Wernicke encephalopathy after Roux-en-Y gastric bypass in a young patient

Abstract

We report a case of Wernicke encephalopathy (WE) in a woman in her 20s who had Roux-en-Y gastric bypass surgery for severe obesity, which resulted in a severe depletion of the patient’s thiamine reserve and development of WE syndrome, we also emphasise the importance of prompt diagnosis of this serious complication in addition to the importance of adequate therapy.

Background

Thiamine (vitamin B1) is a vitamin found in food and manufactured as a dietary supplement and medication. It can be gained from whole grains, legumes, meats, and fish.¹

Thiamine deficiency disorders include beriberi, Wernicke-Korsakoff syndrome (WKS), optic neuropathy, Leigh’s disease, African seasonal ataxia and central pontine myelinolysis.² Roux-en-Y gastric bypass is a common bariatric operation for weight loss; nutritional deficiencies are among the common complications. Thiamine deficiency can rarely occur after a gastric bypass especially if severe vomiting is encountered.³

Case presentation

An African American woman in her 20s presented to the emergency department reporting of a 2-week history of intermittent diplopia and blurry vision. Her previous medical history included severe obesity, pre-diabetes and obstructive sleep apnea. Previous surgical history includes Roux-en-Y gastric bypass performed approximately 6 weeks ago and a diagnostic laparoscopy with adhesions’ lysis performed last month. Her medications before admission included oral pantoprazole 40 mg/day and oral ondansetron 4 mg up to four times/day, and the patient had stopped taking metformin. Multivitamins and minerals that included thiamine, vitamin B12, vitamin D, calcium, zinc and iron were prescribed before her previous hospital discharge. She denied any alcohol, tobacco or illicit drug use history. There was no significant family history. On further questioning, the patient informed that she was taking her prescribed medications only occasionally despite frequent counselling regarding compliance to medications.

Vital signs on admission revealed a normal heart rate of 96 bpm, blood pressure of 119/90 mm Hg, temperature of 36.3°C, respiratory rate of 16 bpm with 98% oxygen saturation. The patient was conscious, responsive and space–time oriented. Physical examination revealed bilateral constricted pupils that were sluggishly responsive to light, bilateral abduction deficit with no other significant cranial nerve or neurologic abnormalities. Neurology examination revealed bilateral sixth cranial (abducens) nerve palsy, in addition to horizontal and vertical nystagmus (figure 1). Ophthalmology examination showed papilledema with visual acuity of 20/30 oculus dextrus (OD=right eye) and 20/25 oculus sinister (OS=left eye) without correction, pupils were equal, round and reactive to light and accommodation bilaterally with no afferent pupillary defect, and intraocular pressure was 22 mm Hg via Tonopen bilaterally. Examination was significant for bilateral deficits in extraocular movements graded at −3 abduction with end-gaze nystagmus in all fields of gaze. Colour vision was slightly decreased in both eyes (11/16 OD, 12/16 OS via Ishihara Color Plates). Anterior examination was unremarkable in both eyes, whereas on posterior examination, a grade 2–3 papilledema was noted in the right eye and a grade 3 papilledema was noted in the left eye associated with signs of gliosis (chronicity) in both eyes. In this setting, the patient denied the use of oral contraceptives, tetracyclines, amiodarone, sulfa antibiotics, lithium and steroids medications.

Figure 1.

Bilateral abducens nerve palsy and horizontal and vertical nystagmus.

Next morning, follow-up examination showed that the patient continued to experience symptoms of diplopia and blurry vision; family also reported that she was having short-term memory loss and personality changes. Repeat physical examination demonstrated impaired bilateral abduction, impaired right eye adduction, pupils were responsive to light but constricted sluggishly.

Investigations

Haemoglobin A1c was 5.8% (5.7%–6.4%), free T4 was 1.22 ng/dL (0.8–1.8), thyroid-stimulating hormone 1.34 mIU/L (0.5–5.0), vitamin B12 level was 756 pg/mL (200–900), albumin was 3.8 gm/dL (3.5–5.7), total protein was 7.2 gm/dL (6.4–8.9), 25-hydroxyvitamin D was 49 ng/dL (30–70), whole blood thiamine pyrophosphate (TPP) level was low at 33.6 nMol/L (66.5–200; reference range as per US LabCorp),⁴ urine drug screen was negative, and all electrolytes were within normal limits. CT of the head without contrast showed no acute abnormalities. MRI of the brain with and without contrast revealed symmetric signal abnormality on T2-weighted sequences with diffusion restriction and lack of normal enhancement in the bilateral thalami, which could be attributed to osmotic myelinolysis or WE (figure 2). Magnetic resonance venography of the head and MRI of the orbits were recommended by neurology and ophthalmology to assess for idiopathic intracranial hypertension (IIH) and cavernous sinus thrombosis as causes of elevated intracranial pressure. Both tests were normal.

Figure 2.

Brain MRI with and without contrast showing symmetric signal abnormality with diffusion restriction and lack of normal enhancement in the bilateral thalami. (A) Coronal section. (B) Sagittal section.

Lumbar puncture (LP) was performed, it showed an opening pressure of 28.5 cm H₂O (10–20), cerebrospinal fluid (CSF) was sent for analysis, closing pressure was 19–20 cm H₂O. All other CSF results were within normal limits.

Differential diagnosis

The differential diagnosis included alcohol-related thiamine deficiency, IIH and cavernous sinus thrombosis. The patient did not have history of alcohol drinking and had the bariatric surgery performed recently, and the recommended tests ruled these disorders out.

Treatment

Partial Wernicke encephalopathy (WE) syndrome (bilateral ophthalmoplegia) coupled with abnormal MRI findings of thalami placed thiamine deficiency due to bariatric surgery highest on the differential diagnosis, so the patient was started on intravenous thiamine 200 mg three times per day for 4 days, which was later switched to oral thiamine.

Outcome and follow-up

Next day, the patient reported improvement in photopsia, blurry vision, tinnitus and diplopia symptoms. Ophthalmology examination showed visual acuity improvement to 20/20 bilaterally without correction. Examination was significant for improvement in right-sided abduction from −3 to −2 deficit with gaze-evoked nystagmus in left, right and up-gaze. Left-sided abduction improved from −3 to −1 abduction deficit with gaze-evoked nystagmus in left, right and up-gaze. LP was not repeated because ophthalmology reported no papilledema and the patient had no clinical signs of increased intracranial pressure.

The patient’s vision significantly improved, and she was eventually discharged home in a stable condition. She was heavily counselled on taking her multivitamins and thiamine supplements, while avoiding use of alcohol to prevent worsening of WE syndrome. Her repeated TPP levels improved to 221.3 nMol/L before being discharged. She was discharged on thiamine 100 mg two times per day. She was instructed to follow-up with her primary care physician, neurology and bariatric surgeon.

Discussion

WE was first described by Carl Wernicke more than 125 years ago.⁵ It is caused by thiamine deficiency. Most common cause in the USA is alcoholism, other causes of nutritional deficiencies such as hyperemesis gravidarum, intestinal obstruction and malignancy. It is diagnosed clinically, and common signs and symptoms include mental status changes, ocular dysfunction and a gait apraxia, present in only 10% of cases.^{5 6}

A study was performed in 2017 in an academic institution for 47 patients who underwent bariatric surgery (36 patients with Roux-en-Y gastric bypass, 9 patients with sleeve gastrectomy and 2 with duodenal switch) and developed neurologic complications in the period of 2004–2015. Median duration to onset of neurologic manifestation following surgery was 12 months. Thirty patients had thiamine deficiency, and 12 patients had vitamin B12 deficiency. The most common manifestations as of symptoms were paresthesia in 31 patients, muscle weakness in 15 patients and abnormal gait in 11 patients. Only four patients were diagnosed with WKS. Seven patients were admitted for severe vitamin B deficiencies’ management. Overall, resolution of neurologic symptoms with nutritional interventions and medications was noted in 40 patients, which was 85% of patients. Unfortunately, the WKS was not reversible, and all four patients had residual mild ataxia and nystagmus on consequent follow-up.⁷ As per another study for WE after bariatric surgeries, nearly half of the cases that are identified and treated, neurologic deficits persist.⁸

Most case reports concluded that the onset of WE symptoms can range from 4 to 6 weeks or up to 12 weeks as per one study.^{7 9} One case reported manifestations as early as 2 weeks, which was for a 29-year-old female patient who presented with multiple neurological symptoms of headache, vertigo, diplopia, nystagmus, bilateral upper and lower extremities’ weakness and tingling, memory loss, in addition to urinary incontinence, all symptoms occurred exactly 2 weeks after her surgery. The patient had marked improvement on 100 mg intravenous thiamine per day.¹⁰

Some odd presentations of WE after bariatric surgery were reported as well, an example is a case reported in 2006 that was mistakenly diagnosed as acute psychosis, which was scheduled to be treated with electroconvulsive therapy, then was diagnosed as WE, and the patient was successfully treated with thiamine replacement and parenteral nutrition.⁶

According to an article published in 2016 about the American society for metabolic and bariatric surgery nutritional guidelines for surgical weight loss patients, the prevalence of thiamine deficiency can be up to 49% after weight loss surgeries depending on the type of surgery and time frame, the risk is higher with malnutrition, excessive and/or rapid weight loss and excessive alcohol use. Based on the guidelines, all patients should take at least 12 mg of daily thiamine (grade C) and preferably once or two times per day of 50 mg dose of thiamine from a B-complex supplement or multivitamin (grade D). Of notice, African American women and patients who have heart failure especially on furosemide are considered among high-risk groups to develop thiamine deficiency, which warrants close routine postweight loss surgery screening by performing nutrient assessment every 3–6 months in the first year and annually afterward (grade B), unless otherwise specified.¹¹

Laboratory ways of testing for thiamine deficiency include measuring thiamine phosphorylated esters in the whole blood using high-performance by liquid chromatography-tandem mass spectrometry (reported usually as TPP), which is the most common available test and the one our patient had. Erythrocyte Transketolase test is another way to assess thiamine status by measuring the functional enzymatic assay of transketolase activity before and after the addition of TPP with a suggested result of >25% stimulation response to be abnormal. No exact normal range cut-offs of these tests have been established yet.^{12 13} It is encouraged and recommended that clinicians rely on the clinical diagnosis in the absence of either of these tests and to avoid waiting for laboratory testing in case of high suspicion of thiamine deficiency as it can lead to diagnosis delay, which has fatal and irreversible complications.¹⁴

Our patient was a young African American woman without many comorbidities who presented early (6 weeks after her bariatric surgery) with WE due to thiamine deficiency (by ruling out other causes and having immediate response to thiamine supplementation). We believe that the main risk factor for her complication was postoperative thiamine supplements’ non-compliance, especially with her early presentation (less than 3 months).

Patient’s perspective.

I was very scared when I started to have those symptoms, I initially thought they might go on their own, but when they persisted, I decided to come to the emergency. When I went through all these advanced tests like MRI and lumbar tap, I really started to think about serious diseases including cancer, when the doctors gave me thiamine, I quickly started to feel better. It felt really good to have a normal vision so quick.

Learning points.

• To shed the light on a rare complication of bariatric surgery, thiamine deficiency causing Wernicke encephalopathy (WE).

• Increase awareness among healthcare practitioners regarding importance of prompt diagnosis of WE, in addition to the importance of adequate and urgent therapy to avoid irreversible symptoms.

• Emphasising the importance of vitamins and minerals’ intake after bariatric surgery among patients and involved healthcare practitioners to avoid preventable and serious complications that can result from nutrients’ deficiencies.

• After bariatric surgery, close follow-up with primary care physician, surgeons and nutritionists is a very important step for minerals and vitamin deficiencies’ screening postoperatively.

• To report our patient’s quick improvement of WE symptoms by thiamine supplements.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).