Not applicable

Limbic encephalitis, excluding other causes like infection or metastasis, may be an immune-mediated process associated with malignancies like small cell carcinoma. Paraneoplastic syndromes with brain stem and cerebellar involvement typically have eye movement disorders but have never been associated with acute persistent gaze paresis.

A 72-year-old female who has been having subacute changes in short-term memory had sudden left-gaze deviation not associated with facial asymmetry, motor weakness, or numbness. Gaze preference could not be overcome by the oculocephalic maneuver. MRI brain showed T2FLAIR hyperintensities in the bilateral mesial temporal lobes and hippocampi with no abnormal enhancement. Routine EEG showed no interictal abnormalities. CSF protein was 112. Autoimmune encephalitis panel was positive for ANNA-1 antibodies. Liver biopsy was positive for small cell carcinoma. Patient was treated with pulse dose steroids and then with IVIG with minimal improvement of symptoms.

Limbic encephalitis is a paraneoplastic syndrome that present with short-term memory loss, personality changes, or seizures and is typically associated with small cell carcinoma. A frequently identified onconeural antibody is ANNA-1 antibody. Paraneoplastic syndromes involving the brainstem or the cerebellum present as double vision and problems with coordination and balance. Abnormal eye movements include primary gaze nystagmus, multi-directional gaze-evoked nystagmus, or slow dysmetric saccades. Acute gaze paresis however is typically a clue of an acute ischemic event involving the cortex. In this patient, MRI brain was negative for stroke. Ipsiversive gaze deviation may be a lateralizing sign of a seizure. This patient had persistent left gaze preference with retained awareness and no abnormal involuntary movements.

Acute limbic encephalitis and eye movement disorders may be paraneoplastic syndromes associated with underlying malignancies but acute gaze paresis which is typically known to be caused by an acute stroke or a post-ictal phenomenon has not been documented as one of its manifestations.