Botulinum toxin-induced paralysis of frontotemporal muscles improves seizure focus localization.
BACKGROUND
Scalp EEG localization of epileptic foci may be obscured by electromyographic (EMG) artifact produced by ictal contraction of cranial muscles. Injection of botulinum toxin type A (BTX-A) into frontotemporal scalp muscles reduces EMG activity. Initial scalp video-EEG monitoring in three patients suggested partial seizures, but definitive lateralization or localization was precluded by EMG artifact.


METHODS
EMG-guided BTX-A injection to bilateral frontotemporal muscles was performed. When artifact persisted, BTX-A administration was selectively repeated. Patients subsequently underwent scalp video-EEG monitoring 1 week later.


RESULTS
All patients had reduction of EMG artifact during subsequent scalp video-EEG monitoring. No patient had adverse effects after BTX-A administration. All three patients had localization to either frontal or temporal lobes and definitive lateralization. Two of the three patients were able to proceed to invasive placement of frontotemporal subdural grid electrodes based on the BTX-A scalp video-EEG localization, and the third patient was determined to have a multifocal seizure disorder.


CONCLUSIONS
Paralysis of frontotemporal scalp muscle after BTX-A administration reduces EMG artifact and may improve localization and lateralization of a seizure focus, providing a noninvasive technique for advancement toward epilepsy surgery.
Eisenschenk
S
S
Department of Neurology, University of Florida, Gainesville 32610-0236, USA. eisensj@neurology.ufl.edu
Gilmore
R L
RL
Uthman
B
B
Valenstein
E
E
Gonzalez
R
R
D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D004569:Electroencephalography; D004576:Electromyography / Q000379:methods; D005152:Facial Muscles / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009465:Neuromuscular Agents / Q000494:pharmacology; D010243:Paralysis / Q000139:chemically induced*; D012640:Seizures / Q000175:diagnosis* / Q000503:physiopathology
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A