Parkinsons Disease Flashcards
Underlying pathology of PD
Loss of dopaminergic neurones in the substantia negra of the midbrain
Describe the genetic aetiology of PD
Multifactorial and genetically heterogeneous
Possible risk factors for PD (2)
Positive family history, environmental toxins
Three potential cause of secondary PD
Vascular insult (e.g. basal ganglia infarct)
Repeated head injury (e.g. boxing)
Post-encephalitis
Four cardinal symptoms of PD
Bradykinesia
Rest tremor
Rigidity
Postural and gait impairment
Classical tremor seen in hands of PD patients
Pill-rolling tremor
Features of muscle tone seen in PD (2)
“Lead pipe” rigidity
Superimposed tremor- “cogwheel rigidity” particularly seen in pronation of wrist
Classical description of gait in PD
Stooped, “simian”, shuffling gait
Hypomimia
Decreased facial expression
Hypophonia
Soft monotonous voice
Micrographia
Progressively smaller writing
How is tremor best observed in clinical practice?
Distraction- ask the patient to focus on a particular mental task
Positive Froment’s manouevre
Rigidity increases in body segment when other body segments are being moved voluntarily
Early non-motor symptoms (3)
Hyposmia
Constipation
Depression
Late nonmotor symptoms (2)
Dementia
Hallucinations
Diagnosis of PD (2)
Mainly clinical
Levodopa trial may be useful
Features which might suggest a vascular cause of parkinsonism rather than classic PD (5)
Lower body predominately affected Poor levodopa response Lack of rest tremor Dementia prominent or early Occurs in people older than 70
Feature which might suggest drug-induced parkinsonism
Emergence of symptoms after exposure; resolution after withdrawal
Distinguish between essential tremor and PD?
ET tends to be symmetrical, usually not at rest
Improves with alcohol
Has a mean onset of about 15 years
Imaging modality which can be used as an aid to clinical diagnosis?
SPECT (commonly known as DAT-SCAN) which looks for dopamine-releasing cells in the brain
Treatment for daytime somnolence in PD?
Modafinil
Autonomic failure + parkinsonism + pyramidal signs + ataxia
Multi-system atrophy (Shy-Drager syndrome)
Up and down gaze palsy + axial rigidity and falls + dysarythria and dysphagia
Progressive supranuclear palsy
Drugs which can induce parkinsonism?
Neuroleptics e.g. haloperidol
Anti-emetics e.g. metoclopramide
Most appropriate anti-emetic to prescribe in Parkinson’s, and why?
Domperidone
Does not cross blood brain barrier
