Dear listmembers, I got so many requests that I must cut it off at this point- but for those who may still be interested it seems worthwhile to post this much shortened version. I'll still answer specific questions about references, etc. by e-mail if I can: In an organ as complex as the brain, one can't expect each of its many illnesses to be precisely defined and distinct from all the others. Moreover, conditions having similar or related symptoms may often be combined. Partly for those reasons, the job of diagnosis is best left to the highly trained neurologist: Primarily Motion Disorders: Abbr. Terminology Relative Suspicious Frequency* Features PD Parkinson's Disease 78% tremor, rigidity, slowness; responds to dopaminergic drugs ET Essential Tremor ?? tremor alone; responds to Inderal, Mysoline, alcohol -- Parkinsonism Plus 12% various forms of Multiple System Atrophy (MSA) below: PSP Progressive Supranuclear 7.5% eye and eyelid control Palsy problems SDS Shy-Drager Syndrome 1.7% orthostatic hypotension OPCA OlivoPontoCerebellar < 1% parkinsonism plus ataxia Atrophy SND StriatoNigral Degeneration < 1% early-onset falling, dysarthria; may respond to levodopa at first CBGD CorticoBasal-Ganglionic < 1% parkinsonism plus apraxia Degeneration plus marked asymmetry -- Secondary Parkinsonism 8% toxin, trauma, stroke, tumor etc. *These frequencies occurred in a sample of some 2000 patients a few years ago. ET often occurs together with PD; when occurring alone it is often misdiagnosed as PD, or may go untreated, so its frequency is unknown. Other diseases which at onset may suggest PD or occur with PD: MS Multiple Sclerosis ALS Amyotrophic Lateral Sclerosis (Lou Gehrig Disease) AD Alzheimer's Disease CJD Creutzfeldt-Jakob Disease Not a cheerful message, but I hope useful. J. R. Bruman (818) 789-3694 3527 Cody Road Sherman Oaks CA 91403