Does the L5 spinal nerve move? Anatomical evaluation with implications for postoperative L5 nerve palsy.

PURPOSE: While palsy of the L5 nerve root due to stretch injury is a known complication in complex lumbosacral spine surgery, the underlying pathophysiology remains unclear. The goal of this cadaveric study was to quantify movement of the L5 nerve root during flexion/extension of the hip and lower lumbar spine. METHODS: Five fresh-frozen human cadavers were dissected on both sides to expose the lumbar vertebral bodies and the L5 nerve roots. Movement of the L5 nerve root was tested during flexion and extension of the hip and lower lumbar spine. Four steps were undertaken to characterize these movements: (1) removal of the bilateral psoas muscles, (2) removal of the lumbar vertebral bodies including the transforaminal ligaments from L3 to L5, (3) opening and removing the dura mater laterally to visualize the rootlets, and (4) removal of remaining soft tissue surrounding the L5 nerve root. Two metal bars were inserted into the sacral body at the level of S1 as fixed landmarks. The tips of these bars were connected to make a line for the ruler that was used to measure movement of the L5 nerve roots. Movement was regarded as measurable when there was an L5 nerve excursion of at least 1 mm. RESULTS: The mean age at death was 86.6 years (range 68-89 years). None of the four steps revealed any measurable movement after flexion/extension of the hip and lower lumbar spine on either side (< 1 mm). Flexion of the hip and lower lumbar spine revealed lax L5 nerve roots. Extension of the hip and lower lumbar spine showed taut ones. CONCLUSION: Significant movement or displacement of the L5 nerve root could not be quantified in this study. No mechanical cause for L5 nerve palsy could be identified so the etiology of the condition remains unclear.

Catheter-based Minimally Invasive Evacuation of Extensive Spinal Epidural Abscess: A Technical Report.

Surgical treatment of extensive spinal epidural abscess (SEA) usually involves multilevel exposure of the dural sac with subsequent risk for iatrogenic instability. A minimally invasive technique using an epidural catheter inserted through a limited approach for distant irrigation and drainage of the abscess represents an interesting alternative. Most described techniques involve blind placement of the catheters, with the potential risk of damage to the spinal cord and incomplete abscess drainage. We present and analyze a new technique used in two cases of SEA. Those were successfully treated using a minimally invasive approach supplemented with fluoroscopically-guided catheter drainage. We suggest that fluoroscopic placement of the catheter is a safe and effective method that offers a more focused and potentially safer way to proceed to this technique.

Sphenopalatine Ganglion Block and Radiofrequency Ablation: Technical Notes and Efficacy.

Background: Sphenopalatine ganglion (SPG) blockade or lesioning can offer significant pain relief for cluster headaches (CHs) and a variety of other pain syndromes involving the head and face. Methods: We reviewed the literature on the efficacy of SPG block and radiofrequency ablation (RFA) using PubMed and Google Scholar. Results: The infrazygomatic technique can be used to directly access the SPG for injection of local anesthetic or lesioning using RFA. Important technical points to achieve these procedures are described. SPG blockade efficacy is supported by randomized controlled studies but SPG RFA is not. Conclusion: Targeting the SPG is a promising treatment option for refractory CHs. RFA and neuromodulation have the potential to offer long-term significant pain relief, but more randomized studies are needed to demonstrate their efficacy.

Laminoplasty for Cervical Spinal Cord Stimulator Implantation in Patients With Cervical Spondylosis and Fusion: A Technical Note.

Background: Epidural spinal cord stimulator (SCS) implantation is a commonly used strategy for treating refractory neuropathic pain, but the literature on the technical aspects of cervical SCS surgery remains scarce. Degenerative cervical stenosis and prior fusion surgery are relatively frequent conditions in this population, and the optimal method for cervical lead placement among such patients has not been established. Decompressive laminectomy may be required for cervical SCS placement in the presence of spinal stenosis. However, extensive decompression may increase the rate of lead migration and destabilize the spine, especially when performed above an existing fusion. Case Series: We present a surgical technique for cervical SCS implantation and the cases of 3 patients with significant spinal stenosis and/or prior fusion. In these patients, the paddle lead placement was safely achieved using cervical laminoplasty techniques. Conclusion: In addition to stabilizing the epidural paddle lead, laminoplasty offers several potential advantages compared to decompression alone.

Minimally invasive repair of a pseudomeningocele caused by a sheared intrathecal catheter following implantation of a drug delivery system.

BACKGROUND: Shearing of an intrathecal catheter during implantation of a drug delivery system is an underreported complication that can be challenging to manage. CASE DESCRIPTION: A 53-year-old man with refractory cancer pain had an intrathecal pump system implanted. The procedure was complicated with catheter shear and retention in the intrathecal space. A second catheter was successfully placed but formation of a painful pseudomeningocele and ineffective pain relief complicated the outcome. A minimally invasive approach through a tubular retractor was employed to access the spinal canal via a laminotomy, the sheared catheter was removed and the dural defect repaired. Complete resolution of the pseudomeningocele and efficient pain control were observed at follow-up. CONCLUSION: Minimally invasive approach to the spine is demonstrated as a safe and effective alternative in this case of retained catheter induced cerebrospinal fluid (CSF) leak.

Cervical spondylosis: a rare and curable cause of vertebrobasilar insufficiency.

BACKGROUND: Spondylotic vertebral artery (VA) compression is a rare cause of vertebrobasilar insufficiency and stroke. CASE DESCRIPTION: A 53-year-old man experienced multiple brief vertebrobasilar transient ischemic attacks (TIAs) and strokes, not apparently triggered by neck movements. Brain magnetic resonance imaging (MRI) documented consecutive infarcts, first in the left then right medial posterior inferior cerebellar artery (PICA) territories. Angiography showed two extracranial right vertebral artery (VA) stenoses, left VA hypoplasia, absence of left PICA and a dominant right PICA. Computed tomography angiography revealed right VA compression by osteophytes at C5-C6 and C6-C7 levels. No further vertebrobasilar insufficiency symptoms occurred in the 65 months following VA surgical decompression. Our literature review found 49 published surgical cases with vertebrobasilar symptoms caused by cervical spondylosis. Forty cases had one or more brief TIAs frequently triggered by neck movements. Three cases presented with stroke without prior TIA, with symptoms suggesting a top of the basilar artery embolic infarcts (one combined with a PICA infarct). Six cases had both TIAs and minor stroke. VA compression by uncovertebral osteophytes at the C5-C6 level was common. Dynamic angiography done in 38 cases systematically revealed worsening of VA stenosis or complete occlusion with either neck extension or rotation (ipsilateral when specified). Contralateral VA incompetence was found in 14 patients. CONCLUSION: Spondylotic VA stenosis can cause hemodynamic TIAs and watershed strokes, especially when contralateral VA insufficiency is combined to specific neck movements. Low-amplitude neck movement may suffice in severe cases. Embolic vertebrobasilar events are less frequent. VA decompression from spondylosis may prevent recurrent ischemic episodes.

Inflammatory myofibroblastic tumors of the central nervous system that express anaplastic lymphoma kinase have a high recurrence rate.

BACKGROUND: Inflammatory myofibroblastic tumors (IMTs) of the central nervous system (CNS) are rare entities with diverse histopathological features and varying propensities to recur. CASE DESCRIPTION: A 26 year-old male with an IMT of the CNS of the left tentorium had tumor progression 2 months after partial surgical resection. Histopathological studies confirmed expression of ALK. Macroscopic total resection was performed followed by radiotherapy. A recurrence occurred 20 months after the second surgery that necessitate reoperation. Including the present case, we identified 30 cases of IMT of the CNS corresponding to our search criteria in the literature. The extent of resection was reported in 26 of these cases. Gross total resection was done in 75% of ALK-positive and in 61% of ALK-negative cases. Recurrence rate after gross total resection for ALK-positive and ALK-negative cases was 33% and 9%, respectively. Every recurrence in ALK-positive patients occurred within 2 years after surgery. CONCLUSION: IMT of the CNS are a heterogeneous group of tumors and the treatment of choice is complete surgical resection. Because of the high recurrence rate reported for IMT of the CNS expressing ALK, a closed follow-up is recommended. When faced with an early recurrence, a surgical resection followed by radiotherapy may be advised.