By Ellen I. Leonard, M.D.
Spastic hypertonia, otherwise known as spasticity, is
typically easier to recognize than it is to characterize – and
it is even more difficult to treat successfully. Yet, it is treatable
and successful treatment will prevent other difficulties that it can
cause.
Disorders of the central nervous system create spasticity, which is
defined as velocity-dependent increased muscle tone. These disorders
are numerous and may include traumatic brain injury, stroke, spinal
cord injury, multiple sclerosis, cerebral palsy and amyotropic lateral
sclerosis (ALS). In treating spasticity, the physician should consider:
- Is the spasticity causing functional impairment? Spasticity
can cause difficulty in the patient’s ability to complete
activities of daily living (ADLs).
- Are the spasms causing pain?
- Will skeletal abnormalities be caused by untreated spasticity?
Spasticity can cause contractures, hip dislocations, gait changes
and growth
abnormalities.
- How much will the absence of spasticity affect a patient’s
ability to ambulate? A decrease in spasticity may reveal
underlying muscle
weakness or may improve gait.
- Will a decrease in spasticity make it easier to care for a patient?
In a number of cases, spasticity interferes with positioning
and hygiene.
Physicians treating spasticity have a variety of methods to consider
including, from least- to most-invasive:
- Modalities: icing and stretching;
- Pharmaceuticals: diazepam, baclofen, dantrolene sodium, clonidine and
tizanidine;
- Selective nerve blocks: phenol and botulinum toxin; and
- Surgical: Intrathecal baclofen pump placement and selective dorsal
rhizotomy.
Less than 20 years ago one of the standards of care for spasticity
was regular icing and stretching. In fact, daily therapy for many spinal
cord patients began in this manner. Although the recent development
of pharmacological treatments has outmoded this type of treatment,
it is still useful for patients with hypersensitivity to drugs, for
patients on drug holidays and for patients with temporary tonal exacerbations.
Another traditional treatment for spasticity was the prescription
of diazepam. However, patients gradually required higher doses due
to developed tolerances, necessitating concern for potential dependence.
Diazepam and baclofen are both effective treatments for spinal cord
patients but, due to their sedating effects, are not recommended for
brain injured patients.
Dantrolene sodium works at the muscle level and apparently has lesser
sedating effects. Thus, it is seen as an effective treatment for cerebral
forms of spasticity. Clonidine, also known as catapress, was developed
as a medication for hypertension and was found to be useful in the
treatment of spasticity. Tizanidine is in the same chemical family
but was developed specifically for the treatment of spasticity.
Selective nerve blocks, whether chemical neurolysis with phenol or
neuro-muscular blockade with botulinum toxin, are an effective manner
of treating spasticity that occurs in a few, selected muscles. Botulinum
toxin has simplified the application of neuro-muscular blockade due
to its natural properties that require much less precision than earlier
phenol treatments. These techniques are most effective in cases where
a temporary treatment of spasticity is desired, such as in brain injury
cases where an improvement in function is expected.
The efficacy of baclofen is greatly increased when applied intrathecally
because the drug does not have to cross the blood-brain barrier. Doses
of baclofen may be changed electronically and the drug is administered
daily in micrograms. Pediatric pumps hold 10 milliliters and adult
pumps hold 20 milliliters, and each is about three inches in diameter.
The surgical implantation of baclofen pumps is a recent phenomenon
for which great hope is held but there are possible complications,
including infection, catheter leak and pump malfunction.
Selective dorsal rhizotomy is probably the most invasive procedure
for controlling spasticity, but if patients are selected appropriately
it can be most effective as a permanently tone-altering treatment.
It is particularly useful for pediatric patients with spastic diplegia.
It is rarely performed on patients older than 16 years of age. An extensive
period of physical therapy is necessary following dorsal rhizotomy
in order to strengthen the muscles now unaffected by spasticity.
Determination of the appropriate treatment for spasticity must be
individualized to each patient. It is helpful to have the patients
evaluated by a multidisciplined team of physicians, including orthopaedic
surgeons, neurosurgeons, neurologists and physiatrists. Each specialty
brings a unique diagnostic and therapeutic expertise to produce an
all-encompassing treatment plan for each patient.
About the author: Ellen I. Leonard, M.D.,
a partner in South Texas PM&R, is board-certified in Physical
Medicine and Rehabilitation and is the only fellowship-trained pediatric
PM&R physician in San Antonio. She is a team member of Methodist
Children’s Hospital’s Spasticity Clinic.
