Wernicke's encephalopathy due to hyperemesis gravidarum: Clinical and magnetic resonance imaging characteristics.

Hyperemesis gravidarum-induced Wernicke's encephalopathy (WE) is an underestimated condition. The purpose of this study is to improve its awareness and early diagnosis. We report five cases of WE secondary to hyperemesis gravidarum. Classic triad of encephalopathy, ataxia, and ocular signs was seen in four out of five patients. Two unusual features noted in this series were papilledema in one patient and severe sensory-motor peripheral neuropathy in one patient. Magnetic resonance imaging (MRI) was abnormal in all the five patients, and high signal in medial thalamus and surrounding the aqueduct was the most common abnormality (5/5). Involvement of caudate nucleus was seen in two patients with severe psychosis, and two patients had bilateral cerebellar peduncle involvement. Median time delay between onset of neurological symptoms and diagnosis was 7 days. All patients improved with thiamine, but minor sequelae were seen in four patients at 12 months follow-up. One patient had a fetal demise. Hyperemesis gravidarum-induced WE is a common cause of maternal morbidity. Typical MRI findings of symmetric medial thalamic and periaqueductal signal changes may permit a specific diagnosis. A delay in diagnosis, therefore treatment, leads to worse prognosis.