Gordon Findlay

Report of a controlled clinical trial comparing automated percutaneous lumbar discectomy and microdiscectomy in the treatment of contained lumbar disc herniation.

Study Design The results of a randomized controlled trial comparing automated percutaneous lumbar discectomy (APLD) with lumbar microdiscectomy for the treatment of small contained lumbar discal herniations are reported. All patients gave full informed consent and were assessed by an independent observer. Seventy-one patients with radiologically confirmed small contained lumbar disc herniations were randomly assigned to undergo either APLD or lumbar microdiscectomy. All patients were formally assessed by the independent assessor using the Macnab outcome classification at 3 weeks, 2 months, and 6 months after the procedure with follow-up being continued for the duration of the study. Objective The objective was to complete the first randomized and blinded study with sufficient numbers to provide a valid statistical evaluation of these procedures. Summary of Background Data No previous randomized controlled study comparing these methods has been previously reported. Methods Each procedure was performed by the same surgeon using standard techniques. Statistical analysis was by the chi-square method. Results In the APLD group only 9 of 31 (29%) had satisfactory outcomes as compared to 32 of 40 (80%) for the microdiscectomy group. Of those patients in the APLD group who had an unsatisfactory outcome and who then opted to undergo surgery (20 of 22 patients), the final success rate was only 65%. Thus, the cumulative success rate of the group initially randomized to APLD including those undergoing either APLD alone or APLD and microdiscectomy after unsuccessful APLD was 22 of 31 (71%). Conclusion In this group of patients, APLD is seen to be ineffective in the treatment of contained lumbar disc herniation.

Differences in low back pain behavior are reflected in the cerebral response to tactile stimulation of the lower back.

Study Design. Two groups of patients with chronic low back pain (cLBP) were scanned with functional magnetic resonance imaging during stimulation of the lower back; those showing 4 or 5 positive Waddell signs (WS-H) and those showing 1 or none (WS-L) as an index of pain-related illness behavior. Objective. We hypothesized that patients showing good versus poor adjustment to cLBP mobilize cortical affective-cognitive functions differently in response to sensory stimulation and show increased reorganization of somatosensory cortex corresponding to the back. Summary of Background Data. Some patients with cLBP go on to develop significant disability while the majority do not, and physical disease or psychosocial factors alone do not account for the difference. Neuroimaging studies have suggested abnormalities in cortical pain modulation systems can lead to variable pain and behavioral responses, which may account for these differences. Methods. Fifteen WS-L and 13 WS-H patients were scanned with functional magnetic resonance imaging while receiving intense tactile stimulation to the lower back. Questionnaire measures of psychosocial function were also collected. Results. There were no significant differences in cLBP duration or lumbar stimulation tolerance threshold between the 2 groups. Significantly more activation was seen in the WS-L versus WS-H group in regions previously associated with normal affective-cognitive processing of sensory input including posterior cingulate and parietal cortices; the magnitude of this activation negatively correlated with catastrophizing scores. WS-H patients showed a modest medial shift in primary somatosensory cortex activation relative to the WS-L group. Conclusion. Successful adjustment to cLBP is associated with a patients ability to effectively engage a sensory modulation system. In patients in whom such activation does not occur, subjective lack of control maypredispose to altered affective and behavioral responses with poor adjustment to pain. Pain experience may be furthermodified by reorganization of somatosensory cortex, contributing to maintenance of the chronic pain state.

Can hindbrain decompression for syringomyelia lead to regression of scoliosis

Abstract Scoliosis in childhood develops secondary to syringomyelia in some children. The existing literature does not provide a clear answer as to whether surgical treatment of the syrinx can allow subsequent improvement of the spinal deformity, thus preventing the need for scoliosis surgery. This series comprised 16 patients with syringomyelia who presented with significant scoliosis in the absence of major neurological deficit. All underwent a hindbrain decompression, and follow-up ranged from 1 to 6 years (mean 2.5 years). Subsequent deformity surgery was necessary in eight cases, but the scoliosis was seen to improve or arrest its progression in six (37.5%). Improvement was found to be statistically more likely in children of younger age at the time of syrinx surgery and in those with left thoracic curves. Improvement occurred in 71.4% of those under the age of 10 at the time of hindbrain decompression.

Outcome predictors and complications in the management of intradural spinal tumours.

The results of the management of 115 patients with intradural spinal tumours are presented. Data was collected retrospectively from the case notes. Tumours were categorized as intramedullary or extramedullary for statistical analysis. Meningioma, schwannoma and ependymoma accounted for 70% of tumours. Complete macroscopic excision was achieved in 84% of extramedullary and 54% of intramedullary tumours. There were two post-operative deaths, one of which was secondary to methacillin-resistant staphylococcus aureus (MRSA) meningitis. Cerebrospinal fluid leak (10%) and meningitis (7%) were the commonest complications. Ninety-six percent of patients with extramedullary tumours improved or remained unchanged on the Frankel scale. In the intramedullary group, 82% remained unchanged or improved after treatment. Pre-operative functional status was a predictor of good post-operative function for intra- and extramedullary tumours and for intramedullary tumours a good post-operative Frankel score predicted long-term survival.

The value of MR imaging in differentiating between hard and soft cervical disc disease: a comparison with intraoperative findings.

Abstract The aim of this study is to assess the accuracy of MRI alone in the differentiation of soft cervical disc protrusion from osteophytic compression in cervical disc disease. In a retrospective study, the MRI scans of 41 patients with cervical disc disease, who had previously undergone surgery, were presented to three independent observers, randomly on two different occasions, to identify the accuracy of the diagnosis of the presence of hard or soft disc or both as a cause of compression. The observers (two neurosurgeons and one neuroradiologist) were not involved with the treatment of the cases at any stage and were unaware of the surgical findings. Their observations were compared with those of the surgeon recorded at operation. The intra-observer agreement was poor for diagnosis into three categories as hard or soft disc or both. In distinguishing between the presence or absence of hard disc, there was moderate to good (Kappa = 0.6) intra observer and fair to moderate (Kappa = 0.4) interobserver agreement. The sensitivity of diagnosis of a hard disc was high (87%) but specificity was low (44%), due to the overestimation of the presence of hard disc. There was a significantly higher incidence of hard disc in the elderly age group (76% over the fifth decade, P = 0.0073). It is concluded that MRI alone is not a very efficient diagnostic tool in distinguishing between hard and soft disc in the cervical disc disease.

Thoracic spinal stenosis in two brothers due to vitamin D-resistant rickets

SummaryX-linked hypophosphataemic vitamin D-resistant rickets is a rare cause of spinal canal stenosis. Two brothers with this condition presented in adulthood with thoracic myelopathy due to spinal canal stenosis. Both were treated by laminectomy using diamond-tipped burrs, with symptomatic improvement.

Multiple schwannomas: report of two cases

In this paper authors present two cases of multiple schwannomas without the features of neurofibromatosis (NF). The authors retrospectively reviewed the hospital charts, radiology films, operative notes and pathology slides of these two patients. There was no family history of neurofibromatosis. The two patients had contrast enhanced MRI, which was negative for vestibular schwannomas. Both underwent surgical excision of symptomatic lesions. Histopathology confirmed these lesions as schwannomas. Molecular genetic analysis in case 1 demonstrated two distinct mutations of the NF2 gene in two different schwannomas, with concomitant loss of heterozygosity in both tumours. In contrast peripheral blood lymphocytes did not reveal mutations of NF2. The authors recommend surgery for symptomatic lesions. Asymptomatic tumours can be monitored. Regular follow up is essential as they may develop fresh lesions at any time. The relevant literature is discussed.

Iatrogenic spinal infection following epidural anaesthesia: case report

We present a case of epidural spinal abscess as a rare complication of epidural anaesthesia and discuss the diagnosis and management of this condition in patients presenting without neurological deficit.

Intradiscal electrothermal therapy can alter compressive stress distributions inside degenerated intervertebral discs.

Study Design. Mechanical testing of cadaveric motion segments. Objectives. To test the hypothesis that intradiscal electrothermal therapy (IDET) can affect the internal mechanical functioning of lumbar discs. Summary of Background Data. The clinical efficacy of IDET is variable, and its mode of action uncertain. Methods. Eighteen lumbar motion segments (64–97 years old) were incubated at 37°C. A miniature pressure transducer, side mounted in a 1.3-mm diameter needle, was used to measure the distribution of compressive “stress” along the midsagittal diameter of each disc while it was compressed at 1.5 kN. Measurements were repeated in 3 simulated postures. Standard IDET was performed using biplanar radiography to confirm the placement of the heating element and an independent thermocouple to measure temperature in the inner lateral anulus. Stress profilometry was repeated immediately after IDET. Results. Peak temperatures in the inner lateral anulus during IDET averaged 40.0°C (standard deviation [STD] 2.3o). Stress measurements repeated before IDET differed by less than 8%, and a sham IDET procedure produced no consistent changes. After IDET, pressure in the nucleus decreased by 6% to 13% (P < 0.05), and stress concentrations in the anulus were reduced by an average 0.28 MPa (P < 0.004). In 12 of the 18 specimens, anulus stress concentrations were reduced by more than 8%, and in these “responders,” mean reduction was 78%. Stress concentrations were increased by more than 8% in 2 specimens. Conclusions. IDET has a significant but inconsistent effect on compressive stresses within intervertebral discs. These results may partly explain the variable clinical success of IDET.

Illness behavior in patients with chronic low back pain and activation of the affective circuitry of the brain.

Objective Patients with chronic low back pain (cLBP) show a range of behavioral patterns that do not correlate with degree of spinal abnormality found in clinical, radiological, neurophysiological, or laboratory investigations. This may indicate an augmented central pain response, consistent with factors that mediate and maintain psychological distress in this group. Methods Twenty-four cLBP patients were scanned with functional magnetic resonance imaging while receiving noxious thermal stimulation to the right hand. Patients were clinically assessed into those with significant pain-related illness behavior (Waddell signs [WS]-H) or without (WS-L) based on WS. Results Our findings revealed a significant increase in brain activity in WS-H versus WS-L patients in response to noxious heat in the right amygdala/parahippocampal gyrus and ventrolateral prefrontal and insular cortex (at a VoxelPThreshold = 0.01). We found no difference between groups for heat pain thresholds (t(22) = −1.17, p = .28) or sensory-discriminative pain regions. Conclusions Patients with cLBP displaying major pain behavior have increased activity in the emotional circuitry of the brain. This study is the first to suggest an association between a specific clinical test in cLBP and neurobiology of the brain. Functional magnetic resonance imaging may provide a tool capable of enhancing diagnostic accuracy and affecting treatment decisions in cases where no structural cause can be identified.