Cauda equina syndrome and lumbar disc herniation.

In a retrospective chart review of the cases of thirty-one patients with cauda equina syndrome secondary to a central disc lesion, we identified two modes of presentation. The first was an acute mode (ten patients) in which there were abrupt, more severe symptoms and signs and a slightly poorer prognosis after decompression, especially for the return of bladder function. The second mode of presentation (twenty-one patients) was a slower onset, characterized by prior symptoms for varying time-intervals before the more gradual onset of the cauda equina syndrome. All patients had urinary retention preoperatively. Bladder function was the most seriously affected function preoperatively and remained so postoperatively. The prognosis for return of motor function was good, since twenty-seven of the thirty patients who were operated on regained normal motor function. Preoperatively all patients had sciatica, which was bilateral in fourteen and unilateral in seventeen. The average time to surgical decompression after the patient was seen ranged from 1.1 days for the more acute lesions to 3.3 days for the second group. There was no correlation of these times with return of function. Therefore, even though early surgery is recommended, decompression does not have to be performed in less than six hours if recovery is to occur, as has been suggested in the past.