Anterior temporal

lobectomy Lobectomy means ''surgical excision of a lobe''. This may refer to a lobe of the lung (also simply called a lobectomy), a lobe of the thyroid ( hemithyroidectomy), a lobe of the brain (as in anterior temporal lobectomy), or a lobe of the liver ...

is the complete or partial removal of the anterior portion of the

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pro ...

of the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...

. The exact boundaries for removal can vary slightly in practice and between neurosurgeons. It is a treatment option for

temporal lobe epilepsy Temporal lobe epilepsy (TLE) is a chronic disorder of the nervous system which is characterized by recurrent, unprovoked focal seizures that originate in the temporal lobe of the brain and last about one or two minutes. TLE is the most common ...

for those in whom anticonvulsant medications do not control

epileptic seizures An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

, and who have frequent seizures, and who additionally qualify based on a

WADA test The Wada test, also known as the intracarotid sodium amobarbital procedure (ISAP), establishes cerebral language and memory representation of each hemisphere. Method Medical professionals conduct the test with the patient awake. Essentially, th ...

to localize the dominant hemisphere for

language module The language module or language faculty is a hypothetical structure in the human brain which is thought to contain innate capacities for language, originally posited by Noam Chomsky. There is ongoing research into brain modularity in the fields o ...

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Techniques

The techniques for removing temporal lobe tissue vary from resection of large amounts of tissue, including lateral temporal cortex along with medial structures, from using more restricted anterior temporal lobectomy (ATL) to more restricted removal of only the medial structures (selective

amygdalohippocampectomy Amygdalohippocampectomy is a surgical procedure for the treatment of epilepsy. It consists of the removal of the hippocampus, which has a role in memory, spatial awareness, and navigation, and the amygdalae, which have a role in the processing and ...

). Nearly all reports of seizure outcome following these procedures indicate that the best outcome group includes patients with MRI evidence of

mesial temporal sclerosis Hippocampal sclerosis (HS) or mesial temporal sclerosis (MTS) is a neuropathological condition with severe neuronal cell loss and gliosis in the hippocampus, specifically in the CA-1 (Cornu Ammonis area 1) and subiculum of the hippocampus. It wa ...

(hippocampal atrophy with increased T-2 signal). The range of seizure-free outcomes for these patients is reported to be between 80% and 90%, which is typically reported as a sub-set of data within a larger surgical series.

Risks/Complications

Open surgical procedures such as ATL have inherent risks including damage to the brain (either directly or indirectly by injury to important blood vessels), bleeding (which can require re-operation), blood loss (which can require transfusion), and infection. Furthermore, open procedures require several days of care in the hospital including at least one night in an

intensive care unit 220px, Intensive care unit An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensi ...

. Although such treatment can be costly, multiple studies have demonstrated that ATL in patients who have failed at least two anticonvulsant drug trials (thereby meeting the criteria for medically intractable temporal lobe epilepsy) has lower mortality, lower morbidity and lower long-term cost in comparison with continued medical therapy without surgical intervention. The strongest evidence supporting ATL over continued medical therapy for medically refractory temporal lobe epilepsy is a prospective, randomized trial of ATL compared to best medical therapy (anticonvulsants), which convincingly demonstrated that the seizure-free rate after surgery was ~ 60% as compared to only 8% for the medicine only group. Furthermore, there was no mortality in the surgery group, while there was seizure-related mortality in the medical therapy group. Therefore, ATL is considered the standard of care for patients with medically intractable

mesial temporal lobe epilepsy Temporal lobe epilepsy (TLE) is a chronic disorder of the nervous system which is characterized by recurrent, unprovoked focal seizures that originate in the temporal lobe of the brain and last about one or two minutes. TLE is the most common ...

Recovery

Recovery after ATL can take several weeks to months. Anti-seizure medications will be continued for several months after ATL. As it is an

open surgery Minimally invasive procedures (also known as minimally invasive surgeries) encompass surgical techniques that limit the size of incisions needed, thereby reducing wound healing time, associated pain, and risk of infection. Surgery by definiti ...

it takes time for the brain to heal. Speech therapy, occupational therapy, etc can help you recover. About 90% of people experience an improvement in seizures after temporal lobectomy. In mesial temporal lobe epilepsy, NAA( N-Acetyl Aspartate) has reduced concentration in epileptogenic

hippocampus The hippocampus (via Latin from Greek , ' seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, ...

and contralateral hippocampus. In post-operative seizure free patients, NAA levels were significantly higher than post-operative non-seizure free patients and then returned to the normal level.

History

Anterior temporal lobectomy (ATL) was popularised in the early 1980s and was found effective.

References

External links

Surgery Encyclopedia: Anterior temporal lobectomy
{{Central nervous system tests and procedures Epilepsy Neurosurgical procedures Surgical removal procedures