Pathogenesis Of Cauda Equina Syndrome Experimental Studies And Clinical Implications

Cauda equina syndrome (CES) is a complications of disease or injury of lumbar spine, The cauda equina consists of peripheral nerves,both motor and sensory,below the level of the conus medullaris and within the spinal canal. The conus medullaris contains the myelomeres of the five sacral nerve roots, damage to any part of this structure may result in the cauda equina syndrome (CES). The clinical symptoms of CES are manifest by low back pain , sciatica, saddle and perineal hypoesthesia or anesthesia, a decrease in anal tone, absent ankle ,knee,or bulbocavernous reflexes, and bowel and bladder dysfunction.the literature continues to be conflicting and controversial with regard to timing of surgical decompression Judicious physical examination and prompt diagnosis remain the cornerstones of effective management of this syndrome.but when it does occur it can lead to poor outcomes with significant legal implications. Controversy exists as to whether the timing of surgical intervention may affect these outcome.Expeditious surgery is,however, only one factor that can affect outcome in this syndrome.Timing of surgical intervention attack mechanism early diagnosis can all affect outcome of CES,and was studied by this experiment.1. Experimental study of pathogenesis of Cauda equina syndrome Healthy adult New Zealand rabbits were used.The cauda equina and nerve root were compressed with device specifically designed for this purpose.Nerve compression was applied to the dura mater and nerve roots after partial laminectomy.The specimens(The conus medullaris and nerve roots)were sampled at difference times after acude cauda equina and nerve compressed. Samples from The conus medullaris were put in fixative overnight,and serial 5 u m coronnal sections were cut.HE staining,TUNEL staining were used to observe the pathological changes and apoptosis and necrosis of the celles in nerve root ganglia. The apoptosis was related to genes of Bcl-2> Bax> Fas^ P53. Significant neurologic changes were observed with 75% restriction of the cauda equina.neural tissue damage included an inflammatory response and axonal and wallerian degeneration followed by proliferating Schwann cells and regenerating axonal buds and necrosis of the pseudounipolar neuron in the nerve root ganglion.and apoptosis of anterior horn cell of the conus medullaris.2. Clinic study of pathogenesis of Cauda equina syndrome Cauda equina syndrome can be regarded as a complex of low back pain,sciatica(pain extending down the lower limb in a dermatomal pattern),saddle hypoesthesia,and motor weakness in the lower extremities in association with either bowel or bladder dysfunction.not all criteria are required for the diagnosis to be established.sympoms of urinary dysfunction and saddle hypoesthesia with varying degrees of motor and sensory loss in either of the extremities are , however,necessary for the diagnosis.Shepard has grouped the symptoms into three convenient areas.Motor manifestations include limb weakness or weakness of some movements,hypotonia in the limb or some muscle groups,and diminished or absent reflexes, sensorymanifestation include hypoesthesia or hyperesthesia with objective signs of sensory loss in a dermatomal or myotomal distribution.Sphincter involvemet of the bladder includes difficulty in initiating micturition, retention ,stress incontinence, and loss of urethral sensation .Bowel dysfunction includes constipation, loss of appreciation of rectal distension ,and loss of anal tone and sensation, sexual dysfunction may also be reported.Early surgical decompression has been suggested to obtain a satisfactory recovery. Shepard has implicated delayed surgical decompression with a poor outcome and advocates early intervention as a prerequisite to return of full neurologic fimction.Nielson et al support this concept of early decompression,establishing by urodynamic parameters that early intervention correlates with improved bladder function.Other authors have also reported on the advantages of early operative decompression.Despite this ,ther...