Deep brain stimulation
( DBS )
It is a treatment for symptoms of Parkinson's disease ( and others ) including tremors, stiffness, and trouble walking. It can also treat side effects of Parkinson's medicines. DBS isn't a cure for Parkinson's and won't stop it from getting worse. But it may be an option if the patient had the disease at least 5 years and don't get enough relief from medicine.
DBS technology involves placement of a quadripolar (four contacts) lead into a specific and pre-determined brain target . Selective placement of the DBS leads within different anatomical regions and somatotopies may affect the neuronal network and, in the best possible cases, lead to improvement in clinical symptoms. The lead is usually connected to a neurostimulator placed subcutaneously under the clavicle, although the battery can be placed in a multitude of regions. The neurostimulator can then be programmed or adjusted in order to tailor a setting to an individual patient. There are thousands of different combinations that may be chosen. The voltage, frequency, and pulse width may all be changed. The optimal settings are patient and symptom specific, and generally require that patients be reprogrammed frequently for the first 4–6 months. Additionally, medications as well as stimulation settings must be monitored .
Each disorder or symptom considered for treatment with DBS should be carefully evaluated. Only a fraction of the patients with a given neurological or neuropsychiatric disorder may be eligible for this type of therapy. Most patients receiving DBS should be medication resistant and should undergo a complete screening by a neurologist, psychiatrist, neuropsychologist, and neurosurgeon. Following screening there should be a detailed interdisciplinary discussion about the goals of therapy including symptoms targeted, symptoms that will likely respond, symptoms that are not likely to respond, and an individual patient’s expectations.
In cases of Parkinson Disease (PD), patients should undergo an “off/on” levodopa medication challenge to determine which symptoms respond best to medication.
The symptoms that respond best to medication usually are those that respond best to stimulation (with the exceptions of tremor and dyskinesia).
One recent review of DBS hardware-related complications cited lead migration, lead fracture, lead erosion/ infection, and lead malfunctions as not uncommon occurrences .
Surgically related and stimulation-related complications can occur and may include but are not limited to hemorrhage, infections, strokes, seizures, paresthesias, dysarthria, hypophonia, dystonia, mood worsening, suicide, apathy, and worsening of co-morbidities. Difficulty with verbal fluency and anger seem to be common sequelae in PD patients .
Note : Animal models of DBS have revealed increased extracellular concentrations of glutamate, GABA, adenosine, and dopamine .
رد مع اقتباس
