Movement Disorders Flashcards
What is the basic summary of the system that needs to be in place to have effective movement?
Intacy pathway from cortex to NMJ
Fined tuned by functional cerebellum and basal ganglia for fluid movement
What are the key features of the movement disorder?
Concerned with the amplitude and degree of movement rather than any weakness within the movement.
Movement that is no longer fluid or controlled
What are some common causes of movement disorders?
Stroke
Multiple sclerosis
Motor Neuron Disease
Myasthenia gravis
Metabolic issues
What are the two broad descriptive categories of movement disorders?
Hypokinesia - too little movement
Hyperkinesia - too much movement
How does the substantia nigra influence the direct basal ganglia pathway?
Dopaminergic projections from the SN act on D1 receptors in the striatum
Has an excitatory effect - increases GABAergic projections from the striatum to the GPi, resulting in disinhibition of the thalamus.
Able to active movement.
Increases activity of the direct pathway
How does the substantia nigra influence the indirect basal ganglia pathway?
Has dopaminergic projections from the SN act on D2 receptors in the striatum.
Has an inhibitory effect, reduces GABAeric projections to the GPe.
Results in inhibition of the subthalamic nucleus via GABAergic projections from GPe to ST.
Inhibits the indirect pathway.
Increases activity of the thalamus.
What is the effect of an active substantial nigra on the direct and indirect basal ganglia pathway?
Increased activity along the direct pathway
Decreases activity along the indirect pathway.
Overall facilitates movement.
What is an examples of hypokinesia movement disorders?
Akinetic-rigid syndromes aka
Parkinsonism
What is the quadrad of parkinsonism?
To be diangosed with parkinsonism must have bradykinesia.
Also 1 of:
Rigidity (lead pipe)
Rest tremor
Postural instability.
What is meant by lead pipe rigidity in Parkinson disease?
Hypertonicity throughout the range of motion/movement.
What is the key feature of bradykinesia to look for in parkinsons disease?
Movement gets smaller and slower over time, ask by testing to clench and release a fist.
What is meant by postural instability during Parkinson disease?
The inablity to maintain balance during dynamic and stable movements.
What are some key symptoms of Parkinsons disease?
Hypomimic face
Forward tilt of trunk and stooped posture
Global flexion
Rigid back
Reduced arm swing during agit
Shuffling, short and stepped gait.
Hand and leg tremor.
What is the basic neuroanatomy of parkinsons disease?
Damage to the substantia nigra - reduces dopamine production
Reduced activity along Dopaminergic projections to the striatum
Less activity at D1 receptors on striatum - less activation of the direct pathway
Less activity at D2 receptors on the striatum - less inhibition of the indirect pathway
Overall leads to greater activity along the indirect pathway, results in hypokinesia.
What are the different causes of Parkinson disease?
Idiopathic parkinsons disease
Vascular parkinsonism
Medication that block dopamine
Rarer - dementia with Lewy bodies, Parkinsons plus syndromes (PSP and MSA)