Parkinson

Parkinson’s Disease

Background

  • Tremor is typically a very early symptom, and worse on one side
  • Cogwheel rigidity can be confused for paratonia, which is seen in demented or encephalopathic patients who have involuntary variable resistance movements during passive ROM assessment
  • Gait, speech changes (low volume), hand-writing changes of slow small movements
  • Festination – slow start with movements that gradually build up speed
  • En bloc turning – taking multiple steps to turn around
  • Anosmia and REM behavior sleep disorders are very common

 

Evaluation

  • Clinical diagnosis; there are some supportive imaging studies like DaTscan that looks for activity of substantia nigra (usually not necessary)
  • Clinical response to dopamine replacement is so typical that if a patient does not respond, it is important to consider a Parkinson plus syndrome (see below)

 

Management

  • Dopamine replacement – carbidopa/levodopa; dosed at regular intervals several times a day. These generally do not need to be held on admission.
    • If pt is altered, can hold anticholinergics, MAO-B inhibitors or COMT inhibitors
  • Dopamine agonists – can cause confusion, hallucinations, dyskinesias
  • MAO-B inhibitors (MAOIs): can cause confusion, hallucinations, insomnia and dyskinesias
    • Theoretical risk of Serotonin Syndrome (usually need both MAO-A and MAO-B for serotonin syndrome risk)
  • COMT inhibitors – can cause confusion, hallucinations, insomnia, and dyskinesias
  • Anticholinergics – useful for tremor when there is not much bradykinesia or gait disturbances. In older pts cognitive changes are a bigger concern along with hallucinations
  • PD medications are rarely titrated in the hospital because acute medical illness makes PD symptoms worse and everything will need to be re-adjusted as an outpatient
  • Be cautious with PRN anti-emetics in patients with PD. Many work via dopamine antagonism. Zofran is generally the safest option.
  • Similarly, many antipsychotics have dopamine antagonism. Safest options include seroquel, nuplazid (less effective in acute setting) and clozapine.

 

Parkinson Plus Syndromes

  • Atypical features such as bilateral symmetric onset, early cognitive/personality changes, cerebellar findings, or prominent autonomic dysfunction early
  • Progressive Supranuclear Palsy – PD symptoms with early falls and minimal tremor, vertical eye movement abnormalities
  • Multisystem Atrophy (there are three types)
    • Each typically has profound orthostatic hypotension without any increase in HR
    • MSA-A – autonomic features prominent (previously Shy-Drager Syndrome)
    • MSA-P – prominent atypical Parkinsonism features
    • MSA-C – prominent cerebellar dysfunction
  • Lewy Body Dementia – Parkinsonism with prominent early cognitive impairment and hallucinations