The treatment, control or prevention of medical, psychiatric or neurological disorders may be accomplished by application of modulating electric signals to one or both of a patient's trigeminal and glossopharyngeal nerves. The disorders treatable, controllable or preventable by such nerve stimulation include voluntary and involuntary disorders, migraine, epileptic seizure, motor disorders, Parkinson's disease, cerebral palsy, spasticity, chronic nervous illnesses and involuntary movement; pancreatic endocrine disorders including diabetes and hypoglycemia; dementia including cortical, subcortical, multi-infarct, Alzheimer's disease and Pick's disease; sleep disorders including central sleep apnea, insomnia and hypersomnia; eating disorders including anorexia nervosa, bulimia and compulsive overeating; and neuropsychiatric disorders including schizophrenia, depression and borderline personality disorder.