Encephalitis associated with anti-mGluR5 antibodies.

A 30-year-old woman had 5 days of visual hallucinations, nystagmus, memory impairment and mutism. On examination, she was disorientated with reduced attention span, gaze-evoked nystagmus, paratonia and abnormal frontal reflexes. Cerebrospinal fluid (CSF) showed 80 cells, protein 0.41 g/L and glucose 3.2 mmol/L (plasma glucose 5.0 mmol/L). MR scan of the brain showed involvement of limbic and extra-limbic regions and brainstem. Commercial cell-based assays were negative, but tissue-based assays showed neuropil staining, and cell-based assays for anti-metabotropic glutamate receptor 5 (mGluR5) antibodies were positive in serum and CSF. Six months later, she was diagnosed with Hodgkin's lymphoma. This case emphasises the broader clinical spectrum of anti-mGluR5 encephalitis, challenging its initial characterisation as Ophelia syndrome. It underscores the significance of interpreting commercial cell-based assays and advocates for tissue-based assay testing followed by cell-based assay testing in serum and CSF for diagnosing rare autoimmune encephalitis.

Utility of initial EEG in first complex febrile seizure.

OBJECTIVE: The risk of developing epilepsy following febrile seizures (FS) varies between 2% and 10%, with complex febrile seizures (CFS) having a higher risk. We examined the utility of detected epileptiform abnormalities on the initial EEG following a first CFS in predicting subsequent epilepsy. METHODS: This was a retrospective study of consecutive patients (ages 6-60 months) who were neurologically healthy or mildly delayed, seen in the ED following a first CFS and had both an EEG and minimum of 2-year follow-up. Data regarding clinical characteristics, EEG report, development of subsequent epilepsy, and type of epilepsy were collected. Established clinical predictors for subsequent epilepsy in children with FS and EEG status were evaluated for potential correlation with the development of subsequent epilepsy. Sensitivity, specificity, and positive and negative predictive values of an abnormal EEG (epileptiform EEG) were calculated. RESULTS: A group of 154 children met our inclusion criteria. Overall, 20 (13%) children developed epilepsy. The prevalence of epilepsy was 13% (CI 8.3-19.6%). Epileptiform abnormalities were noted in 21 patients (13.6%), EEG slowing in 23 patients (14.9%), and focal asymmetry in six (3.8%). Epileptiform EEGs were noted in 20% (4/20) of patients with epilepsy and 13% (17/134) of patients without epilepsy (p=0.48). At an estimated risk of subsequent epilepsy of 10% (from population-based studies of children with FS), we determined that the PPV of an epileptiform EEG for subsequent epilepsy was 15%. None of the clinical variables (presence of more than 1 complex feature, family history of epilepsy, or status epilepticus) predicted epilepsy. CONCLUSIONS: An epileptiform EEG was not a sensitive measure and had a poor positive predictive value for the development of epilepsy among neurologically healthy or mildly delayed children with a first complex febrile seizure. The practice of obtaining routine EEG for predicting epilepsy after the first CFS needs clarification by well-defined prospective studies.