Acquired lesions of the corpus callosum: MR imaging

Marchiafava-Bignami Disease in a Postoperative Non-alcoholic Patient

Marchiafava-Bignami disease (MBD) is a neuropathological condition characterized by demyelination and necrosis of the corpus callosum. This condition is commonly found in malnourished and alcoholic patients, but it is rarely observed in non-alcoholic individuals. In this case report, we describe a non-alcoholic patient who underwent two consecutive gastrointestinal surgeries. After the surgeries, he developed seizures and was diagnosed with MBD based on a plain head MRI. However, with the proper treatment, his condition stabilized, and he was discharged. This case serves as a beacon of hope, demonstrating that MBD, even in non-alcoholic patients, can be reversible with appropriate imaging and treatment.

FLAIR Hyperintensities in the Anterior Part of the Callosal Splenium in the Elderly Population: A Large Cohort Study

RATIONALE AND OBJECTIVES

Although hyperintensity in the anterior portion of the callosal splenium on FLAIR (aCS-hyperintensity) is a common finding in elderly adults, no previous studies have examined the clinical significance. In this large elderly population study, we aimed to investigate the associations of aCS-hyperintensity with vascular risk factors, cognitive decline, and other MRI measurements.

MATERIALS AND METHODS

This cross-sectional study included 2110 participants (median age, 69 years; 61.1% females) who underwent 3 T MRI. The participants were grouped as 215 with mild cognitive impairment (MCI) and 1895 cognitively normal older adults (NOAs). Two neuroradiologists evaluated aCS-hyperintensity by using a four-point scale (none, mild, moderate, and severe). Periventricular hyperintensities (PVHs) were also rated on a four-point scale according to the Fazekas scale. The total intracranial volume (ICV), total brain volume, choroid plexus volume (CPV), and lateral ventricle volume (LVV) were calculated.

RESULTS

Logistic regression analysis showed diabetes was the main predictor of aCS-hyperintensity after adjusting for potential confounders (age, sex, hypertension, and hyperlipidemia) (p < 0.01), whereas PVH was associated with hypertension (p < 0.01). aCS-hyperintensity rated as "severe" was associated with a presence of MCI (p < 0.01). For the imaging factors, LVV was an independent predictor of aCS-hyperintensity when brain volume and PVH grade were added to the analysis (p < 0.01).

CONCLUSION

Cerebral small vessel disease due to diabetes is a major contributor to the development of aCS-hyperintensity. Cerebrospinal fluid clearance failure may also relate to aCS-hyperintensity, which may offer new insights into the pathologic processes underlying MCI.

Cytotoxic lesions of the corpus callosum: a systematic review

OBJECTIVES

Cytotoxic lesions of the corpus callosum (CLOCC) are a common magnetic resonance imaging (MRI) finding associated with various systemic diseases including COVID-19. Although an increasing number of such cases is reported in the literature, there is a lack of systematic evidence summarizing the etiology and neuroimaging findings of these lesions. Thus, the aim of this systematic review was to synthesize the applied nomenclature, neuroimaging and clinical features, and differential diagnoses as well as associated disease entities of CLOCC.

MATERIALS AND METHODS

A comprehensive literature search in three biomedical databases identified 441 references, out of which 324 were eligible for a narrative summary including a total of 1353 patients.

RESULTS

Our PRISMA-conform systematic review identifies a broad panel of disease entities which are associated with CLOCC, among them toxic/drug-treatment-associated, infectious (viral, bacterial), vascular, metabolic, traumatic, and neoplastic entities in both adult and pediatric individuals. On MRI, CLOCC show typical high T2 signal, low T1 signal, restricted diffusion, and lack of contrast enhancement. The majority of the lesions were reversible within the follow-up period (median follow-up 3 weeks). Interestingly, even though CLOCC were mostly associated with symptoms of the underlying disease, in exceptional cases, CLOCC were associated with callosal neurological symptoms. Of note, employed nomenclature for CLOCC was highly inconsistent.

CONCLUSIONS

Our study provides high-level evidence for clinical and imaging features of CLOCC as well as associated disease entities.

CLINICAL RELEVANCE STATEMENT

Our study provides high-level evidence on MRI features of CLOCC as well as a comprehensive list of disease entities potentially associated with CLOCC. Together, this will facilitate rigorous diagnostic workup of suspected CLOCC cases.

KEY POINTS

• Cytotoxic lesions of the corpus callosum (CLOCC) are a frequent MRI feature associated with various systemic diseases. • Cytotoxic lesions of the corpus callosum show a highly homogenous MRI presentation and temporal dynamics. • This comprehensive overview will benefit (neuro)radiologists during diagnostic workup.

Case Report: Callosal disconnection syndrome manifesting as mixed frontal-callosal-posterior alien hand syndrome following extensive corpus callosum infarct

Alien hand syndrome (AHS) is a rare neurological phenomenon first described by Van Vleuten over a century ago. The most widely recognized variants in literature are frontal, callosal, and posterior AHS. AHS due to the corpus callosum lesion can occur alone or as part of callosal disconnection syndrome (CDS). This report presents a unique CDS case manifesting clinical features from all three AHS variants, resulting from an extensive corpus callosum infarct. Our patient exhibited various clinical features from the three AHS variants, which include grasping, groping, and difficulty releasing objects from the hand (anterior); intermanual conflict (callosal); arm levitation, mild hemiparesis, and hemisensory loss (posterior). Additionally, the extensive disruption of the corpus callosal fibers produced neurological manifestations of CDS, such as cognitive impairment, ideomotor and constructional apraxia, behavioral disorder, and transcortical motor aphasia. We employed a range of rehabilitation interventions, such as mirror box therapy, limb restraint strategy, verbal cue training, cognitive behavioral therapy, bimanual hand training, speech and language therapy, and pharmacological treatment with clonazepam. The patient showed almost complete resolution of CDS and AHS features by nine months post-stroke Our case report highlights distinctive clinical variations of AHS and the challenging correlation between clinical manifestations and neuroanatomical substrates. Future studies are necessary to explore the intricate neural connections and the precise function of the corpus callosum. This can be achieved by combining comprehensive neuropsychological testing with diffusion tensor tractography studies. It is also essential to develop a validated tool to standardize AHS assessment. Finally, the scarcity of evidence in rehabilitation interventions necessitates further studies to address the wide knowledge gap in AHS and CDS management.

Machine Learning Analysis Classifies Patients with Primary Angle-Closure Glaucoma Using Abnormal Brain White Matter Function

Objective

Primary angle-closure glaucoma (PACG) is a globally prevalent, irreversible eye disease leading to blindness. Previous neuroimaging studies demonstrated that PACG patients were associated with gray matter function changes. However, whether the white matter(WM) function changes in PACG patients remains unknown. The purpose of the study is to investigate WM function changes in the PACG patients.

Methods

In total, 40 PACG patients and 40 well-matched HCs participated in our study and underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans. We compared between-group differences between PACG patients and HC in the WM function using amplitude of low-frequency fluctuations (ALFF). In addition, the SVM method was applied to the construction of the PACG classification model.

Results

Compared with the HC group, ALFF was attenuated in right posterior thalamic radiation (include optic radiation), splenium of corpus callosum, and left tapetum in the PACG group, the results are statistically significant (GRF correction, voxel-level P < 0.001, cluster-level P < 0.05). Furthermore, the SVM classification had an accuracy of 80.0% and an area under the curve (AUC) of 0.86 for distinguishing patients with PACG from HC.

Conclusion

The findings of our study uncover abnormal WM functional alterations in PACG patients and mainly involves vision-related regions. These findings provide new insights into widespread brain damage in PACG from an alternative WM functional perspective.

Clinico-radiologic subtypes and therapeutic observation of acute Marchiafava-Bignami disease

We aimed to investigate the clinico-radiologic features of acute Marchiafava-Bignami disease (MBD) and its evolutionary process after effective treatment through subgroup comparison. The clinical and MRI data of 23 patients with acute MBD were retrospectively analyzed and divided into type A (12 cases, with entire callosal involvement) and type B (11 cases, with focal callosal involvement). The clinical assessments and MRI findings (before and after treatment) were compared between the two subtypes. Compared with type B, type A had lower MoCA (Montreal Cognitive Assessment) scores at admission (16.50 ± 1.73 vs 18.27 ± 1.68, P = 0.021) and were more common with extracallosal involvement (66.67% vs 18.18%, P = 0.036) and longer illness duration (18.3 ± 2.1 days vs 15.6 ± 2.4 days, P = 0.012). During the treatment, the residual lesion in the splenium was more common in type A (58.33% vs 9.09%, P = 0.027). After treatment, the MoCa scores of both subtypes gradually increased (P < 0.001), and the callosal and extracallasal lesions disappeared completely. Clinico-radiologic typing of acute MBD is related to the severity of early symptoms, but not to the prognosis. Complete clinico-radiologic recovery is possible for both subtypes with combined treatment. The clinico-radiologic reversibility is helpful for accurate diagnosis and therapeutic evaluation.

A model of traumatic brain injury in rats is influenced by neuroprotection of diurnal variation which improves motor behavior and histopathology in white matter myelin

Traumatic brain injury (TBI) represents a significant public health concern and has been associated with high rates of morbidity and mortality. TBI generates two types of brain damage: primary and secondary. Secondary damage originates a series of pathophysiological processes, which include metabolic crisis, excitotoxicity, and neuroinflammation, which have deleterious consequences for neuronal function. However, neuroprotective mechanisms are also activated. The balance among these tissue responses, and its variations throughout the day determines the fate of the damage tissue. We have demonstrated less behavioral and morphological damage when a rat model of TBI was induced during the light hours of the day. Moreover, here we show that rats subjected to TBI in the dark lost less body weight than those subjected to TBI in the light, despite no change in food intake. Besides, the rats subjected to TBI in the dark had better performance in the beam walking test and presented less histological damage in the corpus callosum and the cingulum bundle, as shown by the Klüver-Barrera staining. Our results suggest that the time of day when the injury occurs is important. Thus, this data should be used to evaluate the pathophysiological processes of TBI events and develop better therapies.

Case report: Reversible punctate inflammatory foci in the corpus callosum: A novel radiological finding of CAR T-cell therapy-related neurotoxicity

Introduction

Chimeric antigen receptor T-cell therapy-related neurotoxicity is a novel cytokine-mediated neurological syndrome that may present with a broad spectrum of manifestations. Descriptions of novel distinctive features are pivotal to untangling this condition's clinical and instrumental signature in order to inform diagnosis and pathophysiology.

Case

A 27-year-old female patient received anti-CD19 CAR T cells for a refractory primary mediastinal B-cell lymphoma. At 6 days after the infusion, she developed mild ideo-motor slowing, dysgraphia, and drowsiness. Despite specific treatment with dexamethasone, her neurological status progressively worsened to a comatose state within 24 h. EEG and CSF analyses were non-specific, showing background slowing and inflammatory findings. Brain MRI revealed multiple focal punctate areas of T2-weighted hyperintensity localized in the body and isthmus of the corpus callosum. Following the administration of high-dose intravenous methylprednisolone, her neurological status resolved within 48 h. Notably, the follow-up brain MRI did not reveal any abnormalities in the corpus callosum, except for a reduction of fractional anisotropy.

Conclusion

Reversible punctate inflammatory foci of the body and isthmus of the corpus callosum may represent a novel radiological finding of CAR T-cell therapy-related neurotoxicity.

Three Dimensional Brain Parameters of Multiple Sclerosis (MS) Patients

BACKGROUND & OBJECTIVES

MS is not only a demyelinating disease of central nervous system, but it also affects cortical and deep gray matter (GM). Furthermore, it causes axonal damage in the brain and spinal cord through inflammation and axonal degeneration. It is mostly seen between the ages of 20 and 40 and prevalence of the disease is higher among females than males. In the present study, we measured different parameters in the brains of patients with multiple sclerosis (MS) and healthy controls in both genders to determine the amount of brain atrophy quantitatively in MS patients.

METHODS

We used T2-weighted MRI scans of 40 MS patients (25 females + 15 males) with clinically definite relapsing-remitting multiple sclerosis that was determined according to Poser criteria in multiple parts of the brain, and we compared these data with those of sex-matched healthy controls in the same numbers.

RESULTS

Wideness of the lateral and third ventricles and the volumes of cerebral sulci in MS patients were significantly increased compared to both male and female controls. Brain width, corpus callosum area and the total brain/cerebellum + brain stem volumes of MS patients were decreased considerably.

INTERPRETATION & CONCLUSIONS

The present measurements indicated that MS caused parenchymal destruction in the cortex, axonal degeneration and myelin loss in the white matter of the brain. Consequently, the current observations correlate well with worsening disability in MS patients.

A Rare Case Report of a Corpus Callosal Splenial Lesion in the Context of Atypical Neuroleptic Malignant Syndrome

In this report, we describe a case of atypical neuroleptic malignant syndrome (NMS) presenting with an isolated lesion in the splenium of the corpus callosum (ILSCC). There is a paucity of information regarding this topic within the literature and only 7 previous case reports have been published at the time of writing. To our knowledge, this case report is also the first to describe an atypical NMS variant in the context of an ILSCC. In this report, we describe the important considerations in formulating differential diagnosis for ILSCC and are the first report to propose a possible pathophysiological mechanism relating ILSCC with NMS.

Diverse MRI findings and clinical outcomes of acute Marchiafava-Bignami disease

BACKGROUND

The acute onset of Marchiafava-Bignami disease (MBD) is difficult to capture, and its clinical manifestations are overlapped. Magnetic resonance imaging (MRI) is very useful in the diagnosis of acute MBD.

PURPOSE

To investigate the MRI features and clinical outcomes of acute MBD.

MATERIALS AND METHODS

Sagittal T2-weighted (T2W) or T1-weighted (T1W) imaging, axial T1W and T2W imaging, and axial FLAIR and diffusion-weighted imaging (DWI) sequences were performed in 17 patients with acute MBD on 1.5-T MR. According to the different ranges of callosal restricted diffusion, MBD was divided into Type I (n = 7, the completely involved), Type II (n = 5, the mostly involved), and Type III (n = 5, the partly involved). The MRI findings and outcomes of each type were retrospectively analyzed.

RESULTS

With the reduced range of the callosal restricted diffusion, the callosal atrophy or cavitation was more common: no case of Type I; 1 (20%) case of Type II; and 3 (60%) cases of Type III. With the increased range of callosal restricted diffusion, the extracallosal involvement was more common: 6 (86%) cases of Type I; 3 (60%) cases of Type II; and 1 (20%) case of Type III. During the follow-up, five cases had neuropsychiatric sequelae: 1 (14%) case of type I; 1 (20%) case of Type II; 3 (60%) cases of Type III.

CONCLUSION

The MRI findings and clinical outcomes of acute MBD are regular. The extensive restricted diffusion of acute MBD may present the curable condition. Callosal heterogeneity may affect the outcome of acute MBD.

Vertigo and Cytotoxic Lesions of the Corpus Callosum: Report with Review of the Literature

Background

The term cytotoxic lesions of the corpus callosum (CLOCCs) encompasses the entity reversible splenial lesion syndrome (RESLES). RESLES typically presents with altered levels of consciousness, seizures, and delirium and is distinguished radiographically by reversible focal lesions of the splenium of the corpus callosum. This disease pathology is associated with withdrawal of antiepileptic medications, infections, metabolic disturbance, or high-altitude cerebral edema.

Methods

We presented an otherwise healthy 72-year-old female that was consulted for an episode of isolated vertigo lasting four hours. Initial workup included CT head without contrast, CT angiogram head and neck, and MRI brain with and without contrast. The patient experienced recurrent episodes of vertigo at one and four months after initial presentation. An extensive workup at one month included a wide spectrum of laboratory tests and repeat imaging.

Results

Noncontrast CT of the head and CT angiogram of the head and neck were reassuring. MRI brain with and without contrast demonstrated hyperintensity in the splenium of the corpus callosum on FLAIR sequencing. A follow-up visit at one month revealed vitamin B12 deficiency and unchanged hyperintensity of the splenium of the corpus callosum. History and workup were negative for typical risk factors associated with RESLES.

Conclusion

An otherwise healthy patient who presented with an isolated episode of vertigo was discovered to demonstrate radiographic features consistent with RESLES but lacked the common risk factors and typical presentation of RESLES. This case expands the possible clinical presentation of RESLES and highlights the possible relationship between vitamin B12 deficiency and radiographic features of RESLES.

Multiple Border-Zone Infarcts Triggered by Influenza A Virus Infection in a Patient With Cerebral Autosomal Dominant Arteriopathy Presenting With Subcortical Infarcts and Leukoencephalopathy

Patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) can develop multiple border-zone infarcts due to hypotension, hypovolemia, or surgery. We report the case of a 41-year-old woman with CADASIL who developed multiple border-zone infarcts due to influenza A virus infection. The patient had no apparent history or episode of stroke or altered consciousness following the onset of respiratory symptoms, which were due to the influenza A infection. Diffusion-weighted magnetic resonance images of the brain showed multiple acute-phase infarcts in border-zone areas of both cerebral hemispheres and the corpus callosum; fluid-attenuated inversion-recovery magnetic resonance images showed increased signal in the subcortical areas of both temporal poles. Gene analysis identified a heterozygous mutation c.160C>T in exon 2 of the NOTCH3 gene (p.Arg54Cys). A diagnosis of CADASIL was established. Our case demonstrates that infectious conditions such as influenza A can trigger multiple border-zone infarctions in patients with CADASIL.

A Callosal Catastrophe: Toxic Leukoencephalopathy Associated with Thermogenic Weight Loss Supplement Use

BACKGROUND

The use of weight loss drugs and dietary supplements is common, but safety profiles for these drugs are largely unknown. Reports of toxicity have been published, and the use of these agents should be considered in clinical differential diagnoses.

METHODS

We report the case of a patient with toxic leukoencephalopathy and hyponatremia associated with oral consumption of a thermogenic dietary supplement and essential oils.

RESULTS

A 30-year-old woman presented after 2 days of headache, blurred vision, photophobia, vomiting, and hand spasms. She was taking a thermogenic dietary supplement daily for 6 months as well as a number of essential oils. Examination revealed mild right sided ataxia and diffuse hyperreflexia. Neuroimaging demonstrated bilaterally symmetric T2 hyperintensities of the corpus callosum and periventricular white matter. Approximately 18 h after admission she became unresponsive with brief extensor posturing and urinary incontinence. She partially recovered, but 1 h later became unresponsive with dilated nonreactive pupils and extensor posturing (central herniation syndrome). She was intubated, hyperventilated, and given hyperosmotic therapy. Emergent imaging showed diffuse cerebral edema. Intracranial pressure was elevated but normalized with treatment; she regained consciousness the following day. She was extubated one day later and discharged on hospital day 5. She was seen 2 months later with no further symptoms and a normal neurologic examination.

CONCLUSIONS

The pathophysiology of this patient's hyponatremia and toxic leukoencephalopathy is unknown. However, physicians must be aware of the association between thermogenic dietary supplements and toxic leukoencephalopathy. Vigilance for life-threatening complications including hyponatremia and cerebral edema is critical.

Intermittent alien hand syndrome caused by Marchiafava-Bignami disease: A case report

RATIONALE

Alien Hand syndrome (AHS) is characterized in most patients by seemingly purposeful, involuntary movements of the extremities. It is not well known among physicians on account of its diverse clinical manifestations.

PATIENT CONCERNS

We present a 57-year-old Chinese man who could not stop or turn himself around as he involuntarily and uncontrollably walked forward, which had happened frequently in the month prior to treatment. He had been a heavy drinker for thirty years before the onset of the disease, with an alcohol intake of 600 to 800 ml/day.

DIAGNOSES

History of alcohol intake and the brain magnetic resonance imaging findings indicated a diagnosis of Marchiafava-Bignami disease. The patient was additionally diagnosed with Alien Hand Syndrome according to his clinical symptoms.

INTERVENTIONS

The patient was treated with high doses of vitamin B for 1 month.

OUTCOMES

The patient's abnormal behaviors never appeared during the treatment, and no instance of recurrence was observed during the 6 months of follow-up.

LESSONS

The clinical manifestation of AHS is non-specific. Only by considering its diverse manifestation can doctors better understand the disease and achieve early intervention.

Clinical Features, Etiology, and 6-Month Prognosis of Isolated Corpus Callosum Infarction

As the largest subcortical commissural fiber, the corpus callosum plays an important role in cerebral functions and has abundant blood supply from bilateral circulation. Isolated corpus callosum infarction (ICCI) may have specific characteristics. The aim of the study is to evaluate the clinical features, etiology, and 6-month prognosis of ICCI. Consecutive patients with acute ICCI treated at the China-Japan Friendship Hospital between June 2012 and June 2016 were retrospectively assessed for clinical and imaging findings. These cases were compared with patients suffering from other isolated supratentorial subcortical infarctions, matched for age, sex, and infarction size (n=60; control group). ICCI etiology and 6-month prognosis were further analyzed. ICCI cases accounted for 2.9% (33/1125) of all acute ischemic strokes and 30 patients were included. Most patients (n=28, 93.3%) presented nonspecific clinical symptoms, and only two (6.7%) with diffuse infarction developed callosal disconnection syndrome (CDS). The splenium was the most frequent site (37.5%). Large artery atherosclerosis (LAA) (n=16, 53.3%) was the most common etiology. Only four (13.3%) patients developed transient ischemic attacks (n=1, 3.3%) or cerebral infarction (n=3, 10%) during the 6-month follow-up. The frequency of good prognosis (modified Rankin score of 1-2 and without cardiovascular events) was higher in patients with ICCI compared with controls (P=0.024). Poor prognosis was associated with multiple cerebrovascular stenosis, diffuse/large infarction, and diabetes (all P<0.05). ICCI is a rare stroke type, frequently involving the splenium; its common etiology is likely LAA. Most patients show nonspecific symptoms, with only a few developing CDS. ICCI generally shows favorable short-term outcome.

Diffusion tensor imaging changes following mild, moderate and severe adult traumatic brain injury: a meta-analysis

Diffusion tensor imaging quantifies the asymmetry (fractional anisotropy; FA) and amount of water diffusion (mean diffusivity/apparent diffusion coefficient; MD/ADC) and has been used to assess white matter damage following traumatic brain injury (TBI). In healthy brains, diffusion is constrained by the organization of axons, resulting in high FA and low MD/ADC. Following a TBI, diffusion may be altered; however the exact nature of these changes has yet to be determined. A meta-analysis was therefore conducted to determine the location and extent of changes in DTI following adult TBI. The data from 44 studies that compared the FA and/or MD/ADC data from TBI and Control participants in different regions of interest (ROIs) were analyzed. The impact of injury severity, post-injury interval (acute: ≤ 1 week, subacute: 1 week-3 months, chronic: > 3 months), scanner details and acquisition parameters were investigated in subgroup analyses, with the findings indicating that mild TBI should be examined separately to that of moderate to severe injuries. Lower FA values were found in 88% of brain regions following mild TBI and 92% following moderate-severe TBI, compared to Controls. MD/ADC was higher in 95% and 100% of brain regions following mild and moderate-severe TBI, respectively. Moderate to severe TBI resulted in larger changes in FA and MD/ADC than mild TBI. Overall, changes to FA and MD/ADC were widespread, reflecting more symmetric and a higher amount of diffusion, indicative of white matter damage.

Defining the Normal Dorsal Contour of the Corpus Callosum with Time

BACKGROUND AND PURPOSE

Morphological changes of the corpus callosum have been associated with a large number of congenital neurocognitive and psychiatric disorders. Focal defects or notches of the dorsal surface of the corpus callosum have not been well characterized. Our purpose was the following; 1) to characterize the dorsal contour of the corpus callosum during the life span, 2) to characterize the relationship of contour deviations to neighboring vessels, and 3) to determine whether contour deviations are congenital or acquired.

MATERIALS AND METHODS

We retrospectively reviewed normal sagittal T1-weighted brain MR images. A "notch" was defined as a concavity in the dorsal surface at least 1 mm in depth. The corpus callosum was considered to be "undulating" if there were >2 notches, including an anterior and posterior notch. The presence of a pericallosal artery and its relationship to a notch were assessed.

RESULTS

We reviewed 1639 MR imaging studies, spanning 0-89 years of age. A total of 1102 notches were identified in 823 studies; 344 (31%) were anterior, 660 (60%) were posterior, and 98 (9%), undulating. There was a positive correlation between the prevalence (P < .001) and depth (P = .028) of an anterior notch and age and a negative correlation between the prevalence of a posterior notch and age (P < .001). There was no difference between patient sex and corpus callosum notching (P = .884). Of the 823 studies with notches, 490 (60%) were associated with a pericallosal artery (P < .001).

CONCLUSIONS

The prevalence and depth of notches in the anterior corpus callosum increase significantly with age; this finding suggests that most notches are acquired. There is a significant positive association between the presence of a corpus callosum notch and adjacent pericallosal arteries, suggesting that this may play a role in notch formation.

Reversible lesions of the corpus callosum with initially restricted diffusion in a series of Caucasian children

BACKGROUND

Reversible lesions of the corpus callosum with initial restricted diffusion on diffusion-weighted imaging (DWI) are rare and mainly described in the south Asiatic population.

OBJECTIVE

The purpose of this study was to describe the clinical presentation, imaging findings, prognosis and etiology of transient restricted diffusion lesions of the corpus callosum in a series of Caucasian children.

MATERIALS AND METHODS

Seven children presenting with a transient restricted DWI lesion of the corpus callosum were included. Their clinical presentations and paraclinical examinations were investigated in addition to their MRI findings during the acute phase and at follow-up.

RESULTS

Five patients initially presenting with prodromal flu-like symptoms were diagnosed with mild encephalopathy with reversible corpus callosum lesions, three of which were due to the influenza virus. For two patients (twins) with a stroke-like presentation and without febrile illness, a central nervous system manifestation of X-linked Charcot-Marie-Tooth disease with connexin 32 mutation was diagnosed. All patients had a good clinical prognosis without clinical sequelae or residual MRI lesion for all patients at follow-up.

CONCLUSION

A transient lesion of the corpus callosum with restricted diffusion should prompt the radiologist to suggest an infectious trigger in children. The prognosis of these patients was good with normalization of clinical symptoms and MRI without any specific treatment.

Splenial Lesions of the Corpus Callosum: Disease Spectrum and MRI Findings

The corpus callosum (CC) is the largest white matter structure in the brain, consisting of more than 200–250 million axons that provide a large connection mainly between homologous cerebral cortical areas in mirror image sites. The posterior end of the CC is the thickest part, which is called the splenium. Various diseases including congenital to acquired lesions including congenital anomalies, traumatic lesions, ischemic diseases, tumors, metabolic, toxic, degenerative, and demyelinating diseases, can involve the splenium of the CC and their clinical symptoms and signs are also variable. Therefore, knowledge of the disease entities and the imaging findings of lesions involving the splenium is valuable in clinical practice. MR imaging is useful for the detection and differential diagnosis of splenial lesions of the CC. In this study, we classify the disease entities and describe imaging findings of lesions involving the splenium of the CC based on our experiences and a review of the literature.

The Corpus Callosum and Forensic Issues-An Overview

The corpus callosum is a large central white matter tract that connects the right and left cerebral hemispheres. It permits placental mammals to have a more sophisticated interhemispheric integration of sensory cortices and allows communication between cortical and subcortical neurons. Search of the literature and the pathology archives at The University of Adelaide was undertaken to identify lesions and injuries within the corpus callosum that may have forensic significance. These include developmental/congenital lesions with agenesis/dysgenesis, vascular malformations, and lipomas; inherited syndromes such as neurofibromatosis; and acquired lesions involving trauma, neoplasia, demyelination, vascular conditions, infections, fat embolism, aging/dementia, and the effects of toxins. The finding of lesions within the corpus callosum should initiate careful examination of the adjacent brain and other organ systems for related phenomena as this may shed some light on the nature of the underlying condition, and also help to determine whether there are any forensic implications.

Ectopic intracranial germinoma

Intracranial ectopic germinomas are often associated with synchronous midline disease. Germinomas involving the corpus callosum are exceedingly rare. The reported imaging appearance is not as varied as one might expect and a review of the literature reveals a few common imaging features amongst most ectopic lesions, including cyst formation. We report a 24-year-old man with panhypopituitarism. Neuroimaging revealed three enhancing lesions involving the pituitary infundibulum, the pineal region, and a parenchymal lesion involving the genu of the corpus callosum. The described ectopic mass, a parenchymal lesion, was associated with small peripheral cysts. Stereotactic biopsy and histopathological evaluation revealed this mass to be a germinoma. Following chemotherapy and radiation therapy, there was near-total resolution of the intracranial disease. Preoperative imaging plays an important role, not only in delineating the extent of disease, but also in assisting in generating an appropriate differential diagnosis. Germinomas in the corpus callosum are exceedingly rare but should be considered in the differential of any young patient with a characteristic cystic and solid intra-axial mass.

Diffuse corpus callosum infarction - Rare vascular entity with differing etiology

INTRODUCTION

Infarctions of the corpus callosum are rare vascular events. It is relatively immune to vascular insult because of its rich vascular supply from anterior and posterior circulations of brain.

OBJECTIVE

Report of 3 patients with largely diffuse acute corpus callosum infarction.

METHODS

3 patients with largely diffuse acute corpus callosum infarction were studied and each of these 3 patients had 3 different aetiologies.

RESULTS

The 3 different aetiologies of largely diffuse acute corpus callosum infarction were cardioembolism, tuberculous arteritis and takayasu arteritis.

CONCLUSION

Diffuse corpus callosum infarcts are rare events. This case series narrates the three different aetiologies of diffuse acute corpus callosum infarction which is a rare vascular event.

Infarction of the corpus callosum: a retrospective clinical investigation

Objectives

The aim of this study was to investigate patients with ischemic infarctions in the territory of the corpus callosum to advance our understanding of this rare stroke subtype by providing comprehensive descriptive and epidemiological data.

Methods

From January 1, 2010 to June 30, 2014, all cases of acute ischemic stroke diagnosed by clinical manifestation and diffusion weighted imaging in Dalian Municipal Central Hospital were investigated. The patients presenting with corpus callosum infarctions were selected and further allocated into genu and/or body and splenium infarction groups. Proportion, lesion patterns, clinical features, risk factors and etiology of corpus callosum infarction were analyzed.

Results

Out of 1,629 cases, 59 patients (3.6%) with corpus callosum infarctions were identified by diffusion weighted imaging, including 7 patients who had ischemic lesions restricted to the corpus callosum territory. Thirty six patients had lesions in the splenium (61.0%). Corpus callosum infarction patients suffered from a broad spectrum of symptoms including weakness and/or numbness of the limbs, clumsy speech, and vertigo, which could not be explained by lesions in corpus callosum. A classical callosal disconnection syndrome was found in 2 out of all patients with corpus callosum infarctions. Statistical differences in the risk factor and infarct pattern between the genu and/or body group and splenium group were revealed.

Conclusion

Corpus callosum infarction and the callosal disconnection syndrome were generally rare. The most susceptible location of ischemic corpus callosum lesion was the splenium. Splenium infarctions were often associated with bilateral cerebral hemisphere involvement (46.2%). The genu and/or body infarctions were associated with atherosclerosis. The most common cause of corpus callosum infarction probably was embolism.

Progressive Wallerian Degeneration of the Corpus Callosal Splenium in a Patient with Alexia Without Agraphia: Advanced MR Findings

The corpus callosal splenium is an uncommon location for Wallerian degeneration (WD), which may be mistaken for new pathology on magnetic resonance imaging (MRI). We describe the case of a 69-year-old woman with a left posterior cerebral artery infarct in whom progressive WD of the splenium of the corpus callosum seen on MRI was misinterpreted as new infarction or neoplasm. We address how magnetic resonance spectroscopy, perfusion MRI, diffusion tensor MRI, and serial imaging were utilized in establishing the correct diagnosis. Interestingly, the patient also presented with alexia without agraphia, which has never been reported in association with splenial WD. It is conceivable that WD affected critical splenial association fibers resulting in this uncommon dissociation syndrome.

Diagnosis and management of Marchiafava-Bignami disease: a review of CT/MRI confirmed cases

OBJECTIVE

Marchiafava-Bignami disease (MBD) is a rare condition mainly associated with alcoholism, although it may be mimicked by several other disorders that cause corpus callosum lesions. Our objective was to identify helpful features for differential diagnosis and assess whether any treatment can be recommended.

METHODS

We reviewed 122 reports containing data on 153 subjects with confirmed MBD that was associated with either alcoholism or malnutrition, and 20 reports with data on 53 subjects with conditions mimicking MBD. All the cases had been verified antemortem by brain imaging. Unconditional logistic regression was used to demonstrate factors that were associated with the outcome of MBD.

RESULTS

The mimicking conditions were differentiated from MBD by the occurrence of solitary and rapidly disappearing splenial lesions; fewer signs and symptoms with exception of seizures, hemiparesis and tetraparesis; nystagmus; and rapid and complete recovery. MBD occurred most frequently among alcoholics, but it was also reported in 11 non-alcoholics (7.2% of all the MBD cases). A better outcome was observed among those who were treated within 2 weeks after onset of symptoms with parenteral thiamine (p=0.033).

CONCLUSIONS

As thiamine deficiency is frequently associated with alcoholism, malnutrition and prolonged vomiting; we recommend prompt treatment of MBD with parenteral thiamine in such subjects. Recovery should be followed by repeated neuropsychological and MRI examinations, preferably using diffusion tensor imaging.

Congenital and acquired abnormalities of the corpus callosum: a pictorial essay

The purpose of this review is to illustrate the wide spectrum of lesions in the corpus callosum, both congenital and acquired: developmental abnormalities, phakomatoses, neurometabolic disorders, demyelinating diseases, infection and inflammation, vascular lesions, neoplasms, traumatic and iatrogenic injury, and others. Cases include fetuses, children, and adults with rich iconography from the authors' own archive.

Imaging spectrum of pediatric corpus callosal pathology: a pictorial review

A wide spectrum of pediatric corpus callosal diseases can occur in the pediatric age group. Cross-sectional magnetic resonance imaging plays an important role in the diagnosis of these patients. We reviewed our imaging record and collected cases of corpus callosal pathology. The purpose of this review is to illustrate the imaging features of various corpus callosal lesions encountered in children.

Postshunting corpus callosum swelling with depiction on tractography

Alterations in the appearance of the corpus callosum occasionally occur following successful ventricular decompression in patients with chronic hydrocephalus. There are certain features on imaging that suggest the diagnosis of what the authors propose be termed "postshunting corpus callosum swelling," including diffuse high T2 signal predominantly affecting the body of the corpus callosum, with transverse orientation along the crossing white matter tracts and scalloping along the posterior margin of the structure. In this report, the authors demonstrate preservation of the corpus callosum white matter fiber tracts by using diffusion tensor imaging with tractography.

Clinical and radiologic spectrum of corpus callosum infarctions: clues to the etiology

Infarctions of the corpus callosum are rare. The clinical picture varies from an acute onset to slow evolving symptoms, frequently with poor localizing signs; however, the location of the infarct in the callosum often correlates with a specific etiology. We describe three patients with varying degrees of callosal infarction, each corresponding to a particular etiology.

Grade II oligodendroglioma localized to the corpus callosum

The presence of a primary central nervous system (CNS) neoplasm within the corpus callosum generally portends a grave prognosis. Common pathologies encountered include glioblastomas and primary CNS lymphomas. In contrast, World Health Organization grade II oligodendroglial tumors demonstrating loss of heterozygosity at 1p and 19q are generally less aggressive, often responding favorably to chemotherapy. The authors present a case of a primary brain tumor isolated to the corpus callosum diagnosed as a grade II oligodendroglioma. A 52-year-old woman presented with new-onset generalized seizure. Magnetic resonance imaging (MRI) revealed a non-contrast-enhancing lesion with associated edema and regional mass effect. The patient underwent a craniotomy and subtotal resection of the lesion using an endoscopic port. Pathological examination revealed a grade II oligodendroglioma. Molecular analysis identified 1p and 19q deletion as well as MGMT promoter methylation. The patient subsequently underwent adjuvant radiation therapy with an excellent response. We present, to our knowledge, the first report of a grade II oligodendroglioma isolated within the corpus callosum with the characteristic molecular features of this tumor type. Histopathologic diagnosis is essential to appropriately guide therapy of callosal tumors.

Brain regional lesion burden and impaired mobility in the elderly

This study investigated the relationship of brain white matter (WM) lesions affecting specific neural networks with decreased mobility in ninety-nine healthy community-dwelling subjects ≥75 years old prospectively enrolled by age and mobility status. We assessed lesion burden in the genu, body and splenium of corpus callosum; anterior, superior and posterior corona radiata; anterior and posterior limbs of internal capsule; corticospinal tract; and superior longitudinal fasciculus. Burden in the splenium of corpus callosum (SCC) demonstrated the highest correlation particularly with walking speed (r=0.4, p<10(-4)), and in logistic regression it was the best regional predictor of low mobility performance. We also found that independent of mobility, corona radiata has the largest lesion burden with anterior (ACR) and posterior (PCR) aspects being the most frequently affected. The results suggest that compromised inter-hemispheric integration of visuospatial information through the SCC plays an important role in mobility impairment in the elderly. The relatively high lesion susceptibility of ACR and PCR in all subjects may obscure the importance of these lesions in mobility impairment.

Germinoma of the Corpus Callosum

A case is described of a young man presenting with diabetes insipidus and a junctional scotoma. A diffuse infiltrating mass centred in the corpus callosum and suprasellar area is found, which on pathological examination proved to be a primary intracranial germinoma. The case illustrates that rarely the corpus callosum can be involved by this tumour and that diagnosis may be delayed in atypical presentations.

Reversible pancallosal signal changes in febrile encephalopathy: report of 2 cases

Transient CC involvement has been reported in encephalopathies/encephalitis of different etiologies. Here we report 2 patients with AFE, who showed transient pancallosal involvement with restricted diffusion on neuroimaging. Both patients had excellent clinical outcomes: The lesion disappeared completely in 1, though there was mild residual gliosis in the other. Serology for dengue virus was positive in 1 of the patients.

[Corpus callosum. Landmark of the origin of cerebral diseases]

Diseases of the corpus callosum include developmental disorders, immunomodulated CNS diseases, vascular malformations, disturbances of metabolism including the electrolyte homeostasis, secondary degenerations and mechanical injuries. This report provides information on the differential diagnosis of reversible and irreversible pathological changes of the corpus callosum with special focus on the localization, which often allows conclusions on the pathogenesis to be drawn.

Multiple symptoms of higher brain dysfunction caused by Marchiafava-Bignami disease in a patient with dermatomyositis

A 65-year-old woman with dermatomyositis (DM) was admitted because of disorientation, mental dysfunction, and disturbance of consciousness. Prior to admission, she suffered from septic and hypovolemic shock. There was no evidence of active DM on physical examination and laboratory tests. Cerebrospinal fluid examination revealed no signs of meningitis. Because of clinical symptoms and findings on magnetic resonance images, such as the lesion in the splenium of the corpus callosum that was a low-intensity area on T1-weighted images and a high intensity on T2-weighted images; she was diagnosed as Marchiafava-Bignami disease (MBD). She received a combination of vitamin B, vitamin E, vitamin C, and nicotinic acid. Her symptoms improved gradually, and she was discharged at 1.5 months after admission. There has been no report of a case of DM with MBD. This report may provide useful data with regard to the mechanisms of central nervous system (CNS) disorders in patients with DM.