Radiofrequency ablation (RFA) is a viable minimally invasive surgery alternative for refractory focal epilepsy, according to a report on the first Australian patient to receive the procedure from Queensland neurologists.
The team, led by Dr Lisa Gillinder from the Mater Centre for Neurosciences, said the minimally invasive surgery was safe and effective with the patient experiencing no complications or postoperative deficits and still seizure-free on medication at two years.
The patient, a 45 year-old male at the time, had presented with a history of eight years of epilepsy.
“Seizures had a bland semiology comprising behavioural arrest, non-sustained swallowing, right arm and face dystonia with occasional secondary generalisation,” the report published in the Internal Medicine Journal said.
Neuroimaging was non-lesional and neuro-psychology testing was normal.
Stereo-electroencephalography (SEEG) identified frequent seizures arising from the left entorhinal cortex which remained localised and only after a prolonged period began to involve the left amygdala.
RFA of the epileptogenic zone was performed with intra-operative electrocorticography between each ablation to monitor the evolution of epileptiform activity.
“After completion there was significantly reduced activity in both the entorhinal cortex and the amygdala. Post-operatively the patient recovered well and was functionally normal with no deficits.”
“Post-ablation magnetic resonance imaging demonstrated a small area of ablation in the entorhinal cortex and amygdala, approaching the margin of the hippocampus,” the report said.
“We hypothesise that this case was successful due to the localised seizure onset. These arose in the entorhinal cortex and only spread after a prolonged period. It is possible that such cases are more amenable to ablation due to their highly focal nature.”
The authors said RFA can be performed at the conclusion of SEEG without the need for a second procedure and was particularly useful “…as the decision to proceed can be aided by functional cortical stimulation prior to ablation.”
They said it was a safe procedure compared with open resection and with only rare and minor complications.
Evidence suggested it was effective in about 50% of cases.