[Intrathecal glutamate receptor antibodies in a patient with elderly-onset refractory epilepsy]

Antibodies against a glutamate receptor in the central nervous system are reported to be an important autoimmune factor in infantile or childhood refractory epilepsy and in adult-onset paraneoplasstic cerebellar ataxia. We here reported a patient with glutamate receptor antibodies-positive elderly-onset intractable epilepsy and advanced-stage stomach cancer. A 77-year-old man with a history of resected bladder cancer suddenly developed an attack of epilepsia partialis continua in the right arm, followed by a generalized epileptic status. The ictal EEG showed spikes in the left parietal region with diffuse slow wave backgrounds. The brain MRI demonstrated a focal high signal intensity in the left postcentral gyrus on the T2-weighted and FLAIR images. The SPECT showed a high uptake in the focal area corresponding to the MRI lesion, suggesting a seizure focus. The routine analysis in the CSF was normal, but the glutamate receptor antibodies (IgG, IgM and C-terminal) were all positive. The status epilepticus was refractory to anticonvalsants, and the barbiturate anesthesia was introduced. Subsequently, the epilepsy has been fairly controlled by valproic acid and phenobarbital. The post ictal MRI demonstrated a focal atrophy in the left postcentral gyrus. The systemic evaluations revealed an advanced-stage stomach cancer. The glutamate receptor antibodies may play a role in late-onset refractory epilepsy, and may be an autoimmune factor in paraneoplstic neurologic syndrome presenting with epilepsy.