Compressive Radiculopathy Research Articles

Endoscopic laser foraminoplasty and a aware-state surgery: a treatment concept and 2-year outcome analysis

Aware-state surgery has been used in this unit to identify the source of spinal pain in over 2500 patients as part of a process termed “viviprudence”. This process consists of clinical analysis, dynamic radiology and scanning tested by differential discography, endoscopy and patient feedback. This replaces guesswork with sighted diagnosis and allows keyhole tissue-preserving techniques to be used not only for the treatment of compressive radiculopathy but also for back pain, failed back syndrome, perineural scarring, multilevel degenerative disc disease, lateral recess stenosis and dynamic listhesis. This has led to the identification of new pathology and the refinement of the inclusion criteria for laser disc decompression and endoscopic laser foraminoplasty. Since 1994, an endoscopic system has been developed to explore the intervertebral foramen and epidural space via the postero-lateral route. The system has been used to address lateral recess stenosis, epidural scarring, osteophytosis, settlement, listhesis, disc extrusion and sequestration and failed back syndrome. The objective has been the endoscopic aware-state definition of the source of pain with decompression of the foramen, mobilisation and neurolysis of the exiting and transiting nerves and ablation of osteophytes and other causes of failed back syndrome confirmed endoscopically. This prospective study involved day-case endoscopic laser foraminoplasty performed on 101 men, and 99 women with an average age of 56 years (range, 22–83 years). They were followed for an average period of 34 months (range, 26–43 months). The average preoperative duration of symptoms was 5.6 years (range, 5–11 years). A total of 46 patients had had one to four previous open operations, and 14 patients were on narcotic analgesics prior to surgery. At other centres, 106 of these patients were evaluated and open surgical procedures were not deemed appropriate or likely to benefit. A cohort integrity of 96% was maintained at the final follow-up. Back, buttock and leg pain were separately compared and analysed using the Oswestry Disability Index, a patient satisfaction scoring scale, a visual analogue pain scale and a patient target achievement score. Using an Oswestry Disability Index of 50 or more to determine good and excellent outcomes, 55% of patients exceeded this score for back pain, 52% for buttock pain and 53% for leg pain. In patients with one prior operation, the corresponding figures were 51%, 33% and 29%. These results indicate that endoscopic laser foraminoplasty provides a minimalist means of exploring the extraforaminal zone, the foramen and the epidural space and performing discectomy, osteophytectomy and neurolysis. It incorporates the prophylactic advantage of foraminal undercutting and provides a promising means of identifying and treating the pain of failed back surgery and back pain and sciatica of indeterminate origin. It serves to identify and localise the source of pain generation. Endoscopic laser foraminoplasty avoids the morbidity associated with open spinal surgery and serves as a useful means of effecting keyhole neurolysis without extensive exploration and fusion. Current improvements in equipment promise wider application and more encouraging results in the future.

Murine nucleus pulposus-derived cells secrete interleukins-1-beta, -6, and -10 and granulocyte-macrophage colony-stimulating factor in cell culture.

Cultures established from murine disc-derived cells were stimulated by lipopolysaccharide. The cells' capacity to secrete proinflammatory cytokines and interleukin-10 with and without lipopolysaccharide stimulation was determined using enzyme-linked immunosorbent assays. To determine the capacity of disc-derived cells to secrete proinflammatory cytokines, and the effect of lipopolysaccharide stimulation on such secretion. The pathophysiology of compressive radiculopathy is unclear. Inflammation is a possible explanation. Proinflammatory cytokine secretion was demonstrated in herniated nucleus pulposus. It is unknown whether these cytokines are secreted from disc-derived cells or from infiltrating inflammatory cells in the herniated nucleus pulposus. Discs were microsurgically harvested from inbred mice and cut to allow the nucleus pulposus to establish cell culture. A study group was exposed to lipopolysaccharide stimulation. Media were harvested from the study and control groups 24 hours later. Secretion of interleukins-1-, -6, and -10, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-alpha were determined using enzyme-linked immunosorbent assays. Basal secretion of interleukins-6 and -10, but no basal secretion of interleukin-1-, granulocyte-macrophage colony-stimulating factor, or tumor necrosis factor-alpha was detected. Secretion of interleukin-1- rose from zero to 27.69 pg/10(5) cells, and granulocyte-macrophage colony-stimulating factor secretion rose from zero to 9.77 pg/10(5) cells after lipopolysaccharide stimulation. A 75-fold increase in interleukin-6 secretion and a 150-fold increase in interleukin-10 secretion were detected after stimulation with lipopolysaccharide. No tumor necrosis factor-alpha secretion was detectable. All result had high statistical significance (all P < 0.001). Cultured murine disc-derived cells have the capacity to secrete proinflammatory cytokines and interleukin-10 in the absence of inflammatory cells. This finding supports the hypothesis that disc-derived cells are capable of initiating or amplifying an inflammatory process.

Dermatomal SEP Testing in the Workup of Lumbosacral Radiculopathy

ABSTRACTDermatomal somatosensory evoked potentials (DSEPs) have been used in the diagnosis of patients with compressive radiculopathies. Several investigators have reported yields high enough to warrant the possible clinical use of dermatomal SEPs in the identification of lumbar root entrapment; however, the test is relatively insensitive. Since the validity and the utility of dermatomal SEPs remains controversial, the purpose of this investigation is to test the hypothesis that the routine clinical documentation of dynamic lumbosacral nerve root pathology may be complemented by dermatomal SEPs. We studied the clinical, electrophysiological, and neuro-imaging features of ten patients in whom DSEPs added significant data to the work-up of either unilateral compressive radiculopathy or in more complex structural problems involving herniated disc pathology plus a tethered cord (two cases). Technical methodology and waveform analysis, in particular the latency of N1 as defined by onset of downward slope from baseline to P1, illustrated the reliability of DSEPs in both our normal and abnormal populations. DSEPs show a limited potential for improving upon a standard electrodiagnostic evaluation. We suspect that the neural generator for the N1 waveform lies within the primary somatosensory cortices on the medial surfaces of the postcentral gyri.

Anterior cervical discectomy without fusion in cervical disc herniation with radicular complaints.

Only cervical disc herniation that provokes root compression unresponsive to conservative treatment should be selected for operation. The operative technique must allow adequate removal of the disc and relieve any root pressure without distressing the patient. Operative decompression of the root can be attained via laminectomy and arthrotomy or by way of an anterior approach. With this second procedure, the ventral discectomy can be done in conjunction with an interbody fusion. We report our experience with 216 patients who unterwent anterior cervical microsurgical discectomy without fusion between 1980 and 1944. All these patients were suffering from compressive cervical radiculopathy caused by disc displacement without significant degenerative deformation of the motion segment and without manifest segmental instability. The follow-up ranged between 6 and 185 months (average 71 months) in the 175 patients in whom it was possible. Only in 7 patients (4 %) is the result unsatisfactory; 79 patients (45 %) are completely free of symptoms 99; (56.6 %) are very satisfied and 45 (25.7 %) satisfied with the result of the procedure.

P135 Retest reliability in facial nerve conduction studies

The H-reflex on stimulation of the tibial nerve in the popliteal fossa is routinely used in the diagnosis of first sacral (S1) nerve-root radiculopathy. The H-reflex latency, however, is considered to lack sensitivity since a small change from the focal root pathology can be diluted in a relatively long reflex latency. We have studied the soleus H-reflex elicited by stimulation of the S1 nerve root at the S1 foramen. The normal values for the S1-foramen H-reflex have been reported in a previous study, but there are no definitive reports in patients with S1 radiculopathy. This study was undertaken to determine whether stimulating at the S1 nerve root can improve the utility of the H-reflex for detecting an S1-root lesion.A randomised paired-study design was utilised to evaluate two H-reflexes: one elicited with tibial nerve stimulation and one elicited with S1-root stimulation. Fifty-five patients with unilateral S1 radiculopathy, confirmed by clinical, electrodiagnostic and magnetic resonance imaging (MRI) evidences were studied. A high-voltage electrical stimulator was used to elicit H-reflexes bilaterally at the S1 foramen and L4/L5 spine level. Latencies were compared with previously generated normal values and similar responses from the asymptomatic leg, focussing on the interval between the peak of M- and H-waves (HMI).On the symptomatic side, 39 of the 55 patients had abnormal tibial H-reflex latencies and 54 patients had abnormal responses on S1-foramen stimulation (absent in 18; HMI prolonged >0.4 ms in 36). On the asymptomatic side, all 55 patients had normal tibial H-reflexes, and 52 had normal responses on S1-foramen stimulation. In three patients, the HMI was abnormal on S1-foramen stimulation. In 46 patients tested with L4/L5-level stimulation, H-reflex was present in 39 and absent in seven. The latency of the M-wave to S1 stimulation was normal.Abnormal S1-root H-reflexes reveal lesions at the S1 root in patients with normal tibial H-reflexes; therefore, enhancing diagnostic sensitivity. The appearance of the H-reflex to L4/L5-level stimulation in patient with absent H-reflex to S1-foramen stimulation further localises the site of S1 nerve-root lesion to the L5/S1 spine level. Thus, H-reflex to S1-root stimulation significantly increases the diagnostic sensitivity for S1 radiculopathy.In our study, the S1-root H-reflex with high-voltage electrical stimulation has shown greater sensitivity than the tibial H-reflex in evaluating S1 compressive radiculopathies. An abnormal S1-root H-reflex helps to localise the lesion to the S1 root in patients with concurrent abnormal tibial nerve H-reflex, which may increase diagnostic specificity.

Micro-technological anterior discectomy without fusion in cervical disk displacement with radicular symptoms

Only cervical disc herniation that provokes root compression unresponsive to conservative treatment should be selected for operation. The operative technique must allow adequate removal of the disc and relieve any root pressure without distressing the patient. Operative decompression of the root can be attained via laminectomy and arthrotomy or by way of an anterior approach. With this second procedure, the ventral discectomy can be done in conjunction with an interbody fusion. We report our experience with 216 patients who underwent anterior cervical microsurgical discectomy without fusion between 1980 and 1944. All these patients were suffering from compressive cervical radiculopathy caused by disc displacement without significant degenerative deformation of the motion segment and without manifest segmental instability. The follow-up ranged between 6 and 185 months (average 71 months) in the 175 patients in whom it was possible. Only in 7 patients (4%) is the result unsatisfactory; 79 patients (45%) are completely free of symptoms 99; (56.6%) are very satisfied and 45 (25.7%) satisfied with the result of the procedure.

Magnetic Stimulation as a Diagnostic Tool in Cervical Nerve Root Compression and Compression-Induced Neuropathy

Magnetic stimulation of motor cortex and cervical spinal cord was used to assess motor impairment in patients with either cervical nerve root compression or myelopathy. Evoked potentials were recorded from biceps brachii and abductor pollicis brevis. Our interest centered on whether the paresis resulting from root compression is accompanied by an increased latency of magnetically evoked muscle potentials and whether latency is increased in cases of cervical root compression or myelopathy in which no paresis occurs. Latency increase does appear to be a moderately good indicator of disturbed nerve conduction. In particular, prolonged latencies in cases of "subclinical" paresis could be used as an important diagnostic tool for the early detection of motor deficits in cervical compression radiculopathy and myelopathy.

Identification and Management of Radiculopathy

Proper identification of compressive radiculopathy is essential before any treatment can be undertaken. The differential recognition of different pain patterns, sensory symptoms, and neurologic deficits provides the clinical guide to specific nerve root involvement. Appropriate radiology and imaging must correlate with symptoms and signs. Management includes surgical intervention when indicated for relief of radicular pain and restoration of function.

Motor evoked responses after lumbar spinal stimulation in patients with L5 or S1 radicular involvement

Motor evoked responses were recorded bilaterally in the tibialis anterior and soleus muscles after lumbar spinal stimulation in 45 patients suffering from L5 or S1 radiculopathies due to disc protrusion, and in 25 healthy controls. A significant prolongation ( P < 0.01) of motor evoked response latency was observed in 72% of the patients with L5 radiculopathy and in 66% of the patients with S1 radiculopathy. These anomalies were observed in patients with objective neurological signs as well as in patients free of objective signs. These findings indicate that subclinical compressive radiculopathy can be detected by this method which represents a useful adjunct in the assessment of radicular pain of discopathic origin.

Fatiguing weakness: An initial symptom in cervical compressive radiculopathy

Exercise-induced weakness (fatiguing) is described in three patients with cervical compressive radiculopathy. In all three cases, the patients had symptoms only while at work, and in two cases, symptoms occurred in life-threatening situations. All patients had seen several physicians with a functional diagnosis being considered in all cases because of symptoms only at work and the absence of objective findings during examination. Precise history and examination techniques led to the correct diagnosis and treatment after appropriate investigation. The fatiguing weakness in our cases is thought to be a manifestation of early or mild neurologic involvement unmasked by exercise, rather than a manifestation of compression or ischemia.

Great-toe extensor reflexes in the diagnosis of lumbar disc disorder.

The tendon reflexes obtainable from the extensors of the great toe require practice to elicit, but have been found particularly valuable in the assessment of lesions affecting the fifth lumbar nerve root, especially compression radiculopathy from disc prolapse.