Parkinson's disease Flashcards
Signs of Parkinson’s disease on general inspection
Asymmetrical resting tremor: 5Hz - exacerbated by counting backwards
Hypomimia (reduced facial expression)
Extrapyramidal posture
Signs of Parkinson’s disease in the arms
Bradykinesia
Tone: cogwheel rigidity, may be enhanced by performing an action with the other limb
Normal power and reflexes
Coordination: abnormal if MSA
Signs of Parkinson’s disease in the eyes
Nystagmus: MSA
Vertical gaze palsy: PSP
Saccades: slow initiation and movement
Definition of cogwheel rigidity
Tremor superimposed on increased tone
Gait signs in Parkinson’s disease
Slow initiation
Shuffling (preceded by reduced stride length)
Hurrying = festination
Absent arm swing
Extra signs in Parkinson’s`
Glabellar tap (Myerson’s sign)
Write sentence and draw spiral (micrographia)
BP lying and standing
Completion of Parkinson’s exam
MMSE
Drug chart review
Abdominal examination: hepatomegaly + signs of CLD (DDx hepatic encephalopathy)
Causes of Parkinsonism
Idiopathic PD Parkinson Plus Syndromes: Progressive Supranuclear Palsy (PSP) Multiple system atrophy (MSA) Lewy-body dementia Corticobasilar degeneration Multiple infarcts in the substantial nigra Wilson's disease Drugs: neuroleptics, metoclopramide
Specific history for Parkinsonism
Symptoms: tremor, rigidity, akinesia Autonomic: postural hypotension, urinary problems, constipation, hypersalivation ADLs: Handwriting, buttons, shoelaces Getting in and out of a car Sleep: Turning in bed, insomnia, daytime sleepiness Complications: Depression Drug SEs esp. motor fluctuation Cause: Sudden onset? Eye or balance problems Visual hallucinations, reduced memory DHx FHx
Investigations for Parkinsonism
Bloods: caerulopasmin (low in Wilson’s)
Imaging: CT/MRI to exclude vascular cause
DaTscan: ioflupane I123 injection binds to domapinergic neurones and allows visualisation of substantial nigra - can exclude other causes of tremor e.g. benign essential tremor.
General management of Parkinsonism
MDT
Assess disability e.g. using UPDRS (Unified Parkinson’s Disease Rating Scale)
Physiotherapy: postural exercises
Depression screen
Specific medical treatment of Parkinson’s
Choice of treatment depends on balance between improvement in motor symptoms and motor and psychiatric side-effects.
MAO-B: selegiline, rasagiline.
Oral/transdermal dopamine agonist: ropinirole, pramipexol.
Levodopa (most effective symptomatic drug)
For more advanced disease:
Apomorphine SC as a rescue agent for severe ‘off’ episodes.
Amantadine or an antimuscarinic e.g. procyclidine.
COMT inhibitors e.g. tolcapone.
Use of levodopa in Parkinson’s
Given with a peripheral dopa-decarboxylase inhibitor. Preparations e.g. Sinemet. Use lowest effective dose. Long term use may cause weight loss. Side effects (N+V) are rare.
Use of dopamine agonists in Parkinson’s
Effective in controlling motor symptoms, used early in disease. Fewer motor side-effects and weaker effect cf long-term levodopa, therefore used more in younger patients. All eventually require levodopa.
Adjunct medications in Parkinson’s
Domperidone: nausea
Quetiapine: psychosis
Citalopram: depression
Epidemiology of idiopathic Parkinson’s disease
Mean onset 65 yoa
2% prevalence
Pathophysiology of Parkinson’s disease
Destruction of dopaminergic neurones in pars compact and substantial nigra
Beta amyloid plaques
Neurofibrillary tangles: hyperphosphorylated tau
Features of Parkinson’s disease
Asymmetric onset: side of onset remains worst
TRAPPS PD
Tremor (increased by stress, reduced by sleep)
Rigidity (lead pipe, cog-wheel)
Akinesia (slow initiation, difficulty with repetitive movement, micrographia, monotonous voice, mask-like face)
Postural instability (stooped gait, festination)
Postural hypotension (plus other autonomic dysfunction)
Sleep disorders (insomnia, excessive daytime sleepiness, obstructive sleep apnoea, RBD)
Psychosis esp visual hallucinations
Depression / Dementia / Drug SEs
Sleep disorder in Parkinson’s Disease
Affects ~90% of PD patients
Insomnia + frequent waking leads to excessive daytime sleepiness (EDS)
Due to: inability to turn, restless legs, early morning dystonia (drugs wearing off), nocturne, obstructive sleep apnoea
REM Behavioural sleep Disorder (RBD): loss of muscle atone during REM sleep, violent enactment of dreams
Dopamine side effects: insomnia, drowsiness, EDS
Autonomic dysfunction in Parkinson’s disease
Combined effects of drugs and neurodegeneration
Postural hypotension
Constipation
Hypersalivation (dribbling d/t reduced ability to swallow saliva)
Urgency, frequency, nocturne
Erectile dysfunction
Hyperhidrosis
L-DOPA side-effects
DOPAMINE Dyskinesia On-off phenomena = motor fluctuations Psychosis Autonomic BP problems (orthostatic hypotension) Mouth dryness Insomnia N/V Excessive daytime sleepiness
Motor fluctuations with levodopa treatment
End-of-dose (wearing off): progressively decreased benefit
On-off effect: unpredictable fluctuations in motor performance unrelated to timing of dose
Pathology of multi system atrophy
Papp-Lantos Bodies: alpha-synuclein inclusions in glial cells
Features of multi system atrophy
Autonomic dysfunction: postural hypotension
Parkinsonism
Cerebellar ataxia
Differentiating MSA from Parkinson’s
Main differentiating factor is in MSA parkinsonism does not improve with levodopa
Name of MSA if autonomic features predominate
Shy Drager Syndrome
Features of progressive supranuclear palsy (PSP)
Postural instability leading to falls
Vertical gaze palsy
Pseudobulbar palsy (speech and swallowing problems)
Parkinsonism (but: symmetrical onset, tremor is unusual)
Features of corticobasilar degeneration
Unilateral parkinsonism, esp rigidity
Aphasia
Astereognosis: cortical sensory loss
Alien limb phenomenon: autonomous arm movements
Pathology of Lewy-Body Dementia
Alpha synuclein and ubiquitin Lewy Bodies in brainstem and neocortex
Features of Lewy-Body dementia
Fluctuating cognition
Visual hallucinations
Parkinsonism
Features of Parkinsonism
Sudden onset
Parkinsonism worse in legs than arms
Pyramidal signs
Prominent gait abnormality
Causes of tremor
Resting tremor: parkinsonism
Intention tremor: cerebellar
Postural tremor (worse with arms outstretched): Benign essential tremor, hyperthyroidism, alcohol withdrawal, beta agonists, anxiety.
Features of benign essential tremor
Autosomal dominant
Occurs with movement and worse with anxiety, caffeine
Doesn’t occur during sleep
Better with EtOH
