Kotaro Sakurai

Generalized spike-wave discharges involve a default mode network in patients with juvenile absence epilepsy: A MEG study

This study uses magnetoencephalography (MEG) to examine whether cortical regions that constitute a default mode network are involved during generalized spike-wave discharges (GSWs) in patients with juvenile absence epilepsy (JAE). We studied five JAE patients for whom MEG was recorded using a 204-channel, whole-head gradiometer system. Dynamic statistical parametric mapping (dSPM) was done to estimate the cortical source distribution of GSW. The dSPM results showed strong medial prefrontal activation in all patients, with activation in the posterior cingulate and precuneus in three of five patients simultaneously or slightly after medial prefrontal activation. Furthermore, dSPM showed that the initial activation of a GSW appears in the focal cortical regions. Cortical regions that constitute a default mode network are strongly involved in the GSW process in some patients with JAE. Results also show that focal cortical activation appears at the onset of a GSW.

Persistent déjà vu associated with hyperperfusion in the entorhinal cortex

Déjà vu is a common experience among the normal population. However, in individuals with temporal lobe epilepsy, it often occurs as a seizure manifestation. The specific cause of such déjà vu is not yet known. Here, we report a case of epilepsy with persistent déjà vu. The patient described the state as if he were living the same life he had lived before. Blood perfusion single-photon-emission computed tomography (SPECT) performed during the persistent déjà vu showed hyperperfusion in the left medial temporal area; discontinuation of déjà vu was accompanied by disappearance of the hyperperfused area on SPECT. Analysis with three-dimensional co-registration of SPECT and MRI revealed that the hyperperfused area during the persistent déjà vu was in the entorhinal cortex of the left temporal lobe. According to recent theories of recognition memory, malfunction of the parahippocampal area may cause déjà vu. It is also suggested that epileptic activity in the parahippocampal area, especially the entorhinal cortex, may elicit déjà vu.

Direct correlation between the facial nerve nucleus and hemifacial seizures associated with a gangliocytoma of the floor of the fourth ventricle: A case report

A dysplastic neuronal lesion of the floor of the fourth ventricle (DNFFV) causes hemifacial seizures (HFS) from early infancy. However, it is still controversial whether HFS is generated by the facial nerve nucleus or cerebellar cortex. In this study, we confirm a direct correlation between the rhythmic activities in the DNFFV and HFS using intraoperative electroencephalography (EEG) and electromyography (EMG) monitoring. Our results support the theory that a DNFFV provokes ipsilateral HFS via the facial nerve nucleus.

Very Long-Term Outcome of Non-Surgically Treated Patients with Temporal Lobe Epilepsy with Hippocampal Sclerosis: A Retrospective Study

Objective Surgical intervention can result in complete seizure remission rates of up to 80% in patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). However, certain patients cannot be treated surgically for various reasons. We analyzed the very long-term clinical outcomes of patients with TLE-HS who could not be treated surgically. Methods Subjects were selected from among patients with TLE-HS who were actively followed up for >10 years and treated with medication without surgical treatment. Patient medical records were used to retrospectively study seizure frequency, various clinical factors, and social adjustment. Patients who were seizure-free or had only aura were classified into Group 1; the others were classified into Group 2. Clinical factors including both patient and disease-specific factors were compared between the two groups. Current social adjustment, including the education, work, and economic status of each patient, was also investigated. Results Forty-one (41) subjects met the criteria for analysis, of which 12 (29%) were classified into Group 1. The average age of patients in Group 1 was higher than that of Group 2 (p = 0.0468). Group 2 included a significantly higher rate of patients who had more than one seizure per week at the onset (p = 0.0328), as well as a greater mean number of anti-epileptic drugs taken (p = 0.0024). Regarding social adjustment, Group 2 contained significantly fewer current jobholders than Group 1 (p = 0.0288). Conclusions After very long-term follow-up periods, 29% of patients with TLE-HS had a good outcome through treatment with anticonvulsant medications. Older patients tended to have fewer seizures, and seizure frequency at the onset was the only factor that predicted outcome.

Magnetoencephalographic analysis of paroxysmal fast activity in patients with epileptic spasms.

PURPOSE This study sought to demonstrate the origin and propagation of paroxysmal fast activity (PFA) in patients with epileptic spasms (ESs), using time-frequency analyses of magnetoencephalogram (MEG) PFA recordings. METHODS A 204-channel helmet-shaped MEG, with a 600Hz sampling rate, was used to examine PFA in 3 children with ESs. We analyzed MEG recordings of PFA by short-time Fourier transform and the aberrant area or high-power spectrum was superimposed onto reconstructed three-dimensional magnetic resonance images as moving images. One ictal discharge was collected. One child and one adult with PFA due to Lennox-Gastaut syndrome were also examined for comparison. RESULTS All four PFAs in Patient 1 and five PFAs in Patient 3 were generated from one hemisphere. In Patient 2, four of seven PFAs were generated from one hemisphere and the remaining three were generated from both hemispheres. In Patient 3, one ictal MEG showed ictal discharges that were generated from the same area as the PFA, although the electroencephalogram showed no discharge. In Patients with Lennox-Gastaut syndrome, all 10 PFAs were generated from bilateral hemispheres simultaneously. CONCLUSION Short-time Fourier transform analyses of MEG PFA can show the origin and form of propagation of PFA. These results suggest that ESs are representative of focal seizures and the mechanism of PFA is different between ESs and Lennox-Gastaut syndrome.

Neuromagnetic source localization of epileptiform activity in patients with graphogenic epilepsy.

Summary:  Purpose: To clarify the source localization of epileptiform activity by using magnetoencephalography (MEG) in patients with graphogenic epilepsy.

Akinetopsia as epileptic seizure

Akinetopsia is a rare syndrome in which a patient specifically loses the ability to perceive visual motion following bilateral cortical lesions outside the striate cortex. We describe a patient who showed akinetopsia recurrently as epileptic seizures. The patient was a 61-year-old man. At age 46, a cerebral arteriovenous malformation in the right parietal lobe was discovered. At age 58, he began to have a recurrent visual symptom by which smooth movements of objects suddenly appeared, resembling freeze frames in a motion picture. This symptom was paroxysmal and recurrent. Both EEG and magnetoencephalography showed repetitive right temporal spikes. We diagnosed his visual symptom as akinetopsia, which was aroused by hyperexcitability of the right temporal and parietal cortices, including area MT/V5. We administered carbamazepine 200 mg/day, which suppressed his akinetopsic symptom completely.

Video event data recording of a taxi driver used for diagnosis of epilepsy

A video event data recorder (VEDR) in a motor vehicle records images before and after a traffic accident. This report describes a taxi driver whose seizures were recorded by VEDR, which was extremely useful for the diagnosis of epilepsy. The patient was a 63-year-old right-handed Japanese male taxi driver. He collided with a streetlight. Two years prior to this incident, he raced an engine for a long time while parked. The VEDR enabled confirmation that the accidents depended on an epileptic seizure and he was diagnosed with symptomatic localization-related epilepsy. The VEDR is useful not only for traffic accident evidence; it might also contribute to a drivers health care and road safety.

A patient who misidentified all surrounding persons as her family

This report describes a patient who misidentified all surrounding persons as her family after a cerebral hemorrhage in the right temporal lobe. She had no difficulty with visual face recognition. Single-photon emission computed tomography revealed hyperperfusion in the right amygdala and hippocampus. Electroencephalography showed a bilateral fronto-temporal delta burst intermittently during the symptom. Carbamazepine suppressed the symptom completely. These results suggest that hyperexcitability in the right limbic system and bilateral fronto-temporal cortex might cause the alteration of familiarity. She felt a strong sense of familiarity to others. Perhaps because it lasted a long time, she regarded these other people as her family.

Seizure manifesting as a reaching/grasping movement in a patient with post‐traumatic epilepsy

Electrical stimulation (ES) of the pre‐supplementary or cingulate motor area can cause reaching/grasping (R/G) movements with the hand contralateral to the side of the brain receiving the ES. We report this phenomenon occurring in a 23‐year‐old right‐handed man during spontaneous epileptic seizure, which developed after traumatic brain injury.