Mitsutoshi Okazaki

Duration of postictal psychotic episodes

Summary:  Purpose: To clarify duration of postictal psychosis (PIP) episodes and identify factors that influence its duration.

Effect of electroconvulsive therapy on gray matter volume in major depressive disorder

BACKGROUND Although the clinical efficacy of electroconvulsive therapy (ECT) is well established, the underlying mechanisms of action remain elusive. The aim of this study was to elucidate structural changes of the brain following ECT in patients with major depressive disorder (MDD). METHOD Fifteen patients with MDD underwent magnetic resonance imaging scanning before and after ECT. Their gray matter volumes were compared between pre- and post-ECT. RESULTS There were significant volume increases after ECT in the bilateral medial temporal cortices, inferior temporal cortices, and right anterior cingulate. Further, the increase ratio was correlated with the clinical improvement measured by the Hamilton Depression Rating scale. LIMITATION All subjects were treated with antidepressants that could have a neurotoxic or neuroprotective effect on the brain. CONCLUSIONS We found that there were significant increases of gray matter volume in medial temporal lobes following ECT, suggesting that a neurotrophic effect of ECT could play a role in its therapeutic effect.

Pseudo-continuous arterial spin labeling MRI study of schizophrenic patients

UNLABELLED Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is a novel noninvasive technique that can measure regional cerebral blood flow (rCBF). To our knowledge, few studies have examined rCBF in patients with schizophrenia by ASL-MRI. Here we used pseudo-continuous ASL (pCASL) to examine the structural and functional imaging data in schizophrenic patients, taking the regional cerebral gray matter volume into account. The subjects were 36 patients with schizophrenia and 42 healthy volunteers who underwent 3-tesla MRI, diffusion tensor imaging (DTI), and pCASL. We evaluated the gray matter volume imaging, DTI, and pCASL imaging data in a voxel-by-voxel statistical analysis. The schizophrenia patients showed reduced rCBF in the left prefrontal and bilateral occipital cortices compared to the healthy volunteers. There was a significant reduction of gray matter volume in the left inferior frontal cortex in the schizophrenia patients. With respect to the fractional anisotropy (FA) values in the DTI, there were significant FA reductions in the left superior temporal, left external capsule, and left inferior prefrontal regions in the patients compared to the controls. CONCLUSION Our pCASL study with partial volume effect correction together with volumetry and DTI data demonstrated hypoactivity in the left prefrontal area beyond structural abnormalities in schizophrenia patients. There were also hypofunction areas in bilateral occipital cortices, although structural abnormalities were not apparent.

Evaluation of dissociative experiences and the clinical utility of the Dissociative Experience Scale in patients with coexisting epilepsy and psychogenic nonepileptic seizures

We investigated the relationship between dissociation and psychogenic nonepileptic seizures (PNES) and evaluated the clinical utility of the Dissociative Experience Scale (DES) in patients with epilepsy. The DES was administered to 30 patients with epilepsy and PNES, 50 patients with epilepsy and no PNES, and 85 nonclinical individuals. Patients with epilepsy and PNES scored significantly higher on the DES (29.3) than patients with epilepsy without PNES (13.5) and nonclinical individuals (11.1). High DES scores (>30) were more frequently observed in patients with epilepsy and PNES (53%) than in patients with epilepsy without PNES (12%) and nonclinical individuals (6%). DES score did not differ significantly with respect to epilepsy-related variables. Neither the frequency nor severity of PNES was significantly associated with the DES score. Our findings confirm some associations between PNES and dissociation in patients with coexisting epilepsy and PNES. The DES could be helpful in determining the tendency to have PNES in patients with epilepsy.

Subacute postictal aggression in patients with epilepsy

Three men with epilepsy (age range, 38-62) who exhibited brief episodes of violent behavior during the postictal period are described. Disease duration ranged from 27 to 44 years. Patients had both complex partial seizures and secondarily generalized tonic-clonic seizures, which were refractory to antiepileptic drugs. Postictal aggression occurred shortly after a seizure and lasted 5-30 minutes. The patients displayed physically and verbally aggressive behavior toward others, but regained consciousness promptly and showed regret afterward. Interictal EEGs revealed temporal spikes, SPECT showed hypoperfusion in the temporal and frontal areas in two patients, and neuropsychological examination revealed poor frontal lobe function in two patients. Characteristics of our cases are consistent with subacute postictal aggression (SPA) reported previously. Epilepsy of prolonged duration and brain dysfunction involving a broad area including the temporal and frontal lobes may be associated with the occurrence of subacute postictal aggression.

Interictal psychotic episodes in epilepsy: Duration and associated clinical factors

Purpose:  There have been few reports showing the distribution of the duration of interictal psychosis (IIP) episodes and their association with clinical characteristics. To clarify the nature of IIP, we studied the duration of IIP episodes and their related factors.

Automated subfield volumetric analysis of hippocampus in temporal lobe epilepsy using high-resolution T2-weighed MR imaging.

Background and purpose Automated subfield volumetry of hippocampus is desirable for use in temporal lobe epilepsy (TLE), but its utility has not been established. Automatic segmentation of hippocampal subfields (ASHS) and the new version of FreeSurfer software (ver.6.0) using high-resolution T2-weighted MR imaging are candidates for this volumetry. The aim of this study was to evaluate hippocampal subfields in TLE patients using ASHS as well as the old and new versions of FreeSurfer. Materials and methods We recruited 50 consecutive unilateral TLE patients including 25 with hippocampal sclerosis (TLE-HS) and 25 without obvious etiology (TLE-nonHS). All patients and 45 healthy controls underwent high-resolution T2-weighted and 3D-volume T1-weighted MRI scanning. We analyzed all of their MR images by FreeSurfer ver.5.3, ver.6.0 and ASHS. For each subfield, normalized z-scores were calculated and compared among groups. Results In TLE-HS groups, ASHS and FreeSurfer ver.6.0 revealed maximal z-scores in ipsilateral cornu ammonis (CA) 1, CA4 and dentate gyrus (DG), whereas in FreeSurfer ver.5.3 ipsilateral subiculum showed maximal z-scores. In TLE-nonHS group, there was no significant volume reduction by either ASHS or FreeSurfer. Conclusions ASHS and the new version of FreeSurfer may have an advantage in compatibility with existing histopathological knowledge in TLE patients with HS compared to the old version of FreeSurfer (ver.5.3), although further investigations with pathological findings and/or surgical outcomes are desirable.

Altered Coupling of Regional Cerebral Blood flow and Brain Temperature in Schizophrenia Compared with Bipolar Disorder and Healthy Subjects

Previous studies have suggested that schizophrenia patients have dysfunctional thermoregulation. The aim of this study was to examine whether brain temperature (BT) in schizophrenia patients differs from that in patients with bipolar disorder and healthy subjects by using magnetic resonance imaging. We also evaluated the possible relationship between BT and cerebral blood flow (CBF). We analyzed the temperature of lateral ventricles as the mean BT using diffusion-weighted imaging (DWI) thermometry, and evaluated the relationships between the BT and the CBF using pseudo-continuous arterial spin labeling (pCASL) among 3 diagnostic groups, 22 male patients with schizophrenia, 19 male patients with bipolar disorder, and 23 healthy male subjects. There were significant positive correlations between BT in the lateral ventricles and CBF in both the patients with bipolar disorder and healthy subjects. By contrast, there were significant negative correlations in patients with schizophrenia. We could not detect the significant difference in the surrogates of BT among three diagnostic groups. We showed that patients with schizophrenia, but not those with bipolar disorder, have dysfunctional thermoregulation in the brain. Brain temperature is highly dependent on cerebral metabolism and CBF, and thus uncoupling of cerebral metabolism and CBF may occur in schizophrenics.

Evaluation of amygdala pathology using 11C-methionine positron emission tomography/computed tomography in patients with temporal lobe epilepsy and amygdala enlargement

OBJECTIVE The association between amygdala enlargement (AE) and temporal lobe epilepsy (TLE) has increasingly been reported. However, the pathology of AE remains poorly understood. The purpose of this study was to explore AE pathology using (11)C-methionine (Met) positron emission tomography (PET)/computed tomography (CT) in patients who have TLE with AE. MATERIALS AND METHODS Twenty-six TLE patients with AE and 18 TLE patients without AE underwent (11)C-Met PET/CT and magnetic resonance imaging (MRI). (11)C-Met uptake in amygdala was evaluated by both visual inspection and semi-quantitative measurement. MRI was assessed visually and semi-quantitatively for AE. Laterality index (LI) was obtained by comparing the amygdala volumes of ipsilateral and contralateral sides. The clinical course and histopathological findings of all patients were also analyzed. RESULTS On (11)C-Met PET/CT images, visual examination detected increased uptake in the enlarged amygdala in 7 of 26 (27%) TLE patients with AE, and the results were confirmed by semi-quantitative analysis. Among six TLE patients with AE who underwent surgery, histopathology revealed neoplasms (low grade astrocytoma and gangliocytoma) in two patients and focal cortical dysplasia in one patient with increased (11)C-Met uptake, but non-neoplastic lesions (focal cortical dysplasia, vacuolar degeneration, and hamartoma) in all three patients with no increased (11)C-Met uptake. On MRI, volume of the affected amygdala was significantly larger compared to the contralateral amygdala. LI was significantly higher in the group with AE than in the group without AE. CONCLUSIONS This study revealed that some TLE patients with AE showed increased (11)C-Met uptake in the enlarged amygdala. (11)C-Met PET/CT is potentially useful for the evaluation of AE pathology, and may provide beneficial information for appropriate decision-making.

Do antipsychotic drugs increase seizure frequency in epilepsy patients

To investigate whether addition of antipsychotic drugs (APD) would increase seizure frequency in epilepsy patients who were already treated with anti-epileptic drugs (AED), we compared a one-year seizure control outcome in 150 epilepsy patients with APD treatment for psychiatric conditions and 309 epilepsy patients without APD treatment matched for ages at epilepsy onset and the baseline evaluation and types of epilepsy. The seizure frequency was recorded at the baseline (immediately before the start of APD) and after the 1st, 3rd, 6th and 12th months. The seizure outcome at each of the four follow-up points was compared with the baseline. The seizure outcome was compared between the two groups as a whole and according to the types of epilepsy (idiopathic generalized and partial epilepsies). In the APD group, the seizure outcome was also analyzed according to the types of APD (first and second generation APD and combination of first and second generation APD) and the types of psychiatric conditions (psychosis and non-psychosis). The seizure outcome was significantly better in the APD group than control group at all the four follow-up points. According to the epilepsy types, the improvement in the seizure outcome was only observed in the patients with partial epilepsy. Of the APD group, there was no significant difference in the seizure outcome according to the types of APD or the psychiatric conditions. In epilepsy patients who are already treated with AED, APD treatment seems safe in seizure control outcome for treatment of psychiatric conditions.