Relationship between reflex excitability and symptom duration in hemifacial spasm.
Changes in excitability and symmetry characteristics have been analyzed with blink reflex recovery curve method applied with dual stimuli at 200, 600 and 1000 ms in patients with hemifacial spasm (HFS), spasm duration shorter than 1 year (HFS 1), spasm duration longer than 8 years (HFS 2), and control group. When compared with controls, while HFS cases with short symptom duration had significant decreases in inhibition at 200 ms in the spasm and healthy sides, those with long symptom duration had this finding only in the spasm side at the 200 ms interval. When HFS groups were compared with each other, in cases with HFS 1, decreased inhibition in the spasm side was significant at 200 and 600 ms, while this was significant only at 200 ms in HFS 2 cases. HFS groups were not found to be different in terms of R2 recovery grade. In conclusion, in cases with HFS, decreased inhibition attributed to facial motor neuron and brain stem interneurons is more predominant on the side of the spasm and this was shown to be present also, to some extent, in the contralateral side. It can be said from our findings that the abnormalities of the blink reflex recovery do not progress in cases with HFS when the symptom duration becomes longer.
Uzun
N
N
Istanbul University Cerrahpasa Medical School, Department of Neurology, Istanbul, Turkey. tadatepe@ttnet.net.tr
Erdemir-Kiziltan
M
M
Karaali-Savrun
F
F
D000328:Adult; D000368:Aged; D001767:Blinking / Q000502:physiology*; D016022:Case-Control Studies; D004558:Electric Stimulation; D005260:Female; D019569:Hemifacial Spasm / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D012021:Reflex, Abnormal / Q000502:physiology*; D013997:Time Factors