|
(Continued from page 44)
bromocriptine, carbidopa, clozapine, domperidone, entacapone, levadopa, olanzapine, pergolide, pramipexole, ropinerole, selegilineand tolcapone.
Essential tremor responds to propanolol, metoprolol, primidone, methazolamide and amantadine.
Dystonia is helped with anticholinergics, baclofen, clonazepam, diazepam, lorazepam, carbamazepine, reserpine, tetrabenazine, haloperidol, botulinum toxin A and levadopa.
Spasticity medications include baclofen.
SURGICAL TREATMENT
For tremor predominant PD, isolated dyskinesia e.g. from anti-psychotics and most importantly, essential tremor, the surgical treatment is a thalamic deep brain stimulator (DBS). PD with dyskinesia, bradykinesia, postural instability and excessive "off" time, as well as other patients who have dystonia, chorea or hemiballismus, respond best to pallidal deep brain stimulation or in very rare instances pallidotomy (ablation). The tolerance to L-Dopa is increased with pallidal stimulation or ablation. If pallidal stimulation is too close to the ansa reticularis and the superficial electrodes cannot be used, pallidal stimulation may worsen akinesia, and therefore is best treated with subthalamic stimulation. If PD patients also have akinesia and tremor in addition to bradykinesia and instability, they respond best to sub-thalamic deep brain stimulation. This site does not treat dyskinesia as well, nor can a patient tolerate increased levels of medicine post-operative. Stimulation anywhere does not stop PD, however, recent evidence has shown that sub-thalamic DBS may slow the progression of PD. Another movement disorder, spasticity, can be improved with a permanent lumbar intrathecal baclofen pump. This can be performed in both children and adults. The reservoir is implanted in the subcutaneous abdomen. It is best to implant in children before 6 years old. Spasticity affects 1-2 individuals per 1000 live births or approximately 7000-8000 new cases per year. There are roughly 500,000 Americans with spasticity. In addition to the baclofen pump, severe spasticity has been treated since the 1980s with a selective dorsal root rhizotomy and physical therapy. Once again, because of the plasticity of the child's nervous system, the best results can be obtained if used early on, especially by 6 years of age.
PROCEDURE
Surgery should be treated as all procedures, after medications fail. Usually the procedure is done with an overnight stay. The patient's medications are held the night before so that their symptoms will be present in the OR. Usually a MRI is done days prior. When the patient comes in the morning, a stereotactic frame is applied, a CT scan is obtained and the images as well as the MRI data are placed into the image guided functional navigational system to generate a 3D virtual model. The coordinates of the proposed target are obtain off the CT scanner and verified on the functional navigation software. Then the patients own virtual brain is stretch to conform to a standard cadaver virtual brain that has different areas already identified giving yet a third confirmation of target site. Next the patient is brought to the operating room, awake. Hair is shaved on the opposite side of the movement disorder, local anesthetic injected, incision made and a Burr hole fashioned. The (Continued on page 46)
|
|
