Abstract
Bariatric surgery is being undertaken more frequently in response to rising levels of obesity but is increasingly also requested as a cosmetic choice. Nutritional deficiencies are a recognised consequence of gastrectomy, with potentially severe and permanent neurological sequelae. We present two cases of acute, severe polyneuropathy following sleeve gastrectomy. Severe thiamine deficiency was considered in both cases but with delayed proof and a significant initial differential diagnosis. Neurologists must have a high index of suspicion for the peripheral as well as central presentations of thiamine deficiency to avoid permanent disability. We also call for explicit information resources warning of the risk and signs of thiamine deficiency to be provided routinely to patients after gastrectomy.