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Inhibitory Reflex (inhibitory + reflex)
Selected AbstractsEffect of conditioning electrical stimuli on temporalis electromyographic activity during sleepJOURNAL OF ORAL REHABILITATION, Issue 3 2008F. JADIDI Summary, Inhibitory reflexes during voluntary contractions are well described; however, few studies have attempted to use such reflex-mechanisms to modulate electromyographic (EMG) activity in jaw-closing muscles during sleep. The aim was to apply a new intelligent biofeedback device (Grindcare®) using electrical pulses to inhibit EMG activity in the temporalis muscle during sleep. Fourteen volunteers participated who were aware of jaw-clenching activity as indicated by complaints from sleep partner, soreness or pain in the jaw-muscle upon awakening and tooth wear facets. The EMG activity was recorded from the temporalis muscle, online analysed and the frequency content determined using a signal recognition algorithm. Based on specific individual parameters for pattern recognition, an electrical square-wave pulse train, which was adjusted to a clear, but non-painful intensity (range 1,7 mA) was applied through the EMG electrodes, if jaw-clenching activity was detected. All volunteers had baseline EMG recordings for five to seven consecutive nights, followed by 3-weeks EMG recordings with the feedback turned on, 2 weeks without the feedback and finally 3 weeks with the biofeedback on. There were no session effects on the average duration of sleep hours (P = 0·626). The number of EMG episodes/hour sleep was significantly reduced during the two sessions with biofeedback (54 ± 14%; 55 ± 17%, P < 0·001) compared with baseline EMG activity and the session without biofeedback. The present study suggests that biofeedback with electrical pulses does not cause major disruption in sleep and is associated with pronounced reduction in temporalis EMG activity during sleep. [source] Possible gender-related differences in a jaw reflex evoked by stimulation of the human lipJOURNAL OF ORAL REHABILITATION, Issue 9 2002M. F. LYONS It has been reported that the latency of the jaw jerk reflex in symptom-free human female subjects is significantly shorter than in male subjects (Kossioni et al., 1994). In the present study, we have begun to investigate whether there are any gender-related differences in other jaw reflexes. The EMG recordings were made from an active masseter muscle in 16 young adult age-matched subjects (eight male, eight female; aged 20,43 years). Inhibitory reflexes were evoked in the muscle by applying stimuli through bipolar electrodes clipped over the lower lip with the cathode placed intraorally on the oral mucosa. While the stimuli were being applied, the subjects maintained the EMG level at around 10% of maximum with the aid of visual feedback. The presence or absence of reflex responses was determined as previously described (Louca et al., 1996). Wilcoxon Rank Sum tests were used to compare the properties of the short- (,10,15 ms) and long- (,40,50 ms) latency inhibitory reflexes evoked by the stimuli in the two groups. There was no significant difference between the male and female groups in the threshold or latency of either reflex. However, the duration of the long-latency inhibition was significantly shorter in females than in males (median values: 29·0 versus 44·0 ms, P=0·015). These preliminary findings suggest that, at least in young human subjects, there is a gender-related difference in the strength but not in the presence of long-latency inhibitory jaw reflexes. [source] Modulation of spinal inhibitory reflex responses to cutaneous nociceptive stimuli during upper limb movementEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2008Romildo Don Abstract In the present study we investigated the probability, latency and duration of the inhibitory component of the withdrawal reflex elicited by painful electrical stimulation of the index finger in humans. The stimulus consisted of a train of high-intensity pulses. The investigation was carried out in several upper limb muscles during isometric contractions of different strengths and during a motor sequence consisting of reaching, picking up and transporting an object. We used a new algorithm to detect and characterize the inhibitory reflex. The reflex was found in all muscles except the brachioradialis at all the isometric contraction strengths, and showed a distal-to-proximal gradient of latency and duration. Conversely, during movement the reflex probability was high (> 80%) in the anterior deltoid and triceps muscles during reaching, in the extensor carpi radialis muscle during transporting of the object, and in the first interosseous muscle during both picking up and transporting of the object. This modulation of inhibitory reflex transmission in the upper limb muscles suggests that the motor response is organized in such a way as to inhibit the overall ongoing motor task by interrupting motion during reaching and by releasing the object during transporting. This pattern of modulation appears to differ markedly from that previously reported for the excitatory component of the withdrawal reflex. Study of the nociceptive inhibitory reflexes during movement offers new and more profound insights into the functional anatomical organization of the spinal interneuronal network mediating sensory,motor integration. [source] Evaluation of laparoscopic surgery for Hirschsprung's disease from the standpoint of invasiveness and colonic motility: Prolapsing technique with extra-anal mucosectomyASIAN JOURNAL OF ENDOSCOPIC SURGERY, Issue 3 2009Y Morikawa Abstract Objective: Laparoscopic pull-through has become the standard surgical modality for Hirschsprung's disease in the field of pediatric surgery. This article discusses the minimal invasiveness of the prolapsing technique. This technique allows mucosectomies to be performed under direct vision even at the deepest dissected portion because the procedure is conducted via an extra-anal approach. Method: The laparoscopic prolapsing technique (Lap) is compared with the conventional open Soave technique in terms of the change in CRP and WBC, defecation function, both clinical and manometric, after surgery. Results: As a result, the timing of surgery has become earlier and the patients younger. Soiling occurs in 33% of open Soave and 0% of Lap patients. Manometry after Lap. pull-through revealed a positive recto-anal inhibitory reflex in 39% and evoked high amplitude propagated contraction was demonstrated in 85% of patients. Conclusion: These results suggest that the present technique, including minimal dissections of the mesentery and the preservation of pelvic nerves in combination with fine mucosectomy under direct vision, could be beneficial for postoperative anorectal function in patients with Hirschspurung's disease. [source] Long-term effects of stapled haemorrhoidectomy on internal anal function and sensitivity,BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 11 2001Dr D. F. Altomare Background: Stapled haemorrhoidectomy is gaining wide acceptance but there is still some concern about the risk of injury to the internal anal sphincter (IAS). IAS function and morphology, and anal canal sensitivity were studied prospectively in patients undergoing this operation. Methods: Twenty patients (11 women; mean age 43 years) with stage III haemorrhoids entered the study. All underwent preoperative anorectal manometry, rectoanal inhibitory reflex (RAIR) testing and three-dimensional transanal ultrasonography. A test of anal sensation was administered to evaluate ability to discriminate between air and warm water. All the investigations were repeated 6 months after the operation. Results: The mean(s.d.) maximal resting pressure was 87(30) mmHg before surgery and 81(20) mmHg afterwards (P not significant). The maximal squeeze pressure did not change after operation (178(43) versus 174(60) mmHg). The RAIR showed the same features in 19 of 20 patients before and 18 of 20 after operation. Three-dimensional ultrasonography demonstrated no changes in the width of the IAS (mean(s.d.) 2·1(4) mm before and 2·1(3) mm after surgery). The ability of the anal mucosa to discriminate air from warm water improved in five patients. Continence scores did not differ significantly after 6 months. Conclusion: Stapled haemorrhoidectomy does not affect the function and morphology of the IAS in the long term. The sensitivity of the anal canal can improve in patients with preoperative sensory impairment. © 2001 British Journal of Surgery Society Ltd [source] Penile and clitoral stimulation for faecal incontinence: external application of a bipolar electrode for patients with faecal incontinenceCOLORECTAL DISEASE, Issue 1 2004F. A. Frizelle Abstract Objective, The aim of this study was to assess the effect of a novel pudendal nerve stimulator on clinical and anorectal manometric parameters in patients with faecal incontinence. Method, Retrospective cohort analysis of consecutive patients presenting with faecal incontinence who had failed initial conservative treatment and were not suitable for surgical intervention in a university hospital incontinence clinic. Biofeedback using a pudendal nerve stimulator comprising a bipolar electrode applied to the base of the clitoris or penis. Electrical pulse voltage was self-titrated and defined periods of treatment were prescribed. Anorectal manometry and Cleveland incontinence scores were assessed. Results, There was a significant reduction in incontinence symptom score after pudendal nerve stimulator treatment in the 42 patients treated and who had a complete set of data (median age 57 years (range 37,81); 39 female, 3 male). This was accompanied by significant improvements (P < 0.05) in anal sphincter tone, maximal tolerated rectal volume and the sustained rectoanal inhibitory reflex. Conclusions, An externally applied pudendal nerve stimulator improves symptoms and physiological evidence of faecal incontinence but long-term follow up is not available for these patients. [source] Modulation of spinal inhibitory reflex responses to cutaneous nociceptive stimuli during upper limb movementEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2008Romildo Don Abstract In the present study we investigated the probability, latency and duration of the inhibitory component of the withdrawal reflex elicited by painful electrical stimulation of the index finger in humans. The stimulus consisted of a train of high-intensity pulses. The investigation was carried out in several upper limb muscles during isometric contractions of different strengths and during a motor sequence consisting of reaching, picking up and transporting an object. We used a new algorithm to detect and characterize the inhibitory reflex. The reflex was found in all muscles except the brachioradialis at all the isometric contraction strengths, and showed a distal-to-proximal gradient of latency and duration. Conversely, during movement the reflex probability was high (> 80%) in the anterior deltoid and triceps muscles during reaching, in the extensor carpi radialis muscle during transporting of the object, and in the first interosseous muscle during both picking up and transporting of the object. This modulation of inhibitory reflex transmission in the upper limb muscles suggests that the motor response is organized in such a way as to inhibit the overall ongoing motor task by interrupting motion during reaching and by releasing the object during transporting. This pattern of modulation appears to differ markedly from that previously reported for the excitatory component of the withdrawal reflex. Study of the nociceptive inhibitory reflexes during movement offers new and more profound insights into the functional anatomical organization of the spinal interneuronal network mediating sensory,motor integration. [source] Possible gender-related differences in a jaw reflex evoked by stimulation of the human lipJOURNAL OF ORAL REHABILITATION, Issue 9 2002M. F. LYONS It has been reported that the latency of the jaw jerk reflex in symptom-free human female subjects is significantly shorter than in male subjects (Kossioni et al., 1994). In the present study, we have begun to investigate whether there are any gender-related differences in other jaw reflexes. The EMG recordings were made from an active masseter muscle in 16 young adult age-matched subjects (eight male, eight female; aged 20,43 years). Inhibitory reflexes were evoked in the muscle by applying stimuli through bipolar electrodes clipped over the lower lip with the cathode placed intraorally on the oral mucosa. While the stimuli were being applied, the subjects maintained the EMG level at around 10% of maximum with the aid of visual feedback. The presence or absence of reflex responses was determined as previously described (Louca et al., 1996). Wilcoxon Rank Sum tests were used to compare the properties of the short- (,10,15 ms) and long- (,40,50 ms) latency inhibitory reflexes evoked by the stimuli in the two groups. There was no significant difference between the male and female groups in the threshold or latency of either reflex. However, the duration of the long-latency inhibition was significantly shorter in females than in males (median values: 29·0 versus 44·0 ms, P=0·015). These preliminary findings suggest that, at least in young human subjects, there is a gender-related difference in the strength but not in the presence of long-latency inhibitory jaw reflexes. [source] | ||||||||||