Although the diagnosis of Parkinson’s disease is largely clinical, can take account of hyposmia (may precede up to 20 years to your appearance), positron emission tomography showing decrease of dopamine in the striatum, markers recently biological and electromyography to show subclinical tremor.

An important chapter of this issue is that of drug-induced parkinsonism, which generally refers to the interruption but not always. Drugs that can induce are neuroleptics (phenothiazines, butyrophenones), depleting dopamine (reserpine, tetrabenazine) and calcium channel blockers (cinnarizine, flunarizine).

The clinician, before diagnosing Parkinson’s disease, should take into account the possibility cited in the preceding paragraph as well as a number of neurological disorders that are targets of specialized study.

Fustinoni (in Semiology Nervous System [1997]) says the following signs and symptoms exclude the diagnosis of Parkinson’s disease:

Signs and Symptoms that exclude Parkinson

l buccolingual dyskinesia (parkinsonism drug)

l hyperreflexia not justified by previous stroke (Vascular parkinsonism)

l pseudobulbar syndrome (vascular parkinsonism)

l or intentional tremor predominant attitude (Essential tremor)

l Paralysis of vertical gaze downward or lateral (Progressive supranuclear palsy)

l Early by gait disorders (Hakim-Adams syndrome)

l Early urinary incontinence (Hakim-Adams syndrome)

l marked orthostatic hypotension (Shy-Drager syndrome)

l Cognitive discordant severity or prominence in connection with rigidity, bradykinesia or tremor (DAT)

l oculogyric crisis (parkinsonism drug, posencefalítico)

Inhibition and excitation – dopamine and acetylcholine

In a normal brain, the levels of dopamine and acetylcholine, are in equilibrium and equal in their inhibitory and excitatory roles. When lower levels of dopamine, this balance is broken, because the acetylcholine begins to have an excess of excitatory activity, which causes Parkinson’s disease. Dopamine is found in the pars compacta of the substantia nigra and ignored the reasons why their neurons die and cease to keep the system balanced on the striatum.