Anti-glutamic acid decarboxylase limbic encephalitis without epilepsy evolving into dementia with cerebellar ataxia.

OBJECTIVES To expand the spectrum of the clinical presentation of anti-glutamic acid decarboxylase antibodies-related limbic encephalitis and to improve the recognition of this entity. DESIGN Case study. SETTING University hospital. PATIENT An 11-year-old-girl with progressive mood and behavioral disorder, speech impairment, and short-term memory impairment who manifested cerebellar ataxia with nystagmus during the disease course. INTERVENTIONS Blood and cerebrospinal fluid analysis including autoantibodies, electroencephalography, brain and spinal magnetic resonance imaging, and cognitive and neuropsychological assessment were performed. High-dose methylprednisolone sodium succinate pulses, cycles of intravenous immunoglobulins, mycophenolate mofetil, and rituximab as well as antipsychotics and benzodiazepine were administered. RESULTS Diagnosis of anti-glutamic acid decarboxylase antibodies-related limbic encephalitis was made. The clinical features during the first months of disease included only mood, behavioral, and memory impairment. After 5 months, despite immunotherapies, cerebellar ataxia with nystagmus appeared with brain magnetic resonance imaging evidence of cerebral atrophy. No clinical or infraclinical seizures were recorded during follow-up. CONCLUSIONS Anti-glutamic acid decarboxylase antibodies-related limbic encephalitis can present with only behavioral or neuropsychological symptoms without any epileptic disorder. Moreover, cerebellar ataxia related to anti-glutamic acid decarboxylase antibodies can be observed in patients with limbic encephalitis during the disease course.