Blink reflex recovery cycle in patients with blepharospasm unilaterally treated with botulinum toxin.
To determine whether Botulinum Toxin Type A (BTXA) has an effect on the Central Nervous System, the authors studied the excitability of the blink reflex recovery cycle in 12 patients with blepharospasm before and 3 weeks after unilateral BTXA injections. To avoid recording from severely denervated muscles, the R2 response of the blink reflex was obtained from the untreated orbicularis oculi with both ipsilateral and contralateral supraorbital nerve stimulation. Baseline recovery curves were compared with a control group (n = 11) and showed an enhanced recovery of the R2 component. There were no significant differences between the recovery curves of the R2 component of the blink reflex taken before BTXA treatment and those taken after treatment. This finding confirms that BTXA does not modify the excitability of brainstem interneurons that mediate the bilateral R2 response of the blink reflex in patients with blepharospasm.
Grandas
F
F
Department of Neurology, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Traba
A
A
Alonso
F
F
Esteban
A
A
D000328:Adult; D000368:Aged; D001764:Blepharospasm / Q000188:drug therapy* / Q000503:physiopathology*; D001767:Blinking / Q000502:physiology*; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D007395:Interneurons / Q000187:drug effects / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D009801:Oculomotor Muscles / Q000187:drug effects / Q000502:physiology; D009882:Ophthalmic Nerve / Q000502:physiology; D009915:Orbit / Q000294:innervation; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A