Motor Lesions Flashcards
Atrophy in UMN vs LMN lesion
. LMN: profound or severe
. UMN: disuse
Fasciculations
. LMN sign
. Visible irregular contraction over surface of mm.
Fibrillation
. LMN sign
. Not visible to naked eye
. Only detectable via EMG
Hypertonia
. Spasticity: UMN sign
. Rigidity: basal ganglia disorder (cog-wheel, lead-pipe)
Spasticity
. Hypertonia and hyperreflexia
. Seen primarily in anti-gravity mm.
. Velocity dependent
. Slow passive stretch of m. Fails to exhibit inc. in m. Tone
. Rapid passive stretch will exhibit hypertonicity (clasped-knife effect)
. Clonus often seen
Hypotonia
. LMN sign
. M. Tone depressed, often m. Flaccid
Disorders that effect coordination
. Cerebellar disorders
. Basal ganglia disorders
. Premotor or parietal motor cortex lesion (apraxia)
Hyperreflexia
. UMMN sign
. Inc. exaggerated reflexes
. Clonus may be present
. Positive babinski
Disorders that effect gait
. Extrapyramidal disorder (destinations gait in parkinson’s)
. Cerebellar disorders (spinocerebellar lesions)
. Loss of sensory input (dorsal column ataxia)
Plegia
. Total paralysis
. Quad: all 4 limbs
. Para: both arms or both legs
. Hemi: both limbs on one side of body
Paresis
. Weakness of motor function
. Quad: weakness in all limbs
. Para: weakness in both legs or both arms
. Hemi: weakness in both limbs on one side of body
LMN lesion signs
. Focal and severe m. Weakness and plegia . Dec. m. Tone . Dec. reflexes . No babinski or clonus . Profound and severe m. Atrophy . M. Fasciculations seen
UPM lesions
. General m. Weakness . Inc. m. Tone w/ spasticity and clonus . Inc. deep tendon reflexes . Positive babinski . Little if any atrophy (disuse)
primary motor cortex lesion
. Contralat. M. Weakness not paralysis
. Paresis is worse for more distal mm. And its effects are seen most when fine, skilled movements are attempted
. Subtle weakness tested for using proctor drift
Premotor cortex lesions
. Impairment of ability to develop strategy for complex movements
. No paresis: m. Tone and strength are normal
. Patients make spatial and temporal errors in voluntary movements (apraxia/inability to perform learning skill)
. Individual is able to make simple movements but not complex ones (impair multiple joint coordination)
. Preservation: can start movement but not continue it to achieve goals
Supplementary motor area lesions
. Spatial and temporal errors in learned skilled movements
. No weakness
. Inability to coordinate motor actions on 2 sides of body
. Difficulty learning new motor tasks
Posterior parietal motor area lesions
. Motor disturbances but no weakness
. Difficulty in executing complex movements
. Difficulty w/ proper orientation of hand in relation to an object
. Secondary sensory deficits (agraphesthesia/astereognosia)
. Do not know motor tasks are wrong
Cerebellar dysfunction
. Signs on same side of lesion . Decomposition of movement . Ataxia . Dysmetria: inaccurate range and direction of movements . Dysdiadochokinesia . Intention tremor . Delays in initiation of movement . Hypotonia: in spinocerebellar lesion . Dysarthria: mechanical parts of speech impaired, speech is slow and slurred
Basal ganglia disorders
. Voluntary movement dysfunction
. Akinesia: inability to move
. Dyskinesia: presence of abnormal involuntary movement
. Hypertonia or hypotonia
Parkinsonism
. Basal ganglia disorder w/ akinesia and hypertonia . Dec. dopaminergic nigrostriatal input to striatum . Akinesia/bradykinesia . Difficulty initiating movements . Cog wheel rigidity . Tremor at rest . Stooped posture and shuffling gait . Fear of losing balance . Expressionless face
Chorea
. Dyskinesia w/ dance-like movements
. Assoc. w/ lesions of corpus striatum
. M. Strength not diminished
. Assoc. w/ Huntington’s
Athetosis
. Form of dyskinesia
. Slow writhing movements of neck, trunk, and extremities
. Worm-like
Choreoathetosis
. Combo of chorea and athetosis
Ballism
. Lesion of subthalmic nucleus
. Symptoms seen contralat. To Lesion
