【Abstract】 Objective To establ ish an artificial physiological reflex arc with reconstruction of the sensory and themotorial functions of atonic bladder simultaneously after the conus medullary injury in rats. Methods Twenty 3-month-oldmale SD rats, with the weight of 250 to 300 g, were included. The right side was the experimental side, while the left side served as a control. Intradural microanastomosis of the right L5 ventral root to S2 ventral root and L5 dorsal root to S2 dorsal root wasperformed to reconstruct the sensory and the motorial functions of atonic bladder. After axonal regeneration, the new motor-tomotor and sensory-to-sensory artificial bladder reflex pathway was establ ished. At 5 months postoperatively, the early function of the reflex arc was observed by electrophysiological examinations, and the bladder pressure was tested. Results Eighteen rats survived for 5 months after the operation. Single stimul i (3 mA, 0.3 ms) of the S2 dorsal root of the experimental side resulted in evoked potentials recorded from the right vesical plexus before and after the spinal cord was destroyed horizontally between L6 and S4 segmental levels. The ampl itudes of the evoked potentials were (0.10 ± 0.02) mV and (0.11 ± 0.03) mV, respectively, before and after paraplegia, and there was no statistically significant difference (P gt; 0.05). The figures of the evoked potentials were similar to those of the control side. Bladder contraction was initiated by trains of stimul i (3 mA, 20 Hz, 5 s) of the S2 dorsal root of the experimental side. The bladder pressures were (6.55 ± 1.33) cmH2O and (6.11 ± 2.01) cmH2O, respectively, and the ampl itudes of bladder smooth muscle complex action potential were (0.11 ± 0.02) mV and (0.11 ± 0.03) mV, respectively, beforeand after paraplegia. There was no significant difference (P gt; 0.05). These figures were similar to those of the control side before paraplegia. Before paraplegia, when the S2 dorsal root of the control side was stimulated, the ampl itude of the evoked potential was (0.14 ± 0.02) mV, the bladder pressures was (10.77 ± 1.78) cmH2O and the ampl itude of bladder smooth muscle complex action potential was (0.17 ± 0.02) mV. There was statistically significant difference bewteen the experimental side and the control side (P lt; 0.01). All the results of electrophysiological examinations and bladder pressure were negative when the left S2 dorsal root was stimulated after paraplegia. Conclusion Suprasacral nerve motor-to-motor and sensory-to-sensory transfers after the spinal cord injury to reconstruct the bladder autonomic reflex arc by intradural microanastomosis of ventral root and the dorsal root between L5 and S2 simultaneously is practical in a rat model and may have potential in cl inical appl ication.
Objective To establish the artificial bladder reflex arc by the normal body reflex pathway above the horizon of spinal cord injury to reinnervate the flaccid bladder and restore bladder micturition function. Methods An intradural microanastomosis was performed on the L6 ventral root tothe S2 ventral root. After axonal regeneration,the “patellar ligament-spinal cord center-bladder” reflex pathway was reestablished. A longterm function of the reflex arc was observed in the nerve electrophysiological experiment, detrusor electromyography experiment, and urodynamic testing 8 months after anastomosis. Results Trains of the stimuli(200 μV,5 ms) in the left L6 dorsal root and the nerve at the anastomosizedsite resulted in motor evoked potential from the disal to the anastomosized site before and after the spinal cord was destroyed horizontally between S1 and S4 segment levels in 2 Beegle dogs.The figure and amplitude of the evoked potential were similar to those of the control and general stability which showed anoninterventional wave. The urodynamic test revealed a rapid increase of the bladder pressure and a minor increase in the abdominal pressure. This showed that the bladder detrusor mainly resulted in the pressure increase.The bladder pressure increased to 60% of the normal on average compared with the controls when resulted in the left L6 dorsal root and the nerve anastomosized site were stinulated. Conclusion The long-term observation by the nerveelectrophysiological experiment, detrusor electromyography experiment, and urodynamic test indicate that the new artificial reflex arc can be established successfully. The somatic motor axons can regenerate into the parasympathetic endoneurial tubes of the autonomic nerve.
OBJECTIVE To establish an artificial bladder reflex arc in canines to reinnervate the neuropathic bladder and restore bladder function after spinal cord injury. It involves a somatic reflex arc with a modified efferent branch which passes the somatic motor impulses to the bladder and initiates autonomic bladder detrusor contraction. METHODS Intradural microanastomosis of the right L5 ventral root to S2 ventral root was performed to maintain the right L5 dorsal root intact. After axonal regeneration, the new patellar ligament-spinal cord center-bladder artificial bladder reflex pathway was established, and micturition was induced by knocking the patellar ligament. The early and final function of the reflex arc was observed by electrophysiological examinations, bladder pressure tests and detrusor electromyograms(EMG) at 6 months and 18 months postoperatively. RESULTS Single stimuli (115 mV, 1.0 ms) of the right L5 dorsal root resulted in evoked potentials recorded from the right S2 ventral root distal to the anastomosis site before and after the spinal cord was transected horizontally at the T10 segment level in all 6 canines. Bladder contraction was very quickly initiated by trains of stimuli(1,000 mV, 10 Hz, 2 s) of the right L5 dorsal root and bladder pressures increased rapidly to 65% of normal, and bladder contraction induced by knocking the right patellar ligament was increased to 51% of normal through the new reflex arc in 4 canines after 6 months of operation. Bladder pressures were increased by the same stimuli to average 84% of normal and to 62% of normal by knocking the patellar ligament in 2 canines after 18 months of operation. Stimuli(3.8 mA, 1.0 Hz) of the right L5 dorsal root and femoral nerve resulted in EMG similar to normal EMG could be recorded from the detrusor in 2 canines after 18 months postoperatively. CONCLUSION The somatic motor axons can be regenerated into the parasympathetic endoneurial tubes of autonomic nerve. Using the survived somatic reflex under the horizon of spinal cord injury to reconstruct the bladder autonomic reflex arc by intradural microanastomosis of ventral root is practical in the canine model and may have a potential of clinical application.
Objective To observe the characteristics of pupillary light reflex in the patients with retrobulbar neuritis, and to evaluate the effects of pupi llary light reflex on the diagnosis and treatment of retrobulbar neuritis. Methods Thirtyfive patients (thirtyfive eyes with the retrobulbar neuritis and thirtyfive fellow eyes) aged from 10 to 58 years and 50 healthy individuals (100 eyes) who didnlsquo;t differ from the patients in age and sex were examined by a automatic pupillometer. The pupillary area and response amplitude, latency and speed of papillary reflex were recorded. Results The latency of the pupillary light reflex delayed and the maximum amplitude decreased in patients with retrobulbar neuritis during the diseas eperiod, and the differences were highly significant compaired with the control group. After the treatment, as the symptoms were alleviated and the visual acuity improved, the latency of the pupillary light reflex and the maximum amplitude recovered. The statistic differences were both found between the results after treatment and those at the onset stage, and the results after treatment and those in the control group.Before the onset of the disease of the involued eyes and after the treatment, the papill ary light reflex and the maxium amplitude decreased, but didnamp;#146;t differe much from which in the control group. Conclusions The latency of the pupillary light reflex delayes and the maximum amplitude decreases in patients with retrobulbar neuritis. The examination of pupillary light reflex is helpful to diagnose retrobulbar neuritis early and inspect the condition of the disease. (Chin J Ocul Fundus Dis,2006,22:370-372)