Mårten Annertz

A prospective and consecutive study of surgically treated lumbar spinal stenosis: Part I : Clinical features related to radiographic findings

Study Design. A prospective study of consecutive patients undergoing surgery for central lumbar spinal stenosis. Objectives. To evaluate symptoms and signs in patients undergoing surgery for central spinal stenosis and to correlate the findings to age, preoperative duration of symptoms, and radiographically detected constriction. Summary of Background Data. The degree of constriction of the spinal canal considered to be symptomatic of lumbar canal stenosis is not clear, nor is the relation between the clinical appearance of the disease and the degree of radiographically verified constriction. Material and Methods. One hundred five consecutive patients scheduled for decompression surgery were included in a prospective study. The day before surgery, all patients were interviewed and examined, using a defined protocol that included data on age, gender, preoperative duration of symptoms, walking ability, and occurrence of pain at rest and at night. Included were data recording straight leg raising test results, reflex disturbance, and extensor hallucis longus muscle weakness. All radiographs were examined by a neuroradiologist. The anteroposterior diameters at each site from L1‐L2 to L5‐S1 were recorded. For the computer analysis, the site of and width at the narrowest site was registered, as well as the number of sites with an anteroposterior diameter of less than 10 mm. A statistical analysis was performed using chi‐square analysis, nonparametric tests, analysis of variance, and logistic regression. Results. Pain at rest and at night was reported by 68 and 60 patients, respectively, and was more common in younger patients (P = 0.065 and 0.015, respectively). A severe reduction of walking ability (<0.5 km) was reported by 70 patients. The straight leg raising test results were negative in 70 patients, positive >60° in 16, positive 30‐60° in 14, and positive <30° in 5. Younger patients had a positive straight leg raising result (P = 0.028, analysis of variance) more often. Reflex disturbances correlated to patient age: Older patients had reflex disturbances more often. There was no correlation between preoperative duration and pain or neurologic disturbances: Patients with longer preoperative duration of symptoms did not demonstrate more severe symptoms. There was a total myelographic block of the spinal canal in 13 patients. The mean value of the anteroposterior diameter in the other patients was 6.8 mm (range, 4‐11 mm). In patients younger than 70 years L4‐L5 was the site for the most pronounced constriction, whereas L3‐L4 was the narrowest site in the older patients. Degenerative spondylolisthesis was found in 32 patients, and they had a more pronounced constriction of the spinal canal (5.6 mm compared with 6.7 mm in those without displacement, P = 0.02). There was a (nonsignificant) tendency toward more walking disturbances in patients with a more pronounced constriction of the spine. There was no correlation between reflex disturbances or extensor hallucis longus weakness and radiographically detected constriction. Conclusion. Pain was more intense and positive straight leg raising test results were more common in younger patients, whereas reflex disturbances were more common in the elderly. The vertebral site for the lowest anteroposterior value was higher with higher age. Preoperative duration did not affect the severity of symptoms or signs. Patients with more pronounced stenosis tended to have a more severe reduction of walking ability. There was no correlation between symptoms and signs and radiographically detected constriction.

No relationship between epidural fibrosis and sciatica in the lumbar postdiscectomy syndrome : a study with contrast-enhanced magnetic resonance imaging in symptomatic and asymptomatic patients

Study Design. Symptomatic patients were retrospectively analyzed and compared with a control group from an ongoing prospective and consecutive study. Objectives. To determine the presence and extent of epidural fibrosis in patients with and without recurrent sciatic pain after previous lumbar discectomy, contrast-enhanced magnetic resonance images were evaluated and correlated with surgical findings in the symptomatic patients. Recurrent hemia and bony stenosis were ruled out as the probable causative agent, as well as any morphologic explanation other than fibrosis. Summary of Background Data. Repeat surgical results for patients with the lumbar postdiscectomy syndrome with epidural fibrosis alone are often unfavorable. The pathogenic role of epidural fibrosis, however, has not been established. Methods. The magnetic resonance images of eight patients with recurrent or persistent sciatic pain after lumbar discectomy were compared with those of eight asymptomatic patients constituting a control group. All were examined with magnetic resonance imaging on a 0.3 T unit before and after intravenous injection of gadolinium-DTPA, and clinically, 6 months to 4 years after surgery. The symptomatic patients subsequently underwent reoperation. Results. Fourteen patients had focal or diffuse epidural fibrosis around the nerve root and/or the thecal sac at the operated level, whereas the postoperative findings for two patients were “normal,” one in the operated and one in the control group. No difference between the groups regarding mass effect or affection of the nerve roots or thecal sac was noted. At reoperation of the eight symptomatic patients, fibrosis was the only pathologic finding in all cases except one, in which surgery confirmed the normal finding on magnetic resonance imaging. Six of the eight operated patients had recurrent or persistent symptoms within a year of the reoperation. Conclusion. No differences regarding the presence and extent of epidural fibrosis between the symptomatic and asymptomatic patients could be demonstrated with contrast-enhanced magnetic resonance imaging. The role of epidural fibrosis as the causative agent in the lumbar postdiscectomy syndrome is questioned.

Transforaminal steroid injections for the treatment of cervical radiculopathy: a prospective and randomised study

Steroid injections are often employed as an alternative treatment for radicular pain in patients with degenerative spinal disorders. Prospective randomised studies of the lumbar spine reveal contradictory results and non-randomised and most often retrospective studies of the cervical spine indicate pain reduction from steroid injections. No prospective randomised study on transforaminal steroid injections for the treatment of radicular pain in the cervical spine focusing on short-term results has been performed. Forty consecutive patients were employed for the study. The inclusion criteria were one-sided cervical radiculopathy with radicular distribution of arm pain distal to the elbow and corresponding significant degenerative pathology of the cervical spine at one or two levels on the same side as the radicular pain and visualised by MRI. A transforaminal technique was used for all injections. A positive response to a diagnostic selective nerve root block at one or two nerve roots was mandatory for all patients. The patients were randomised for treatment with steroids/local anaesthetics or saline/local anaesthetic. Only the neuroradiologist performing the blocks was aware of the content of the injection; all other persons involved in the study were blinded. Follow up was made 3 weeks after the randomised treatment by a clinical investigation and with a questionnaire focusing on the subjective effects from the injections. At follow up, there were no differences in treatment results in the two patient groups. Statistical analysis of the results confirmed the lack of difference in treatment effect. Further studies have to be performed before excluding steroids in such treatment and for evaluating the influence of local anaesthetics on radiculopathy in transforaminal injections.

Paragangliomas of the spinal canal

Abstract We report the clinical MRI and histopathological features of five consecutive cases of spinal paraganglioma. Three intradural tumours were found in the typical location (two at the L4, one at the S2 level); one intradural extramedullary tumour arose at an unusual level, from the ventral C2 root, and one extradural tumour growing along the L5 nerve root sheath had an aggressive growth pattern with early, local paraspinal recurrence and, eventually, intradural metastatic spread. This type of growth pattern has not been described previously. Paragangliomas of the spinal canal are more common than previously thought and can be located anywhere along the spine, although the lumbosacral level is the most common. Their appearance on MRI can not disinguish them from other tumours in the spinal canal. Even though paragangliomas in general are benign and slowly growing their growth pattern can vary and be more aggressive, to the point of metastatic spread.

Selective diagnostic cervical nerve root block - correlation with clinical symptoms and MRI-pathology.

SummaryBackground. The aim of this study is to describe the method of a cervical selective diagnostic nerve root block (SNRB) technique and assess its ability to correlate clinical symptoms with MRI findings in patients with cervical radicular pain and a single level degenerative disease. Methods. Twenty consecutive patients with cervical radiculopathy and correlating single level MRI pathology were studied. All patients underwent clinical investigation and neck and arm pain measurement with visual analog scales (VAS). The last 10 consecutive patients also underwent provocation with active neck motion when arm and neck pain were measured. They all underwent SNRB and 1 ml local-anesthesia (Mepivacaine 10 mg/ml) was injected, with the aid of fluoroscopy, close to the nerve-root. The VAS estimation and clinical investigation including provocation were repeated 30 minutes after the block.Criteria for a positive block response are a significant subjective pain reduction and at least 50% VAS pain reduction in the arm. Findings. For the whole group mean VAS arm pain reductions were 86% and mean VAS neck pain reductions were 65%. When the results from the provocation were added all patients had a positive block. Eighteen were operated on by an anterior procedure and all 18 were free from radicular pain at follow up. Interpretation. The block procedure seems relevant for revealing a relationship between radiological pathology and clinical symptoms and signs.

Selective diagnostic nerve root block for the evaluation of radicular pain in the multilevel degenerated cervical spine

In patients with radiculopathy due to degenerative disease in the cervical spine, surgical outcome is still presenting with moderate results. The preoperative investigations consist of clinical investigation, careful history and most often magnetic resonance imaging (MRI) of the cervical spine. When MRI shows multilevel degeneration, different strategies are used for indicating which nerve root/roots are affected. Some authors use selective diagnostic nerve root blocks (SNRB) for segregating pain mediating nerve roots from non-pain mediators in such patients. The aim of the present study is to assess the ability of transforaminal SNRB to correlate clinical symptoms with MRI findings in patients with cervical radiculopathy and a two-level MRI degeneration, on the same side as the radicular pain. Thirty consecutive patients with cervical radiculopathy and two levels MRI pathology on the same side as the radicular pain were studied with SNRBs at both levels. All patients underwent clinical investigation and neck and arm pain assessment with visual analogue scales (VAS) before and after the blocks. The results from the SNRBs were compared to the clinical findings from neurological investigation as well as the MRI pathology and treatment results. Correlation between SNRB results and the level with most severe degree of MRI degeneration were 60% and correlation between SNRB results and levels decided by neurological deficits/dermatome radicular pain distribution were 28%. Twenty-two of the 30 patients underwent treatment guided by the SNRB results and 18 reported good/excellent outcome results. We conclude that the degree of MRI pathology, neurological investigation and the pain distribution in the arm are not reliable parameters enough when deciding the affected nerve root/roots in patients with cervical radiculopathy and a two-level degenerative disease in the cervical spine. SNRB might be a helpful tool together with clinical findings/history and MRI of the cervical spine when performing preoperative investigations in patients with two or more level of degeneration presenting with radicular pain that can be attributed to the degenerative findings.

Serial MRI in the early postoperative period after lumbar discectomy

The aim of this study was to determine MRI findings in patients successfully operated upon for lumbar disc herniation. We investigated 20 patients with a successful outcome after L4-5 or L5-S1 disc operations clinically and with MRI preoperatively, and at 5 days, 6 weeks, and 4 months after surgery. Postoperatively, T1- and T2-weighted images were obtained. At 4 months gadolinium-enhanced images were added. Pronounced intraspinal MRI changes were seen during follow-up. Deformation of the dural sac was seen in 13 patients preoperatively, in 19 at 5 days after operation, in 15 at 6 weeks, and in 12 at 4 months. Nerve root involvement was seen in all cases both preoperatively and at 5 days after operation, in 17 at 6 weeks, and in 15 at 4 months. No correlation between symptoms or the straight leg raising test and the size or nature of the abnormal tissue in the spinal canal postoperatively could be demonstrated. It was concluded that early postoperative MRI after lumbar discectomy must be interpreted carefully, and that oedema and scar formation are probable reasons for difficulties in interpretation.

ISTHMIC LUMBAR SPONDYLOLISTHESIS WITH SCIATICA MR imaging vs myelography

Seventeen patients with sciatica and isthmic lumbar spondylolisthesis were studied with magnetic resonance (MR) imaging. In 13, myelography was also performed: 5 had dural sac deformation and root sleeve shortening, 2 had deformation with unilateral root sleeve shortening, one had bilateral root sleeve shortening only, and one had sac deformation only. In 4, myelography was normal. On sagittal MR examinations the neural foramen had an altered shape bilaterally with the long axis horizontal in all cases. In addition to altered shape the following was found in the 33 foramina evaluated. I: normal nerve (n = 8); II: compressed nerve (n = 16); III: disappearance of fat, nerve not possible to identify (n = 9). In patients with unilateral sciatica, the degree of foraminal stenosis correlated well with the side of symptoms. Coronal views showed the course of the nerve and pedicular kinking. Eight patients underwent decompressive surgery which revealed nerve compression by hypertrophic fibrous tissue and pedicular kinking, which correlated well with the findings on MR. Since the site of nerve compression often was peripheral to the root sleeves, myelography did not give complete information.

Mondini-like malformation mimicking otosclerosis and superior semicircular canal dehiscence.

In 2003, it was reported that superior semicircular canal dehiscence can mimic otosclerosis because of low-frequency bone conduction hearing gain and dissipation of air-conducted acoustic energy through the dehiscence. We report the case of a 17-year-old girl with left-sided combined hearing loss thought to be due to otosclerosis. Bone conduction thresholds were -10 dB at 250 and 500 Hz and she had a 40 dB air-bone gap at 250 Hz. When a tuning fork was placed at her ankle she heard it in her left ear. Acoustic reflexes and vestibular evoked myogenic potentials could be elicited bilaterally. Imaging of the temporal bones showed no otosclerosis, superior semicircular canal dehiscence or large vestibular aqueduct, but a left-sided, Mondini-like dysplasia of the cochlea with a modiolar deficiency could be seen. Mondini-like cochlear dysplasia should be added to the causes of inner-ear conductive hearing loss.

Posterior wiring without bony fusion in traumatic distractive flexion injuries of the mid to lower cervical spine. Long-term follow-up in 30 patients.

Thirty-four patients with traumatic distractive flexion injuries in the mid to lower cervical spine were treated with posterior wire stabilization without bony fusion from January 1981 through May 1987. Fifteen had cord involvement, and nine had root involvement. Ten were neurologically intact. Thirty patients were followed for a mean of 38 months. Two neurologically intact patients had root deficits postoperatively. One patient was reoperated because of redislocation due to a spinous process fracture. Mean loss of lordosis was 7.5°, Eight patients had a wire break at follow-up, but no case of late instability was observed. Sixteen patients had signs of spontaneous anterior inter-body fusion at follow-up, and 11 patients had signs of posterior fusion. Twenty-four patients complained of late—but in most cases—minor pain. These results indicate that simple posterior wiring without bony fusion is a reliable method to obtain good immediate stability in traumatic distractive flexion injuries of the mid to lower cervical spine. The wires provide sufficient stability during the time of soft tissue healing.