Our report supports the excellent effect and good tolerance of this novel therapy, and we propose the use of propranolol as first-line treatment for IH.
Key points• While the eye movements have been well characterized during the vestibulo-ocular reflex, the corresponding motor unit activity in human eye muscles is not well understood.• The present study describes the first single motor unit recordings during the vestibulo-ocular reflex in human eye muscles.• Simultaneous needle and surface recordings identified the inferior oblique as the eye muscle of origin of the ocular vestibular evoked myogenic potential (oVEMP), thus validating the physiological basis of this clinical test of otolith function.• The results demonstrate short-latency vestibulo-ocular projections from the otoliths to individual eye muscles.• Single motor unit activity of eye muscles provides a window into neural activity of the ocular motor nuclei in humans.Abstract Motor unit activity in human eye muscles during the vestibulo-ocular reflex (VOR) is not well understood, since the associated head and eye movements normally preclude single unit recordings. Therefore we recorded single motor unit activity following bursts of skull vibration and sound, two vestibular otolith stimuli that elicit only small head and eye movements. Inferior oblique (IO) and inferior rectus (IR) muscle activity was measured in healthy humans with concentric needle electrodes. Vibration elicited highly synchronous, short-latency bursts of motor unit activity in the IO (latency: 10.5 ms) and IR (14.5 ms) muscles. The activation patterns of the two muscles were similar, but reciprocal, with delayed activation of the IR muscle. Sound produced short-latency excitation of the IO muscle (13.3 ms) in the eye contralateral to the stimulus. Simultaneous needle and surface recordings identified the IO as the muscle of origin of the vestibular evoked myogenic potential (oVEMP) thus validating the physiological basis of this recently developed clinical test of otolith function. Single extraocular motor unit recordings provide a window into neural activity in humans that can normally only be examined using animal models and help identify the pathways of the translational VOR from otoliths to individual eye muscles. Abbreviations cVEMP, cervical vestibular evoked myogenic potential; EMG, electromyography; IO, inferior oblique eye muscle; IR, inferior rectus eye muscle; oVEMP, ocular vestibular evoked myogenic potential; VOR, vestibulo-ocular reflex.K. P. Weber and S. M. Rosengren contributed equally to this work.
Persistent and complete absence of choroidal hemangioma associated with persistent improvement in visual acuity and central visual fields can be obtained with verteporfin PDT.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.