Basal Ganglia & Cerebellum Flashcards
Spasms
– sudden involuntary contractions
Cramps
– severe spasms
Fasciculations
– quick twitches of muscle fibers of a single motor unit – visible
Myoclonus
– brief involuntary contractions of muscle or group of muscles
Akinesia (Dyskinesia)
- Hyper and Hypo
- Impairment of voluntary movement
- Most abnormal movements occur in extrapyramidal system
- Basal ganglia
- All tracts outside of pyramidal tracts
- Pyramidal tracts are those connecting with pyramidal cells of motor cortex for voluntary movement
Hypokinesia
- Poverty of movement
- Mostly related to Parkinson’s disorders (3)
- Festinating gait – Marked by very small rapid steps and occurs in persons with Parkinson’s disease when the posture of the head and trunk involuntarily lean forward ahead of the feet, moving the center of gravity forward. Rather than taking a large step to correct the imbalance, several hurried small steps increasing gait velocity occurs, resulting in running or “chasing” one’s center of gravity, which remains in front of the feet.
- Bradykinesia – Slowness or poverty of body movement
Hyperkinesia
- Rhythmic or nonrhythmic excessive movement
- Rhythmic: regular alternating or oscillatory
- At rest (resting tremor)
- During attempted movement (intention tremor)
Tardive Dyskinesia
– (side effect of neuroleptic drugs)
-involuntary movement disorder most often characterized by puckering of the lips and tongue and/or writhing of the arms and legs.
Tics
– nonrhythmic, rapid, suppressible movements that are simple or complex, idiosyncratic, repetitive, and done almost unconsciously.
- They can be suppressed only for brief periods and with conscious effort.
Tourettes Syndrome
– hereditary tic disorder that begins in childhood.
-Symptoms include simple, complex, and vocal tics.
Fibrillations
– brief contractions of single muscle fibers (not visible)
Chorea
– nonrhythjmic, jerky, rapid, nonsuppressible movement that involves mostly distal muscles or the face
- movements may merge imperceptibly into purposeful or semipurposeful acts that mask the involuntary movement.
- Caused by dopaminergic overactivity in the basal ganglia.
Huntington’s chorea
– Degenerative disease of the basal ganglia in the brain.
- characterized by abnormalities in postural reactions, trunk rotation, distribution of tone, and extraneous movements.
Athetosis
– nonrhythmic, slow writhing, sinuous movements, predominantly in distal muscle
- alternating postures of the proximal limbs often blend continuously to produce a flowing stream of movement.
- Athetosis often occurs with chorea as choreoathetosis.
- Caused by dopaminergic overactivity in the basal ganglia.
Hemiballismus
– (ballistic movement) nonrhythmic, rapid, nonsuppressible movement characterized usually by unilateral, violent, flinging movements of the proximal arm.
-Caused by a lesion, usually an infarct, around the contralateral subthalamic nucleus.
Dystonias
– sustained involuntary muscle contractions, often distorting body posture.
- Distorted positioning of limbs, neck, or trunk held for few seconds, then released.
-Generalized dystonia – rare, progressive and characterized by movements that result in sustained, often bizarre postures. Often hereditary.