Analysis of Relation Between Electroclinical Features and Cerebrospinal Fluid Antibody Titers in Patients With anti-NMDAR Encephalitis

Contribution of cerebrospinal fluid antibody titers and sex to acute cerebral blood flow in patients with anti-NMDAR autoimmune encephalitis

Objective

The objective of this study was to elucidate the contribution of cerebrospinal fluid (CSF) antibody titers (AT) and sex to acute cerebral blood flow (CBF) in patients diagnosed with anti-N-methyl-d-aspartate receptor autoimmune encephalitis (NMDAR AE).

Methods

Forty-five patients diagnosed with NMDAR AE were recruited from December 2016 to January 2023. The acute CBF in patients with NMDAR AE at the early stage of the disease was analyzed using arterial spin labeling. The groups were compared based on CSF AT and sex. The connectivity of the CBF in the region of interest was also compared between groups.

Results

The patients with different CSF AT exhibited varied brain regions with CBF abnormalities compared to the healthy subjects (p = 0.001, cluster-level FWE corrected). High antibody titers (HAT) in CSF contributed to more brain regions with CBF alterations in female patients than in female patients with low antibody titers (LAT) in CSF (p = 0.001, cluster-level FWE corrected). Female patients with HAT in CSF displayed more decreased CBF in the left post cingulum gyrus, left precuneus, left calcarine, and left middle cingulum gyrus than the male patients with the same AT in CSF (p = 0.001, cluster-level FWE corrected). All patients with NMDAR AE showed increased CBF in the left putamen (Putamen_L) and left amygdala (Amygdala_L) and decreased CBF in the right precuneus (Precuneus_R), which suggests that these are diagnostic CBF markers for NMDAR AE.

Conclusion

CSF AT and sex contributed to CBF abnormalities in the patients diagnosed with NMDAR AE. Altered CBF might potentially serve as the diagnostic marker for NMDAR AE.

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.