Multiple subpial transection was pioneered as an alternative to removal of brain tissue. It is used to control partial seizures originating in areas that cannot be safely removed.
For example, if the seizure focus involves the dominant temporal-lobe language area (Wernicke’s area), which is critical for comprehension, the removal of this area to control seizures would cause a devastating complication: the inability to understand spoken or written language.
Similarly, if the primary motor area is part of the seizure focus, its removal would cause permanent weakness on the opposite side of the body.
The operation involves a series of shallow cuts (transections) into the cerebral cortex.
The transections are made only as deep as the gray matter, approximately a quarter of an inch deep.
Because of the complex way in which the brain is organized, these cuts are thought to interrupt some fibers that connect neighboring parts of the brain, but they do not appear to cause long-lasting impairment in the critical functions served by these areas.
Examination of brain tissue after multiple subpial transections reveals that some nerve cells are destroyed.
Multiple Subpial Transection is a surgical approach for patients with well-localized epileptogenic areas which are unresectable due to their functional importance.
This procedure aims to sever horizontal intracortical fibers that are presumed responsible for spreading seizure activity while preserving the other fibers that control neurologic function.
What are the risks involved ?
There may be bleeding at the site of the transection, but the procedure is generally well tolerated. Major complications appear to be rare.
Transections in language areas may cause mild impairments in the language function served by that area. The risks and benefits of multiple subpial transections need to be better defined.
What to expect
The morning of the procedure you will arrive from home.
You will be taken to the operating room where you will have anesthesia, then the Neurosurgeon will perform the procedure.
Once the surgery is completed (approximately 4-6 hours) you will go to the neurological Intensive Care Unit. Pediatric patients will be taken to the Pediatric Intensive Care Unit. You will spend the first night in the intensive care unit.
The next morning you will be taken to the Neurological Medical Unit.
You will have a dressing on your head.
You will be discharged to home a few days after the operation.
What is the success rate ?
Multiple subpial transections can help reduce or eliminate seizures arising from vital functional cortical areas.
Transections have been used successfully in Landau-Kleffner syndrome, a disorder in which language problems appear in a child whose language was previously developing normally.
One concern is that the epileptic activity may recur after a period of 2 to 20 months. It is uncertain whether this procedure can achieve long-term seizure control.4
When are multiple subpial transections (MSTs) offered?
When the zone of seizure onset can be localized to one region of the brain, removal (resection) of the area of seizure onset is the preferred intervention.
However, in some cases the zone of seizure onset is also an area of important brain function. In these cases, a newer technique called multiple subpial transections (MSTs) may be offered.
In this operation, the neurosurgeon makes multiple, small incisions in the surface of the brain where the seizures arise. Most seizure activity spreads laterally across the brain, like a ripple on a pond.
Thus, the multiple tiny incisions in the brain can inhibit seizure spread while preserving normal brain function.