Neurologic (involving autonomic dysfunction) -
Central
Multiple system atrophy (previously Shy-Drager syndrome)
Parkinson's disease
Strokes (multiple)
Spinal cord
Tabes dorsalis
Transverse myelitis
Tumors
Peripheral
Amyloidosis
Diabetic, alcoholic, or nutritional neuropathy
Familial dysautonomia (Riley-Day syndrome)
Guillain-Barré syndrome
Paraneoplastic syndromes
Pure autonomic failure (formerly called idiopathic orthostatic hypotension)
Surgical sympathectomy
http://www.merck.com/mmpe/sec07/ch069/ch069d.html