Focused ultrasound shows promise in drug-resistant epilepsy
Low-intensity focused ultrasound (FUS) can be delivered to the target zone in patients with drug-resistant epilepsy (DRE) without significant adverse events, as shown in a phase I study. Moreover, the treatment produces meaningful changes in stereo-electroencephalography (SEEG) activity.
The study included six patients with DRE undergoing SEEG for localization of the seizure onset zone (SOZ). They received treatment with FUS, which was delivered to the SOZ using a neuronavigation-guided system (ceiling spatial-peak temporal-average intensity level 2.8 W/cm2, duty cycle 30 percent, modulating duration 10 min).
Researchers collected simultaneous SEEG recordings sonication and for 3 days after treatment. They also monitored seizures, interictal epileptiform discharges, and adverse events after FUS.
FUS led to a reduction in seizure frequency within the 3-day follow-up in two patients. However, one patient had an increase in the frequency of subclinical seizures.
There was neither lesion nor brain oedema identified on magnetic resonance imaging following treatment. Of note, there were significant changes in spectral power of SEEG seen at the targeted electrodes during FUS treatment.
One patient reported subjective scalp heating during FUS, while another patient developed transient naming and memory impairment that resolved within 3 weeks after FUS.
The findings of the present pilot study suggest that FUS may have a neuromodulation effect. Further investigation with a larger patient cohort and a wider range of sonication parameters is warranted to establish the utility of FUS for the treatment of epilepsy.