motor function Flashcards
upper motor neurone lesions: recognise the signs and symptoms of upper motor neuron lesions
what regions are lower motor neuron
motor neurones in ventral horn of spinal cord and bulbar in brainstem
what regions are upper motor neuron
corticospinal, corticobulbar
what regions are pyramidal
lateral corticospinal tract
what regions are extrapyramidal
basal ganglia, cerebellum
what are negative signs associated with
loss of function
2 negative signs of an upper motor neurone lesion
paresis, paralysis (plegia)
what is paresis
graded weakness of movements
what is paralysis (plegia)
complete loss of muscle activity
what are positive signs associated with, and what causes them
increased abnormal motor function due to loss of inhibitory descending inputs
3 positive signs of an upper motor neurone lesion
spasticity, hyper-reflexia, clonus
what is spasticity
increased muscle tone
what is hyper-reflexia
exaggerated reflexes
what is clonus
abnormal oscillatory muscle contraction
what is Babinski’s sign
movement of toes after stimulation of base of foot (distinctive change in normal reflex)
what is the name given to a disorder of skilled movement
apraxia (mainly damage to parietal cortex)
features of patients with apraxia
not paretic but have lost information about how to perform skilled functions e.g. dressing
causes of apraxia related to upper motor neurone lesion
any disease or lesion of inferior parietal lobe, or of frontal lobe (premotor cortex, supplementary motor area)
what are the 2 most common causes of apraxia
stroke and dementia
6 features of a lower motor neurone lesion
weakness, hypotonia (reduced muscle tone), hyporeflexia (reduced reflexes), muscle atrophy, fasciculations, fibrillations
what are fasciculations
where damaged motor units produce spontaneous action potentials, resulting in a visible, uncontrolled twitch
what are fibrillations and when are they recorded
spontaneous twitching of individual muscle fibres; recorded during needle electromyography examination
