[Wernicke encephalopathy with lesions in the bilateral abducens nuclei: a case report]

A 35-year-old Japanese man had been treated for alcoholism until 6 months before coming to our hospital, after which he discontinued treatment for alcoholism. He noticed dizziness from two weeks ago. He visited our hospital because his dizziness was worsened and he noticed diplopia from two days ago. Physical examination revealed bilateral abducens nerve palsy, decreased limb tendon reflex, and ataxia. His blood vitamin B₁ level was 16 ng/ml (normal range 24-66 ng/ml). FLAIR images on brain MRI showed high signal intensity lesions in the bilateral abducens nuclei and mammillary body. We diagnosed him as Wernicke encephalopathy (WE) with lesions in the bilateral abducens nuclei. Treatment with thiamine rapidly resulted in improvement of his neurological symptoms and MRI findings. He was discharged from our department on the 10th hospitalization day. Previous reports have shown that abducens nerve palsy and horizontal gaze evoked nystagmus may occur in the early state of WE. This case report highlights the importance to comprehend the atypical MRI findings of WE to treat a patient at the early stage.