Search results for " Nerve"
showing 10 items of 885 documents
Cortical representation of saccular vestibular stimulation: VEMPs in fMRI
2006
Short tone bursts trigger a vestibular evoked myogenic potential (VEMP), an inhibitory potential which reflects a component of the vestibulocollic reflex (VCR). These potentials arise as a result of activation of the sacculus and are expressed through the vestibulo-collic reflex (VCR). Up to now, the ascending projections of the sacculus are unknown in humans, only the representation of the semicircular canals or the entire vestibular nerve has been demonstrated. The aim of this study was to determine whether a sacculus stimulus that evoked VEMPs could activate vestibular cortical areas in fMRI. To determine this, we studied the differential effects of unilateral VEMP stimulation in 21 heal…
Assessment of the reliability of central and peripheral fatigue after sustained maximal voluntary contraction of the quadriceps muscle
2007
The aim of the present study was to further confirm the validity of measurements for characterizing neuromuscular alterations by establishing their reliability both before and after fatigue. Thirteen men (28 5 years) volunteered to participate in two separate identical sessions requir- ing the performance of a sustained maximal voluntary contraction (MVC) with the quadriceps muscle for 2 min. MVC and transcutaneous electrical stimulations were used before and immediately after the fatiguing contrac- tion to investigate the reliability of MVC torque, central activation, and peripheral variables (M-wave properties, peak twitch, peak doublet) within and between sessions. Based on previous and …
Unchanged H-reflex during a sustained isometric submaximal plantar flexion performed with an EMG biofeedback.
2008
The aim of this study was to assess H-reflex plasticity and activation pattern of the plantar flexors during a sustained contraction where voluntary EMG activity was controlled via an EMG biofeedback. Twelve healthy males (28.0+/-4.8 yr) performed a sustained isometric plantar flexion while instructed to maintain summed EMG root mean square (RMS) of gastrocnemius lateralis (GL) and gastrocnemius medialis (GM) muscles fixed at a target corresponding to 80% maximal voluntary contraction torque via an EMG biofeedback. Transcutaneous electrical stimulation of the posterior tibial nerve was evoked during the contraction to obtain the maximal H-reflex amplitude to maximal M-wave amplitude ratio (…
Changes in neuromuscular function after tasks involving control of EMG versus torque feedback of the same duration.
2006
This study was designed to compare alterations in neuromuscular function after two tasks of similar duration involving the control of (1) torque level fixed at 40% maximal voluntary contraction (MVC) torque (torque task) and (2) EMG level when exerting 40% MVC torque on the knee extensor muscles. Ten healthy subjects volunteered to participate in two testing sessions separated by approximately 2 h. Contraction duration for the EMG task was fixed for each subject to the time to task failure of the torque task (104+/-20s). MVC, maximal voluntary activation level, muscle compound action potential (M-wave), peak twitch and potentiated peak doublet were assessed before and immediately after each…
Cystic vestibular schwannoma: classification, management, and facial nerve outcomes.
2009
OBJECTIVE: Review of postoperative morbidity and facial nerve outcomes of cystic vestibular schwannoma (CVS) patients compared with solid vestibular schwannoma (SVS) patients and a proposal for a new CVS classification system. STUDY DESIGN: Retrospective review. SETTING: Tertiary care facility. PATIENTS: Ninety-six patients with surgically treated CVS (1998-2008). Outcomes were assessed in a subpopulation of 57 patients with greater than or equal to 1-year follow-up compared with 57 SVS patients. INTERVENTION: Fifty-six CVS patients underwent the enlarged translabyrinthine approach with transapical extension (Type I), and 1 patient underwent a transcochlear/transzygomatic approach. MAIN OUT…
Simple endoscopic decompression of cubital tunnel syndrome with the Agee system: anatomic study and first clinical results.
2010
BACKGROUND Simple decompression in ulnar nerve compression syndromes offers options for endoscopic applications. OBJECTIVE The authors present their initial experience with the Agee device. PATIENTS AND METHODS The monoportal endoscopic technique (Agee system) was evaluated on 10 cadaveric arms. Subsequently, 32 arms of 29 patients were operated on between January 2006 and March 2009. All patients presented with typical clinical signs and neurophysiologic studies. Long-term follow-up examinations were obtained in 27 of 32 arms. RESULTS In the cadaver study, the ulnar nerve was always correctly identified. No nerve damage occurred, and sufficient decompression of the ulnar nerve was always a…
Endoscopic decompression of the ulnar nerve at the elbow.
2010
OBJECTIVE: Recently, several studies suggested that simple decompression is as effective as anterior transposition in ulnar nerve entrapment syndrome. Simple decompression might be performed with minimally invasive techniques. The authors present their technique and results with endoscopic decompression in ulnar nerve entrapment syndrome. MATERIAL AND METHODS: Between January 2005 and March 2008, 24 patients (mean age, 45.5 years; range, 26-67 years) underwent surgery for 26 ulnar nerve entrapment syndromes (2 bilateral). All patients presented with typical clinical signs and neurophysiologic studies. RESULTS: Intraoperatively, the ulnar nerve was localized directly at the sulcus, and subse…
Treatment of injuries to the inferior alveolar nerve after endodontic procedures.
1998
Overextension of filling material into the mandibular canal after root treatment in the lower jaw is a rare but serious complication. Mechanical compression, chemical neurotoxicity and local infection may cause irreversible nerve damage. A report on 11 patients with neurological complaints of the inferior alveolar nerve after endodontic treatment is summarised. The neurological findings are dominated by hypaesthesia and dysaesthesia. Half of the patients reported pain. Hyperaesthesia is found much more rarely. Nearly all the patients had a combination of one or more symptoms. Initial X-rays showed root filling material in the area of the mandibular canal. Nine cases were treated with apicec…
Cardiovascular autonomic neuropathy in type 1 diabetic patients with and without peripheral neuropathy.
1998
One hundred Type 1 diabetic patients (54 men, 46 women) mean age 28.9 +/- 8.4 years, were selected from among individuals referred to our hospital, with no previous diagnosis of diabetic chronic complications including diabetic neuropathy. After clinical and physical examinations, subjects were divided into two groups: with (n = 37) and without (n = 63) peripheral neuropathy. The percentage of subjects with cardiovascular autonomic neuropathy (AN), diagnosed by positive results to at least two of the five cardiovascular tests (Valsalva ratio, EI ratio, 30/15 ratio, blood-pressure response to standing up and handgrip test), was 40%: 72.9% in the group with peripheral neuropathy and 20.6% in …
Electrically stimulated axon reflexes are diminished in diabetic small fiber neuropathies.
2004
Axon reflex mediated flare depends on the density and the function of cutaneous C-fibers and may be impaired in diabetic neuropathy. We induced neurogenic axon reflex flare by intracutaneous electrical stimulation and analyzed size and intensity of the flare on the dorsum of the foot and ventral thigh with laser Doppler imaging (LDI). We investigated 12 diabetic subjects with small fiber neuropathies (SFNs), 5 diabetic subjects without neuropathy (NO-Ns), and 14 healthy control subjects. Five of the normal subjects were reassessed after 12 months. In comparing patients with SFN to control subjects, we found that SFN flare size but not the intensity of vasodilation (flux) was reduced on the …