Using EEG and MEG to characterize extreme delta brush in a patient with anti-NMDA receptor encephalitis.

BACKGROUND: Extreme delta brush (EDB) is considered a potential marker for anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. The brain regions involved in EDB are unclear. CASE PRESENTATION: A 16-year-old woman with anti-NMDAR encephalitis who was experiencing psychosis was admitted. Electroencephalography (EEG) and magnetoencephalography (MEG) were used to analyze EDB in the patient. EDB on EEG could be disturbed by opening and closing the eyes, by occipital alpha rhythms and by sleep-wake cycles. The MEG results showed beta activity originating from bilateral superior parietal lobes. However, the delta wave originated from bilateral superior temporal gyri, the right middle temporal gyrus, the right inferior frontal gyrus, and the left inferior parietal lobe. CONCLUSIONS: Delta wave and beta activity might originate from different brain regions. Beta activity might be transmitted forward to the frontotemporal lobe and superimposed with delta activity to form EDB on EEG.

Influencing electroclinical features and prognostic factors in patients with anti-NMDAR encephalitis: a cohort follow-up study in Chinese patients.

The clinical manifestations of patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis in East China and factors associated with prognosis were analyzed. A retrospective study of 106 patients (58 females; 48 males) with anti-NMDAR encephalitis in East China was carried out from June 2015 to February 2019. Clinical features and factors influencing outcomes were reviewed. Behavioral changes were observed in 74.5% (79/106) of patients, and comprised the initial symptoms in 61.3% (65/106). Seizures were observed in 67% (71/106) of patients, and served as initial symptoms in 31.1% (33/106). A total of 54.9% (39/71) of seizures were focal seizures. More clinical symptoms were observed in female patients than in male patients (P = 0.000). Similarly, background activity (BA) with high cerebrospinal fluid (CSF) antibody titers at the peak stage was more severe in female patients than in male patients (P = 0.000). The Binary logistic regression and receiver operating characteristic (ROC) curve analyses revealed the factors associated with poor outcomes included consciousness disturbance (OR 4.907, 95% CI 1.653-14.562, P = 0.004; area: 65.4%, sensitivity: 44.2%, specificity: 86.5%, P = 0.014), EEG BA (OR 3.743, 95% CI 1.766-7.932, P = 0.001; area: 76.6%, sensitivity: 73%, specificity: 75%, P = 0.000), number of symptoms (OR 2.911, 95% CI 1.811-4.679, P = 0.000; area: 77.1%, sensitivity: 59.5%, specificity: 78.6%, P = 0.000) and CSF antibody titer (OR 31.778, 95% CI 8.891-113.57, P = 0.000; area: 83.9%, sensitivity: 89.2%, specificity: 78.6%, P = 0.000). EEG BA and number of symptoms were associated with CSF antibody titers. Consciousness disturbances, EEG BA, number of symptoms and CSF antibody titers served as predictors of poor outcomes.

Altered cerebral blood flow in patients with anti-NMDAR encephalitis.

OBJECTIVE: This study aimed to identify to resting-state cerebral blood flow (CBF) connectivity alterations in patients with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. METHODS: Three-dimensional pseudo-continuous arterial spin labeling (pcASL) imaging was performed to measure the resting-state CBF in 23 patients with anti-NMDAR encephalitis at the peak stage of the disease and 32 healthy subjects. CBF was normalized to reduce variations among subjects. CBF was compared between the groups, and the correlations between the CBF alterations and clinical parameters were assessed. Differences in CBF connectivity in specific brain regions were also compared between groups. RESULTS: Compared with the healthy subjects, the patients with anti-NMDAR encephalitis exhibited increased CBF in the left insula (L_insula), left superior temporal lobe (L_STL), L_hippocampus, L_pallidum, bilateral putamen (Bi_putamen), and Bi_caudate, and decreased CBF in the bilateral precuneus (Bi_Pc) and bilateral occipital lobe (Bi_OL) (P < 0.05, FEW corrected). Compared with healthy subjects, the patients with anti-NMDAR encephalitis exhibited increased negative CBF connectivity between the Bi_Pc, Bi_OL and L_TL, L_insula (P < 0.05, FEW corrected). Anti-NMDAR encephalitis patients with behavioral changes exhibited higher CBF in the L_insula and lower CBF in the R_Pc, Bi_calcarine, Bi_cuneus, and Bi_lingual than patients without behavioral changes and health controls. The ROC curve shows changed CBF in the L_insula, and R_Pc, Bi_calcarine, Bi_cuneus, and Bi_lingual served as a predictor of behavioral changes in patients with anti-NMDAR encephalitis. CONCLUSIONS: Our results suggest that patients with anti-NMDAR encephalitis may exhibit both regional CBF abnormalities and deficits in CBF connectivity, which may underlie the clinical symptoms of anti-NMDAR encephalitis.

Ictal Source Locations and Cortico-Thalamic Connectivity in Childhood Absence Epilepsy: Associations with Treatment Response.

Childhood absence epilepsy (CAE), the most common pediatric epilepsy syndrome, is usually treated with valproic acid (VPA) and lamotrigine (LTG) in China. This study aimed to investigate the ictal source locations and functional connectivity (FC) networks between the cortices and thalamus that are related to treatment response. Magnetoencephalography (MEG) data from 25 patients with CAE were recorded at 300 Hz and analyzed in 1-30 Hz frequency bands. Neuromagnetic sources were volumetrically scanned with accumulated source imaging. The FC networks between the cortices and thalamus were evaluated at the source level through a connectivity analysis. Treatment outcome was assessed after 36-66 months following MEG recording. The children with CAE were divided into LTG responder, LTG non-responder, VPA responder and VPA non-responder groups. The ictal source locations and cortico-thalamic FC networks were compared to the treatment response. The ictal source locations in the post-dorsal medial frontal cortex (post-DMFC, including the medial primary motor cortex and the supplementary sensorimotor area) were observed in all LTG non-responders but in all LTG responders. At 1-7 Hz, patients with fronto-thalamo-parietal/occipital (F-T-P/O) networks were older than those with fronto-thalamic (F-T) networks or other cortico-thalamic networks (p = 0.000). The duration of seizures in patients with F-T-P/O networks at 1-7 Hz was longer than that in patients with F-T networks or other cortico-thalamic networks (p = 0.001). The ictal post-DMFC source localizations suggest that children with CAE might experience initial LTG monotherapy failure. Moreover, the cortico-thalamo-cortical network is associated with age. Finally, the cortico-thalamo-cortical network consists of anterior and posterior cortices and might contribute to the maintenance of discharges.