Micronutrient-Related Neurologic Complications Following Bariatric Surgery

Abstract

Nearly two thirds of American adults are either overweight or obese. Accordingly, bariatric surgery experienced explosive growth during the past decade. Current estimates place the worldwide volume of bariatric procedures at greater than 300,000 cases annually. Micronutrient deficiencies are well-described following bariatric surgery, and they may present with devastating and sometimes irreversible neurologic manifestations. Clinical symptoms range from peripheral neuropathy to encephalopathy, and are most commonly caused by thiamine, copper, and B(12) deficiencies.

Thiamin Deficiency in People with Obesity

“…Thiamin is absorbed primarily in the duodenum mainly through active transport, so individuals who have undergone bariatric surgery to treat severe obesity (especially surgical procedures that bypass the duodenum, such as the Roux-en-Y gastric bypass) are particularly at risk of developing thiamin deficiency after surgery because of a combination of factors: the surgical stress leading to increased thiamin demand, malabsorption of the vitamin in the gastrointestinal tract due to bypass of the duodenum, and the significantly decreased oral intake (sometimes exacerbated by nausea and vomiting) that occurs after surgery as a result of restriction of the stomach size. Indeed, many case reports and observational studies documented the occurrence of Wernicke's encephalopathy after bariatric surgery even in non-alcoholic individuals (17)(18)(19)(20)(21)(22)(23), and the identification of thiamin deficiency as a potential postoperative complication led to the recommendations that all patients be screened for thiamin deficiency before bariatric surgery and that all bariatric surgery patients receive thiamin supplementation after surgery (24). Although the mechanisms underlying thiamin deficiency in bariatric surgery patients postoperatively are clear, a surprising finding is that many obese patients are found to be deficient in thiamin before undergoing surgery.…”

An overview of complications affecting the Central Nervous System following bariatric surgery

“…Folate deficiency is also a potential contributor and the clinical features are indistinguishable from vitamin B12 deficiency. 32,71,72 Vitamin E (tocopherol) deficiency has also been identified as a cause of treatable myelopathy. 73,74 Pyridoxine deficiency is another cause as described by Koffman et al 72 The treatment of these micronutrient deficiencies often result in improvement in clinical signs and symptoms.…”

Critical Care Management of Bariatric Surgery Complications

“…If fluid replacement is indicated, start infusing nonglucose-containing solutions (normal saline or Ringer lactate) and administer thiamine before infusing glucose to avoid an acute onset of Wernicke syndrome. 70,71 exertional dyspnea, OSA, OHS, PE, and aspiration pneumonia. Obesity hypoventilation syndrome is associated with abnormalities of pulmonary physiology from long-standing severe obesity, pulmonary hypertension, right-sided cardiac failure, and abnormalities of arterial gas exchange at rest.…”