Extrapyramidal system/TREMOR Flashcards
name and explain the types of tremor?
—Resting tremor Present at rest but abolished on voluntary movement. Most common cause—PD when tremor is rhythmic
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— (cerebellar) Intention tremor– Irregular large amplitude tremor worse on movement, e.g. reaching for something. Typical of cerebellar disease
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—–Postural/Movement Tremors –Thyrotoxicosis, anxiety, benign essential tremor (inherited), and drugs (e.g. β-agonists) cause a fine tremor abolished at rest. Alcohol and β-blockers may help
—Flapping- hepatic failure, resp failure, renal failure
http://www.aafp.org/afp/1999/0315/p1565.html
what is asterixis?
Asterixis Intermittent lapses of an assumed posture. May involve arms, neck, tongue, jaw, and eyelids. Usually bilateral, absent at rest, and asynchronous on each side.
Causes: liver failure (flapping tremor), heart failure, respiratory failure, renal failure, hypoglycaemia, barbiturate intoxication.
in the TREMOR OSCE, what could you see on general inspection?
Hint: Face, posture
poverty of facial expression- mask like, lack of micro-movements
Simian posture- flexed head, hands held in front of hernial orifices
What are the core features of parkinsonianism?
TRAP Tremor rigidity akinesis postural instability
describe the tremor in parksinsons? and how to test this in a physical exam?
at rest
coarse resting tremor
3-5Hz
pill rolling
tibutation in the head (yes-yes or no-no)
hold hands out, fingers spread, postural tremor will get worse, but rest tremor will dissolve
describe the rigidity in parkinsons and how to test it in a physical exam?
checking for cogwheel rigidity—-
let arms go completely floppy
hold pt’s arm at elbow
pronate/supinate
flex/extend the elbow and wrist
—-synkinesis—-tap your hand on your knee with other hand (synkinesis)
repeat with other arm
Describe akinesia? and how to examine this in an exam?
loss or impairment of the power of voluntary movement
touch thumb to each finger in turn as quickly as possible
describe postural instability? and how to examine this in an exam?
loss of balance/ axial instability/ sign of PD
ask patient to rise from chair, walk accross room, turn and come back……
look for parkinsonian features: hesitancy, shuffling gait, loss of arm swing, hurried steps, festinating (quickening and shortening of normal gaits), retroopulsion (tendency to walk backwards)
name some other tests in testing the extrpyramidal system?
glabellar tap
speech
writing
what are the causes of parkinsonism?
idiopathic parkinsons disease
drug induced parkinsonism (lithium, antipsychotics)
(antipsychotics—-haloperidol + “-azines” eg ).
parkinson plus syndromes (MSA) (multiple system atrophy)
vascular/athersclerotic pseudoparkinsonism
what is the MOA of antipsychotics?
dopamine antagonists. block D2 receptors
Main classes of treatments used in parkinsons?
L-Dopa Dopamine agonists anticholinergics- COMT inhibitors MAO-B- inhibitors glutamate antagonists
secondary causes of a tremor?
MS anxiety states fever brain abscess, tumour alcohol withdrawl phaeochromocytoma peripheral neuropathy psychogenic disorders thyrotoxicosis
DDX of parkinsons?
Benign essential tremor
Wilsons disease
MOA of L Dopa? and Carbidopa?
level of dopamine in brain. Unlike dopamine, L-dopa can cross blood-brain barrier and is converted by dopa decarboxylase in the CNS to dopamine.
Carbidopa, a peripheral decarboxylase inhibitor, is given with L-dopa tothe bioavailability of L-dopa in the brain and to limit peripheral side effects.
