epilepsy
EPILEPSY
Epilepsy is a clinical multiaxial diagnosis.
Epileptic seizure is a transient occurrence of signs/symptoms brought about by abnormal excessive or synchronous neuronal activity in the brain.
It is recommended that all patients having a first seizure be referred as soon as possible to a specialist to ensure accurate and early diagnosis and initiation of treatment appropriate to the needs of the patients.

Surgical Intervention

Surgery

  • May be an option for epileptic patients with seizures uncontrolled by pharmacological therapy and those with surgically remediable epileptic syndrome
  • Assess patient for the suitability of curative resective procedures before considering palliative procedures

Curative Resective Procedures

  • Aim to eliminate seizures completely that would potentially lead to permanent remission without the need of antiepileptic drugs
  • Temporal lobe resection
    • The lateral temporal  cortex is resected first then the amygdala and hippocampus are resected
    • Approximately 70-90% of the patients become seizure-free
  • Lesionectomy/focal resection
    •  Resection of epileptogenic focus based on semiology, EEG finding, neuropsychological tests, magnetic resonance imaging (MRI) and positron emission tomography scan
    •  Approximately 50% of the patients become seizure-free
  • Extratemporal resection (frontal, parietal and occipital lobectomy)
    • Resection of respective section of the brain where epileptogenic focus was identified on electrophysiological tests or functional imaging, with no obvious lesion on MRI
    • Approximately 50% of the patients become seizure-free

Palliative Procedures

  • Aim to disconnect the epileptogenic area from other parts of the brain to reduce the severity of seizure
  • Multiple subpial transections for epileptogenic focus at eloquent functional area
  • Anatomical or functional hemispherectomy and hemispherotomy are typically reserved for children with very large areas of seziure onset (eg Rasmussen’s syndrome or cerebral mega-gyrus malformation)
  • Corpus callosotomy - for uncontrolled frequent drop attacks
Laser Interstitial Thermal Therapy
  • Focal ablation of epileptogenic focus using image-guided focal laser thermal energy
Stereotactic Radiosurgery
  • Focal ablation of epileptogenic focus using image-guided focal high-dose radiation

Neurostimulation Device Implantations

  • Reduce frequency of seizures in patients refractory to pharmacological therapy and who are not suitable for resection or palliative surgical procedures
  • Vagus nerve stimulation (VNS)
    • Modulation of cerebral neurotransmitter via stimulation of left vagal nerve in the neck
    • Around 50% of the patients got >50% reduction in seizure frequency
  • Responsive neurostimulation (RNS)
    • A device that can record seizure activity directly from the brain & delivers stimulation to stop seizures
  • Deep brain stimulation (DBS)
    • A surgery that involves implanting an electrode into a specific deep part of the brain amd placing a stimulating device under the skin in the chest
    • The cyclical stimulation reduces the frequency of the seizure
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