#5 What are the different types of involuntary muscle contractions, & under what conditions do they occur? How do interventions such as botox, dorsal rhizotomy, & deep brain stimulation wk in treating abnormal muscle tone?
Name the 5 different types of Involuntary Muscle contractions
muscle spasms, cramps, fasciculations, myoclonus and fibrillation
What are Muscle spasms
sudden, involuntary contractions of muscle
What are Cramps
particularly severe & painful muscle spasms
Cramps are common
following prolonged exercise, particularly if sweating has led to sodium depletion.
What are Fasciculations
quick twitches of muscle fibers of a single motor unit that R visible on the surface of the skin
Fasciculations are responsible for
eyelid twitches that sometimes accompany anxiety
What are Myoclonus
brief, involuntary contractions of a muscle or group of muscles
If you experience hiccups & muscle jerks that some people experience when falling asleep it is a result of
What are Fibrillations
brief contractions of single muscle fibers NOT visible on surface of skin
Fibrillations abnormal movements are
- Abnormal movements are generated by
dysfunctional basal ganglia
Pathologic myoclonus occurs which disorders
epilepsy, brain or SC injury, stroke, & chemical or drug poisoning.
What is the Surgical procedure used to reduce hyperreflexia/spasticity (decreasing stretch reflexes)
Dorsal rhizotomy Involves sectioning (cutting) of some of the sensory nerve fibers that come from the
muscles & enter the spinal cord.
During a Dorsal rhizotomy the
Abnormal rootlets are selectively cut, leaving the normal rootlets intact.
By cutting the abnormal rootlets Dorsal rhizotomy goal is to
reduces messages from the muscle, resulting in a better balance of activities of nerve cells in the SC, & reduces spasticity.
Botox is used to treat
abnormal muscle tone
Botox is Injected directly into the muscles that
produce excessive force.
Botox injections allows clinician to specifically
target particular muscles without interfering w/ the contraction of other muscles.
Botox injections Inhibits release of
Ach at the neuromuscular junction, preventing active muscular contraction.
Botox Injections into calf muscles produces
significant improvement in gait velocity, self-ratings of pain & gait function, manual muscle tests, & ankle clonus post stroke.
Deep brain stimulation (DBS) in treating abnormal muscle tone
Effective adjunct to drug therapy
Deep brain stimulation (DBS)
Requires surgical implantation of a stimulator & electrodes
Deep brain stimulation (DBS) Example to treat tremors in Parkinson's
electrodes R implanted into thalamus
Deep brain stimulation (DBS) with a Parkinson's Pt would promote
Continuous high-frequency electrical stimulation which would inhibits the firing of overactive thalamic neurons.