Johns Hopkins Psychiatry Guide

Parkinson Disease

Katie Holroyd, , Jacob Taylor, M.D., M.P.H.
Parkinson Disease is a topic covered in the Johns Hopkins Psychiatry Guide.

To view the entire topic, please or purchase a subscription.

Johns Hopkins Guides provide diagnosis, management, and treatment guidance for infectious diseases, diabetes, and psychiatric conditions. Explore these free sample topics:

Johns Hopkins Guides

~~ The first section of this topic is shown below ~~

DEFINITION

  • Parkinson disease (PD) is a progressive neurodegenerative movement disorder.
  • Hallmark symptoms of PD include: bradykinesia plus at least one of the following – rest tremor, rigidity, gait disturbance.
  • Pathologically, PD is characterized by dopaminergic neuron death in the substantia nigra pars compacta (SNpc) of the midbrain.
    • In early, pre-symptomatic stages of PD, pathological changes are thought to occur in the medulla oblongata, pontine tegmentum, and olfactory bulb.
    • Motor symptom onset occurs after 60%-80% of the SNpc neurons are lost.
    • From there, the disease continues to progress and eventually affects structures in the basal forebrain and neocortex.
  • Lewy bodies, cytoplasmic inclusions composed of aggregated α-synuclein protein and proteolysis proteins including ubiquitin, are a second pathological signature of PD [1].
  • The specific etiology and mechanism of PD neurodegeneration is still unknown.
  • Cognitive impairment due to Parkinson disease is classified under the neurocognitive disorders (NCDs) section of the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) [2].

~~ To view the remaining sections of this topic, please
or purchase a subscription ~~

Last updated: November 21, 2014