Mark N. Hadley
A review of 53 cases of extradural cervicomedullary compression
Mark N. Hadley, Robert F. Spetzler and Volker K. H. Sonntag
✓ The transoral-transclival surgical approach is the most direct operative approach to pathology ventral to the brain stem and superior spinal cord. In selected patients, this approach is efficacious in the treatment of extradural compressive lesions from the cervicomedullary junction to the C-4 vertebra.
The authors have used the transoral surgical approach in treating 53 patients with lesions compressing the ventral extradural brain stem or the cervical cord. The evaluation, management, and long-term outcome of these patients are described (median follow-up time 24 months). The operative morbidity rate in this series was 6%, and the operative mortality rate was zero. The authors review specific features of the transoral procedure, including methods of retraction, microsurgical techniques, and adjunctive measures to avoid cerebrospinal fluid fistulae, that contributed to these good results.
Randolph C. Bishop, Karen A. Moore and Mark N. Hadley
✓ The authors conducted a prospective study of 132 patients requiring interbody fusion without instrumentation following anterior cervical discectomy to compare the efficacy of tricortical iliac crest allograft versus autograft fusion substrates. The objectives of the study were to assess the potential differences in interspace collapse, angulation, maintenance of cervical alignment and lordosis, and clinical and radiographic fusion success rates between the two fusion substrates. The impact of habitual cigarette smoking on fusion rates was also examined.
Autograft tricortical iliac crest bone was found to be superior to allograft bone as an interbody fusion substrate after both single- and multiple-level anterior cervical decompression procedures with respect to maintenance of cervical interspace height, interspace angulation, and radiographic and clinical fusion success rates. Cigarette consumption had a significant adverse effect on successful anterior cervical interbody fusion for both autograft and allograft substrate, an effect that was most pronounced among smokers treated with allograft bone (p = 0.004).
A summary of seven cases
Mark N. Hadley, Volker K. H. Sonntag and Hal W. Pittman
✓ The suprascapular nerve, formed from the upper trunk of the brachial plexus, can be entrapped at the suprascapular notch and result in significant patient morbidity. Seven patients with suprascapular nerve palsy are presented, and their evaluation, treatment, and outcome over a mean follow-up period of 24 months are described. Six of these patients were treated surgically and one medically; all experienced good results. In a review of the relevant literature, this entity is distinguished from other causes of shoulder pain, the typical presenting signs and symptoms are outlined, and the appropriate management of these patients is addressed.
Jay M. Meythaler, Anne McCary and Mark N. Hadley
✓ Twelve consecutive patients with severe spasticity and hypertonia following acquired brain injury were treated with continuous intrathecal infusion of baclofen via an implanted, programmable infusion pump—catheter system for a minimum of 3 months. In every case intrathecal baclofen therapy resulted in a statistically significant reduction in upper- and lower-extremity tone, spasm frequency, and reflexes, contributing to improved functional abilities. There were no untoward side effects or complications associated with treatment.
This preliminary assessment indicates that intrathecal administration of baclofen is effective in treating the disabling spasticity caused by acquired brain injury in selected patients.
Paul M. Foreman, Christoph J. Griessenauer, Michelle Chua, Mark N. Hadley and Mark R. Harrigan
Approximately 10% of patients with blunt traumatic extracranial cerebrovascular injury have a complete occlusion of the vertebral artery (VA). Ischemic stroke due to embolization of thrombus from an occluded VA following cervical spine surgery has been observed. The risk of ischemic stroke with cervical spine surgery in the presence of an occluded VA, however, has never been determined.
A retrospective chart review of 52 patients with a VA occlusion following a blunt trauma was performed. Clinical and radiographic characteristics were collected and analyzed.
Ten patients (19.2%) suffered an ischemic stroke attributable to a traumatic VA occlusion. Univariate analysis demonstrated that patients with ischemic stroke were significantly older (p = 0.042) and had a lower rate of cervical spine surgery (p < 0.005). Multivariate analysis found cervical spine surgery to be protective against ischemic stroke (OR 0.049 [95% CI 0.014–0.167], p = 0.014); increasing age and bilateral VA injury (bilateral occlusion or unilateral occlusion with contralateral dissection) were risk factors for ischemic stroke (OR 1.05 [95% CI1.02–1.07], p = 0.065 and OR 13.2 [95% CI 2.98–58.9], p = 0.084, respectively).
Traumatic VA occlusion is associated with a risk of ischemic stroke and mortality. Corrective cervical spine surgery potentially decreases the risk of ischemic stroke by stabilizing the spine and thereby reducing motion across the occluded segment of the VA and preventing embolization of thrombus. While a high stoke risk may be inherent to the disease, novel therapies should be investigated.
Report of 10 cases
Mark J. Cuffe, Mark N. Hadley, Guillermo A. Herrera and Richard B. Morawetz
✓ Ten patients undergoing long-term renal dialysis for end-stage renal failure developed a destructive, noninfectious spondylarthropathy. All 10 patients had biopsy-proven dialysis-associated spondylarthropathy and subsequent spinal instability secondary to beta 2-microglobulin deposition in the vertebrae, intervertebral disc spaces, and support structures of the spine. Nine patients had cervical spinal instability and one had thoracolumbar spinal instability, with resultant neural compression. In at least one patient, the spinal instability was rapidly progressive. All had received renal dialysis for 34 months or longer (mean 109 months, range 34 to 154 months). Each patient required spinal stabilization (external in seven patients, internal in three). Nine of the 10 patients underwent neural decompression and spinal stabilization and fusion procedures.
One patient's neurological condition was worse following surgery due to a postoperative cervical epidural hematoma; in the other nine patients, the presenting symptoms and signs improved. Three of these chronically ill patients did not survive their hospitalization, for a perioperative mortality rate of 30%. Death was due to cardiopulmonary arrest in two patients on Day 5 and 9 postoperatively and to sepsis in the third on Day 14. Of the seven early survivors, two additional patients died: one on Day 59 due to congestive heart failure and the other on Day 273 due to a cerebrovascular accident. Four of five patients who were followed for 8 months or longer (mean 14 months, range 8 to 20 months) had successful neural decompression and spinal stabilization procedures with evidence of stable bone fusion, indicating that these chronically ill, difficult-to-manage patients can be successfully treated. Clinicians who treat patients with renal disease and neurosurgeons who treat spinal disorders should be aware of dialysis-associated spondylarthropathy as a potential cause of degenerative vertebral column instability.
Paul M. Foreman, Robert P. Naftel, Thomas A. Moore II and Mark N. Hadley
Since its introduction in 1976, the lateral extracavitary approach (LECA) has been used to access ventral and ventrolateral pathology affecting the thoracolumbar spine. Reporting of outcomes and complications has been inconsistent. A case series and systematic review are presented to summarize the available data.
A retrospective review of medical records was performed, which identified 65 consecutive patients who underwent LECA for the treatment of thoracolumbar spine and spinal cord pathology. Cases were divided according to the presenting pathology. Neurological outcomes and complications were detailed. In addition, a systematic review of outcomes and complications in patients treated with the LECA as reported in the literature was completed.
Sixty-five patients underwent the LECA to the spine for the treatment of thoracic spine and spinal cord pathology. The most common indication for surgery was thoracic disc herniation (23/65, 35.4%). Neurological outcomes were excellent: 69.2% improved, 29.2% experienced no change, and 1.5% were worse. Two patients (3.1%) experienced a complication. The systematic review revealed comparable neurological outcomes (74.9% improved) but a notably higher complication rate (32.2%).
The LECA provides dorsal and unilateral ventrolateral access to and exposure of the thoracolumbar spine and spinal cord while allowing for posterior instrumentation through the same incision. Although excellent neurological results can be expected, the risk of pulmonary complications should be considered.