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Objective: Intense air-conducted sound (ACS) elicits an ocular vestibular-evoked myogenic potential (oVEMP), and it has been suggested that it does so by stimulating saccular receptors and afferents in the inferior vestibular nerve and so activating a crossed sacculo-ocular pathway. Bone conducted vibration (BCV) also elicits an oVEMP probably by activating utricular receptors and a crossed utriculo-ocular pathway. Are there two separate pathways mediating oVEMPs for ACS and BCV? If saccular receptors and afferents are primarily responsible for the oVEMP to ACS, then the oVEMP to ACS should be normal in patients with reduced or absent utricular function--unilateral superior vestibular neuritis (SVN). If utricular receptors and afferents are primarily responsible for oVEMP n10, then oVEMP to ACS should be reduced or absent in SVN patients, and in these patients there should be a close relationship between the size of the oVEMP n10 to BCV and to ACS., Methods: The n10 component of the oVEMP to 500 Hz BCV and to 500 Hz ACS was recorded in 10 patients with unilateral SVN but who had saccular and inferior vestibular nerve function preserved, as shown by their normal cVEMP responses to ACS., Results: In SVN patients with normal saccular and inferior vestibular nerve function, the oVEMP n10 in response to ACS was reduced or absent. Across SVN patients there was a very close correspondence between the size of oVEMP n10 for ACS and for BCV., Conclusions: The n10 component of the oVEMP to ACS is probably mediated predominantly by the superior vestibular nerve and so most likely by utricular receptors and afferents., Significance: The n10 component of the oVEMP to either ACS or BCV probably indicates mainly superior vestibular nerve function., (Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objective: Two indicators of otolithic function were used to measure dynamic otolith function in the same patients both during an acute attack of Ménière's disease (MD) and in the quiescent period between attacks., Methods: The early negative component (n10) of the ocular vestibular-evoked myogenic potential (the oVEMP) to brief 500 Hz bone conducted vibration (BCV) stimulation of the forehead, in the midline at the hairline (Fz) was recorded by surface EMG electrodes just beneath both eyes while the patient looked up. It has been proposed that the n10 component of the oVEMP to 500 Hz Fz BCV indicates utricular function. It has been proposed that the early positive component (p13) of the cervical vestibular-evoked myogenic potential (the cVEMP) recorded by surface electrodes on both tensed SCM neck muscles to 500 Hz Fz BCV indicates saccular function., Results: Sixteen healthy control subjects tested on two occasions showed no detectable change in the symmetry of oVEMPs or cVEMPs to 500 Hz Fz BCV. In response to 500 Hz Fz BCV 15 early MD patients tested at both attack and quiescent phases showed a dissociation: there was a significant increase in contralesional of n10 of the oVEMP during the attack compared to quiescence but a significant decrease in the ipsilesional p13 of the cVEMP during the attack compared to quiescence., Conclusions: During an MD attack, dynamic utricular function in the affected ear as measured by the n10 of the oVEMP to 500 Hz Fz BCV is enhanced, whereas dynamic saccular function in the affected ear as measured by the p13 of the cVEMP to 500 Hz Fz BCV is not similarly affected., Significance: The MD attack appears to affect different otolithic regions differentially., (Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objective: Bone-conducted vibration (BCV) in the midline at the hairline (Fz), results in short latency potentials recorded by surface electrodes beneath the eyes - the ocular vestibular-evoked myogenic potential (oVEMP). The early negative component of the oVEMP, n10, is due to vestibular stimulation, however it is similar to the early R1 component of the blink reflex. Here we seek to dissociate n10 from R1., Methods: Surface potentials were recorded from the infraorbital electromyogram of 10 healthy subjects, 6 patients with bilateral vestibular loss, 2 with unilateral vestibular loss, 4 with facial palsy and 3 with facial and vestibular nerve lesions on the same side. BCV was delivered at Fz, the inion, the glabella or the supraorbital ridge using a tendon hammer or a bone-conduction vibrator., Results: Onset latencies of the n10 evoked by taps at Fz or inion were significantly shorter than the R1 components of blink responses to supraorbital and glabellar stimuli. Upward gaze increased the amplitude of n10 but not R1. The n10 was absent bilaterally in patients with bilateral vestibular loss and beneath the contralesional eye in patients with unilateral vestibular loss, but in both these groups of patients R1 was preserved. In severe facial palsy the R1 component was absent or delayed and attenuated ipsilesionally, but n10 was preserved bilaterally. In subjects with unilateral facial and vestibular nerve lesions (Herpes Zoster of the facial and vestibulocochlear nerves) the dissociation was complete - the ipsilesional R1 was absent or attenuated whereas the ipsilesional n10 was preserved., Conclusions: n10 is distinguished from R1 by its earlier onset, laterality, modulation by gaze position and dissociation in patient groups., Significance: The n10 component evoked by BCV at Fz is not the R1 component of the blink reflex.

Objective: The n10 component (n10) of the ocular vestibular evoked myogenic potential (oVEMP) to brief bone conducted vibration (BCV) of the forehead at Fz is probably caused by the vibration selectively activating vestibular otolithic receptors. If the n10 is due primarily to utricular activation then diseases which affect only the superior division of the vestibular nerve (SVN) should reduce or eliminate n10., Methods: The n10 component of the oVEMP was measured in 13 patients with unilateral SVN but with inferior vestibular nerve function preserved., Results: We compared the n10 to BCV of these 13 SVN patients to previously published data for healthy subjects and patients after complete unilateral vestibular loss. We found that in 12 out of the 13 patients with SVN, n10 was markedly reduced or absent under the contralesional eye., Conclusion: Since all utricular afferents course in the superior vestibular nerve and in 12/13 of these patients the n10 was reduced we conclude that the n10 component of the oVEMP to BCV is probably mediated by the superior vestibular nerve and probably due to activation of mainly utricular receptors., Significance: The n10 appears to be a simple new test of superior vestibular nerve and probably mainly utricular function.

Objective: To provide the empirical basis for using ocular vestibular evoked myogenic potentials (oVEMPS) in response to Fz bone conducted vibration (BCV) stimulation to indicate vestibular function in human subjects. To show the generality of the response by testing a large number of unselected healthy subjects across a wide age range and the repeatability of the response within subjects. To provide evidence that the response depends on otolithic function., Methods: The early negative component (n10) of the oVEMP to brief BCV of the forehead, in the midline at the hairline (Fz) is recorded by surface EMG electrodes just beneath the eyes. We used a Bruel and Kjaer 4810 Mini-Shaker or a light tap with a tendon hammer to provide adequate BCV stimuli to test a large number (67) of unselected healthy people to quantify the individual differences in n10 magnitude, latency and symmetry to Fz BCV. A Radioear B-71 bone oscillator at Fz is not adequate to elicit a reliable n10 response., Results: The n10 oVEMP response showed substantial differences in amplitude between subjects, but is repeatable within subjects. n10 is of equal magnitude in both eyes with an average asymmetry around 11%. The average n10 amplitude for Mini Tone Burst BCV is 8.47microV+/-4.02 (sd), the average latency is 10.35ms+/-0.63 (sd). The amplitude of n10 decreases and its latency increases with age., Conclusions: oVEMPs are a new reliable, repeatable test to indicate vestibular and probably otolithic function., Significance: This study shows the optimum conditions for recording oVEMPs and provides baseline values for individual differences and asymmetry. oVEMPs can be measured in senior subjects without difficulty.

Purpose: Although the technical feasibility of pedal artery bypass for limb salvage is now well established, questions remain about its most appropriate use and its long-term durability., Methods: We reviewed our experience over an 8-year period in 367 consecutive patients undergoing 384 vein bypass grafts to the dorsalis pedis for limb salvage., Results: Ninety-five percent of the patients had diabetes mellitus. Infection complicated ischemia at initial presentation in 55.2% of patients. The preoperative arteriogram demonstrated a patent dorsalis pedis in 362 extremities (92.8%). Four hundred two patients underwent exploration for bypass, including 29 patients without demonstrated arteries on the arteriogram but audible pedal Doppler signals. Successful bypasses were carried out in 357 of 362 cases, where preoperative arteriography demonstrated a patent dorsalis pedis artery (98.6%), 16 of 28 cases explored on the basis of a Doppler signal alone (57%), and 11 of 12 patients where angiographic status was unknown. All procedures were performed with vein: in situ 38.5%, reversed 29%, nonreversed 18%, arm vein 7%, and composite vein 8%. Inflow was taken from the common femoral artery in 34%, superficial femoral or popliteal arteries in 60%, a previously placed graft in 5%, and a tibial artery in 1%. There were seven perioperative deaths (1.8%) and 21 myocardial infarctions (5.4%). Twenty-nine grafts failed within 30 days (7.5%), but 19 were successfully revised. Eight of the 10 failed grafts resulted in major amputation (80%). Over the remaining study period, there were 39 additional graft failures, of which 17 were successfully revised, and 17 additional major amputations. Actuarial primary and secondary patency and limb salvage rates were 68%, 82%, and 87%, respectively, at 5 years' followup. The actuarial patients survival rate was 57% at 5 years. Patency rates were similar for in situ and translocated saphenous vein grafts., Conclusions: Dorsalis pedis arterial bypass is an effective limb salvage procedure with long-term durability comparable to distal vein grafts placed into more proximal arteries.

Purpose: The purpose of this study was to assess functional status, well-being, and symptom relief of patients after infrainguinal revascularization for severe peripheral vascular disease., Methods: Two questionnaires were used to assess symptoms, functional status, and well-being before operation and 6 months after operation. Sociodemographics, comorbidities, indications for surgery, graft location, and morbidity, mortality, patency, and limb salvage rates were obtained via vascular registry., Results: Of 318 patients who underwent revascularization over a 1-year period, 276 patients were asked to complete the questionnaires. Of the 156 patients who completed both questionnaires, mean age was 66 years, 67% were men, 84% had diabetes mellitus, and 83% had various heart-related conditions. Mean length of stay was 15.3 days. Distal graft sites were popliteal (29%), tibial/peroneal (40%), and pedal/plantar (31%). The operative morbidity rate was 21%, the cumulative primary graft patency rate was 93%, the cumulative secondary graft patency rate was 95%, and the limb salvage rate was 97% at 6 months. At follow-up, improved functioning of instrumental activities of daily living, mental well-being, and vitality were reported. Symptoms of calf cramping and toe or foot pain when walking and at rest were also improved. Sores or ulcers improved, but leg swelling did not. The only independent predictor of improved function and well-being was the patients' perception of their status at baseline: those patients who functioned better before operation reported improved function and well-being at 6 months. Only 45% of patients reported feeling "back to normal" at 6 months., Conclusion: Reported health status at baseline was a predictor of improved function, mental well-being, and resolution of symptoms after infrainguinal revascularization. Expected return to "normal" may take longer than 6 months.