Seizure as the Main Manifestation of Nonalcoholic Wernicke's Encephalopathy but Without Cortical Involvement: A Case Report.

Wernicke's encephalopathy (WE) is an underdiagnosed entity. A seizure can be the main manifestation of WE even without cortical involvement. This is a case report of a 45-year-old female patient with a past medical history of depression and poor oral intake who presented with a single episode of unwitnessed seizure and three days of unsteady gait and vertigo. She then had two episodes of seizure, focal and then generalized tonic. Her physical examination was remarkable for lethargy and bilateral gaze-induced horizontal nystagmus with a rotational component and change in direction. Magnetic resonance imaging (MRI) of the brain with contrast showed non-enhancing bilateral symmetrical fluid-attenuated inversion recovery (FLAIR) hyperintensities in the medial thalami and tectum. Vitamin B1 level was found to be low. Lumbar puncture (LP) was unyielding. She was loaded with high-dose thiamine replacement. After a few days, a neurological examination revealed improvement with unilateral nystagmus with less lethargy. The valproate that was started initially was eventually discontinued during follow-up after the resolution of neurological deficits. Interestingly, baseline echocardiography showed heart failure with reduced ejection fraction at 40% with clinical euvolemia. It was believed to be secondary to beriberi.