Diagnostic Criteria

 Key Facts

  • To diagnose PD you should make sure that parkinsonism is present, that there are no other features suggesting a different condition, and that parkinsonism improves with dopaminergic medications.
  • To diagnose parkinsonism you need to establish bradykinesia and at least one of the following: muscular rigidity, tremor, or postural instability.
  • There are no tests to diagnose PD.
  • The diagnosis of PD should be reviewed regularly and reconsidered if atypical clinical features develop.
  • Evidence shows that the way a diagnosis of PD is communicated affects how patient-reported outcomes long after.

Clinical Best Practices

  • People with suspected PD should be referred to a neurologist or movement disorder specialist to confirm diagnosis.
  • DaTSCAN should not be ordered in place of referral to a neurologist.
  • It is important to consider caregivers in communicating a diagnosis of PD.
  • Discussion should balance provision of honest, realistic information and promotion of a feeling of optimism.

Diagnosis of PD should be based on clinical findings. The most widely accepted clinical criteria for the diagnosis of PD are those introduced by the UK PDS Brain Bank Diagnostic Criteria.

Diagnosis of Parkinsonism

Bradykinesia and at least one of the following:

Exclusion Criteria for PD

History of the following:

  • Repeated strokes with stepwise progression
  • Repeated head injury
  • Antipsychotic or dopamine-depleting drugs
  • Definite encephalitis and/or oculogyric crisesi on no drug treatment
  • More than 1 affected relative
  • Sustained remission
  • Negative response to large doses of levodopa (up to 1,000-1,500 mg/day if tolerated), if malabsorption is excluded
  • Strictly unilateral features after 3 years
  • Other neurological features: supranuclear gaze palsy, cerebellar signs, early severe autonomic involvement, Babinski sign, early severe dementia with disturbances of language, memory, or praxis
  • Exposure to known neurotoxin
  • Presence of cerebral tumor or communicating hydrocephalus on neuroimaging

Features that Support a Diagnosis of PD

Three or more required for diagnosis of definite PD:

  • Unilateral onset
  • Rest tremor present
  • Progressive disorder
  • Persistent asymmetry affecting the side of onset most
  • Excellent (70%–100%) response to levodopa
  • Severe levodopa-induced chorea
  • Levodopa response for ≥5 years
  • Clinical course of ≥10 years
References: 

UK National Institute for Health and Clinical Excellence (NICE)

Parkinson’s Disease Guidelines http://www.nice.org.uk/guidance/CG35