Spasticity
Objective Measures of Spasticity
Objective testing includes both electrophysiologic studies and biometric testing. EMG, with simultaneous measure of agonist and antagonist muscles, can be used alone or in combination with gait analysis. The most widely employed electrophysiologic testing, multichannel EMG, provides quantification of the H/M ratio, F waves, the tonic vibration reflex, the flexor withdrawal response, and lumbosacral spinal evoked potentials.
Treatment
Left untreated, spasticity can lead to contracture. However, not all spasticity requires treatment. Indeed, in some cases, the inappropriate treatment of spasticity may lead to loss of function, particularly when spasticity is counterbalancing the effects of paresis.
Contracture is a fixed shortening of the muscle, tendons, or ligaments—or a combination thereof—that prevents normal movement of the associated joint or limb. Untreated contracture can result in permanent deformity.
Another important consideration before commencing treatment is to determine which muscles are involved in spasticity. Spasticity may need to be treated when it causes
- Pain
- Difficulty performing activities of daily living
- Impaired mobility, whether related to ambulation or transfers
- Poor joint positioning
- An increased risk for the development of contracture
- Skin breakdown
Outlining the Treatment Goals
The primary aim of treatment is to improve quality of life for people with spasticity and for their caregivers.
The treatment of spasticity is usually initiated with the most conservative treatments that have the fewest risks. Therapy directed at reducing or eliminating spasticity almost universally involves a multimodal approach.28
A variety of factors may lead to or increase the severity of spasticity. These issues should be ruled out as underlying causes or exacerbating factors and should be effectively treated, if necessary, before attempting to treat the spasticity. Examples of commonly occurring causes of a new onset of spasticity or a worsening of existing spasticity include
- Urinary tract infections or retention
- Other sources of infection
- Pressure sores
- Extremes of heat or cold
- Fatigue
- Renal calculi
- Ill-fitting orthotics
- Constipation or bowel obstruction
Treatment should be based on assessment by the relevant health professionals.
For spastic muscles with mild-to-moderate impairment, exercise should be the mainstay of management, and is likely to need to be prescribed by a physical therapist or other health professional skilled in neurological rehabilitation.
Muscles with severe spasticity are likely to be more limited in their ability to exercise, and may require help to do this. They may require additional interventions, to manage the greater neurological impairment and also the greater secondary complications. These interventions may include serial casting, flexibility exercise such as sustained positioning programs, and medical interventions..
Interventions
Medications as baclofen, diazepam, dantrolene, or clonazepam.
Local anaesthetic block or Phenol injections can be used, or botulinum toxin injections into the muscle belly, to attempt to dampen the signals between nerve and muscle.
The effectiveness of medications vary between individuals, and vary based on location of the upper motor neuron lesion (in the brain or the spinal cord).Some studies have shown that medications have been effective in decreasing spasticity, but that this has not been accompanied by functional benefits
In spastic CP, selective dorsal rhizotomy has also been used to decrease muscle overactivity.
Surgery could be required for a tendon release in the case of a severe muscle imbalance leading to contracture.