Neuro (movement disorders) Flashcards
What do the basal ganglia do?
- Coordination of habitual movement
- Controls voluntary movements
- Learning patterns
What does the thalamus do?
Relays info from basal ganglia to motor cortex
What do the brainstem nuclei do?
Maintain posture, muscle tone and reflex
What its chorea?
- Brief, abnormal, involuntary movements that are unpredictable
- Affect distal limbs more than proximal
In which diseases is chorea seen?
- Huntington’s
- Systemic disease like SLE and polycythaemia vera
- Basal ganglia lesions
- Sydenham’s chorea (rheumatic fever)
- Drugs
What drugs can cause chorea?
- Phenytoin
- Carbamazepine
- Neuroleptics
What is myoclonus?
Brief electric shock like jerking
What is ballismus?
- Uncontrollable flinging of a limb
- Normally unilateral (hemiballismus)
A lesion in which part of the brain usually causes ballismus?
Subthalamic nucleus
What is dystonia?
- Persistent and sustained muscle contraction causing spasm
- Abnormal posturing
What are the types of dystonia?
- Torticollis (neck)
- Focal dystonia (e.g. writer’s cramp)
What is athetosis and where is it seen?
- Slow writhing movements like a snake
- Seen in cerebral palsy
What is the pathophysiology of Parkinson’s?
- Loss of dopaminergic neurones in the substantial nigra
- Loss of D1 excitatory = difficulty in initiating movement
- Loss of D2 inhibitory = unwanted movement
- Accumulation of alpha pysnucelam (lewy bodies) in the remaining neuronal cytoplasm
What is the Parkinson’s triad?
- Bradykinesia
- Tremor
- Rigidity
Where is lead pipe rigidity seen?
Neuroleptic malignant syndrome
What are some other features of Parkinson’s?
- Parkinson’s mask
- Serpentine stare
- Micrographia
- Anosmia
- Mood disturbane
- Parkinson’s with dementia
- Restless leg syndrome may be precursor
What investigations may be useful in diagnosis Parkinson’s and why?
- LFTs and and copper (to rule out Wilson’s)
- MRI brain (will show Parkinsons plus)
- Dopamine uptake (bilateral changes in drug incurred Parkinsonism)
What drugs can induce Parkinson’s disease?
- Metoclopramide
- Prochlorperazine and chlorpromazine
- All antipsychotics except clozapine
- Carbon monoxide poisoning
- Mercury poisoning (Mad Hatter)
What are the 3 Parkinson’s plus syndromes?
- Progressive supra nuclear palsy
- Multisystem atrophy
- Corticobasal degeneration
What signs are more suggestive of PSP than Parkinson’s?
- Patients fall forwards (fall back in Parkinson’s)
- Vertical gaze palsy
- Pseudobulbar palys
- Look surprised
What is seen on MRI that may suggest PSP?
- Hummingbird ssign
- Frontotemporal lobe and midbrain degeneration
What signs are more suggestive of MSA?
- Autonomic dysfunction (erectile dysfunction, autonomic bladder and orthostatic hypotension)
- Cerebellar dysfunction (VANISHED)
- Rigidity more prominent than tremor
What may be seen on MRI to suggest MSA?
Hotcross bun sign
What signs are more suggestive of corticobasal degeneration?
- Alien limb
- Myoclonus
- Relentless progression
What are some other causes of Parkinsonism?
-Post trauma aka dementia pullisgans (seen in boxers)
- Infection (encephalitis, HIV and creutzfeldt jakob disease)
- Wilsons
- Huntingtons
- Lewy Body dementia
What antiemetic can be given in Parkinson’s instead o metoclopramide and why?
- Domperidone
- It doesn’t cross the BBB
What side effects are dopamine agonists (e.g. ropinarole) associated with?
Disinhibition
