Occipital neuralgia is a result of neuropathic pain transmission in the distribution of the greater occipital nerve. Because it is well anatomically localized, occipital neuralgia has been the focus of various surgical treatments. Ablation, decompression, and modulation of the C-2 nerve have all been described as effective treatments. The C-2 dorsal root ganglionectomy provides effective treatment for this disorder with a low incidence of unpleasant side effects. In this review the authors summarize the current treatment of occipital neuralgia.
Michael Y Wang and Allan D. O. Levi
David M. Benglis Jr., Steve Vanni and Allan D. Levi
Minimally invasive anterolateral approaches to the lumbar spine are options for the treatment of a number of adult degenerative spinal disorders. Nerve injuries during these surgeries, although rare, can be devastating complications. With an increasing number of spine surgeons utilizing minimal access retroperitoneal surgery to treat lumbar problems, the frequency of complications associated with this approach will likely increase. The authors sought to better understand the location of the lumbar contribution of the lumbosacral plexus relative to the disc spaces encountered when performing the minimally invasive transpsoas approach, also known as extreme lateral interbody fusion or direct lateral interbody fusion.
Three fresh cadavers were placed lateral, and a total of 3 dissections of the lumbar contribution of the lumbosacral plexus were performed. Radiopaque soldering wire was then laid along the anterior margin of the nerve fibers and the exiting femoral nerve. Markers were placed at the disc spaces and lateral fluoroscopy was used to measure the location of the lumbar plexus along each respective disc space in the lumbar spine (L1–2, L2–3, L3–4, and L4–5).
The lumbosacral plexus was found lying within the substance of the psoas muscle between the junction of the transverse process and vertebral body and exited along the medial edge of the psoas distally. The lumbosacral plexus was most dorsally positioned at the posterior endplate of L1–2. A general trend of progressive ventral migration of the plexus on the disc space was noted at L2–3, L3–4, and L4–5. Average ratios were calculated at each level (location of the plexus from the dorsal endplate to total disc length) and were 0 (L1–2), 0.11 (L2–3), 0.18 (L3–4), and 0.28 (L4–5).
This anatomical study suggests that positioning the dilator and/or retractor in a posterior position of the disc space may result in nerve injury to the lumbosacral plexus, especially at the L4–5 level. The risk of injuring inherent nerve branches directed to the psoas muscle as well as injury to the genitofemoral nerve do still exist.
Michael Y. Wang, Barth A. Green, Sachin Shah, D.O. Steven Vanni and Allan D. O. Levi
An aging population will require that surgeons increasingly consider operative intervention in elderly patients. To perform this surgery safely will require an understanding of the factors that predict successful outcomes as well as complications.
Records of patients older than the age of 75 years who underwent lumbar spinal stenosis surgery were retrospectively reviewed. Preexisting medical illnesses were analyzed using the Charlson Weighted Comorbidity Index. Ambulatory function was rated on a four-point scale. Statistical analysis was performed using a one-tailed t-test with unpaired variance.
Eighty-eight patients treated between 1994 and 2001 were identified. Forty-five percent were women and 52 patients underwent spinal fusion. The follow-up period averaged 21 months. Back pain was present preoperatively in 89%; after surgery 43% experienced complete relief and 33% partial improvement. Leg pain was present preoperatively in 98%; after surgery 43% experienced complete relief and 42% partial improvement. Of the 33 patients with preoperative gait disturbances, 61% improved at least one point on the ambulatory scale. Wound complications and systemic complications were demonstrated in 24 and 16 patients, respectively. There were no deaths. Age (p = 0.322), number of fused levels (p = 0.371), and the number of laminectomy levels (p = 0.254) were not predictive of complications. Length of operative time (p = 0.003) and the CharlsonWeighted Comorbidity Index score (p = 0.088) were associated with both systemic and wound complications.
Surgery in patients older than age 75 years can be conducted safely and with similar outcome rates as in younger patients. The CharlsonWeighted Comorbidity Index score and operative time were predictive of the risk of complications.
Matthew D. Cummock, Steven Vanni, Allan D. Levi, Yong Yu and Michael Y. Wang
The minimally invasive transpsoas interbody fusion technique requires dissection through the psoas muscle, which contains the nerves of the lumbosacral plexus posteriorly and genitofemoral nerve anteriorly. Retraction of the psoas is becoming recognized as a cause of transient postoperative thigh pain, numbness, paresthesias, and weakness. However, few reports have described the nature of thigh symptoms after this procedure.
The authors performed a review of patients who underwent the transpsoas technique for lumbar spondylotic disease, disc degeneration, and spondylolisthesis treated at a single academic medical center. A review of patient charts, including the use of detailed patient-driven pain diagrams performed at equal preoperative and follow-up intervals, investigated the survival of postoperative thigh pain, numbness, paresthesias, and weakness of the iliopsoas and quadriceps muscles in the follow-up period on the ipsilateral side of the surgical approach.
Over a 3.2-year period, 59 patients underwent transpsoas interbody fusion surgery. Of these, 62.7% had thigh symptoms postoperatively. New thigh symptoms at first follow-up visit included the following: burning, aching, stabbing, or other pain (39.0%); numbness (42.4%); paresthesias (11.9%); and weakness (23.7%). At 3 months postoperatively, these percentages decreased to 15.5%, 24.1%, 5.6%, and 11.3%, respectively. Within the patient sample, 44% underwent a 1-level, 41% a 2-level, and 15% a 3-level transpsoas operation. While not statistically significant, thigh pain, numbness, and weakness were most prevalent after L4–5 transpsoas interbody fusion at the first postoperative follow-up. The number of lumbar levels that were surgically treated had no clear association with thigh symptoms but did correlate directly with surgical time, intraoperative blood loss, and length of hospital stay.
Transpsoas interbody fusion is associated with high rates of immediate postoperative thigh symptoms. While larger, prospective studies are necessary to validate these findings, the authors found that half of the patients had symptom resolution at approximately 3 months postoperatively and more than 90% by 1 year.
Report of 4 cases
Hamad I. Farhat, Brian Hood, Steven Vanni and Allan D. Levi
Spontaneous spinal CSF leakage with the development of intracranial hypotension is a well-described entity. Cerebrospinal fluid leaks, mostly from the thoracic spine, are the major cause of spontaneous intracranial hypotension (SIH). Conservative treatment options include hydration, oral caffeine, and epidural blood patching. Alternatively, open surgical correction of meningeal diverticula is a therapeutic option. The authors describe 4 cases of spontaneous spinal CSF leakage producing symptoms of intracranial hypotension. All patients had multiple spinal diverticula with an identified leaking level. The patients were treated using a minimally invasive approach via surgical correction of the meningeal diverticulum.
Report of three cases
Eric Belanger, Claude Picard, Daniel Lacerte, Pierre Lavallee and Allan D. O. Levi
✓ Subacute posttraumatic ascending myelopathy is a rare disorder, unrelated to syrinx formation or mechanical instability, that may gradually emerge within the first 1 to 2 weeks after a spinal cord injury. The authors describe three patients with this syndrome and discuss its possible causes as well as its clinical presentation, imaging characteristics, treatment, and patient prognosis.
Allan D. O. Levi, Hector Dancausse, Xiuming Li, Suzanne Duncan, Laura Horkey and Maria Oliviera
Object. Partial restoration of hindlimb function in adult rats following spinal cord injury (SCI) has been demonstrated using a variety of transplantation techniques. The purpose of the present study was twofold: 1) to determine whether strategies designed to promote regeneration in the rat can yield similar results in the primate; and 2) to establish whether central nervous system (CNS) regeneration will influence voluntary grasping and locomotor function in the nonhuman primate.
Methods. Ten cynomologus monkeys underwent T-11 laminectomy and resection of a 1-cm length of hemispinal cord. Five monkeys received six intercostal nerve autografts and fibrin glue containing acidic fibroblast growth factor (2.1 µg/ml) whereas controls underwent the identical laminectomy procedure but did not receive the nerve grafts. At 4 months postgrafting, the spinal cord—graft site was sectioned and immunostained for peripheral myelin proteins, biotinylated dextran amine, and tyrosine hydroxylase, whereas the midpoint of the graft was analyzed histologically for the total number of myelinated axons within and around the grafts. The animals underwent pre- and postoperative testing for changes in voluntary hindlimb grasping and gait.
Conclusions. 1) A reproducible model of SCI in the primate was developed. 2) Spontaneous recovery of the ipsilateral hindlimb function occurred in both graft- and nongraft—treated monkeys over time without evidence of recovering the ability for voluntary tasks. 3) Regeneration of the CNS from proximal spinal axons into the peripheral nerve grafts was observed; however, the grafts did not promote regeneration beyond the lesion site. 4) The grafts significantly enhanced (p < 0.0001) the regeneration of myelinated axons into the region of the hemisected spinal cord compared with the nongrafted animals.
Allan D. O. Levi, Curtis A. Dickman and Volker K. H. Sonntag
The authors retrospectively reviewed 452 consecutively treated patients who underwent a spinal instrumentation procedure at a single institution to establish which patients and which surgical approaches might be associated with an increased risk of developing deep wound infections and to determine the efficacy with which the institution's current treatment strategy eradicates these infections. Wound infections occurred in 17 patients (10 men and seven women) with spinal instrumentation (incidence 3.8%). All infections occurred after posterior spinal instrumentation procedures (7.2%); there were no infections after anterior instrumentation procedures regardless of the level. Each patient was assigned an infection risk factor (RF) score depending on the number of RFs identified in an individual patient preoperatively. The mean RF score of patients who developed infections was 2.18, whereas the mean RF score for a procedure-matched, infection-free control group was 0.71. The mean number of days from surgery to clinical presentation was 27.6 days (range 4-120 days), and the mean increase in hospitalization time for the subset of patients who developed infections was 16.6 days. The most common organism isolated from wound cultures was Staphylococcus aureus (nine of 17 cases). Of the 17 patients, five had infections involving multiple organisms. All patients were infection free at a minimum of 8 months follow-up review. The current treatment regimen advocated at this institution consists of operative debridement of the infected wound, a course of intravenous followed by oral antibiotic medications, insertion of an antibiotic-containing irrigation-suction system for a mean of 5 days, and maintenance of the instrumentation system within the infected wound.
Allan D. O. Levi, Curtis A. Dickman and Volker K. H. Sonntag
✓ The authors retrospectively reviewed 452 consecutively treated patients who underwent a spinal instrumentation procedure at a single institution to establish which patients and which surgical approaches might be associated with an increased risk of developing deep wound infections and to determine the efficacy with which the institution's current treatment strategy eradicates these infections. Wound infections occurred in 17 patients (10 men and seven women) with spinal instrumentation (incidence 3.8%). All infections occurred after posterior spinal instrumentation procedures (7.2%); there were no infections after anterior instrumentation procedures regardless of the level. Each patient was assigned an infection risk factor (RF) score depending on the number of RFs identified in an individual patient preoperatively. The mean RF score of patients who developed infections was 2.18, whereas the mean RF score for a procedure-matched, infection-free control group was 0.71. The mean number of days from surgery to clinical presentation was 27.6 days (range 4–120 days), and the mean increase in hospitalization time for the subset of patients who developed infections was 16.6 days. The most common organism isolated from wound cultures was Staphylococcus aureus (nine of 17 cases). Of the 17 patients, five had infections involving multiple organisms. All patients were infection free at a minimum of 8 months follow-up review. The current treatment regimen advocated at this institution consists of operative debridement of the infected wound, a course of intravenous followed by oral antibiotic medications, insertion of an antibiotic-containing irrigation—suction system for a mean of 5 days, and maintenance of the instrumentation system within the infected wound.
Kevin S. Cahill, Joseph L. Martinez, Michael Y. Wang, Steven Vanni and Allan D. Levi
The aim of this study was to determine the incidence of motor nerve injuries during the minimally invasive lateral interbody fusion procedure at a single academic medical center.
A retrospective chart review of 118 patients who had undergone lateral interbody fusion was performed. Both inpatient and outpatient records were examined to identify any new postoperative motor weakness in the lower extremities and abdominal wall musculature that was attributable to the operative procedure.
In the period from 2007 to 2011 the lateral interbody fusion procedure was attempted on 201 lumbar intervertebral disc levels. No femoral nerve injuries occurred at any disc level other than the L4–5 disc space. Among procedures involving the L4–5 level there were 2 femoral nerve injuries, corresponding to a 4.8% injury risk at this level as compared with a 0% injury risk at other lumbar spine levels. Five patients (4.2%) had postoperative abdominal flank bulge attributable to injury to the abdominal wall motor innervation.
The overall incidence of femoral nerve injury after the lateral transpsoas approach was 1.7%; however, the level-specific incidence was 4.8% for procedures performed at the L4–5 disc space. Approximately 4% of patients had postoperative abdominal flank bulge. Surgeons will be able to minimize these motor nerve injuries through judicious use of the procedure at the L4–5 level and careful attention to the T-11 and T-12 motor nerves during exposure and closure of the abdominal wall.