Studies have shown that both lesioning and DBS can dramatically improve dystonia. Both approaches are associated with a small, but real, risk of complications. There has not been a clinical study to compare the results of lesioning procedures and DBS, and the advantages and disadvantages of each remain an open issue.
Lesioning procedures and DBS have many elements in common including:
• Patient selection criteria
• Area of brain targeted
• Basic surgical procedure
• Potential for profound benefit to eligible patients
• Risk of complications including hemorrhage during surgery, hemiplegia or hemiparesis, sensory impairments, speech/language impairment
In both cases, the surgery is lengthy. While every effort is made to help make the patient comfortable, both procedures require the individual to remain awake and responsive for hours at a time while in positioned in a head frame. The chance of benefit must be weighed against the risk of complications. No two cases of dystonia are alike, and determining the specific approach to treatment—in this case lesioning or DBS—must be decided after careful discussions among the patient, family members, the neurologist, and neurosurgeon.
Of the dystonia patients who are eligible for brain surgery, more individuals are currently being recommended for DBS than pallidotomy. The pallidotomy, however, is not an obsolete procedure. Unless a patient is against having hardware installed in his/her body, the tendency is to try DBS before proceeding to the pallidotomy because DBS is adjustable and reversible.
Financial and geographical issues cannot be overlooked. Persons who have DBS must visit the doctor regularly for maintenance check-ups. People who live in remote areas or areas not in proximity to a major movement disorder center may be at a disadvantage. Travel to and from the center—and the expense of this travel—is a part of the ongoing management required of DBS patients.
Because lesioning creates a permanent change in the brain tissue, there is a slightly higher risk of permanent complications during the surgery such as swallowing difficulty, speech difficulty, and cerebral hemorrhage. Because DBS involves the implantation of hardware, complications associated with the apparatus are possible, including infection, erosion through the skin, hardware breakage, and stimulator failure. The risk of hardware complications exists for as long as the hardware is implanted.
It remains to be seen whether the pallidotomy or DBS is more effective than the other. The experience of the surgeon and medical team are the most important determinants of success and risk. The lowest incidence of complications occurs in major medical centers that perform these procedures often. Patients should choose a center with a long-standing expertise in movement disorders and a clinical team devoted to surgery for dystonia and movement disorders. A movement disorder neurologist and a surgeon should be specially trained in functional surgery, and an electrophysiologist should be on staff for brain mapping. An experienced nursing staff is also important.