Faculty Bibliography

The clinical, neuroradiological, and surgical management of three cases of intradural disc herniations--one each in the cervical, thoracic, and lumbar regions--are presented. Intradural disc herniations comprise only 0.27% of all herniated discs. Three percent occur in the cervical, 5% in the thoracic, and 92% in the lumbar spinal canal. Those with cervical or thoracic lesions frequently exhibit profound myelopathy, whereas those with lumbar lesions demonstrate radicular or cauda equina syndromes. Although varying combinations of the MRI, non-contrast CT, myelogram, and myelo-CT scans may at times fail to accurately establish the diagnosis of an intradural disc herniation prior to surgery, the index of suspicion raised by the lack of clinical correlation with surgical findings justifies an intradural exploration.

Two patients with pain referable to the low back and sacroiliac regions had bone scans with similar findings. In each, one sacroiliac joint was "warm" (uptake on that side was slightly greater than that in the contralateral area). Ga-67 imaging also demonstrated increased uptake in the same locale. Subsequent CT scanning revealed pelvic abscesses adjacent to the affected joints. Asymmetric uptake of bone imaging agent may have been related to hyperemia and "heating" of the sacroiliac joint. Rapid defervescence with antibiotics and drainage (and no CT evidence of bone involvement) suggested that osteomyelitis was not involved in these cases.

The management of 60 patients with far lateral lumbar disc herniations operated on over a 5-year period are presented. These lesions were located superiorly within the neural foramens beneath or distal to the facet joints. The type of surgery performed in 43 of 60 (72%) of these patients was significantly altered by the presence of diffuse and lateral recess stenosis. This was better appreciated on the myelogram and myelo-CT (M-CT) studies than with the noncontrast CT and MRI examinations alone. Myelo-CT findings were particularly valuable in assessing patients who had previous surgical procedures

In six patients, operations for bilateral carpal tunnel syndromes (CTS) were performed or were about to be performed without the awareness of the presence of underlying cervical spondylo-stenosis. Only later, when symptoms of myeloradiculopathy were recognized, was the diagnosis confirmed and decompressive laminectomy performed. Because the symptoms of CTS may resemble or be masked and accentuated by the cervical disorder, patients with the presumed diagnosis of bilateral CTS should undergo appropriate critical neurologic, electrodiagnostic, and neuroradiologic (magnetic resonance imaging, computed tomography, myelo-computed tomography) assessment. If these guidelines are followed, the radiculopathy caused by cervical pathology will be appropriately recognized and treated, possibly averting the need for carpal tunnel decompression or modifying treatment

Spinal stenosis should be considered in the differential diagnosis of disc disease when evaluating an adolescent presenting with unrelenting back and leg pain. Although they typically exhibit mechanical signs alone without neurological findings, they nevertheless may prove more vulnerable to rapidly progressive neurological changes. If motor deficits occur, protracted courses of conservative care should be avoided, and proper surgical management considered. Our recent experience with a 14-year-old boy with disc disease and stenosis indicated that aggressive surgical management facilitates a rapid return to an asymptomatic existence

A massive hemispheric "high"-grade astrocytoma, diagnosed in a 6-week-old infant, was totally excised by means of two craniotomies. The child is still alive and well with minimal neurological dysfunction 1.5 years after operation. This case report illustrates the benefit of aggressive surgical excision (without radiation or chemotherapy) of massive malignant neonatal astrocytomas. While surgical deficits may be minimized by the plasticity of the developing nervous system, extensive excision may yield occasional long-term palliation.

Unilateral S-1 nerve root compression after an S-1 sacral fracture was found in an 18-year-old man after a motor vehicle accident. The positive myelogram, myelogram-computed tomogram, and magnetic resonance studies led to surgical intervention. Marked bony callous formation contiguous with the S-1 alar fracture protruded into the canal and was responsible for tethering the S-1 nerve root. A right L-5 hemilaminectomy, an L-4, L-5 and L-5, S-1 medial facetectomy, and foraminotomy facilitated nerve root decompression. Postoperatively, the patient was markedly improved. The authors suggest a more aggressive attitude in the diagnostic, radiographic, and surgical management of sacral fractures now that more specific technical facilities are available to define the precise character of the lesions involved

An attempt has been made to identify and manage patients symptomatic from both cervical and lumbar spinal stenosis. The order of operative intervention was related to the degree of myelopathy and radiculopathy. Patients requiring cervical surgery first had absolute stenosis with a spinal canal equal to or less than 10 mm in anteroposterior diameter. Those requiring lumbar surgery first presented with stenosis and a canal between 11 and 13 mm in depth. In the latter group, patients presented with radiculopathy in their upper and lower extremities. A significant portion (50%) had intermittent neurogenic claudication (INC). Motor and sensory changes were severe in those with absolute as compared to relative stenosis. After cervical laminectomy, myelopathy improved or stabilized, and the subsequent lumbar decompression could be completed with less risk. Cervical cord decompression often resulted in improvement in lumbar symptoms with resolution of pain, spasticity, and sensory deficits of myelopathic origin. However, latent symptoms of INC caused by lumbar stenosis were not affected by cervial decompression and increased in severity. Electrodiagnostic studies were helpful in that somatosensory evoked potentials showed conduction delays in the cervical cord in patients with significant disease. The identification of motor neuron disease and peripheral neuropathies was essential. The surgical management included extensive, multiple level laminectomy, unroofing of the lateral recesses, and foraminotomy. Neurolysis and untethering of the spinal cord was essential. Significant improvement was shown by 90% of these patients

The treatment over the past 12 years of 60 patients with degenerative spondylolisthesis with an intact neural arch is reviewed. The patients averaged 65 years of age, with women outnumbering men by a ratio of 2:1. Symptoms in the lower extremities had been present for 3 months to 10 years, although varying back pain had existed for longer periods. Two-thirds showed signs of motor dysfunction. Sensory alterations and a positive Las egue's sign could be demonstrated in only one-half of the patients studied. Four of 5 patients developed intermittent neurogenic claudication, with varying evidence of painful radiculopathy. The marked disability caused by claudication contrasted sharply with the lesser neurological changes, and these patients required early surgical decompression. Diagnostic studies included electromyography, plain x-ray films, tomography, computed tomographic scanning, and myelography. The latter outlined a relative stenosis caused by olisthesis as well as arthrotic and spondylotic changes that determined the extent of decompressive operation required. The L-4, L-5 interspace was involved in 56 patients, L-3, L-4 was involved in 2, and L-5, S-1 was involved in 2. The ideal operation with L-4, L-5 olisthesis included complete laminectomy of L-4 and L-5 with unroofing of the lateral recesses and foraminotomy. This more extensive procedure was justified because of the failures encountered in previous patients in whom inadequate decompression had been performed. Among failures, obesity, diabetes, hyperlordosis, and extensive long-standing dysfunction were prominent. The relief of symptoms of intermittent neurogenic claudication was the most gratifying response observed. There was no unusual morbidity