RESUMEN
Morbid obesity is a systemic disease which can result in chronic complications, including hypertension, diabetes mellitus, depression, osteoarthritis and low self-esteem in the adolescent population.Bariatric surgery can be indicated to treat more severe forms of obesity, but these procedures are not without long-term risks. Therefore, adequate preoperative and postoperative care, which includes preoperative psychosocial evaluation for compliance, ongoing nutrition counselling and vitamin and micronutrient supplementation, is required for all patients, especially adolescent patients, who generally may not comply with medical therapies and/or be able to developmentally fully appreciate or comprehend the health consequences of their behaviours, prior to as well as after bariatric surgery to prevent complications.Thiamine pyrophosphate, an active form of thiamine (also known as vitamin B1, a water-soluble vitamin), which functions as a coenzyme in glucose and energy metabolism, is one such vitamin that requires supplementation postoperatively. It is mandatory for glucose to be administered concomitantly with thiamine, as glucose alone can precipitate Wernicke's encephalopathy (WE) in thiamine-deficient individuals. WE is a medical emergency, with a mortality rate of up to 20%. WE is best understood as a classic triad of mental confusion, gait ataxia and eye movement abnormalities, and atypical WE or Wernicke's syndrome (WS) is seen when the classic triad is not present. Cases that meet some, but do not necessarily meet all three criteria, are referred to as atypical WE or WS which can lead to delayed diagnosis. Atypical WE has an incidence of 19% which can lead to misdiagnosis of a preventable medical emergency with fatal complications.The following case reviews the consequences of post-bariatric thiamine supplementation therapy non-adherence and resulting in a deficiency in an adolescent patient.