Surgical removal of the eyelid and brow-squeezing muscles is referred to as a myectomy procedure and is used to treat blepharospasm. Myectomy prevents the muscles surrounding the eyes from being stimulated by removing the muscle.
Before the availability of botulinum toxin, myectomy was essentially the only treatment option for blepharospasm. The introduction of botulinum toxin injections in 1989 benefited many persons with blepharospasm thereby changing the population of individuals eligible for myectomy. Candidates for myectomy became those for whom botulinum toxin is not sufficient.
Just as the patient selection changed, the procedure itself evolved. Initially, the procedure involved removing all eyelid-squeezing muscles in both upper and lower lids as well as the brow area at one time. At the present time, the procedure is tailored to the needs of the patients. It is most common for the surgeon to remove the muscle in the upper eyelids and brow (full upper myectomy) and then re-evaluate the need for a lower myectomy at a later date. Patients heal faster when the procedure is done in stages, and some individuals do not require the lower myectomy.
The full upper myectomy may be done entirely through an eyebrow incision. The incision lies immediately adjacent to the brow hair and allows access to the upper lid orbicularis muscle, and part of the lower lid orbicularis muscle as well as the procerus and corrugator muscles in the brow area. Most of the orbicularis muscle is removed during the eyelid surgery. A strip of dense muscle is left at the margin of the upper eyelid to help maintain some voluntary closure and to protect the eyelash roots.
A limited upper myectomy is a partial upper myectomy. It is available for those individuals who are benefiting from botulinum toxin but need something extra to restore function of the eyes. It may be helpful for those patients who have apraxia (difficulty opening the eyes) or for those who in addition to blepharospasm have ptosis (drooping lids). Partial removal of the orbicularis may subsequently decrease the need for botulinum toxin in these patients. A limited myectomy is done through an upper eyelid crease incision and involves removal of the orbicularis muscle within the upper lid area only. Because there is less tissue removal than the full upper myectomy, patients recover in less time. A limited myectomy also gives more predictable cosmetic improvement because less tissue is removed. It is not designed to replace a full upper myectomy. Most patients will still require botulinum toxin injections following the limited myectomy procedure.
Persons who have stopped responding to botulinum toxin as well as those rare individuals who fail to respond at all may be eligible for myectomy. Individual surgical centers have treated hundreds of blepharospasm patients with myectomy. Techniques used for cosmetic surgery, such as sculpting the fat beneath the brow and manipulating the placement of the brow, may be implemented to provide a beneficial aesthetic as well as functional result.
Myectomy surgery can be done under local or general anesthesia. The healing process following a myectomy may take up to a year. In most cases, the patients are able to keep their eyes open immediately following the operation. However, considerable swelling, hematomas (blood accumulation in lid), lymphedema (tissue fluid), and bruising may be present early in the post-operative period and prevent complete eyelid opening. Cool compresses in the first four to five days followed by warm compresses are very helpful at settling the lid swelling and bruising.
There are numerous potential side effects associated with myectomy surgery that are predictable and, to some degree, occur in most patients. Numbness of the forehead region often occurs and is usually temporary but may last a year or more. Loss of tissue volume in the eyelid area may occur with the muscle removal, but the improved brow, lid position, and decreased eyelid wrinkling generally gives an improved cosmetic appearance. Decreased eyelid closure occurs as a result of eyelid muscle removal and may require the need for additional artificial tears and lubricating ointment. As the eyelid swelling resolves, the eyelid closure improves and the dry eye symptoms generally improve. Chronic lid swelling which may last six months or longer in some patients can be a chronic and troublesome complication. Chronic lid selling is much less severe and persistent in the modern myectomy practices in which upper and lower lid myectomies are performed separately. Infection, hematoma, brow hair loss, and abnormal positioning of the lower lid can occasionally occur but are uncommon.
Patients continue to improve in function as well as in appearance for about six months to a year after myectomy surgery. Reports have shown that visual disability is improved in approximately 90% of patients. Some patients have more improvement than others. Touch-up procedures are required in some cases, and some individuals continue to require botulinum toxin injections.
Generalized Dystonia - Intrathecal Baclofen
Intrathecal Baclofen: The Baclofen Pump
Baclofen (Lioresol®) is a medication introduced in the late 1960s as a treatment for spasticity. The medication is also commonly used to treat select cases of dystonia. Baclofen in the spinal fluid around the brain and spinal cord supplements the body’s supply of a chemical neurotransmitter called GABA, which relaxes muscle movement. The drug may be given orally, but very high doses must often be used to ensure that the drug saturates the blood stream and reaches the spinal fluid. High doses of oral baclofen may cause intolerable side effects such as muscle weakness and fatigue. A surgically implanted baclofen pump delivers baclofen directly to the spinal fluid, and only very small doses are needed. (The term intrathecal means in the spinal fluid.)
Intrathecal baclofen therapy is a non-destructive, adjustable, and reversible treatment. Several hundred dystonia patients have been treated with intrathecal baclofen. It has been used for children and adults with generalized dystonia (both primary and secondary) and hemidystonia who respond to oral baclofen. Many persons treated with intrathecal baclofen have a combination of dystonia and cerebral palsy. Intrathecal baclofen may be used to treat dystonia affecting the upper and lower limbs.
In order to determine if an individual is eligible for intrathecal baclofen, he/she will undergo a screening test to observe the body’s response to baclofen. A response to the oral drug may necessitate a screening test to observe the body’s response to a small dose injected directly into the spinal fluid. The medication is injected using a standard lumbar puncture. The screening test procedure involves injection of the medication followed by several hours of observation. Relaxation of the muscles indicates that an implanted baclofen pump will likely be effective. The effects of the screening test are temporary and may last several hours after the injection. If a patient does not respond at all to the screening test, a second test using the same procedure may be tried the next day or at a later date.
Some physicians use a continuous intrathecal infusion of baclofen as a screening method, since more patients respond to continuous infusion than to single injection screening doses. In the infusion technique, a small catheter is inserted into the spinal fluid and is connected to an external pump that infuses baclofen in increasing doses over two to three days.
Starting intrathecal baclofen therapy involves surgically implanting a pacemaker-like device into the abdomen. The device is usually placed either to the right or left of the belly button, beneath the skin and fat of the abdomen. The pump is connected to a thin tube that is tunneled around the side of the body to the back. A small needle introduces the tube to the spinal canal. Once the surgical incisions are closed, the pump is adjusted by a remote computerized device to deliver the amount of medication appropriate for the individual. The procedure takes one to two hours, and hospital stay may range from four to seven days. Modest improvement of symptoms may be noticeable before the individual is discharged from the hospital, and it make take six months or more to achieve the full extent of benefit.
Regular maintenance is a key component of intrathecal baclofen therapy. Regular exams and physical therapy may be a component of postoperative care. Pumps must be refilled every one to four months in the physician’s office as a straightforward outpatient procedure. The pump is refilled by inserting a thin needle through the skin, into the pump. The frequency of refilling the pump depends on the dose required. If necessary, the doctor may adjust the delivery rate of the pump at the time of the refill by remote control. The pump battery needs to be replaced about every seven years.
Baclofen in the spinal fluid relaxes muscles throughout the body, and appears especially effective for targeting dystonia in both the upper and lower half of the body. Intrathecal baclofen may be more effective for treating secondary dystonia than for primary dystonia.
Studies have shown that intrathecal baclofen can dramatically improve symptoms and quality of life. Some centers have reported significant improvement in as much as 85% of patients. However, like any surgery, the procedure is not without risks. Hardware complications may also arise including infection and catheter breakage and disconnection. In a small percentage of cases, patients may lose effect within the first year of therapy or experience a worsening of symptoms. The most common side effects are constipation, decreased muscle control, and drowsiness.