Parkinson's disease is diagnosed clinically, by finding bradykinesia, meaning slowness and reduction in movement, together with either a resting tremor or rigidity. There is no blood test or scan that confirms it, so the examination is the diagnostic step.
Parkinson's disease is diagnosed clinically, by finding bradykinesia, meaning slowness and reduction in movement, together with either a resting tremor or rigidity. There is no blood test or scan that confirms it, so the examination is the diagnostic step.
Slowness and progressive reduction in the size of repeated movements is the necessary feature; tremor alone is not sufficient. It shows up as smaller handwriting, a quieter and more monotone voice, reduced facial expression, less arm swing on one side when walking, and difficulty with fine tasks such as buttons or fastening jewellery. Examination tests it directly, watching repeated finger tapping or hand opening and closing for both slowness and decrementing amplitude. Bradykinesia plus either resting tremor or rigidity is what establishes parkinsonism.
Parkinson's disease characteristically begins on one side and remains asymmetric for years, which is one of the more useful diagnostic clues, since symmetrical onset points towards other causes. Supporting features include reduced sense of smell, REM sleep behaviour disorder where dreams are physically acted out, constipation and low mood, any of which may precede movement symptoms by years. A clear and sustained response to dopaminergic treatment also supports the diagnosis, though that is assessed over time rather than at the first visit.
Essential tremor is the commonest confusion, and it differs by occurring during action rather than at rest, usually affecting both hands, and lacking bradykinesia. Drug-induced parkinsonism from certain antipsychotics and anti-nausea medications is genuinely common and reversible, which is why a full medication history matters. Other parkinsonian syndromes progress differently and respond less well to treatment; early falls, rapid progression or prominent autonomic symptoms point that way and warrant reassessment.
Clinical Neurology Specialists has been physician-owned since 1998, when Leo Germin, M.D., FAANEM founded it. Five board-certified neurologists and four advanced practice providers see patients at the Las Vegas and Henderson offices, each with its own AANEM-accredited electrodiagnostic laboratory.
Clinical Neurology Specialists is an adult outpatient neurology practice for patients 18 and older. The practice performs no surgery and operates no imaging suite, infusion suite or interventional pain programme, and provides no emergency or inpatient care.
Physician-reviewed. Reviewed by the physicians of Clinical Neurology Specialists — board-certified neurologists, AANEM-accredited electrodiagnostic laboratories, physician-owned since 1998. Reviewed 1 August 2026. This article is general education for adults 18 and older and is not a substitute for a consultation.
Sources and further reading: MedlinePlus: Parkinson's disease; National Institute of Neurological Disorders and Stroke; National Institute on Aging.
Adults 18 and older, at the Las Vegas and Henderson offices. Call 702-804-1212 or request an appointment online.