Atypical Wernicke's syndrome sans encephalopathy with acute bilateral vision loss due to post-chiasmatic optic tract edema
A 69-year-old male presented with intermittent feeling of blurred vision with mild imbalance while walking for 2 days followed by acute loss of vision in both his eyes. He had undergone partial gastrectomy for poorly differentiated adenocarcinoma of the pylorus before 1 month. He had no other health related problems previously. His family history was unremarkable and he had no history of alcohol or tobacco consumption. The immediate post-operative period was unremarkable. Ophthalmologic evaluation revealed total loss of visual acuity with no light appreciation or finger counting with preserved bilateral pupillary reaction to light. There was mild opthalmoparesis with reduced saccadic and pursuit movements toward the sound and patient's own finger movements. There was bilateral horizontal gaze evoked nystagmus with fast component in the direction of gaze. Bilateral optic fundi were normal. He had symmetric trunk and gait ataxia, but no limb ataxia or dysarthria. His alertness, mood, memory, behavior and other cognitive functions were well-preserved. His other systemic and neurologic examination was unremarkable. An urgent plain and contrast magnetic resonance imaging (MRI) of the brain was done to rule out either of posterior circulation stroke (Bilateral Posterior Cerebral Artery infarct), intracranial metastasis and paraneoplastic neurological dysfunction in view of recently operated carcinoma of stomach.\nMRI brain revealed bilateral symmetrical hyper-intensities over the mammillary bodies and periventricular regions of the third ventricle, bilateral inferior colliculi on T2-weighted and fluid attenuated inversion recovery (FLAIR) images [Figure , , and ] with homogenous enhancement postcontrast [Figure and ] with no restriction on diﬀusion-weighted and apparent diffusion coefficient (ADC) images (ruling out ischemia/cytotoxic edema). In addition to these classic findings of WE, focal hyper-intensities were also observed in bilateral post-chiasmatic optic tract on FLAIR images []. Based on the imaging findings and clinical background of patient, diagnosis of non-alcoholic acute Wernicke's syndrome was considered and treatment with intravenous thiamine hydrochloride (500 mg/d) was promptly started. His visual symptoms significantly improved in 24 h and his vision became completely normal in 72 h. His ataxia improved gradually over the next 3 weeks. He was discharged with the advice to take intravenous thiamine injections once every month to prevent the thiamine deficiency. A follow-up MRI brain carried out after 1 month revealed complete resolution of MR signal intensities [Figure and ].