Lesions of Motor Cortex - Cerebellum & BG Flashcards
Distinguish between pyramidal and extra-pyramidal upper motoneurone signs
Pyramidal - positive babinski sign, absent superficial abdominal reflexes, absent cremasteric reflex, loss of performance of fine skilled voluntary movements
Extrapyramidal - spastic paralysis (increased muscular tone, hyperreflexia), little or no muscular atrophy, exaggerated deep muscle reflexes, flapping clonus, hypertonia, clasp knife response
Name and describe the function of the three functional zones of the cerebellum
Vestibulocerebellum (archicerebellum) - main input from vestibular system, balance, ocular reflexes
Spinocerebellum (paleocerebellum) - error correction
Cerebrocerebellum (neocerebellum) - movement planning, motor learning, visually guided movement, coordination of muscle activation
List clinical signs present in cerebellar dysfunction
Dysmetria Dysdiadochokinesia Ataxia Nystagmus Intention tremor Slurred speech (dysarthria) Hypotonia Cannot learn new movements
Differentiate between positive and negative motor lesion signs
Positive sign - emergence of a feature
Negative sign - loss of a function or capacity
Describe the function of the basal ganglia and name conditions that may lead to its dysfunction
Regulate the amplitude and velocity of planned movement, particularly in relation to the use of internal information
Dysfunction = hypo/hyperkinetic disorders e.g. Parkinson’s disease, Huntingdon’s disease
Consider the specific case of Parkinson’s disease as an example of a CNS degenerative disease process that impairs the motor system
Progressive degeneration of dopaminergic neurones in substantia nigra in BG –> bradykinesia, hypertonia (cog-wheel/leadpipe rigidity), tremor at rest (reduced by movement)
List the components of the basal ganglia
Causade nucleus Putamen Globus pallidus (external, internal) Substantia nigra (compacta, reticulata) Subthalamic nucleus Caudate nucleus + putamen = neostriatum Putamen + globus pallidus = lenticular nucleus
