Intrathecal
BACLOFEN THERAPY
by A. Leland Albright,
M.D.
Intrathecal
baclofen therapy (ITB)
was released by the Food and Drug Administration
(FDA) in June
1996 for the treatment of spasticity in cerebral palsy and
traumatic brain injury. ITB has been approved previously for the
treatment of spasticity in multiple sclerosis and spinal cord
injury.
The drug, baclofen,
is given continuously directly into the spinal fluid via a small
pump implanted under the skin of the abdomen. Dosage can be
precisely controlled by adjusting the pump of a computer. The
amount of medication used is approximately 1/100th of the
typical oral baclofen dos.
Before a pump is
inserted, trails of different doses of baclofen are injected
into the spinal fluid over one to three days to see if the
individual response. Approximately 90 percent of individuals
respond favorably to these trail doses, which relax only the
legs for six to eight hours. A trail is useful in determining if
ITB reduces spasticity. However, it cannot predict the long term
outcome because a test does not show how an individual will
function during continuous treatment.
Inserting the ITB pump
A child can be
considered for ITB at age three. The hockey-puck size pump might
be too large for the abdomen of a younger child. The pump is
inserted under general anesthesia. While the operation itself
usually takes an hour, the entire process takes about two hours,
including the time required for waking up.
Hospital stays vary
from four to seven days, averaging five or six days. Once the
pump is inserted, the child must lie flat in the hospital bed
for three days to decrease the chance of spinal fluid leakage.
Afterwards, the child can get out of bed, begin to sit in a
chair and then stand.
Recovery and therapy
Soreness in the
abdomen and back might require pain medication fro two to three
days after surgery. By the time of discharge, many children
require no pain medication and those who still do may need only
acetaminophen for discomfort. The pump creates a small bulge in
the abdomen, but most children seem to be able to ignore it
after a few weeks.
Doctors adjust the
baclofen dose carefully after surgery until spasticity improves.
Physical and occupational therapy also begins at this time;
however, therapists need to be very cautious: Transfers and save
mobility are the main goals. Modest improvements in movement
abilities may be apparent before a child goes home. Gains in
complex activities like writing, eating or using a computer are
likely to take six months or more.
Outcome
With ITB and
regular physical therapy, spasticity in the muscles of the arms
and legs improves and, for many children, day to today functions
such as swallowing, speech, use of communication devices and
activities of daily living (ADLs)
improve. Although spasticity
decreases in nearly all children, not all children gain
function.
The advantages of ITB
include the ability to precisely adjust the dose and the fact
that the treatment in reversible. The disadvantages include the
need to refill the pump every few months, to replace it every
four to five years, and a higher risk of infection or mechanical
complication than with rhizotomies. A potential also exists for
an overdose causing breathing problems or temporary
unconsciousness.
ITB allows positive
changes in the day to day abilities, quality of live and self
image of many individuals. However, no medication, including
baclofen, is effective in every individual.
Follow-up care and pump refills
Children are
evaluated at six-month intervals in most clinics, and must
return for pump refills as often as their dosing schedule
requires. The baclofen pump is programmed according to the
child's daily dosage and beeps softly a few days before the
medication runs out so that parents know the pump needs to be
refilled.
During a 15 minute
refill visit, the skin around the pump is cleaned, a needle is
placed into the pump and medication is injected into it. Very
few children have problems with this procedure. Sedation is
rarely necessary. During such visits, team members also check on
the child's muscle tightness and consult with parents.
Based on parent
feedback and clinical observations, the baclofen dose or the
dose schedule may be changed slightly.
In most cases, the
dose is increased slowly over the first year and then remains
relatively stable.
Costs
The total cost of the
implant procedure, includes the cost of the pump, the catheter,
surgery and hospitalization can range from $20,000 to $25,000.
Refilling a pump costs about $500. A new pump and catheter cost
$7,500 to $8,000. A pump lasts about four to five years before
it needs replacing. Thus far, most health insurance companies
have covered these expenses.
Possible risks
Potential risks of
ITB include those involving the implanting of the pump. In five
percent of the procedures, infections required temporary pump
removal.
Side effects from the drug baclofen itself are usually temporary
and manageable by adjusting the dose. The most common side
effects include loose muscles, drowsiness, nausea, headache and
dizziness. Overdose, though rare, could lead to breathing
problems, loss of consciousness, reversible coma and in extreme
cases, could be life threatening. The very few times things like
this have taken place however, the children got better and were
able to return to using ITB Therapy.
Not for everyone
ITB does not help
individuals with low muscle tone
(often described as hypotonia or floppy muscles),
chorea (uncontrollable, jerky typed
of movements of toes and fingers)
or athetosis
(involuntary movements of face, arms, trunk).
Baclofen's effects
on dystonia
(slow, twisting, repetitive movements of
the arm, leg or trunk) are
currently being studied.
credit for this article goes to A. Leland Albright, M.D.and
Exceptional Parent Magazine
