Article: "Obesity Surgery: A word of neurological caution."

The full text of the study I previously posted is here. 

Source:  Neurology.

"Neurologic complications due to weight-reduction surgery can   involve any part of the nervous system: the brain, the spinal   cord, the nerves leaving the spinal cord, or the peripheral   nerves. Often more than one part of the nervous system can be   involved. At times complications can be seen within a few weeks   after the surgery. These patients develop confusion with or   without involvement of the peripheral nerves. This complication   may be associated with rapid weight loss and could be due to   a deficiency of a vitamin called thiamine. More common is the   delayed presentation of neurologic complications. The delayed   complications are generally due to involvement of the spinal   cord or peripheral nerves or both. The commonly identified deficiencies   include vitamin B ₁₂ and copper. Correction of nutritional deficiencies   results in stabilization or improvement of symptoms."