Pathophysiology and Clinical Assessment of Parkinsonian Symptoms and Signs

In his 1817 ‘‘An Essay on the Shaking Palsy,’’ James Parkinson recorded many features of the condition that now bears his name (1). Parkinson emphasized the tremor at rest, flexed posture, festinating gait (Fig. 1), dysarthria, dysphagia, and constipation. Charcot and others later pointed out that the term paralysis agitans used by Parkinson was inappropriate, because in Parkinson’s disease (PD) the strength was usually well preserved and many patients with Parkinson’s disease did not shake.