Investigations

• What are the key diagnostic features of PD?

  MUST have bradykinesia, and 1 of the following;

  • rigidity
  • tremor (4 -6 Hz)
  • postural instability
• What would be shown in a PD examination?

  Bradykinesia

  Resting tremor

  Freezing -> seen during rapid alternating movements & gait examination (esp when turning or in doorways)

  Reduced facial expression

  Parkinsonian gait

  Pull test -> postural instability

  Motor symptoms often present unilaterally, then progress to bilaterally
• What is a Parkinsonian gait?

  Stooped posture

  Shuffling gait

  Reduced arm swing
• What would a DaTSCAN look like in someone with PD?

  Period shaped striatum

  Not definitive for PD

  
• What is a DaTSCAN?

  Dopamine active transporter scan

  Form of CT -> assesses function of dopamine transporters in brain

  Uses radioactive tracer (iodine 123) -> binds to pre-synaptic dopamine transported in striatum
• Why would blood tests be done in PD?

  Rule out other conditions
• What are the differential diagnoses of PD?

  Essential tremor

  Dementia with Lewy bodies

  Vascular Parkinsonism

  Parkinson's plus syndromes
• How can essential tremor be differentiated from PD?

  Will have postural tremor (tremor when holding a posture)

  No bradykinesia

  No increased tone

  Gait is usually unaffected
• How can dementia with Lewy bodies be differentiated from PD?

  Will have early severe dementia with disturbances of memory, language or praxis (planning)

  Onset of cognitive symptoms less than 1 year from Parkinsonism (or before)
• What is dementia with Lewy bodies?

  Dementia caused by Lewy bodies (clumps of protein in brain)
• What is vascular Parkinsonism?

  Caused by poor blood supply to the brain
• How can vascular parkinsonism be differentiated from PD?

  Unilateral features after 3 years

  Repeated strokes with stepwise progression

  Will have lower limb predominance

  Respond less well to levodopa
• What are Parkinson's plus syndromes?

  Group of neurodegenerative diseases similar to PD
• How can Parkinson's plus syndromes be differentiated from PD?

  Will have cerebellar signs

  Will have early severe dysautonomia (ANS does not work)