Magnetic resonance imaging (MRI) results from Tam Anh General Hospital Hanoi revealed a 15x18 mm focal cortical dysplasia in Sam's left occipital lobe. This was diagnosed as a dysembryoplastic neuroepithelial tumor (DNET). Doctor Nguyen Duc Anh, Head of the Neurosurgery - Spine Department, identified this tumor as the cause of Sam's generalized seizures, which included loss of consciousness and increased salivation.

A dysembryoplastic neuroepithelial tumor (DNET) originates from abnormal neural stem cells during embryonic development. Instead of developing into normal brain cells, these cells divide to form excess tissue as a person matures.

This type of tumor grows slowly and often causes no symptoms throughout childhood. When it reaches a significant size, the tumor can disrupt brain structure, altering normal electrical activity in surrounding tissues and triggering epileptic seizures, according to doctor Duc Anh.

Sam's tumor in the left occipital lobe before and after surgical removal. *Photo: Tam Anh General Hospital*

Doctor Duc Anh explained that Sam's tumor was located in the occipital lobe, a crucial brain region responsible for visual processing. The surgical team needed to coordinate multiple approaches and techniques to ensure safety and preserve Sam's visual function.

Sam underwent endotracheal intubation for anesthesia. During surgery, an intraoperative neurophysiological monitoring (IOM) system helped the team clearly define the boundary between the resectable tumor in the epileptogenic zone and the functional areas to be preserved. This system also alerted them to potential risks, allowing for precise adjustments to each surgical maneuver. After pinpointing the tumor's exact coordinates, the team selected the craniotomy site, then precisely dissected and removed the tumor.

Post-surgery, Sam recovered well. He could speak and see clearly, with no impairment to his vision or visual field, and no weakness or paralysis. He was discharged after 5 days.

Sam continued anti-epileptic medication but with a reduced dosage. After one year, he has not experienced any new seizures. MRI results showed no tumor recurrence, leading doctor Duc Anh to assess the surgery as radically effective in resolving Sam's epilepsy.

Doctor Duc Anh (right) performing surgery on Sam. *Photo: Tam Anh General Hospital*

In addition to dysembryoplastic neuroepithelial tumors, other conditions like brain vascular malformations, cortical dysplasia, post-traumatic scars, and hippocampal sclerosis can also cause epilepsy. Doctor Duc Anh noted that when a structural cause for epilepsy in the brain is identified, it can often be treated radically with surgery, eliminating seizures and curing the disease. This offers an alternative to lifelong medication, which is typical for epilepsy with an undetermined cause.

Patients experiencing recurrent seizures, absence seizures, transient loss of consciousness, limb stiffness, or prolonged abnormal behavior should seek a specialized neurological examination at a multi-specialty hospital to identify the underlying cause. Early detection of structural lesions can guide patients toward appropriate treatment from the outset, reducing medication dependency and increasing their chances of recovery.

Thanh Long

*Patient's name has been changed