The patient is a 34 y.o. female with a past medical history significant only for morbid obesity. She had a gastric sleeve placed 3 months ago, in order to promote weight loss. Two weeks ago, the patient experienced the onset of blurred vision, clumsiness, ambulatory dysfunction, and generalized weakness. At that time, she was seen in the local emergency room, and was diagnosed with vertigo. Meclizine was ordered, but it provided no symptom relief. One day after she developed alteration of her mental status, her family brought her to the emergency room at a tertiary teaching hospital. Her initial vital signs were temperature 36.3 degrees Celsius, blood pressure 128/94, heart rate 85, respiratory rate 18, and room air oxygen saturation level 98 percent. The patient’s physical examination was remarkable for her slowed cognition with poor attention, concentration, and short term memory. Her long term memory was fair. Gaze-evoked nystagmus (predominantly horizontal) and an ataxic gait were also noted.
Her initial labs, which included a complete blood count and comprehensive metabolic panel were remarkable only for an albumin level of 2.8 g/dL (normal range 3.5 – 4.8 g/dL). Computed tomography angiograms of the head and neck were unremarkable. The Neurology service was consulted, and due to their suspicion for Wernicke encephalopathy, the administration of intravenous thiamine was initiated within 12 hours of her hospital admission. Complete resolution of the patient’s symptoms was noted within 4 days after starting intravenous thiamine.
On hospital day 5, the result for her thiamine level returned, and it was decreased at 21 nmol/L (normal range 70 – 80 nmol/L).
Wernicke encephalopathy is most commonly seen in patients who have a history of chronic alcoholism; however, it may also develop in several other scenarios, including bariatric surgery. The three symptoms that are classically associated with Wernicke encephalopathy are encephalopathy, gait ataxia, and oculomotor dysfunction. Gait ataxia often develops prior to the other two symptoms. Since not every patient manifests all three of the classic symptoms, Wernicke encephalopathy is likely under-diagnosed. Other signs of Wernicke encephalopathy that this patient exhibited include hypothermia, protein-calorie malnutrition, and peripheral neuropathy. Most patients with Wernicke encephalopathy who are not treated will ultimately develop coma and die.
Thiamine deficiency plays a pivotal role in the development of Wernicke encephalopathy, and when this diagnosis is suspected, parenteral thiamine should be administered immediately. Care should be taken to ensure that glucose is not administered without thiamine, since doing so may either lead to or worsen Wernicke encephalopathy. With the early administration of thiamine, ocular symptoms typically resolve within hours to days, while gait ataxia and confusion usually improve over days to weeks. Most patients who are treated for Wernicke encephalopathy will have some residual deficits.
It is important to recognize that patients who undergo bariatric surgery are at increased risk for the development of Wernicke encephalopathy. When this diagnosis is suspected, the prompt administration of parenteral thiamine is essential, since this can dramatically improve a patient’s outcome.