By: Andrew Yee

Photo Credit: https://www.stlouischildrens.org/conditions-treatments/epilepsy-center/epilepsy-surgery/lesionectomy

What is a Lesionectomy?

As medical technology advances, those with drug-resistant epilepsy now have a cure through surgical procedures. Structural abnormalities, also known as lesions, can be surgically removed to provide patients with seizure relief. A Lesionectomy eliminates any irregularities that may be causing seizure activity (Lesionectomy, The Brain Recovery Project, 2019).

What are Lesions?

A lesion is a damaged or abnormally functioning area of the brain caused by past injuries, infections, or wounds.

Lesions can include:

  • Brain tumors
  • Abnormal blood vessels
  • Scars from head injuries or infections
  • Swelling of blood vessels (hematomas)

Lesions can come as part of two subcategories, congenital and acquired lesions (Lesionectomy, The Brain Recovery Project, 2019).

Congenital: lesions that are brain malformations that developed before or during birth and are present throughout one’s life.

Congenital lesions include:

  • Cortical Dysplasia: abnormal brain folding during development or failed cellular migration during fetal brain development (Lesionectomy, The Brain Recovery Project, 2019).
  • Vascular Malformations: abnormal blood vessel development (angiomas, cavernous malformations, and arteriovenous malformations (AVMs).

Acquired: Acquired lesions are brain malformations that develop after birth.

Acquired lesions include:

  • Brain tumors (ganglioglioma, DNET, astrocytomas)
  • Strokes/brain infections (Epilepsy)
  • Brain injuries/conditions (Hydrocephalus, encephalitis, severe concussions)

         (Mayo Clinic, 2018)


Pre-surgical evaluations will take place to make sure you qualify for a Lesionectomy. These tests may include seizure monitoring, functional and high-resolution MRI scans, positron emission tomography (PET) scans, magnetoencephalography (MEG) tests, Wada tests, SPECT, or electroencephalogram (EEG) monitoring. During these tests, the doctor will pinpoint the lesion and ensure they can surgically remove it without harming other tissues (Lesionectomy for epilepsy).

Upon arrival at the hospital, someone will take your vitals and blood for testing. Your doctor will provide you with specific guidelines on what to eat, if anything, before surgery. Someone may also shave a portion of the head to access the brain during surgery (Lesionectomy for epilepsy).

During Surgery

A Lesionectomy depends on the patient, the lesion, and the lesion location. While surgical plans may differ, surgery generally proceeds as follows:

  • The patient arrives at the hospital on the morning of the surgery.
  • General anesthesia is applied along with an intravenous (IV).
  • The neurosurgeon makes a window through the skull.
  • Thin probes guided by MRI access the brain.
  • An endoscope and laser burn/remove the lesion.
  • The bone window is replaced and secured; the incision is closed.
  • The patient spends the night at the intensive care unit and then 3 to 6 days at the hospital.
  • Sometimes a postoperative MRI is obtained, and follow-up visits will occur 1-2 weeks after discharge and then at 6-month intervals after that.

(Lesionectomy, St. Louis Children’s Hospital)

Success Rate

When surgery is successful, a person may become seizure-free. However, depending on the type of lesion and location, the success rate will vary. For non-mesial temporal sclerosis lesions, the general rate of being seizure-free after a year was 63.2 percent, 50 percent for focal epilepsy, and 66 percent for mesial temporal lobe epilepsy (Villines, 2021). The rates for children are much better. An astounding 81 percent of children with a lesion on an MRI become seizure-free (Lesionectomy, The Brain Recovery Project, 2019).


Since a Lesionectomy only involves removing a lesion, a Lesionectomy comes with a lower risk than many other brain surgeries. However, the stakes will vary by lesion type, location, and size. Some lesions also possess the ability to grow back, meaning a second Lesionectomy may be required.

After the surgery, a Lesionectomy may result in blood clotting, brain swelling, damage to healthy brain tissue, blood loss, infection, or reactions to medication. The patient will most likely require pain medication for several weeks. Side effects from surgery may include fatigue, depression, headaches, numbness in your scalp, nausea, and trouble with memory or speaking (Lesionectomy for epilepsy).


In general, a Lesionectomy is a surgical procedure that can significantly reduce the occurrence of drug-resistant seizures. The surgery is less invasive than others since it only removes lesions from the brain. Like most surgeries, risks come with the procedure. You should consult your doctor to determine if a Lesionectomy is best for you.


Mayo Foundation for Medical Education and Research (2018). Brain lesion causes. Mayo Clinic. Retrieved March 25, 2023 from: https://www.mayoclinic.org/symptoms/brain-lesions/basics/causes/sym-200500692

MyEpilepsyTeam (n.d.). Lesionectomy for epilepsy. MyEpilepsyTeam. Retrieved March 26, 2023 from: https://www.myepilepsyteam.com/treatments/lesionectomy

St. Louis Children’s Hospital (n.d.). Lesionectomy. St. Louis Children’s Hospital. Retrieved March 24, 2023 from: https://www.stlouischildrens.org/conditions-treatment/epilepsy-center/epilepsy-surgery/lesionectomy

The Brain Recovery Project (2019). Lesionectomy. The Brain Recovery Project. Retrieved March 25, 2023 from: https://www.brainrecoveryproject.org/brain-surgeries-to-stop-seizures/lesionectomy/

Villines, Z. (2021). Epilepsy surgery: Types, success rates, recovery, and cost. Medical News Today. Retrieved March 27, 2023 from: https://www.medicalnewstoday.com/articles/epilepsy-surgery#types-of-surgery

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