Chapter 94 – Parkinson’s Disease

Publisher Summary Parkinson's disease (PD) is a neurodegenerative movement disorder defined by its motor features that asymmetric resting tremor, rigidity, bradykinesia, and postural instability. Autonomic symptoms may be present to varying degrees in patients with PD, but very severe dysautonomia in patients with mild motor findings suggests a diagnosis of multiple system atrophy (MSA). There are several differing criteria in use to diagnose PD and parkinsonian syndromes. Histopathology of postmortem tissue is typically required for definitive diagnosis. Commonly, separating PD from parkinsonian syndromes rests largely upon the response of the physical examination to dopamine replacement therapy (DRT). Nonpharmacologic interventions such as compression stockings may be helpful for many patients. In some cases, prophylactic treatments with oral water or midodrine, an alpha1-adrenergic receptor agonist, may also be necessary. Additional drug-induced autonomic effects can also negatively impact PD therapy. Type B monoamine oxidase (MAO-B) inhibitors, used to prolong the duration of action of dopamine, may cause severe hypertension.