[Partial non convulsive epileptic status as initial presentation of limbic encephalitis]

Limbic encephalitis is an unusual presentation of paraneoplastic syndrome, which includes among its symptoms seizures.

We report a case with a rare presentation of limbic encephalitis as initial symptom of small cell lung carcinoma. A 69 year-old woman presented with partial non convulsive status epilepticus and neuropsychiatric disturbances. Chest radiography and computed tomography showed mediastinal lymphadenopathy and lung nodules. Subsequently, small cell lung carcinoma was diagnosed by lymph node biopsy. The cerebrospinal fluid study was normal. The electroencephalography and magnetic resonance imaging (MRI) findings had distinctive features compatible with temporo-limbic dysfunction. The anti-Hu antibodies were negative. The neuropsychiatric symptoms improved significantly after systemic chemotherapy and adjuvant radiotherapy. A serial follow-up MRI of the head showed no evidence of intracranial metastasis three months after the diagnosis of cancer. Limbic encephalitis may be an initial manifestation of lung cancer. Paraneoplastic limbic encephalitis is considered a remote effect of cancer commonly associated with anti-neuronal antibodies (anti-Hu) and small cell lung carcinoma.

Status epilepticus could be an early sign of limbic encephalitis. The absence of anti-Hu antibodies does not rule out the presence of an underlying small cell lung carcinoma in patients with a clinical diagnosis of limbic encephalitis. Greater awareness for diagnosis and early treatment of the primary tumor offers the best chance for improvement in patients with lung cancer presenting with limbic encephalitis.