Comparative Neurocognitive Functions of Schizophrenics and temporal lobe epileptic Patients

Introduction: Shared neuropathology hypothesis in schizophrenia and temporal lobe epilepsy has been introduced long term ago. Similar neuropathology leads to the analogous clinical features like neuropsychological features as an example. The aim of this study was to examine this hypothesis by the means of comparing neuropsychological functions in these two patient groups.Method: Present study consisted of 28 DSM_IV_TR schizophrenics and 29 patients with temporal lobe epilepsy recruited from Roozbeh, Razi and khatamolanbia hospital in Tehran by convenient sampling method. SCID in schizophrenic group and EEG, MRI in epileptic patients were taken in regard to diagnostic determination. Neuropsychological tests were taken later. Package of neuropsychological tests consisted of Modified Wisconsin Card Sorting Test, Stroop Color- Word Test, Logic Memory, Visual Reproduction and Digit Span subscales of Wechsler Memory Scale- Revised and Block Design, Vocabulary and Symbol Digit subscales of Wechsler Adult intelligence Scale- Revised.Result:  there was no significant difference in two groups of patients with respect to demographic and clinical (Age, Depression, premorbid function and duration) variables. Analysis of MANOVA was taken to compare two groups of patients in neuropsychological functions. The results revealed no significant differences between schizophrenics and temporal lobe epileptic patients except for Symbol Digit subscale that was significantly lower in schizophrenic group (p<0.05).Conclusion: the result of current study is consistent with shared neuropathology hypothesis in schizophrenia and temporal lobe epilepsy. Profile of neuropsychological functions in both groups was generalized and beyond temporal lobe. Keywords: schizophrenia, temporal lobe epilepsy, neuropsychological function

Alteration of intracranial blood perfusion in temporal lobe epilepsy, an arterial spin labeling study

Background: A critical necessity before surgical resection in mesial temporal lobe epilepsy (mTLE) is lateralizing the seizure focus in the temporal lobe. This study aimed to investigate the differences in perfusion pattern changes in right and left mTLE. Methods: 42 mTLE patients (22 left and 20 right mTLE) and 14 controls were surveyed with pulsed arterial spin labeling at 3.0 T. The mean cerebral blood flow (CBF) and asymmetry index (AI) were calculated in the bilateral temporal lobe, amygdala, hippocampus, parahippocampus, and nine bilateral vascular territories ROIs. The alterations in whole-brain CBF were identified using statistical parametric mapping (SPM). Results: CBF decreased in ipsilateral sides in both epilepsy subcohorts, with right mTLE showing a significant difference in most ROIs while left mTLE exhibiting no significant change. CBF comparison of left mTLE and controls showed a significant drop in ROI analysis in left middle temporal and left intermediate posterior cerebral artery and in AI analysis in parahippocampus, distal anterior cerebral artery, distal middle cerebral artery, and intermediate anterior cerebral artery. CBF hypoperfusion was seen in ROI analysis in the left intermediate anterior cerebral artery, left middle temporal, right middle temporal, left superior temporal in the right mTLE compared to controls. Left mTLE CBF differed significantly from right mTLE CBF in right distal middle cerebral artery ROI and AI of proximal middle cerebral artery. Conclusion: Our result revealed that mTLE affects extratemporal regions and both mTLE subcohorts with different perfusion patterns, which may enhance the performance of preoperative MRI assessment in lateralization procedures

Cardiac arrest associated with epileptic seizures: A case report with simultaneous EEG and ECG

Ictal asystole is a rare, probably underestimated manifestation of epileptic seizures whose pathophysiology is still debated. This report describes two patients who had cardiac asystole at the end of their seizure. The first patient was a 13-year-old boy with complex partial seizures.. His MRI showed symmetrical signal abnormality in the bilateral parietooccipital lobe accompanied by mild gliosis and volume loss. During a 3-day long-term video-EEG monitoring, he had cardiac arrest at the end of one of his seizures that was secondarily generalized. The second one was a 42-year-old veteran with penetrating head trauma in the left frontal lobe due to shell injury. During long-term video-EEG monitoring, he had one generalized tonic–clonic seizure accompanied by bradycardia and cardiac asystole. Asystoles could have a role in the incidence of sudden unexpected death in epilepsy (SUDEP), meaning that the presence of ictal bradycardia is a risk factor for SUDEP. In cases of epileptic cardiac dysrhythmia, prolonged simultaneous EEG/ECG monitoring may be required. Cardiological investigation should be included in epilepsy management

Dynamic causal modeling of reorganization of memory and language networks in temporal lobe epilepsy

Objective To evaluate the alterations of language and memory functions using dynamic causal modeling, in order to identify the epileptogenic hemisphere in temporal lobe epilepsy (TLE). Methods Twenty-two patients with left TLE and 13 patients with right TLE underwent functional magnetic resonance imaging (fMRI) during four memory and four language mapping tasks. Dynamic causal modeling (DCM) was employed on fMRI data to examine effective directional connectivity in memory and language networks and the alterations in people with TLE compared to healthy individuals. Results DCM analysis suggested that TLE can influence the memory network more widely compared to the language network. For memory mapping, it demonstrated overall hyperconnectivity from the left hemisphere to the other cranial regions in the picture encoding, and from the right hemisphere to the other cranial regions in the word encoding tasks. On the contrary, overall hypoconnectivity was seen from the brain hemisphere contralateral to the seizure onset in the retrieval tasks. DCM analysis further manifested hypoconnectivity between the brain's hemispheres in the language network in patients with TLE compared to controls. The CANTAB® neuropsychological test revealed a negative correlation for the left TLE and a positive correlation for the right TLE cohorts for the connections extracted by DCM that were significantly different between the left and right TLE cohorts. Interpretation In this study, dynamic causal modeling evidenced the reorganization of language and memory networks in TLE that can be used for a better understanding of the effects of TLE on the brain's cognitive functions