Parkinsonism and Movement Disorders Flashcards
What is the role of the basal ganglia
Involved in initiation and modulation of movement
They receive input from the cortex, process it and relay back to the cortex via the thalamus
What can basal ganglia disease lead to
Hypokinesia (little movement) - rigidity, bradykinesia
OR
Hyperkinesia (too much movement) = tics, myoclonus, chorea, tremor etc
What are the pyramidal features
Pyramidal weakness
Spasticity
What is happening to the incidence of Parkinson’s
It is increasing with our ageing population
Second most common neurodegenerative condition
What are the pathological hallmarks of Parkinson’s disease
Loss of the black pigment of the substantia nigra – loss of dopaminergic neurons
Therefore decreased dopamine
Presence of Lewy bodies
Only seen after death as need to section the brain to view
What are the motor symptoms of Parkinson’s
Tremor - resting Bradykinesia - slow movement and slow to initiate Rigidity - cogwheel or lead pipe Postural instability - falls Stooped, fixed posture Lack of facial expression Shuffling gait Micrographia - small handwriting
What are the non-motor symptoms of Parkinson’s
Sleep disorders - REM and poor sleep Hallucinations Gastrointestinal dysfunction - constipation Bladder issues - increased frequency and urgency Depression and anxiety Cognitive impairment / dementia Anosmia - loss of smell Voice changes - lower
How many of the neurons must be lost before Parkinson’s symptoms appear
Around 60%
What are the main patterns of motor symptoms in Parkinson’s
Tremor dominant - relative absence of other symptoms
- associated with slower progression
Non-tremor dominant
How do you test bradykinesia
Finger tapping test
Get patient to repeatedly tap finger together as fast as they can
will be slower and the amplitude will start decreasing (less space each time)
What is lead pipe rigidity
constant resistance throughout passive movement
Like trying to bend a lead pipe
What is cog-wheel rigidity
When you try and move the limb, it will click round in steps like moving around a cog-wheel
Attributed to the underlying tremor
How do you diagnose Parkinson’s
It’s a clinical diagnosis - based on symptoms
Never really a definite diagnosis as this requires brain pathology which obviously cannot be done in
Can do a brain scan to rule out other structural causes etc.
What symptoms alongside the common PD ones suggest the diagnosis is not Parkinson’s
Early-onset bulbar problems, dementia and hallucinations, preferential involvement of lower limbs
Prominent eye movement disorder
Intrusive early autonomic problems
What tests can be done to assess/diagnose Parkinsons
DAT scans can be used
Looks for dopamine activity - will be round instead of comma shaped
How do you test for a supra-nuclear gaze palsy
Ask them to look up (keeping head still) and then down (independently first then by following finger)
If they also cannot fix on a point when moving their head then it means it isn’t just a eye muscle problem
if the patient cannot do these movements it is a SN gaze palsy
Which sex is more commonly affected by Parkinson’s
Men are around 1.5x more likely to get it
Does Parkinson’s affect lifespan
Yes
It has an increased mortality and shorter life span
What are the risk factors for developing Parkinson’s
Advancing age is the major one
Positive family history - genetics
Male sex
May be some environmental triggers - pesticide, head injury, beta blockers etc
What treatments are available for Parkinson’s
Symptomatic treatments enhance intracerebral dopamine concentrations or stimulate dopamine receptors
Levodopa - replaces dopamine
Dopamine agonists
Monoamine oxidase inhibitors (type B) - prolongs available dopamine
Anticholinergic agents, trihexyphenidyl, or clozapine, can be effective for tremor
