Movement disorders Flashcards
LOs
Normal functioning of basal ganglia
Be able discuss about the hypokinetic and hyperkinetic disorders
Differential diagnoses
Neuroanatomy of basal ganglia
Normal movement 2 steps
- Intact cortex (think of something, pass through pyramidal tract, fine-tuned)
- Fine-tuned by cerebellum and basal ganglia for fluid movement
difiiculties in movement
what is too little movement
what is too much?
- Usually refers to problems with fluid movement
Cerebrum, basal ganglia, metabolic
- Too little movement
Hypokinesia akak parkinism
- Too much movement
Hyperkinesia
basal ganglia
Structures deep within brain
normal fluid movement requires pathways to be In balance- pathway that tells you to stop and one that tells you to stop
direct pathway
Cortex is a stimulatory structure, tells your striatum it wants to go
The striatum wants to fine tune that movement- inhibitory structure, it inhibits the globus pallidus interna (also inhibitory). Glob pal int is turned down by striatum in go PATHWAY.
Therefore, thalamus (am excitatory structure) is allowed to go.
indirect pathway of basal ganglia
Cortex ► striatum► Goes through glob pallidus ext (an inhibitory structure) ► allows subthalamic nucleus (a go structure) to excite the glob pall interna (inhibitory structure_ ► inhibits the thalamus
The 2 sides talk to each other and balance each other.
substantia nigra
Lubricates the direct and indirect pathways.
Promotes go via D1 (dopamine) receptor activation
Inhibits go via D2 (dopamine) receptor activation
hypokinesia
diagnostic criteria
causes
AKA akinetic-rigid syndromes
AK parkinsonism
Must have bradykinesia,
+ Any 1 of; rigidity
Rest tremor (4-6Hz)
Postural instability
causes:
Idiopathic
Vascular
Medications that block dopamine
Rarer causes
Dementia w lewy bodies
Parkinson’s plus syndromes
parkinsonism
hyperkinesia conditions (3)
tremor
chorea
dystonia
tremor
3 kinds
tremor
rhymical, sinusoidal, akternating movemnt
shaking
type of tremor will helkp diagnosis
a) postural
when holding a position against gravity
essential tremor
thyrotoxicosis/ salbutamol
b) action/kinetic tremor
seen in cerebellar disease e.g., stroke, tumour, genetic, alcohol
c) rest
parkinsonism
chorea
ballism
hemi-chorea
casues of chorea
Random
“dance-like” unpedictable, flowing movements moving from one area to another
Ballism- chorea that affects proximal joints so movements are large and flinging
Hemi-chorea- affecting half of the body
Affects the indirect pathway- striatum damaged- loss of inhibition
Causes:
- Any structural lesion of the striatum
Stroke, tumour etc.
- Neurodegenerative/ degenerative
Huntington’s chorea, Wilson’s disease
- Immune mediated
Syedenham’s chorea (response to group A strep)
- Drug induced
Levodopa induced dyskinesia in Parkinson’s disease
dystonia
causes
- Sustained or intermittent muscle contraction resulting in abnormal postural movement
- Can be repetitive, can be task specific (writers cramp\0
- Can be paiful
- Geste antagoniste- volunatry movement that temporarily reduces the severity of dystonic postures/ movements
Causes:
- Idiopathic (overuse??)
- Genetic
- Part of another condition (PD)
- Structural lesions (trauma, tumour, stroke)
Brain, spinal cord ormperipheral nerve
- Immune mediated
- Post infectious
- Drugs- antipsychotics, antiemetics
other hyperkinetic movement disorders 3
myoclonus-
jerky, shock like movements
lots of causes
normal► medications ► epilepsy► dementia
can be picked up by EMG
Tics-
usually brief, often stereotyped
can be movement or sound
can be suppressed for short periods of time
tourettes syndrome most common cause
Wilson’s disease-
Can present with parkinsonism, chorea, dystonia, psychiatric issues, liver disease
Important not to miss as further brain/ liver damage can be precented
