text: There is also thought to be considerable overlap between malignant catatonia and NMS in their pathophysiology, the former being idiopathic and the latter being the drug-induced form of the same syndrome.
  The raised white blood cell count and creatine phosphokinase (CPK) plasma concentration seen in those with NMS is due to increased muscular activity and rhabdomyolysis (destruction of muscle tissue). The patient may experience hypertensive crisis and metabolic acidosis. A non-generalized slowing on an EEG is reported in around 50% of cases.
  The fever seen with NMS is believed to be caused by hypothalamic dopamine receptor blockade. The peripheral problems (the high white blood cell and CPK count) are caused by the antipsychotic drugs. They cause an increased calcium release from the sarcoplasmic reticulum of muscle cells which can result in rigidity and eventual cell breakdown. No major studies have reported an explanation for the abnormal EEG, but it is likely also attributable to dopamine blockage leading to changes in neuronal pathways.
  Diagnosis
  Differential diagnosis
  Due to the comparative rarity of NMS, it is often overlooked. Immediate treatment for the syndrome should not be delayed as it has a high mortality of between 10-20%.  Differentiating NMS from other neurological disorders can be very difficult. It requires expert judgement to separate symptoms of NMS from other diseases.