Serum Neurosteroid Levels Are Associated With Cortical Thickness in Individuals Diagnosed With Posttraumatic Stress Disorder and History of Mild Traumatic Brain Injury

Posttraumatic stress disorder (PTSD) co-occurring with mild traumatic brain injury (mTBI) is common in veterans. Worse clinical outcome in those with PTSD has been associated with decreased serum neurosteroid levels. Furthermore, decreased cortical thickness has been associated with both PTSD and mTBI. However, it is not known whether decreased neurosteroids are associated with decreased cortical thickness in PTSD co-occurring with mTBI. This study included 141 individuals divided into the following groups: (a) mTBI group (n = 32 [10 female, 22 male] veterans with a history of mTBI); (b) PTSD + mTBI group (n = 41 [6 female, 35 male] veterans with current PTSD with a history of mTBI); and (c) control group (n = 68 [35 female, 33 male] control participants), which were acquired through the Injury and Traumatic Stress (INTRuST) Clinical Consortium. Subjects underwent clinical assessment, magnetic resonance imaging at 3 T, and serum neurosteroid quantifications of allopregnanolone (ALLO) and pregnenolone (PREGN). Group differences in cortical thickness and associations between serum neurosteroid levels and cortical thickness were investigated. Cortical thickness was decreased in the PTSD + mTBI group compared with the other groups. In the PTSD + mTBI group, decreased cortical thickness was also associated with lower serum ALLO (right superior frontal cortex) and lower serum PREGN (left middle temporal and right orbitofrontal cortex). Cortical thickness in the middle temporal and orbitofrontal cortex was associated with PTSD symptom severity. There were no significant associations between neurosteroids and cortical thickness in the mTBI or control groups. Decreased cortical thickness in individuals with PTSD + mTBI is associated with decreased serum neurosteroid levels and greater PTSD symptom severity. Causality is unclear. However, future studies might investigate whether treatment with neurosteroids could counteract stress-induced neural atrophy in PTSD + mTBI by potentially preserving cortical thickness.

Mild traumatic brain injury impacts associations between limbic system microstructure and post-traumatic stress disorder symptomatology

BACKGROUND

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that afflicts many individuals, yet the neuropathological mechanisms that contribute to this disorder remain to be fully determined. Moreover, it is unclear how exposure to mild traumatic brain injury (mTBI), a condition that is often comorbid with PTSD, particularly among military personnel, affects the clinical and neurological presentation of PTSD. To address these issues, the present study explores relationships between PTSD symptom severity and the microstructure of limbic and paralimbic gray matter brain regions, as well as the impact of mTBI comorbidity on these relationships.

METHODS

Structural and diffusion MRI data were acquired from 102 male veterans who were diagnosed with current PTSD. Diffusion data were analyzed with free-water imaging to quantify average CSF-corrected fractional anisotropy (FA) and mean diffusivity (MD) in 18 limbic and paralimbic gray matter regions. Associations between PTSD symptom severity and regional average dMRI measures were examined with repeated measures linear mixed models. Associations were studied separately in veterans with PTSD only, and in veterans with PTSD and a history of military mTBI.

RESULTS

Analyses revealed that in the PTSD only cohort, more severe symptoms were associated with higher FA in the right amygdala-hippocampus complex, lower FA in the right cingulate cortex, and lower MD in the left medial orbitofrontal cortex. In the PTSD and mTBI cohort, more severe PTSD symptoms were associated with higher FA bilaterally in the amygdala-hippocampus complex, with higher FA bilaterally in the nucleus accumbens, with lower FA bilaterally in the cingulate cortex, and with higher MD in the right amygdala-hippocampus complex.

CONCLUSIONS

These findings suggest that the microstructure of limbic and paralimbic brain regions may influence PTSD symptomatology. Further, given the additional associations observed between microstructure and symptom severity in veterans with head trauma, we speculate that mTBI may exacerbate the impact of brain microstructure on PTSD symptoms, especially within regions of the brain known to be vulnerable to chronic stress. A heightened sensitivity to the microstructural environment of the brain could partially explain why individuals with PTSD and mTBI comorbidity experience more severe symptoms and poorer illness prognoses than those without a history of brain injury. The relevance of these microstructural findings to the conceptualization of PTSD as being a disorder of stress-induced neuronal connectivity loss is discussed.

Neuro-Metabolite Changes in a Single Season of University Ice Hockey Using Magnetic Resonance Spectroscopy

Background: Previous research has shown evidence for transient neuronal loss after repetitive head impacts (RHI) as demonstrated by a decrease in N-acetylaspartate (NAA). However, few studies have investigated other neuro-metabolites that may be altered in the presence of RHI; furthermore, the relationship of neuro-metabolite changes to neurocognitive outcome and potential sex differences remain largely unknown.

Objective: The aim of this study was to identify alterations in brain metabolites and their potential association with neurocognitive performance over time as well as to characterize sex-specific differences in response to RHI.

Methods: 33 collegiate ice hockey players (17 males and 16 females) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation before and after the Canadian Interuniversity Sports (CIS) ice hockey season 2011–2012. The MRS voxel was placed in the corpus callosum. Pre- and postseason neurocognitive performances were assessed using the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). Absolute neuro-metabolite concentrations were then compared between pre- and postseason MRS were (level of statistical significance after correction for multiple comparisons: p < 0.007) and correlated to ImPACT scores for both sexes.

Results: A significant decrease in NAA was observed from preseason to postseason (p = 0.001). Furthermore, a trend toward a decrease in total choline (Cho) was observed (p = 0.044). Although no overall effect was observed for glutamate (Glu) over the season, a difference was observed with females showing a decrease in Glu and males showing an increase in Glu, though this was not statistically significant (p = 0.039). In both males and females, a negative correlation was observed between changes in Glu and changes in verbal memory (p = 0.008).

Conclusion: The results of this study demonstrate changes in absolute concentrations of neuro-metabolites following exposure to RHI. Results suggest that changes in Glu are correlated with changes in verbal memory. Future studies need to investigate further the association between brain metabolites and clinical outcome as well as sex-specific differences in the brain's response to RHI.

EEG: Stellenwerte und technische Voraussetzungen der EEG-Untersuchung

Die EEG-Kommission der DGKN hat Richtlinien für die Durchführung und die Auswertung der EEG-Untersuchung formuliert, mit dem Ziel der Sicherung von Qualität und Vergleichbarkeit von Befunden [1]. Diese Mindestanforderungen umfassen definitionsgemäß nicht das gesamte für eine qualifizierte Ausführung erforderliche Wissen. Eine umfassende Darstellung der Elektroenzephalografie geben entsprechende Lehrbücher [2].

Sex differences in white matter alterations following repetitive subconcussive head impacts in collegiate ice hockey players

Objective

Repetitive subconcussive head impacts (RSHI) may lead to structural, functional, and metabolic alterations of the brain. While differences between males and females have already been suggested following a concussion, whether there are sex differences following exposure to RSHI remains unknown. The aim of this study was to identify and to characterize sex differences following exposure to RSHI.

Methods

Twenty-five collegiate ice hockey players (14 males and 11 females, 20.6 ± 2.0 years), all part of the Hockey Concussion Education Project (HCEP), underwent diffusion-weighted magnetic resonance imaging (dMRI) before and after the Canadian Interuniversity Sports (CIS) ice hockey season 2011-2012 and did not experience a concussion during the season. Whole-brain tract-based spatial statistics (TBSS) were used to compare pre- and postseason imaging in both sexes for fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Pre- and postseason neurocognitive performance were assessed by the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT).

Results

Significant differences between the sexes were primarily located within the superior longitudinal fasciculus (SLF), the internal capsule (IC), and the corona radiata (CR) of the right hemisphere (RH). In significant voxel clusters (p < 0.05), decreases in FA (absolute difference pre- vs. postseason: 0.0268) and increases in MD (0.0002), AD (0.00008), and RD (0.00005) were observed in females whereas males showed no significant changes. There was no significant correlation between the change in diffusion scalar measures over the course of the season and neurocognitive performance as evidenced from postseason ImPACT scores.

Conclusions

The results of this study suggest sex differences in structural alterations following exposure to RSHI. Future studies need to investigate further the underlying mechanisms and association with exposure and clinical outcomes.

Histopathological Findings in Brain Tissue Obtained during Epilepsy Surgery

BACKGROUND

Detailed neuropathological information on the structural brain lesions underlying seizures is valuable for understanding drug-resistant focal epilepsy.

METHODS

We report the diagnoses made on the basis of resected brain specimens from 9523 patients who underwent epilepsy surgery for drug-resistant seizures in 36 centers from 12 European countries over 25 years. Histopathological diagnoses were determined through examination of the specimens in local hospitals (41%) or at the German Neuropathology Reference Center for Epilepsy Surgery (59%).

RESULTS

The onset of seizures occurred before 18 years of age in 75.9% of patients overall, and 72.5% of the patients underwent surgery as adults. The mean duration of epilepsy before surgical resection was 20.1 years among adults and 5.3 years among children. The temporal lobe was involved in 71.9% of operations. There were 36 histopathological diagnoses in seven major disease categories. The most common categories were hippocampal sclerosis, found in 36.4% of the patients (88.7% of cases were in adults), tumors (mainly ganglioglioma) in 23.6%, and malformations of cortical development in 19.8% (focal cortical dysplasia was the most common type, 52.7% of cases of which were in children). No histopathological diagnosis could be established for 7.7% of the patients.

CONCLUSIONS

In patients with drug-resistant focal epilepsy requiring surgery, hippocampal sclerosis was the most common histopathological diagnosis among adults, and focal cortical dysplasia was the most common diagnosis among children. Tumors were the second most common lesion in both groups. (Funded by the European Union and others.).

[Syncope, transient ischemic attacks, transient global amnesia and migraine]

Epileptic seizures can manifest with a variety of clinical symptoms. Depending on the dominant symptom, several differential diagnoses have to be considered. Their differentiation can be challenging, especially after the first episode. The review article summarizes the most common differential diagnoses as well as their characteristics compared to epileptic seizures, aiming at providing guidelines for their clinical differentiation. Whenever a clear diagnosis is not possible based on the patient history and clinical signs, diagnostic evaluation with, e. g. an electroencephalogram (EEG) and finally EEG video monitoring can be helpful.

What is the "L" in LPDs? Localized as well as lateralized

BACKGROUND

Periodic discharges (PDs) are well established as either periodic lateralized epileptiform discharges (LPDs) or generalized discharges. However, PDs in the midline can currently not be adequately classified as they are not generalized and not lateralized.

AIMS OF THE STUDY

To propose a modification of the current LPD classification.

METHODS

We here present a paradigmatic case series of three adult patients with midline LPDs.

RESULTS

In our patients, ictal electroencephalography (EEG) recordings revealed periodic epileptiform discharges in the midline region. All three patients were non-lesional.

CONCLUSION

We, thus, suggest to include periodic localized non-lateralized epileptiform discharges into the term LPDs (in addition to periodic lateralized epileptiform discharges), as they can also be recorded as localized EEG phenomenon in the midline region.

A novel portable, low-cost kinect-based system for motion analysis in neurological diseases

Many neurological diseases, such as Parkinson's disease and epilepsy, can significantly impair the motor function of the patients, often leading to a dramatic loss of their quality of life. Human motion analysis is regarded as fundamental towards an early diagnosis and enhanced follow-up in this type of diseases. In this contribution, we present NeuroKinect, a novel system designed for motion analysis in neurological diseases. This system includes an RGB-D camera (Microsoft Kinect) and two integrated software applications, KiT (KinecTracker) and KiMA (Kinect Motion Analyzer). The applications enable the preview, acquisition, review and management of data provided by the sensor, which are then used for motion analysis of relevant events. NeuroKinect is a portable, low-cost and markerless solution that is suitable for use in the clinical environment. Furthermore, it is able to provide quantitative support to the clinical assessment of different neurological diseases with movement impairments, as demonstrated by its usage in two different clinical routine scenarios: gait analysis in Parkinson's disease and seizure semiology analysis in epilepsy.

NeuroKinect: A Novel Low-Cost 3Dvideo-EEG System for Epileptic Seizure Motion Quantification

Epilepsy is a common neurological disorder which affects 0.5-1% of the world population. Its diagnosis relies both on Electroencephalogram (EEG) findings and characteristic seizure-induced body movements--called seizure semiology. Thus, synchronous EEG and (2D)video recording systems (known as Video-EEG) are the most accurate tools for epilepsy diagnosis. Despite the establishment of several quantitative methods for EEG analysis, seizure semiology is still analyzed by visual inspection, based on epileptologists' subjective interpretation of the movements of interest (MOIs) that occur during recorded seizures. In this contribution, we present NeuroKinect, a low-cost, easy to setup and operate solution for a novel 3Dvideo-EEG system. It is based on a RGB-D sensor (Microsoft Kinect camera) and performs 24/7 monitoring of an Epilepsy Monitoring Unit (EMU) bed. It does not require the attachment of any reflectors or sensors to the patient's body and has a very low maintenance load. To evaluate its performance and usability, we mounted a state-of-the-art 6-camera motion-capture system and our low-cost solution over the same EMU bed. A comparative study of seizure-simulated MOIs showed an average correlation of the resulting 3D motion trajectories of 84.2%. Then, we used our system on the routine of an EMU and collected 9 different seizures where we could perform 3D kinematic analysis of 42 MOIs arising from the temporal (TLE) (n = 19) and extratemporal (ETE) brain regions (n = 23). The obtained results showed that movement displacement and movement extent discriminated both seizure MOI groups with statistically significant levels (mean = 0.15 m vs. 0.44 m, p<0.001; mean = 0.068 m(3) vs. 0.14 m(3), p<0.05, respectively). Furthermore, TLE MOIs were significantly shorter than ETE (mean = 23 seconds vs 35 seconds, p<0.01) and presented higher jerking levels (mean = 345 ms(-3) vs 172 ms(-3), p<0.05). Our newly implemented 3D approach is faster by 87.5% in extracting body motion trajectories when compared to a 2D frame by frame tracking procedure. We conclude that this new approach provides a more comfortable (both for patients and clinical professionals), simpler, faster and lower-cost procedure than previous approaches, therefore providing a reliable tool to quantitatively analyze MOI patterns of epileptic seizures in the routine of EMUs around the world. We hope this study encourages other EMUs to adopt similar approaches so that more quantitative information is used to improve epilepsy diagnosis.

Eye movements differ between ictal ipsilateral and contralateral head turning

PURPOSE

This study evaluated the relation of head and eye movements during ictal ipsilateral and contralateral head turning in patients with focal epilepsies with regard to lateralization of the epileptogenic zone.

METHODS

We reviewed our database and identified patients with ictal head turning ipsilateral and contralateral to the seizure onset as defined by ictal EEG. Twenty-seven seizures of 19 consecutive patients with ipsilateral and 40 seizures of 32 patients with contralateral head turning were investigated. Twenty-four patients had temporal lobe epilepsy (TLE), and 27 patients had extratemporal or multifocal epilepsy.

KEY FINDINGS

Eye movement in the same direction preceded contralateral head turning in 90% (36 of 40 seizures) of the seizures, but this was the case in only 33% (9 of 27 seizures) of the ipsilateral ictal head turning. In contrary, head turning preceded the eye movements in 67% (18 of 27 seizures) of the ipsilateral ictal head turning and in only 10% of the contralateral head turning (p < 0.001). The results were similar in TLE and FLE.

SIGNIFICANCE

The sequence of head and eye movements is different in ictal ipsilateral and contralateral head turning movements which likely reflects different spread patterns of epileptic activity associated with activation of different generators. The analysis of eye movements adds to the lateralization of ictal head movements.

Novel phenotype associated with a mutation in the KCNA1(Kv1.1) gene

Episodic ataxia type 1 (EA1) is an autosomal dominant K(+) channelopathy which manifests with short attacks of cerebellar ataxia and dysarthria, and may also show interictal myokymia. Episodes can be triggered by emotional or physical stress, startle response, sudden postural change or fever. Here we describe a 31-year-old man displaying markedly atypical symptoms, including long-lasting attacks of jerking muscle contractions associated with hyperthermia, severe migraine, and a relatively short-sleep phenotype. A single nucleotide change in KCNA1 (c.555C>G) was identified that changes a highly conserved residue (p.C185W) in the first transmembrane segment of the voltage-gated K(+) channel Kv1.1. The patient is heterozygous and the mutation was inherited from his asymptomatic mother. Next generation sequencing revealed no variations in the CACNA1A, CACNB4, KCNC3, KCNJ10, PRRT2 or SCN8A genes of either the patient or mother, except for a benign variant in SLC1A3. Functional analysis of the p.C185W mutation in KCNA1 demonstrated a deleterious dominant-negative phenotype where the remaining current displayed slower activation kinetics, subtle changes in voltage-dependence and faster recovery from slow inactivation. Structural modeling also predicts the C185W mutation to be functionally deleterious. This description of novel clinical features, associated with a Kv1.1 mutation highlights a possibly unrecognized relationship between K(+) channel dysfunction, hyperthermia and migraine in EA1, and suggests that thorough assessments for these symptoms should be carefully considered for all patients affected by EA1.

A prospective study of physician-observed concussion during a varsity university hockey season: white matter integrity in ice hockey players. Part 3 of 4

OBJECT

The aim of this study was to investigate the effect of repetitive head impacts on white matter integrity that were sustained during 1 Canadian Interuniversity Sports (CIS) ice hockey season, using advanced diffusion tensor imaging (DTI).

METHODS

Twenty-five male ice hockey players between 20 and 26 years of age (mean age 22.24 ± 1.59 years) participated in this study. Participants underwent pre- and postseason 3-T MRI, including DTI. Group analyses were performed using paired-group tract-based spatial statistics to test for differences between preseason and postseason changes.

RESULTS

Tract-based spatial statistics revealed an increase in trace, radial diffusivity (RD), and axial diffusivity (AD) over the course of 1 season. Compared with preseason data, postseason images showed higher trace, AD, and RD values in the right precentral region, the right corona radiata, and the anterior and posterior limb of the internal capsule. These regions involve parts of the corticospinal tract, the corpus callosum, and the superior longitudinal fasciculus. No significant differences were observed between preseason and postseason for fractional anisotropy.

CONCLUSIONS

Diffusion tensor imaging revealed changes in white matter diffusivity in male ice hockey players over the course of 1 season. The origin of these findings needs to be elucidated.

Factors influencing mortality in atrial fibrillation. Post hoc analysis of an observational study in outpatients

BACKGROUND

Whether patients with atrial fibrillation (AF) have an increased mortality compared with the general population is controversially assessed.

METHODS

The mortality of 409 outpatients with AF (36% female, mean age 62 years, 39% paroxysmal AF, 27% lone AF), who were included in a prospective observational study, was compared with the mortality of the general population.

RESULTS

The mortality was 4%/year and constant during the 10 years of follow-up. Age (p<0.0001), heart failure (p=0.0013) and echocardiographically detected reduced left ventricular systolic function (p=0.0353) were independent predictors. The mortality of AF patients was 1.4-fold higher than in the general population, of female 1.5 and of male 1.3. Patients with permanent AF had a 1.5-fold higher and patients with heart failure a 1.7-fold higher mortality than the general population. Patients with lone AF did not differ in the mortality from the general population. The mortality of AF patients was not influenced by the duration of atrial fibrillation.

CONCLUSION

The prognosis of AF patients is dependent on the cardiovascular co-morbidity, especially the presence or absence of heart failure.

Mortality and rate of stroke or embolism in atrial fibrillation during long-term follow-up in the embolism in left atrial thrombi (ELAT) study

BACKGROUND

Patients with atrial fibrillation (AF) have a higher mortality and risk of stroke/embolism than patients with sinus rhythm.

HYPOTHESIS

The aim of the study was to assess the association of clinical and echocardiographic characteristics with mortality and stroke/embolism and the use of antithrombotic medication in the year 2000 in patients who participated 1990-1995 in the Embolism in Left Atrial Thrombi (ELAT) study.

METHODS

The study included 409 outpatients with nonrheumatic AF (62 +/- 12 years, 36% women, 39% intermittent AF). Patients with thrombi received anticoagulation, patients without thrombi aspirin until follow-up in 1995; thereafter, anticoagulation according to clinical risk factors was recommended. Primary events were death and secondary events were stroke/embolism. All patients were contacted during the year 2000.

RESULTS

Mean follow-up was 102 months. Mortality was 4%/year; the cause of death was cardiac (n = 84), fatal stroke (n = 26), malignancy (n = 23), sepsis (n = 5), and unknown (n = 24). Multivariate analysis identified age (p < 0.0001), heart failure (p = 0.0013), and reduced left ventricular systolic function (p = 0.0353) as predictors of mortality. Stroke/embolism occurred in 83 patients, with a rate of 3%/year. Multivariate analysis identified age (p = 0.0006) and previous stroke (p = 0.0454) as predictors of stroke/embolism. In the year 2000, 51 (21%) of the 247 surviving patients received no antithrombotic medication, 88 received (36%) oral anticoagulants, 102 (41%) acetylsalicylic acid, and 6 (2%) low-molecular heparin.

CONCLUSIONS

Therapy for heart failure and oral anticoagulation in AF should be seriously considered, especially in elderly patients and in those with previous stroke.

Diabetic atrial fibrillation patients: mortality and risk for stroke or embolism during a 10-year follow-up

BACKGROUND

To compare in atrial fibrillation patients with and without diabetes, (1) baseline characteristics, (2) additional risk factors for stroke or peripheric or visceral embolism (hypertension, previous stroke, age >75 years), (3) mortality, (4) stroke or embolism, and (5) oral anticoagulation in the year 2000.

METHODS

Included were 409 outpatients with nonrheumatic atrial fibrillation (62 +/- 12 years, 36% female). All underwent transthoracic and transesophageal echocardiography. Patients with thrombi received oral anticoagulation; patients without thrombi received aspirin until the follow-up in 1995; afterwards, oral anticoagulation according to risk factors for stroke or embolism was recommended. Patients were contacted during the year 2000.

RESULTS

Type 2 diabetes was diagnosed in 73 patients (18%). Sixteen (22%) diabetic and 169 (50%) nondiabetic patients had no other risk factors for stroke or embolism (p < 0.0001). Diabetic patients were older, had more frequent heart failure, hypertension, myocardial infarction, left ventricular dysfunction, valvular abnormalities, left atrial or appendage thrombi, larger left atria, and left atrial appendages than nondiabetic patients. Mean follow-up was 115 months. Diabetic patients had a higher mortality than nondiabetic patients (7%/year versus 4%/year, p < 0.0001). The rate of stroke or embolism of diabetic (3%/year) and nondiabetic patients (2%/year) was similar. The rate of oral anticoagulation was higher in diabetic than in nondiabetic patients (p = 0.0066).

CONCLUSIONS

Diabetic patients with atrial fibrillation frequently have additional risk factors for stroke or embolism, and thus should be treated with oral anticoagulation. Whether in the rare cases of atrial fibrillation, in whom diabetes is the only clinical risk factor, oral anticoagulation is indicated cannot be answered by the present study.

Passive fiber optic gyroscope

A fiber optic gyroscope different from the standard concept is presented. A fused fiber 3 x 3 directional coupler provides a constant phase shift thus enabling the detection of rotation rate at the quadrature point without phase modulation. Bias errors due to birefringent coupling centers in the fiber coil are avoided by using an unpolarized light source. A contrast insensitive signal recovery scheme eliminates the influence of polarization fluctuations on the scale factor. First measurements with a prototype gyroscope (90 mm in diameter and 23 mm in height) show a bias stability of <4.7 degrees /h and scale factor accuracy of <0.1% in the range of +/-200 degrees /s.

[Ionomeric vitreous cement for retrograde root filling]

In an in vitro study the sealing properties of materials commonly used for retrograde filling of apicectomized teeth were investigated in extracted teeth and compared with those of ionomeric vitreous cement. Materials tested included: --Heat-sealed guttapercha; --Guttapercha + phosphate cement; --Amalgam; --Standardized ceramic pins (Ulm system); and --Ionomeric vitreous cement. Sealing was established by methylene blue perfusion. Seals produced by heat-sealed guttapercha, guttapercha + phosphate cement and non-gamma-2 amalgam were found to be inferior to those obtained with ionomeric vitreous cement and standardized aluminium oxide ceramic pins.