Abstract: Within a peripheral nerve, the individual nerve fibers are grouped together in fascicles. Whether there is somatotopic organization within these fascicles has long been of interest, the subject of many investigations, and somewhat controversial. Evidence from diverse sources now points to important somatotopic clustering of nerve fibers within most of the length of the nerve. Information is lacking regarding proximal segments, particularly the plexus and spinal nerve root levels. As a result of this somatotopic arrangement, partial focal nerve lesions can produce restricted clinical deficits that defy the classic rules of localization. Examples of such restricted nerve lesions are provided in this review. Recognition of fascicle somatotopy is also important in the surgical approach to disorders of peripheral nerves.

Abstract: Study design The distribution of the lumbar plexus was analyzed using cadavers. Objective To clarify the safety zone to prevent nerve injuries with respect to retroperitoneal endoscopic surgery. Summary of background data Surgical approaches to the retroperitoneal space vary among surgeons. Recently, retroperitoneal endoscopic surgery has been applied to various spinal disorders. When the psoas major muscle is separated during retroperitoneal endoscopic surgery, there is a potential risk of injury to the lumbar plexus or nerve roots. However, there is sparse knowledge regarding the relationship between the greater psoas muscle and the lumbar plexus. Methods A total of 30 cadavers were analyzed. Six lumbar spines of the cadavers were cut in parallel with the lumbar disc space. Each axial section was photographed and captured into a computer. The distribution of the lumbar plexus was analyzed using computer images. The positions where the genitofemoral nerve emerged on the abdominal surface of the psoas major muscle were analyzed using 24 cadavers. Results L2/3 and above, all parts of the lumbar plexus, and nerve roots were located from the dorsal fourth of the vertebral body and dorsally. The genitofemoral nerve descends obliquely forward through the psoas major muscle, emerging on the abdominal surface between the cranial third of the L3 vertebra and the caudal third of the L4 vertebra. The safety zone of the psoas major muscle to prevent nerve injuries, excluding the genitofemoral nerve, is at L4/L5 and above. Conclusions The safety zone, excluding the genitofemoral nerve, is at L4-L5 and above.

Abstract: Study design An intraoperative straight-leg-raising (SLR) test was conducted to investigate patients with lumbar disc herniation to observe the changes in intraradicular blood flow, which then were compared with the clinical features. Objective The legs of each patient were hung down from the operating table as a reverse SLR test during surgery, and intraradicular blood flow was measured. Summary of background data It is not known whether intraradicular blood flow changes during the SLR test in patients with lumbar disc herniation. Methods The subjects were 12 patients with lumbar disc herniation who underwent microdiscectomy. The patients were asked to adopt the prone position immediately before surgery, so that their legs hung down from the operating table. A reverse SLR test was performed to confirm the angle at which sciatica developed. During the operation, the nerve roots affected by the hernia were observed under a microscope. Then the needle sensor of a laser Doppler flow meter was inserted into each nerve root immediately above the hernia. The patient's legs were allowed to hang down to the angle at which sciatica had occurred, and the change in intraradicular blood flow was measured. After removal of the hernia, a similar procedure was repeated, and intraradicular blood flow was measured again. Results Intraoperative microscopy showed that the hernia was adherent to the dura mater of the nerve roots in all patients. The intraoperative reverse SLR test showed that the hernia compressed the nerve roots, and that there was marked disturbance of gliding, which was reduced to only a few millimeters. During the test, intraradicular blood flow showed a sharp decrease at the angle that produced sciatica, which lasted for 1 minute. Intraradicular flow decreased by 40% to 98% (average, 70.6% +/- 20.5%) in the L5 nerve root, and by 41% to 96% (average, 72.0% +/- 22.9%) in the S1 nerve roots relative to the blood flow before the test. At 1 minute after completion of the test, intraradicular blood flow returned to the value obtained at baseline. After removal of the hernia, all thepatients showed smooth gliding of the nerve roots during the second intraoperative test, and there was no marked decrease in intraradicular blood flow. Conclusions This study demonstrated that the blood flow in the nerve root is reduced when the nerve root is compressed in vivo.

Abstract: Macrophages in the periaxonal space and surrounding intact myelin sheath are the most prominent pathological feature of acute motor axonal neuropathy (AMAN). We describe this characteristic in nerve roots from paralyzed rabbits immunized with bovine brain ganglioside or GM1. IgG was deposited on nerve root axons. Distal nerve conduction was preserved, and late F wave components were absent during the acute phase. Initial lesions were located mainly on nerve root axons, as in human AMAN. This study thus provides supportive evidence that the rabbits constitute a model of AMAN.

Abstract: 1. Introduction to neuropathology 2. Elements of CT and MR neuroimaging 3. Developmental and perinatal neuropathology 4. Bacterial, fungal, and parasitic diseases of the central nervous system 5. Viral infections and prion diseases of the central nervous system (excluding retroviral diseases) 6. Neuropathology of acquired immunodeficiency syndrome 7. Injuries to the brain and spinal cord associated with ischemia 8. Cerebrovascular disease 9. Central nervous system trauma 10. Intoxications and metabolic diseases of the central nervous system 11. Neurodegenrative diseases (excluding Alzheimer's Disease) 12. Alzheimer's Disease 13. Diseases of CNS myelin 14. Introduction to neurooncology 15. Laboratory methods of brain tumor analysis 16. CNS tumors 17. Embryonal tumors of the CNS 18. Pituitary tumors and related lesions 19. Tumors of the peripheral nervous system (Including the Craniospinal Nerve Roots) 20. Inherited Tumor Syndromes involving the nervous system 21. Pathology of non-neoplastic, regional disorders of the spinal cord 22. Non-neoplastic diseases of the peripheral nervous system 23. Neuromuscular diseases

Abstract: Brain. 2002;125(pt 5):976-984. Cluster headache is a strictly unilateral headache that occurs in association with cranial autonomic features. We report a patient with a trigeminal nerve section who continued to have attacks. A 59-year-old man described a 14-year history of left-sided episodes of excruciating pain centred on the retro-orbital and orbital regions. These episodes lasted 1-4 h, recurring 2-3 times daily. The attacks were associated with ipsilateral ptosis, conjunctival injection, lacrimation, rhinorrhoea and facial flushing. From 1986 to 1988, he had trials of medications without any benefit. In February 1988, he had complete surgical section of the left trigeminal sensory root that shortened the attacks in length for 1 month without change in their frequency or character. In April 1988, he had further surgical exploration and the root was found to be completely excised; post-operatively, there was no change in the symptoms. From 1988 to 1999, he had a number of medications, including verapamil and indomethacin, all of which were ineffective. Prednisolone 30 mg orally daily rendered the patient completely pain free. Sumatriptan 100 mg orally and 6 mg subcutaneously aborted the attack after approximately 45 and 15 min, respectively. He was completely anaesthetic over the entire left trigeminal distribution. Left corneal reflex was absent. Motor function of the left trigeminal nerve was preserved. Neurological and physical examination was otherwise normal. MRI scan showed a marked reduction in the calibre of the left trigeminal nerve from the nerve root exit zone in the pons to Meckel's cave. An ECG-gated three-dimensional multislab MRI inflow angiogram was performed. No dilatation was observed in the left internal carotid artery during the cluster attack. Blink reflexes were elicited with a standard electrode and stimulus. Stimulation of the left supraorbital nerve produced neither ipsilateral nor contralateral blink reflex response. Stimulation of the right supraorbital nerve produced an ipsilateral response with a mean R2 onset latency of 36 ms and a contralateral response with a mean R2 onset latency of 32 ms. Lack of ipsilateral vessel dilatation makes the role of vascular factors in the initiation of cluster attacks questionable. With complete section of the left trigeminal sensory root the brain would perceive neither vasodilatation nor a peripheral neural inflammatory process; however, the patient continued to have an excellent response to sumatriptan. The case illustrates that cluster headache may be generated primarily from within the brain, and that triptans may have anti-headache effects through an entirely central mechanism. Comment: A truly remarkable case. It has been said that a single case can make one rethink everything about a disorder. Dr. Goadsby's group has demonstrated a potential “cluster generator” in the hypothalamus. Now, with this case, they provide evidence that in a patient with no peripheral afferent information and no internal carotid artery changes, sumatriptan still works—evidence of its central effects in cluster. SJT The efficacy of oral sumatriptan in this patient raises the possibility of loss of blood-brain barrier integrity. Might the surgical interventions have breached the BBB? It would be interesting to know whether a gadolinium MRI showed any evidence for this. DSM

Abstract: BACKGROUND AND PURPOSE: Occipital neuralgia syndrome can cause severe refractory headaches. In a small percentage of people, these headaches can be devastating and debilitating, with the potential for complete relief following surgical rhizotomy. We describe CT fluoroscopy–guided percutaneous C2–C3 nerve block for the confirmation of diagnosis of occipital neuralgia and for demonstrating to patients the sensory effects of intradural cervical dorsal rhizotomy before the definitive surgical procedure. METHODS: Seventeen patients with occipital neuralgia underwent 32 CT fluoroscopy–guided C2 or C2 and C3 nerve root blocks. Of the 17 patients, nine had occipital neuralgia following prior neck or skull base surgeries. On the basis of the positive results of the nerve blocks in terms of temporary pain relief, all 17 patients underwent unilateral (n = 16) or bilateral (n = 1) intradural C1 (n = 9), C2 (n = 17), C3 (n = 17), or C4 (n = 7) dorsal rhizotomies. All patients were followed up for a mean of 20 months (range, 5–37 months) for assessment of pain relief. Sixteen patients were assessed for degree of satisfaction with and functional state after surgery. RESULTS: All patients had temporary relief of symptoms after percutaneous CT-guided block (positive result) and felt that occipital numbness was an acceptable alternative to pain. Immediately after surgery, all patients had complete relief from pain. At follow-up, 11 patients (64.7%) had complete relief of symptoms, two (11.8%) had partial relief, and four (23.5%) had no relief. Seven of eight (87.5%) patients without prior surgery had complete relief of symptoms and one (12.5%) patient had partial relief, as opposed to complete relief in four of nine (44.4%), partial relief in one of nine (11.2%), and no relief in four of nine (44.4%) patients with a history of prior surgery. Because of the small number of patients, this difference was not statistically significant (P = .110). Eleven of 16 (68.8%) patients stated that the surgery was worthwhile. Eight of 16 (50%) patients felt they were more active and functional after surgery, whereas 25% felt they were either unchanged or less functional than before surgery. None of the patients without a history of prior surgery reported a decreased sense of functional activity following rhizotomy. CONCLUSION: CT fluoroscopy–guided percutaneous cervical nerve block is useful for the confirmation of occipital neuralgia, for demonstrating to patients the sensory effects of nerve sectioning, and possibly as a guide for selection of patients for intradural cervical dorsal rhizotomy. Although not statistically significant, there was a trend toward better response to rhizotomy in patients without prior head or neck surgery.

Abstract: The optimal time for brachial plexus nerve repair is debatable. In this study we examined whether early re-establishment of neurotrophic support from the periphery might reduce neuronal loss. In 14 adult rats, the C7 spinal nerve was transsected. All sensory cells of the dorsal root ganglion and spinal motor neurons projecting into the C7 nerve were labelled retrogradely. The proximal and distal portions of the C7 nerve were then reanastomosed by either primary repair or by a vascularised or conventional ulnar nerve graft. At 16 weeks postoperatively, the nerve repair had significantly reduced the loss of both sensory and motor C7 neurons. Most striking was that a 30% motor neuronal loss in the control was almost eliminated by early nerve repair. In the grafted animals, half of the surviving neurons had regenerated through the graft, with no difference between vascularised and conventional nerve grafts. These results suggest that early surgical intervention may promote neuronal survival and regeneration after injuries to the brachial plexus.

Abstract: The aim was to establish an accurate, reproducible, and simple method to evaluate functional recovery after different types of nerve injuries to the brachial plexus of rats. To that end, pawprints, measured as distance between the first and fourth and second and third digits, were used for evaluation of injuries including crush injury, transection/repair, or graft repair of the median, ulnar, and radial nerves. Immunocytochemistry of the C-terminal flanking peptide of neuropeptide Y (CPON) and neurofilaments was used to investigate the cell body response and axonal outgrowth, respectively. Functional recovery was dependent on the severity as well as on the level of the lesion. Neither a single injury to the median nerve nor an injury to the ulnar nerve affected the pawprint, while an injury to both these nerves or a single injury to the radial nerve caused impairment of pawprints. There was a rapid recovery after crush injury to these nerves compared to previous reports of a similar injury to the sciatic nerve. The pattern of axonal outgrowth was related to the severity of the lesion. A conditioning lesion, i.e., an initial lesion of the same nerve preceding a test injury by a few days, of both motor/sensory fibers led to a quicker functional recovery. Surprisingly, conditioning of only sensory fibers had nearly the same effect. The cell body response was dependent on the level of the nerve lesion. The upper extremity of rats might be useful to evaluate the effects of new repair methods after nerve injuries using functional evaluation with pawprints as a simple and accurate method.

Abstract: STUDY DESIGN The effect of an anti-tumor necrosis factor alpha (anti-TNFalpha) antibody on abnormal discharges caused by application of nucleus pulposus to the nerve root was investigated in an electrophysiologic study. OBJECTIVES To assess whether inhibition of TNFalpha can reduce nucleus pulposus-induced abnormal discharges. SUMMARY OF BACKGROUND DATA It has been shown that TNFalpha, a proinflammatory cytokine, is a key pathogenic factor in the development of nucleus pulposus-induced abnormal discharges as a pain sensation. However, the electrophysiologic mechanisms involved in sciatica after disc herniation still have not been elucidated. METHODS Extracellular activities of wide-dynamic-range neurons were assessed in 21 rats. Autologous nucleus pulposus harvested from the tail was applied to the L5 nerve root. The animals were simultaneously treated with antibodies to TNFalpha (anti-TNF + nucleus pulposus group) and with phosphate-buffered saline (nucleus pulposus group). As a control (control group), a similar volume of muscle was applied to the nerve root with phosphate-buffered saline. Responses of wide-dynamic-range neurons to noxious and innocuous stimuli were examined for 2 hours. RESULTS Discharges evoked during noxious stimulation and discharges after withdrawal of stimulation in the nucleus pulposus group were significantly higher than those in the control group (P < 0.05). In the anti-TNF + nucleus pulposus group, discharges after withdrawal of stimulation were remarkably inhibited, as compared with those of the nucleus pulposus group (P < 0.05). However, evoked discharges during stimulation apparently were not inhibited. Responses to innocuous stimulation did not change throughout the measurements. CONCLUSIONS These data indicate that application of TNFalpha antibodies to the nerve root partially prevents the nucleus pulposus-induced abnormal nociresponses. Therefore, anti-TNFalpha treatment may have a therapeutic effect on sciatica after lumbar disc herniation.

Abstract: Reconstruction of shoulder stability and movement in cases with complete paralysis of the brachial plexus was performed to improve the outcomes for universal function of prehension after double free-muscle transfer (Doi's procedure). In cases in which the C5 or C6 nerve root was available as a donor, neurotization of the supra-scapular nerve was performed with a nerve graft. If the C5 or C6 nerve root was not available, then the contralateral C7 nerve root was chosen as the donor motor nerve and was transferred to the suprascapular nerve by using a vascularized ulnar nerve graft. Seven cases with ipsilateral C4, C5, or C6 nerve root transfer to the suprascapular nerve and one with contralateral C7 transfer were evaluated, and the functional outcomes for the range of shoulder motion were compared with those for patients who had undergone arthrodesis of the humeroscapular joint or had undergone no procedures for shoulder function reconstruction. The patients who underwent supra-scapular nerve repair demonstrated statistically significantly better ranges of motion for flexion and abduction of the shoulder, compared with the other two groups. Shoulder function is important for achieving prehensile function among patients with complete paralysis of brachial function, when they undergo double free-muscle transfer.

Abstract: Apparatus and methods for performing spinal disc lesioning procedures while monitoring the temperature near the spinal nerve roots. A needle containing a thermocouple and an injection bore may be placed between the disc and a nerve root. Temperature near the nerve root may be monitored during the lesioning procedure and if raised to a point where damage to the nerve could occur, the procedure may be stopped before damage is done. Coolant may be injected through the injection bore to lower the temperature near the nerve root. Additional dual purpose needles may be placed on the disc adjacent the opposite nerve root or in the spinal canal at the level of the disc for additional control. A hollow, flexible tip electrode needle may be used to repair and lesion the disc tissue. Prior to lesioning, the electrode may be stimulated to assess motor nerve response and avoid motor nerve damage.

Abstract: The authors describe a new endoscopic technique to decompress lumbar nerve roots affected by spondylolysis. Short-term clinical outcome was evaluated. Surgery-related indications were: 1) radiculopathy without low-back pain; 2) no spinal instability demonstrated on dynamic radiographs; and 3) age older than 40 years. Seven patients, four men and three women, fulfilled these criteria and underwent endoscopic decompressive surgery. Their mean age was 60.9 years (range 42-70 years). No subluxation was present in four patients, whereas Meyerding Grade I slippage was demonstrated in three. For endoscopic decompression, a skin incision of 16 to 18 mm in length was made, and fenestration was performed to identify the affected nerve root. The proximal stump of the ragged edge of the spondylotic lesion, and the fibrocartilaginous mass compressing the nerve root were removed. The follow-up period ranged from 6 to 22 months (mean 11.7 months). Clinical outcome was evaluated using Gill criteria; in three patients the outcome was excellent, and in four it was good. This new endoscopic technique was useful in the decompression of nerve roots affected by spondylolysis, the technique was minimally invasive, and the clinical results were acceptable.

Abstract: An ergonomically and functionally improved combination nerve root retractor and sucker device, system, and methods of using such a nerve root retractor and sucker are provided. The nerve root retractor and sucker of the current invention having an adjustable geometry nerve root retractor/sucker shaft.

Abstract: Objective and importance Intradural-extradural dumbbell C2 schwannomas are rare. This report concerns two such cases with the intradural compartment located ventral to the spinal cord and involving both sensory and motor rootlets. Clinical presentation One patient was a 57-year-old woman with sensory disturbances in the right extremities and hyperreflexia in the left extremities. The other patient was a 73-year-old man who presented with tetraparesis, walking disability, atrophy of the nuchal and bilateral shoulder muscles, and pain in the right C2 dermatome. Intervention The extradural component of the tumor was removed first; next, the intradural component was removed successfully via the posterior approach combined with a C1-C2 laminectomy. The patients experienced symptomatic improvement without further deficits except for sensory impairment of the C2 dermatome in one of the patients. Conclusion Intradural-extradural dumbbell C2 schwannomas can be satisfactorily managed with a posterior approach. Removal of the extradural component and opening of the dural ring of the C2 nerve root are necessary for safe extraction of the intradural ventrally located component after debulking. These tumors may arise extradurally within the nerve sheath, extend intradurally and ventrally toward the spinal cord, and involve both sensory and motor rootlets.

Abstract: Study Design. Nerve root blood flow was intraoperatively measured before and after discectomy for lumbar disc herniation and compared with clinical features. Objective. To investigate the relation between nerve root blood flow changes and symptoms associated with lumbar disc herniation. Summary of Background Data. Several authors have reported that recovery of intraneural blood flow, which restores the supply of oxygen and other nutrients to the nerve tissue, is strongly related to the rapid improvement of nerve function after discectomy for lumbar disc herniation. However, no previous study has quantitatively assessed blood flow in the human nerve root in vivo. Methods. Nerve root blood flow was monitored in 21 patients with lumbar disc herniation using laser Doppler flowmetry (ALF 21 N; ADVANCE, Tokyo, Japan) during discectomy. Possible correlations were investigated between the blood flow rates and the following clinical features: age, duration of sciatica, presence or absence of neurologic deficits, latency to pain relief, and morphology of herniated discs. Results. The blood flow rate in 16 patients who reported immediate relief after discectomy was much greater than in 5 patients whose pain was not relieved immediately after surgery (141%vs 8%, P = 0.0364). The increase in the blood flow rate after discectomy was five times greater in patients with neurologic deficits than in patients without neurologic deficits (158%vs 36%, P = 0.0638). Conclusions. The results of the current study suggest that immediate relief from pain and resolution of neurologic deficits soon after surgery are the result of early recovery from nerve root ischemia after discectomy, and that ischemia caused by mechanical nerve root compression is mainly related to the mechanisms underlying sciatic pain production and neurologic deficits.

Abstract: entity. Objective. To raise awareness of this rare condition in the interpretation of preoperative magnetic resonance imaging scans and to assess the results of surgical treatment. Background. Symptomatic epidural varices presenting with radiculopathy are extremely rare, and the diagnosis is often missed in the preoperative evaluation. This condition commonly masquerades as a herniated nucleus pulposus. Diagnosis is often only made intraoperatively. Materials and Methods. Case 1 is a 40-year-old man presenting with acute exacerbation of lower back pain associated with radiculopathy down his right lower limb. Magnetic resonance imaging showed a paracentral disc prolapse. At operation, a congested epidural vein impinging on the L5 nerve root was noted with no intervertebral foramens stenosis. Excision of the vein was performed. The second case, a 50-year-old man with previous spinal instrumentation, was admitted for acute onset of radiculopathy down his left lower limb. At operation, an epidural varix compressing on the L4 nerve root was noted. Retrospectively, features of epidural varices were noted in the preoperative magnetic resonance imaging scans. Both patients reported resolution of symptoms after surgery. Results. Excision was done for the first patient, and coagulative ablation was done in the second patient. Both patients had symptomatic relief and neurologic recovery on follow-up. Conclusion. Our experience and the literature demonstrated that a favorable outcome with resolution of neurologic symptoms can often be achieved after excision or ablation of the epidural varices. [Key words: symptomatic epidural varices, radiculopathy, diagnostic magnetic resonance imaging, surgical excision, coagulative ablation, resolution of symptoms] Spine 2003;28:E347–E350

Abstract: In children and young adults who seek medical treatment for high-grade isthmic dysplastic spondylolisthesis, common clinical symptoms are referable to the lumbosacral spine and/or the lower extremities. Pain in the lumbosacral spine may be secondary to altered lumbosacral alignment and biomechanics. It also may be caused by malalignment of the entire spinal-pelvic axis as a result of anterior sagittal imbalance. Lower extremity radiculopathies involving the L5 nerve root(s) may be present, and in severe forms of spondylolisthesis crisis, marked entrapment of the cauda equina at L5-S1 may occur. High-grade isthmic dysplastic spondylolisthesis are treated surgically and should include appropriate central and foraminal decompressions at the L5-S1 level, followed by lumbosacral fusion. Partial reduction aiming at improving the slip angle (lumbosacral kyphosis) is more beneficial and provides less risk to the L5 nerve roots than complete reduction of the translational component of the slip. Solid anterior and posterior spinal fusion at L5-S1 appears to provide the best long-term results.

Abstract: Object Hemangioblastomas in the lumbosacral region are rare, and the authors of prior reports have not defined the surgical management, histopathological features, or outcome in a group of patients after resection of these tumors. To identify features that will help guide the operative and clinical management of these lesions, the authors reviewed data obtained in a series of patients with von Hippel—Lindau syndrome who underwent resection of lumbosacral nerve root hemangioblastomas. Methods Six consecutive patients (three men and three women; mean age at surgery 39 years [range 31–48 years]) who underwent operations for resection of lumbosacral nerve root hemangioblastomas were included in this study. The mean follow-up period was 23 months (range 6–45 months). Data derived from examination, hospital charts, operative findings, histopathological analysis, and magnetic resonance imaging were used to analyze surgical management and clinical outcome. The resected tumors were located in the lumbar (five case...

Abstract: Transforaminal epidural steroids are a commonly used technique for diagnosis and treatment of nerve root irritation secondary to herniated disc material. The recent reported occurrences of severe complications using the transforaminal technique have led to the search for a novel alternative that is both a safe and accurate method of steroid delivery. The technique described offers improved safety and diagnostic accuracy over traditional transforaminal steroid injections.

Abstract: Object The authors of clinical studies have demonstrated a significant association between the presence of extensive post—lumbar discectomy peridural scar formation and the recurrence of low-back and radicular pain Low-dose perioperative radiotherapy has been demonstrated to inhibit peridural fibrosis after laminectomy in animal models The present study was designed to evaluate the clinical efficacy of preoperative irradiation in patients with failed—back surgery syndrome due to peridural fibrosis who underwent reexploration and nerve root decompression Methods Ten patients with symptomatic post—discectomy peridural fibrosis were randomized Half of the patients underwent 700-cGy external-beam irradiation to the operative site 24 hours prior to reexploration and decompressive treatment of their symptomatic nerve root(s) (treatment group) and the other half underwent reexploration and decompressive treatment without preoperative irradiation (control group) All patients underwent simulated irradiation

Abstract: Object. When performing surgery, the extraforaminal window is very narrow at the L5—S1 level. The authors describe a microsurgical method for decompression of the L-5 nerve root trapped between a marginal osteophyte of the vertebral body and the transverse process. The procedure was performed in 16 patients with extraforaminal stenosis. Methods. The cranial part of the L5—S1 facet joint and the caudal portion of the pedicle and transverse process of L-5 were removed via a midline skin incision and partial resection of the pars interarticularis; a high-speed drill was used as was a surgical microscope. The affected nerve root was decompressed and mobilized cranially. Postoperatively all patients reported excellent relief of their sciatic pain, and there were no technique-associated complications. There was no recurrence during the follow-up period, that ranged from 14 to 70 months. Conclusions. The authors recommend this technique for the effective decompression of symptomatic extraforaminal L5—S1 stenosis...