Senior Director - Neurosurgery, Neuro Critical Care & Spine Surgery, Max Super Speciality Hospital, Noida
Part 4 of 10 in Diagnosis & Management of Epilepsy & Seizures
Resective Epilepsy Surgery: Temporal Lobectomy and Amygdalohippocampectomy for Mesial Temporal Sclerosis
September 4, 2026
Mesial temporal sclerosis is the single most common structural finding behind surgically treatable epilepsy, and Dr. Rattnani applies a specific, measurable threshold to diagnose it on MRI rather than a subjective read.
A measurable definition, not a subjective one
Classically, mesial temporal sclerosis is diagnosed when the temporal lobe volume differs by more than 10% between the right and left sides on MRI. That scarred, shrunken temporal lobe is the source of the seizures, and until the area itself is removed, seizures tend to recur frequently from it.
What the resection actually involves
The standard resection takes roughly 4 centimeters from the temporal pole. The critical part of the operation is maintaining the arachnoid plane throughout: the anterior choroidal artery and the third nerve both lie just medial to this plane. The early part of the dissection is straightforward, but the final portion, closest to these structures, requires the most caution, since this is where the vital structures are most exposed.
Protecting the vein of Labbe
During a temporal lobectomy specifically, the vein of Labbe must be preserved, and the dissection should not extend medial to the tentorium, the fold of tissue separating the temporal lobe from the structures beneath it. Electrocorticography confirms the endpoint of the resection: the epileptic discharges being recorded from the cortex must disappear completely before the operation is considered finished.
Where complications actually come from
In Dr. Rattnani's account, most complications trace back to one specific moment: bleeding severe enough to cause panic, which is when a surgeon is most likely to breach the arachnoid plane and lose track of the anatomy. Following the anatomical rules methodically, rather than reacting to bleeding by pushing past the plane, is what keeps the complication rate in the 5 to 10% range across resective procedures generally.
This article is based on a Jivo Masterclass session conducted by Dr. Dinesh Rattnani, Senior Director - Neurosurgery, Neuro Critical Care & Spine Surgery, Max Super Speciality Hospital, Noida. The article has been summarised with the assistance of an AI tool from the original masterclass recording. Watch the full Masterclass recording
Looking for a neurosurgery consultation or a second opinion on epilepsy surgery? Get in touch with the Jivo team
This guide is based on a live Jivo Masterclass: Dr. Dinesh Rattnani taught doctors across Africa on June 29, 2025.
FROM THE LIVE Q&A
Moderator
Is epilepsy surgery available only in India, and what complications can arise from it?
Dr. Dinesh Rattnani
Epilepsy surgery is not unique to India. It is practiced everywhere a neurosciences centre exists, including the US, UK and Canada, and is done at a minimum of 40 to 50 centres across India alone.
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Frequently Asked Questions
What is the prognosis of epilepsy surgery, and what complications are associated with it?▼
The complications are basically infection, bleeding and meningitis, along with weakness, hemiparesis, hemiplegia and memory loss. An equally important complication is the surgery simply not achieving the expected result, meaning the seizure frequency does not come down even though the operation itself went as planned. That specific outcome happens in roughly 5% of cases.
As a layman with no medical background, if someone asks me for help, is my role simply to get an EEG and an MRI done and share the results?▼
Yes. Get the EEG and MRI done, share the reports, and the surgical team will review them and advise from there.
Which epilepsy cases actually need surgery, and can a teenager undergo it?▼
The best candidates are cases with good concordance between where the seizure semiology points, what the MRI shows, and what the EEG confirms, for example a right temporal lobe abnormality on MRI matching a right temporal EEG focus. Temporal lobe epilepsy accounts for 70 to 80% of these good-responder cases, typically treated with temporal lobectomy along with amygdalohippocampectomy. Teenagers can absolutely undergo the surgery, but medical management is always tried first.
What are the recommended antiepileptic drugs for a patient with a normal EEG and a normal MRI?▼
Sodium valproate and levetiracetam both cover a broad spectrum and rank as the top two choices for most epilepsy types, including generalised tonic-clonic and atonic seizures. For focal seizures with secondary generalisation, carbamazepine is slightly preferred, though sodium valproate also works well. Lacosamide is a newer add-on drug, used alongside a first-line drug rather than as initial therapy. Perampanel is particularly useful when the epilepsy is related to a brain tumour or damaged brain tissue.
Is robotic surgery used for epilepsy surgery?▼
No, not at this centre. In neurosurgery, robotic assistance is currently limited to placing spine screws. No brain surgery is done with a robot here, though other centres may use it differently.
How is mesial temporal sclerosis diagnosed on MRI?▼
Classically, when the temporal lobe volume differs by more than 10% between the right and left sides on MRI, the smaller, scarred side is diagnosed as mesial temporal sclerosis and treated as the seizure source.
How much tissue is removed in a temporal lobectomy for mesial temporal sclerosis?▼
The standard resection takes roughly 4 centimeters from the temporal pole, with the arachnoid plane maintained throughout to protect the anterior choroidal artery and the third nerve, which lie just medial to it.
What structure has to be preserved during a temporal lobectomy?▼
The vein of Labbe. Dissection also should not extend medial to the tentorium, the tissue fold separating the temporal lobe from the structures beneath it.
How do surgeons confirm the resection is complete?▼
Electrocorticography is repeated during the operation, and the resection is only considered complete once the epileptic discharges being recorded from the cortex disappear entirely.
What is the most common cause of complications during this surgery?▼
Bleeding severe enough to cause panic, which is when a surgeon is most likely to breach the arachnoid plane and lose track of the surrounding anatomy.
In This Series: Diagnosis & Management of Epilepsy & Seizures
- 1.Epilepsy and Seizures
- 2.When Epilepsy Becomes Drug-Resistant: Diagnosis, Workup and When to Refer
- 3.Getting the Diagnosis Right: Why EEG and MRI Concordance Decides Who Is a Surgical Candidate
- 4.Resective Epilepsy Surgery: Temporal Lobectomy and Amygdalohippocampectomy for Mesial Temporal Sclerosis
- 5.Disconnection Surgery: Hemispherectomy and Corpus Callosotomy for the Most Resistant Cases
- 6.Neuromodulation for Epilepsy: How Vagal Nerve Stimulation and Deep Brain Stimulation Work
- 7.Risks, Complications and Realistic Success Rates of Epilepsy Surgery
- 8.Antiepileptic Drug Choices and Post-Surgical Drug Tapering After Epilepsy Surgery
- 9.Can Epilepsy Surgery Make a Patient Completely Seizure-Free? Setting Realistic Expectations
- 10.The Multidisciplinary Team Behind Safe Epilepsy Surgery