Sub-lobar dysplasia - A comprehensive evaluation with neuroimaging, magnetoencephalography and histopathology.

Sublobar dysplasia, a rare cortical malformation has been defined in only 8 patients to date. It was identified on the basis of histopathological features and MRI findings. We report a right temporal sublobar dysplasia, with detailed evaluation including neuroimaging, magnetoencephalography and histopathology to further characterize the pathology. Additional pathological features included a deep collateral sulcus in the basal right temporal lobe, thinned out right corticospinal tract, and bilateral asymmetric basal ganglia changes. Magnetoencephalograpy localized the seizure focus to the posterior margin of the dysplasia. Histopathological evaluation helped exclude other types of dysplasia. Similar to a previous study, the child had Engel 1a outcome.

Giant Hypothalamic Hamartoma in an Infant: A Case Report and Review of the Literature.

Giant hypothalamic hamartomas (GHH) are extremely rare lesions in infants and usually intrinsically epileptogenic. We present the case of a 10-month-old girl child presenting with drug-resistant seizures and a giant hypothalamic lesion that was confirmed as hamartoma on histopathology. Surgical decompression and disconnection from the hypothalamus was performed with the intent of controlling her seizures. Unfortunately, the patient developed right middle cerebral artery and posterior cerebral artery territory infarction, possibly due to vasospasm or thrombosis of the vessels. The patient had a stormy postoperative course but has recovered well neurologically at the 18-month follow-up. Histopathological examination revealed abnormal clusters of NeuN-positive neurons, which was confirmatory of hypothalamic hamartoma. A review of the published literature on infantile GHH, its management and the postoperative complications is undertaken in this short report.

Intrinsic brainstem schwannoma - A rare clinical entity and a histological enigma.

Intraparenchymal schwannomas arising in the brainstem are very rare, and only eight cases have been reported in literature till now. We report an intraparenchymal brainstem schwannoma presenting with the classical clinical presentation of an intrinsic brainstem lesion, and discuss its clinicoradiological characteristics and histological origins. We highlight the importance of an intraoperative frozen section diagnosis in such cases. Intraoperative tissue diagnosis significantly may alter the surgical strategy, which should be aimed at near total intracapsular decompression of the schwannoma.

Apoplectic presentation of a cauda equina paraganglioma.

BACKGROUND: Cauda equina paragangliomas (CEPs) are rare spinal tumors that are mostly misdiagnosed preoperatively as ependymomas or schwannomas on magnetic resonance imaging (MRI). Clinically, they usually present with the gradual onset of back pain and radiculopathy rather than an acute cauda equina syndrome. CASE DESCRIPTION: A 36-year-old female presented with an acute flaccid paraparesis/cauda equina syndrome. Based upon MRI studies, the predominant differential diagnoses included ependymoma or schwannoma. The intraoperative findings revealed an acute intralesional hemorrhage or apoplexy, responsible for the acute clinical deterioration. Histopathology and immunohistochemistry (IHC) revealed that the tumor was a paraganglioma. CONCLUSION: CEPs commonly present with mild symptoms and signs rather than the acute-onset of a flaccid paraparesis/cauda equina syndrome as seen in this case. Here, the authors review the radiological and histopathological characteristics of CEP and emphasize the role of IHC in differentiating "CEP" from the more common ependymomas.

Predictors of spontaneous transient seizure remission in patients of medically refractory epilepsy due to mesial temporal sclerosis (MTS).

PURPOSE: To analyze the predictors of spontaneous transient seizure remission for ≥1 year in patients with drug-resistant epilepsy (DRE) due to mesial temporal sclerosis (MTS). METHODS: This analysis included 38 patients with DRE (M:F = 20:18, age: 31.7 ± 10.9 years) diagnosed with unilateral MTS (right:left = 16:22). Group I ('remission' group) comprised of patients with seizure remission (M:F = 10:8, age: 32.8 ± 12.3 years, mean seizure free period: 2.2 ± 1.1 years; median: 2.1 years). Group II ('non-remission' group) comprised of age and gender matched 20 patients (M:F = 10:10, age: 30.7 ± 9.7 years) with unilateral MTS who never had seizure remission and subsequently underwent epilepsy surgery. Groups I and II were compared to find the predictors associated with transient seizure remission. RESULTS: The age at onset of seizures in group I was 13.2 ± 11.8 years and in group II was 12.0 ± 7.6 years. The duration of seizure was: group I - 19.7 ± 12.5 years and group II - 19.3 ± 7.7 years. Past history of seizure remissions (p < 0.001), frequent periods of remissions (p < 0.001), first remission within a year of onset of seizures (p = 0.04) and normal EEG (p = 0.04) were the important clinical predictors associated with seizure remission in this cohort. Fifteen patients in group I (83.3%) experienced remission following either change in AED (p ≤ 0.001) or increase in AED dosages (p < 0.001). There was no difference between the two groups regarding the type of semiology (partial vs. secondarily generalized) (p = 0.50), family history of seizures (p = 1.0), side of the lesion (p = 0.34), history of febrile seizures (p = 1.0) and the number of AEDs used (p = 0.53). CONCLUSION: The present study unfolds, some of the clinically relevant predictors associated with transient seizure remission in patients with DRE and MTS. Future molecular and network studies are required to understand its mechanism.

The Relevance of Interictal Bold Changes to Lateralize Seizure Focus Using Simultaneous EEG-fMRI.

BACKGROUND AND PURPOSE: The main challenge in assessing patients with epilepsy is the localization of neuronal networks involved in seizure generation and the lateralization of seizure onset. Electro encephalogram-functional magnetic resonance imaging (EEG-fMRI) is a noninvasive multimodal imaging technique for epilepsies where the data is acquired based on the interictal epileptiform discharges (IED). Since this is a new technique, the specificity for lateralizing epileptic focus is yet to be established. The peak blood oxygen level dependent (BOLD) signal in an interictal recording is known to correlate with seizure onset focus. In this study we are proposing a simple and practical method without the need for high end post processing techniques of fmri data. The peak BOLD signal derived from EEG-fMRI aids to lateralise seizure focus in a given cerebral lobe (region of interest, ROI). This is a very useful tool in a clinical setting on a given individual clinical case, when other modalities may be conflicting or inconclusive. METHODS: We analyzed simultaneous EEG-fMRI of 10 different types of refractory epilepsy. The lateralization index was calculated from the statistical significant clusters obtained between the different ROI and results were validated with other modalities. RESULTS: Lateralization of seizure focus corroborated well in temporal and extratemporal lobe epilepsy, reflex epilepsy and lesional epilepsy. The only drawback of EEG-fMRI in our study was if insignificant BOLD changes were associated with the given IED. CONCLUSIONS: EEG-fMRI can be helpful additional tool in the pre-surgical work-up of refractory epilepsy particularly when lateralization with other modalities is conflicting or inconclusive.