was more selectively related to right middle white-matter and frontal lesions. Error patterns were differently distributed in CP and in typical development, and depended on right brain impairment: children with more extensive right lesions made more positional than sequential errors.

Discussion: In CP, navigation is affected especially by extensive lesions involving the right frontal lobe. In addition, these are associated with abnormal cognitive strategies. Whereas in typical development positional errors, preserving serial order, increase with age and performance, in CP they are associated with poorer performance and more extensive right-brain lesions. The explanation may lie in lesion side: right brain is crucial for mental rotations, necessary for spatial updating. Left-lateralized spatial memory strategies, relying on serial order, are not efficient if not accompanied by right-brain spatial functions.

Musical hallucinations: review of treatment effects

BACKGROUND

Despite an increased scientific interest in musical hallucinations over the past 25 years, treatment protocols are still lacking. This may well be due to the fact that musical hallucinations have multiple causes, and that published cases are relatively rare.

OBJECTIVE

To review the effects of published treatment methods for musical hallucinations.

METHODS

A literature search yielded 175 articles discussing a total number of 516 cases, of which 147 articles discussed treatment in 276 individuals. We analyzed the treatment results in relation to the etiological factor considered responsible for the mediation of the musical hallucinations, i.e., idiopathic/hypoacusis, psychiatric disorder, brain lesion, and other pathology, epilepsy or intoxication/pharmacology.

RESULTS

Musical hallucinations can disappear without intervention. When hallucinations are bearable, patients can be reassured without any other treatment. However, in other patients musical hallucinations are so disturbing that treatment is indicated. Distinct etiological groups appear to respond differently to treatment. In the hypoacusis group, treating the hearing impairment can yield significant improvement and coping strategies (e.g., more acoustic stimulation) are frequently helpful. Pharmacological treatment methods can also be successful, with antidepressants being possibly more helpful than antiepileptics (which are still better than antipsychotics). The limited use of acetylcholinesterase inhibitors has looked promising. Musical hallucinations occurring as part of a psychiatric disorder tend to respond well to psychopharmacological treatments targeting the underlying disorder. Musical hallucinations experienced in the context of brain injuries and epilepsy tend to respond well to antiepileptics, but their natural course is often benign, irrespective of any pharmacological treatment. When intoxication/pharmacology is the main etiological factor, it is important to stop or switch the causative substance or medication.

CONCLUSION

Treatments for musical hallucinations tend to yield favorable results when they target the main etiological factor of these phenomena. There is a need to establish the natural course of musical hallucinations, their response to non-pharmacological treatments, and their effects on the patient's quality of life. There is also a need to standardize the assessment of treatment responses, and document long-term follow up.

Necessary, yet dissociable contributions of the insular and ventromedial prefrontal cortices to norm adaptation: computational and lesion evidence in humans

Social norms and their enforcement are fundamental to human societies. The ability to detect deviations from norms and to adapt to norms in a changing environment is therefore important to individuals' normal social functioning. Previous neuroimaging studies have highlighted the involvement of the insular and ventromedial prefrontal (vmPFC) cortices in representing norms. However, the necessity and dissociability of their involvement remain unclear. Using model-based computational modeling and neuropsychological lesion approaches, we examined the contributions of the insula and vmPFC to norm adaptation in seven human patients with focal insula lesions and six patients with focal vmPFC lesions, in comparison with forty neurologically intact controls and six brain-damaged controls. There were three computational signals of interest as participants played a fairness game (ultimatum game): sensitivity to the fairness of offers, sensitivity to deviations from expected norms, and the speed at which people adapt to norms. Significant group differences were assessed using bootstrapping methods. Patients with insula lesions displayed abnormally low adaptation speed to norms, yet detected norm violations with greater sensitivity than controls. Patients with vmPFC lesions did not have such abnormalities, but displayed reduced sensitivity to fairness and were more likely to accept the most unfair offers. These findings provide compelling computational and lesion evidence supporting the necessary, yet dissociable roles of the insula and vmPFC in norm adaptation in humans: the insula is critical for learning to adapt when reality deviates from norm expectations, and that the vmPFC is important for valuation of fairness during social exchange.

Detection of circulating tumor cells in the cerebrospinal fluid of a patient with a solitary metastasis from breast cancer: A case report

Brain lesions identified following the diagnosis and eradication of primary cancers are often ambiguous in origin, existing as a solitary metastasis or an independent primary brain tumor. The brain is a relatively common site of metastasis with breast cancer, although determining whether metastases have originated from the breast or brain is often not possible without invasive biopsies. In the current case report, a patient presented with a brain lesion identified by radiography and was without systemic disease. The patient had previously exhibited a complete response to chemotherapy and surgery for a poorly differentiated invasive ductal carcinoma. The origin of the brain lesion could not be determined by magnetic resonance imaging, giving rise to a diagnostic dilemma with diverging treatment options. We previously reported a method to isolate and enumerate tumor cells of epithelial origin in the cerebrospinal fluid (CSF). CSF tumor cell analysis of the patient revealed massive CSF tumor cell burden of epithelial origin, indicating that the brain lesion was likely of breast origin. The current case report highlights the use of CSF tumor cell detection as a differential diagnostic tool, in addition to its previously demonstrated use as a marker of disease burden and therapeutic response.

Neuroanatomical substrates of action perception and understanding: an anatomic likelihood estimation meta-analysis of lesion-symptom mapping studies in brain injured patients

Several neurophysiologic and neuroimaging studies suggested that motor and perceptual systems are tightly linked along a continuum rather than providing segregated mechanisms supporting different functions. Using correlational approaches, these studies demonstrated that action observation activates not only visual but also motor brain regions. On the other hand, brain stimulation and brain lesion evidence allows tackling the critical question of whether our action representations are necessary to perceive and understand others’ actions. In particular, recent neuropsychological studies have shown that patients with temporal, parietal, and frontal lesions exhibit a number of possible deficits in the visual perception and the understanding of others’ actions. The specific anatomical substrates of such neuropsychological deficits however, are still a matter of debate. Here we review the existing literature on this issue and perform an anatomic likelihood estimation meta-analysis of studies using lesion-symptom mapping methods on the causal relation between brain lesions and non-linguistic action perception and understanding deficits. The meta-analysis encompassed data from 361 patients tested in 11 studies and identified regions in the inferior frontal cortex, the inferior parietal cortex and the middle/superior temporal cortex, whose damage is consistently associated with poor performance in action perception and understanding tasks across studies. Interestingly, these areas correspond to the three nodes of the action observation network that are strongly activated in response to visual action perception in neuroimaging research and that have been targeted in previous brain stimulation studies. Thus, brain lesion mapping research provides converging causal evidence that premotor, parietal and temporal regions play a crucial role in action recognition and understanding.

Brain abnormalities and neurodevelopmental delay in congenital heart disease: systematic review and meta-analysis

OBJECTIVES

Studies have demonstrated an association between congenital heart disease (CHD) and neurodevelopmental delay. Neuroimaging studies have also demonstrated a high incidence of preoperative brain abnormalities. The aim of this study was to perform a systematic review to quantify the non-surgical risk of brain abnormalities and of neurodevelopmental delay in infants with CHD.

METHODS

MEDLINE, EMBASE and The Cochrane Library were searched electronically without language restrictions, utilizing combinations of the terms congenital heart, cardiac, neurologic, neurodevelopment, magnetic resonance imaging, ultrasound, neuroimaging, autopsy, preoperative and outcome. Reference lists of relevant articles and reviews were hand-searched for additional reports. Cohort and case-control studies were included. Studies reporting neurodevelopmental outcomes and/or brain lesions on neuroimaging in infants with CHD before heart surgery were included. Cases of chromosomal or genetic abnormalities, case reports and editorials were excluded. Between-study heterogeneity was assessed using the I(2) test.

RESULTS

The search yielded 9129 citations. Full text was retrieved for 119 and the following were included in the review: 13 studies (n = 425 cases) reporting on brain abnormalities either preoperatively or in those who did not undergo congenital cardiac surgery and nine (n = 512 cases) reporting preoperative data on neurodevelopmental assessment. The prevalence of brain lesions on neuroimaging was 34% (95% CI, 24-46; I(2) = 0%) in transposition of the great arteries, 49% (95% CI, 25-72; I(2) = 65%) in left-sided heart lesions and 46% (95% CI, 40-52; I(2) =18.1%) in mixed/unspecified cardiac lesions, while the prevalence of neurodevelopmental delay was 42% (95% CI, 34-51; I(2) = 68.9).

CONCLUSIONS

In the absence of chromosomal or genetic abnormalities, infants with CHD are at increased risk of brain lesions as revealed by neuroimaging and of neurodevelopmental delay. These findings are independent of the surgical risk, but it is unclear whether the time of onset is fetal or postnatal.

Efficient brain lesion segmentation using multi-modality tissue-based feature selection and support vector machines

Support vector machines (SVM) are machine learning techniques that have been used for segmentation and classification of medical images, including segmentation of white matter hyper-intensities (WMH). Current approaches using SVM for WMH segmentation extract features from the brain and classify these followed by complex post-processing steps to remove false positives. The method presented in this paper combines advanced pre-processing, tissue-based feature selection and SVM classification to obtain efficient and accurate WMH segmentation. Features from 125 patients, generated from up to four MR modalities [T1-w, T2-w, proton-density and fluid attenuated inversion recovery(FLAIR)], differing neighbourhood sizes and the use of multi-scale features were compared. We found that although using all four modalities gave the best overall classification (average Dice scores of 0.54  ±  0.12, 0.72  ±  0.06 and 0.82  ±  0.06 respectively for small, moderate and severe lesion loads); this was not significantly different (p = 0.50) from using just T1-w and FLAIR sequences (Dice scores of 0.52  ±  0.13, 0.71  ±  0.08 and 0.81  ±  0.07). Furthermore, there was a negligible difference between using 5 × 5 × 5 and 3 × 3 × 3 features (p = 0.93). Finally, we show that careful consideration of features and pre-processing techniques not only saves storage space and computation time but also leads to more efficient classification, which outperforms the one based on all features with post-processing.

Vicarious motor activation during action perception: beyond correlational evidence

Neurophysiological and imaging studies have shown that seeing the actions of other individuals brings about the vicarious activation of motor regions involved in performing the same actions. While this suggests a simulative mechanism mediating the perception of others' actions, one cannot use such evidence to make inferences about the functional significance of vicarious activations. Indeed, a central aim in social neuroscience is to comprehend how vicarious activations allow the understanding of other people's behavior, and this requires to use stimulation or lesion methods to establish causal links from brain activity to cognitive functions. In the present work, we review studies investigating the effects of transient manipulations of brain activity or stable lesions in the motor system on individuals' ability to perceive and understand the actions of others. We conclude there is now compelling evidence that neural activity in the motor system is critical for such cognitive ability. More research using causal methods, however, is needed in order to disclose the limits and the conditions under which vicarious activations are required to perceive and understand actions of others as well as their emotions and somatic feelings.

White matter integrity assessed by diffusion tensor tractography in a patient with a large tumor mass but minimal clinical and neuropsychological deficits

Diffusion tensor imaging (DTI) tractography and image registration were used to investigate a patient with a massive left-sided brain tumor, whose size was largely disproportionate to his subtle neurological deficits. MRI was obtained from the patient and his healthy identical twin, who acted as anatomical reference for DTI and as a control for quantitative measures. To compensate for the patient's altered anatomy, seed and way points for probabilistic tractography were drawn on the color-coded direction maps of the healthy twin. Registration, based on the combination of b0-images, T2-weighted and T1-weighted images, was used to identify the corresponding regions in the patient. The corticospinal tract (CST), the superior longitudinal fasciculus (SLF), and the cingulum bundle (CB) showed displaced anatomy. A significant difference was found between fractional anisotropy distribution along the left SLF and CB, but not along the CST. These findings fit well with the patient's substantial preservation of his motor abilities, while abnormalities of the SLF and CB could explain the subtle but detectable cognitive deficits.

Conduction aphasia, sensory-motor integration, and phonological short-term memory - an aggregate analysis of lesion and fMRI data

Conduction aphasia is a language disorder characterized by frequent speech errors, impaired verbatim repetition, a deficit in phonological short-term memory, and naming difficulties in the presence of otherwise fluent and grammatical speech output. While traditional models of conduction aphasia have typically implicated white matter pathways, recent advances in lesions reconstruction methodology applied to groups of patients have implicated left temporoparietal zones. Parallel work using functional magnetic resonance imaging (fMRI) has pinpointed a region in the posterior most portion of the left planum temporale, area Spt, which is critical for phonological working memory. Here we show that the region of maximal lesion overlap in a sample of 14 patients with conduction aphasia perfectly circumscribes area Spt, as defined in an aggregate fMRI analysis of 105 subjects performing a phonological working memory task. We provide a review of the evidence supporting the idea that Spt is an interface site for the integration of sensory and vocal tract-related motor representations of complex sound sequences, such as speech and music and show how the symptoms of conduction aphasia can be explained by damage to this system.

"Studying injured minds" - the Vietnam head injury study and 40 years of brain injury research

The study of those who have sustained traumatic brain injuries (TBI) during military conflicts has greatly facilitated research in the fields of neuropsychology, neurosurgery, psychiatry, neurology, and neuroimaging. The Vietnam Head Injury Study (VHIS) is a prospective, long-term follow-up study of a cohort of 1,221 Vietnam veterans with mostly penetrating brain injuries, which has stretched over more than 40 years. The scope of this study, both in terms of the types of injury and fields of examination, has been extremely broad. It has been instrumental in extending the field of TBI research and in exposing pressing medical and social issues that affect those who suffer such injuries. This review summarizes the history of conflict-related TBI research and the VHIS to date, as well as the vast range of important findings the VHIS has established.