The nerve supply of the lumbar intervertebral disc

The anatomical studies, basic to our understanding of lumbar spine innervation through the sinu-vertebral nerves, are reviewed. Research in the 1980s suggested that pain sensation was conducted in part via the sympathetic system. These sensory pathways have now been clarified using sophisticated experimental and histochemical techniques confirming a dual pattern. One route enters the adjacent dorsal root segmentally, whereas the other supply is non-segmental ascending through the paravertebral sympathetic chain with re-entry through the thoracolumbar white rami communicantes. Sensory nerve endings in the degenerative lumbar disc penetrate deep into the disrupted nucleus pulposus, insensitive in the normal lumbar spine. Complex as well as free nerve endings would appear to contribute to pain transmission. The nature and mechanism of discogenic pain is still speculative but there is growing evidence to support a 'visceral pain' hypothesis, unique in the muscloskeletal system. This mechanism is open to 'peripheral sensitisation' and possibly 'central sensitisation' as a potential cause of chronic back pain.

The interstitial nuclei of the human anterior hypothalamus: an investigation of variation with sex, sexual orientation, and HIV status

The interstitial nuclei of the human anterior hypothalamus (INAH1-4) have been considered candidates for homology with the sexually dimorphic nucleus of the preoptic area of the rat. Volumetric sexual dimorphism has been described for three of these nuclei (INAH1-3), and INAH3 has been reported to be smaller in homosexual than heterosexual men. The current study measured the INAH in Nissl-stained coronal sections in autopsy material from 34 presumed heterosexual men (24 HIV- and 10 HIV+), 34 presumed heterosexual women (25 HIV- and 9 HIV+), and 14 HIV+ homosexual men. HIV status significantly influenced the volume of INAH1 (8% larger in HIV+ heterosexual men and women relative to HIV- individuals), but no other INAH. INAH3 contained significantly more neurons and occupied a greater volume in presumed heterosexual males than females. No sex difference in volume was detected for any other INAH. No sexual variation in neuronal size or density was observed in any INAH. Although there was a trend for INAH3 to occupy a smaller volume in homosexual men than in heterosexual men, there was no difference in the number of neurons within the nucleus based on sexual orientation.

Proton magnetic resonance spectroscopy of choroid plexus tumors in children

A variety of lesions may present as intraventricular masses in children. We report quantitative proton magnetic resonance spectroscopy (MRS) of two intraventricular tumors of the choroid plexus: choroid plexus carcinoma (CPC) and choroid plexus papilloma (CPP). Both lesions were characterized by high levels of choline-containing compounds and a complete absence of creatine and the neuronal/axonal marker N-acetyl aspartate. The CPC showed higher levels of choline compared to the CPP, and it also had elevated lactate. These preliminary results, if confirmed in a larger cohort of patients, indicate that proton MRS may have a role in the presurgical diagnosis of choroid plexus tumors in children, which may also have important implications for therapy and prognosis.

MIB-1 staining index of pediatric meningiomas

OBJECTIVE

For adult meningiomas, the staining index (SI) for the anti-Ki-67 monoclonal antibody MIB-1 is well correlated with histological atypia and tumor recurrence. MIB-1 SIs for meningiomas in the pediatric population have not been previously reported. Meningiomas tend to be more histologically aggressive and to recur more frequently in children, compared with adults. The objectives of this study were to determine whether MIB-1 SIs are correlated with pathological atypia and recurrence among pediatric meningiomas and to compare the MIB-1 SIs of pediatric meningiomas with those of adult meningiomas.

METHODS

MIB-1 SIs were assessed on paraffin-embedded sections of 14 pediatric meningiomas (patient age, 2-17 yr), 5 of which contained atypical or malignant features. For comparison with benign pediatric meningiomas, MIB-1 SIs were also assessed on paraffin-embedded sections of 14 adult meningiomas (patient age, 38-90 yr), none of which displayed atypical or malignant features or recurred within a 5-month median follow-up period.

RESULTS

MIB-1 SIs of pediatric meningiomas ranged from 1.2 to 31.6% (median, 9.1%). Significant differences were observed between the MIB-1 SIs for tumors with atypical or malignant features (median, 12.3%; range, 7.0-31.6%) and those for tumors without atypia (median, 7.0%; range, 1.2-12.6%; P = 0.045). There were six recurrences after gross total resection, during a 36.5-month median follow-up period. All five of the tumors with pathological atypia recurred; one tumor without atypia recurred. Significant differences were observed between MIB-1 SIs for nonrecurrent tumors (median, 6.6%; range, 1.2-12.2%) and those for recurrent tumors (median, 12.5%; range, 7.0-31.6%; P = 0.012). The median MIB-1 SI for adult control specimens was 8.8% (range, 1.2-19.3%), which did not differ significantly from that for pediatric meningiomas without atypia (P = 0.68).

CONCLUSION

For this cohort of pediatric meningiomas, pathological atypia and the tendency to recur were correlated with elevated MIB-1 SIs. The median MIB-1 SI for pediatric meningiomas without histological atypia did not differ significantly from that for adult meningiomas without atypia, suggesting that the more aggressive clinical features of meningiomas in children may be attributable to factors other than the rate of cellular proliferation.

Appearance of meningiomas on diffusion-weighted images: correlating diffusion constants with histopathologic findings

BACKGROUND AND PURPOSE

Malignant and atypical meningiomas are prone to recurrence and aggressive growth, which affects treatment planning and prognostication. Investigators have used diffusion-weighted imaging and apparent diffusion coefficient (ADC) maps to compare tumor grade and cellularity with the histopathologic findings of intraaxial primary brain neoplasms. The purpose of this study was to determine whether the signal characteristics of meningiomas on diffusion-weighted images correlate with the average diffusion constant (Dav) from ADC maps and histopathologic findings and whether the Dav can reliably distinguish benign from malignant and atypical meningiomas.

METHODS

Seventeen patients (13 women and four men; average age, 55 years) with meningiomas were prospectively studied using routine MR imaging and diffusion-weighted imaging with a single-shot gradient-echo echo-planar pulse sequence (6000/100 [TR/TE]) and b values of 0 and 1000. Signal characteristics on routine MR and diffusion-weighted images were compared with the histopathologic findings after resection by using World Health Organization criteria. Dav values were calculated within the tumor mass from ADC maps before resection.

RESULTS

Four meningiomas were malignant or atypical (World Health Organization grades II and III). Dav values were lower than normal brain values (average, 0.52 +/- 0.12 x 10(-5) cm2/s; range, 0.45-0.69 x 10(-5) cm2/s) and were hyperintense on diffusion-weighted images and hypointense on ADC maps. Thirteen meningiomas were benign. Dav values were higher than normal brain values (average, 1.03 +/- 0.29 x 10(-5) cm2/s; range, 0.62-1.8 x 10(-5) cm2/s). On diffusion-weighted images and ADC maps, most were isointense. Five benign meningiomas had very high Dav values, bright signal on ADC maps, and distinct histopathologic findings, including microcysts, necrotic infarct, and organizing intratumoral hemorrhage. The difference in Dav values between malignant and benign meningiomas was statistically significant (P < .00029).

CONCLUSION

Albeit a small sample size, meningiomas with low Dav tended to be malignant or highly atypical (P < .00029) whereas meningiomas with the highest Dav had increased water content due to either a specific histologic subtype of meningioma or the presence of associated pathologic abnormality.

Removal of a lumbar melanotic schwannoma via the far-lateral approach in a patient with Carney complex. Case report

The authors describe a patient with Carney's complex who presented with sciatica due to a lumbar nerve root sheath tumor. A far-lateral approach was used to resect a nonpsammomatous melanotic schwannoma. Neurosurgeons surgically treating peripheral nerve sheath tumors should be aware of the features of Carney complex because the extent of the preoperative evaluation and postoperative management of an otherwise routine surgical condition can be significantly affected.

The interstitial nuclei of the human anterior hypothalamus: an investigation of sexual variation in volume and cell size, number and density

The four interstitial nuclei of the anterior hypothalamus (INAH) have been considered as candidate human nuclei for homology with the much studied sexually dimorphic nucleus of the preoptic area of the rat. Assessment of the INAH for sexual dimorphism has produced discrepant results. This study reports the first systematic examination of all four INAH in the human for sexual variation in volume, neuronal number and neuronal size. Serial Nissl-stained coronal sections through the medial preoptic area and anterior hypothalamus were examined from 18 males and 20 females who died between the ages of 17 and 65 without evidence of hypothalamic pathology or infection with the human immunodeficiency virus. A computer-assisted image-analysis system and commercial stereology software package were employed to assess total volume, neuronal number and mean neuronal size for each INAH. INAH3 occupied a significantly greater volume and contained significantly more neurons in males than in females. No sex differences in volume were detected for any of the other INAH. No sexual variation in neuronal size or packing density was observed in any nucleus. The present data corroborate two previous reports of sexual dimorphism of INAH3 but provide no support for previous reports of sexual variation in other INAH.

Spinal growth and a histologic evaluation of the Risser grade in idiopathic scoliosis

STUDY DESIGN

Thirty-four patients with idiopathic scoliosis who underwent anterior spinal surgery as part of the correction of spinal deformity were studied prospectively. Superior and inferior endplates were harvested and examined histologically for evidence of residual growth activity. This was then correlated with Risser grades, chronologic age, and pubertal status.

OBJECTIVES

To clarify the correlation between Risser grade and vertebral endplate growth potential in patients with idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

The importance of longitudinal spinal growth in patients with idiopathic scoliosis and its correlation with curve progression and the crankshaft phenomenon after posterior fusion are well recognized. The Risser grade, which shows the extent of excursion of the iliac apophysis on serial plain radiographs, is commonly used to estimate residual spinal growth. However, the correlation between the Risser grade and vertebral endplate growth potential in patients with idiopathic scoliosis remains unclear.

METHODS

Superior and inferior endplates were harvested from these patients and examined histologically for evidence of residual growth. This was correlated with Risser grade, chronologic age, and pubertal status.

RESULTS

Risser Grade 5 was found to be the only indicator of cessation of vertebral growth in idiopathic scoliosis. Of the 14 patients with Risser Grade 4, 10 showed significant growth activity in the vertebral endplates. The reliability of Risser Grade 4 increases when combined with chronologic age and time since menarche in female patients.

CONCLUSIONS

The crankshaft phenomenon is reported to occur only in patients with Risser Grade 2 or less, particularly those with open triradiate cartilages. Our findings of significant endplate growth activity, even in patients with Risser Grade 4, make it unlikely that the crankshaft phenomenon is caused purely by longitudinal spinal growth.

Fiduciary responsibility and potential liabilities in health care cost management

This article addresses the key legal issues facing ERISA welfare plan fiduciaries in health care cost management and explores the current status of a number of fiduciary obligations particularly relevant to welfare plan trustees. The authors discuss the fiduciary issues raised by the selection of a health care delivery system, plan design decision making and provider discount arrangements with health plans, and provide suggestion for administering reimbursements for health care costs from third party recoveries and addressing provider fraud.

Regulation of in vitro phosphorylation of the casein kinase II sites in B-50 (GAP-43)

Casein kinase II (CKII) phosphorylates the rat neuronal growth-associated protein B-50 (GAP-43) at serines 191/192 and threonines 88, 89 and/or 95 both in vitro and in neuronal growth cones. Since little is known concerning regulation of the phosphorylation of these sites, these studies were undertaken to characterize the factors which determine the degree of B-50 phosphorylation by CKII in vitro. Phosphorylation of rat B-50 on serine and threonine residues by recombinant human CKII is stimulated by polylysine. Maximal stimulation occurs at 10 microg/ml of polylysine, a concentration which has no effect on protein kinase C (PKC)-mediated phosphorylation of B-50. Digestion with Staphylococcus aureus V8 protease demonstrates CKII-mediated phosphorylation of B-501-132 and the C-terminal fragment S3/S4. Phosphorylation of B-50 by either CKII or PKC is inhibited by the N-terminal monoclonal antibody NM2, while the C-terminal antibody NM6 has no effect on phosphorylation by either protein kinase. Protein phosphatase 2A dephosphorylates both the CKII and PKC sites, while protein phosphatases 2B and 1 are more selective for the PKC site. These results indicate that the phosphorylations of B-50 by CKII and PKC are determined by distinct regulatory signals in vivo.

Synthetic porous ceramic compared with autograft in scoliosis surgery. A prospective, randomized study of 341 patients

We have evaluated the use of a synthetic porous ceramic (Triosite) as a substitute for bone graft in posterior spinal fusion for idiopathic scoliosis. In a prospective, randomised study 341 patients at five hospitals in the UK and France were randomly allocated either to autograft from the iliac crest or rib segments (171) or to receive Triosite blocks (170). All patients were assessed after operation and at 3, 6, 12 and 18 months. The two groups were similar with regard to all demographic and baseline variables, but the 184 treated in France (54%) had Cotrel-Dubouset instrumentation and the 157 treated in the UK usually had Harrington-Luque implants. In the Triosite group the average Cobb angle of the upper curve was 56 degrees, corrected to 24 degrees (57%). At 18 months, the average was 26 degrees (3% loss). In the autograft group the average preoperative upper curve of 53 degrees was corrected to 21 degrees (60%). At 18 months the mean curve was 25 degrees (8% loss). Pain levels after operation were similar in the two groups, being mild in most cases. In the Triosite group only three patients had problems of wound healing, but in the autograft group, 14 patients had delayed healing, infection or haematoma in the spinal wound. In addition, 15 autograft patients had pain at the donor site at three months. Seven had infections, two had haematoma and four had delayed healing. The haematological and serum biochemistry results showed no abnormal trends and no significant differences between the groups. There were no adverse events related to the graft material and no evidence of allergenicity. Our results suggest that Triosite synthetic porous ceramic is a safe and effective substitute for autograft in these patients. Histological findings on biopsy indicate that Triosite provides a favourable scaffolding for the formation of new bone and is gradually incorporated into the fusion mass.

Synthetic porous ceramic compared with autograft in scoliosis surgery

We have evaluated the use of a synthetic porous ceramic (Triosite) as a substitute for bone graft in posterior spinal fusion for idiopathic scoliosis. In a prospective, randomised study 341 patients at five hospitals in the UK and France were randomly allocated either to autograft from the iliac crest or rib segments (171) or to receive Triosite blocks (170). All patients were assessed after operation and at 3, 6, 12 and 18 months.

The two groups were similar with regard to all demographic and baseline variables, but the 184 treated in France (54%) had Cotrel-Dubouset instrumentation and the 157 treated in the UK usually had Harrington-Luque implants. In the Triosite group the average Cobb angle of the upper curve was 56°, corrected to 24° (57%). At 18 months, the average was 26° (3% loss). In the autograft group the average preoperative upper curve of 53° was corrected to 21° (60%). At 18 months the mean curve was 25° (8% loss). Pain levels after operation were similar in the two groups, being mild in most cases. In the Triosite group only three patients had problems of wound healing, but in the autograft group, 14 patients had delayed healing, infection or haematoma in the spinal wound. In addition, 15 autograft patients had pain at the donor site at three months. Seven had infections, two had haematoma and four had delayed healing.

The haematological and serum biochemistry results showed no abnormal trends and no significant differences between the groups. There were no adverse events related to the graft material and no evidence of allergenicity.

Our results suggest that Triosite synthetic porous ceramic is a safe and effective substitute for autograft in these patients. Histological findings on biopsy indicate that Triosite provides a favourable scaffolding for the formation of new bone and is gradually incorporated into the fusion mass.

Phosphorylation of the casein kinase II domain of B-50 (GAP-43) in rat cortical growth cones

Growth-associated phosphoprotein B-50 is a neural protein kinase C (PKC) substrate enriched in nerve growth cones that has been implicated in growth cone plasticity. Here we investigated whether B-50 is a physiological substrate for casein kinase II (CKII) in purified rat cortical growth cone preparations. Using site-specific proteolysis and known modulators of PKC, in combination with immunoprecipitation, mass spectrometry, and phosphoamino acid analysis, we demonstrate that endogenous growth cone B-50 is phosphorylated at multiple sites, on both serine and threonine residues. Consistent with previous reports, stimulation of PKC activity increased the phosphorylation of only those proteolytic fragments containing Ser41. Under basal conditions, however, phosphorylation was predominantly associated with fragments not containing Ser41. Mass spectrometry of tryptic digests of B-50, which had been immunoprecipitated from untreated growth cones, revealed that in situ phosphorylation occurs within peptides B-50(181-198) and B-50(82-98). These peptides contain the major and minor in vitro CKII phosphosites, respectively. In addition, cyanogen bromide digestion of immunoprecipitated chick B-50 generated a 4-kDa C-terminal B-50 phosphopeptide, confirming that phosphorylation of the CKII domain occurs across evolutionary diverse species. We conclude that B-50 in growth cones is not only a substrate for PKC, but also for CKII.

Synthesis and biological characterization of 1,4,5,6-tetrahydropyrimidine and 2-amino-3,4,5,6-tetrahydropyridine derivatives as selective m1 agonists

Previous studies identified several novel tetrahydropyrimidine derivatives exhibiting muscarinic agonist activity in rat brain. Such compounds might be useful in treating cognitive and memory deficits associated with low acetylcholine levels, as found in Alzheimer's disease. To determine the molecular features of ligands important for binding and activity at muscarinic receptor subtypes, the series of tetrahydropyrimidines was extended. Several active compounds were examined further for functional selectivity through biochemical studies of muscarinic receptor activity using receptor subtypes expressed in cell lines. Several amidine derivatives displayed high efficacy at m1 receptors and lower activity at m3 receptors coupled to phosphoinositide (PI) metabolism in A9 L cells. Four ligands, including 1b, 1f, 2b, and 7b, exhibited marked functional selectivity for m1 vs m3 receptors. Compound 1f also exhibited low activity at m2 receptors coupled to the inhibition of adenylyl cyclase in A9 L cells. Molecular modeling studies also were initiated to help understand the nature of the interaction of muscarinic agonists with the m1 receptor using a nine amino model of the m1 receptor. Several important interactions were identified, including interactions between the ester moiety and Thr192. Additional interactions were found for oxadiazoles and alkynyl derivatives with Asn382, suggesting that enhanced potency and selectivity may be achieved by maximizing interactions with Asp105, Thr192, and Asn382. Taken together, the data indicate that several amidine derivatives display functional selectivity for m1 muscarinic receptors, warranting further evaluation as therapeutic agents for the treatment of Alzheimer's disease. In addition, several amino acid residues were identified as potential binding sites for m1 agonists. These data may be useful in directing efforts to develop even more selective m1 agonists.

Adenosine 3',5'-cyclic monophosphate/vanadate-sensitive phosphorylation of DARPP-32- and inhibitor-1-immunoreactive proteins

Among the cellular actions of vanadate ions are several that have the potential to be of significance in the regulation of protein phosphorylation. The effects of vanadate on adenosine 3',5' cyclic monophosphate (cAMP)-dependent and independent, alkali-resistant protein phosphorylation in a synaptosomal preparation from rat cortex were examined in this study. Three major vanadate-stimulated, cAMP-independent phosphoproteins (58-, 50-, and 39-kDa) and two cAMP-dependent species (37- and 32-kDa) were detectable. The potentiation between vanadate and cAMP in stimulating the phosphorylation of the latter two proteins is in contrast to the nonadditive combined effect of both on the phosphorylation of other synaptosomal proteins. The two cAMP-dependent, 32P-labeled proteins possess identical or very similar physicochemical properties to two previously cited neuronal phosphoproteins, namely, dopamine- and adenosine 3',5'-monophosphate-regulated phosphoprotein-32 (DARPP-32) and inhibitor-1 (I-1). Such properties include phosphorylation by cAMP-dependent protein kinase, the presence of an alkali-resistant phosphothreonine residue, comigration on two-dimensional gel electrophoresis, dephosphorylation by type-2B protein phosphatase, and crossreactivity with specific antibodies. Costimulation by cAMP and vanadate of phosphorylation of the latter two proteins on threonine residues, at concentrations of vanadate consistent with the regulation of protein tyrosine phosphatase activity, indicates a unique interaction between these two regulators of protein phosphorylation at the nerve terminus.

An unusual presentation of acute lumbar nerve root pain. A case report

STUDY DESIGN

This case report illustrates the need to be vigilant of potential iatrogenic causes of symptoms. A patient with a femoral Hickman line experienced severe back pain after a chemotherapy infusion commenced and developed a right quadriceps weakness and absent knee jerk.

OBJECTIVES

To highlight the severe side effects possible with the use of Hickman lines and chemotherapy.

SUMMARY OF BACKGROUND DATA

There are numerous causes of lumbar radicular pain, and these can coexist in the same patient. This patient had a known malignant process involving the retroperitoneum, but the actual cause of the severe pain related to the management of the malignancy rather than the malignancy itself. There are no reported cases of such a complication from a Hickman line.

METHODS

This patient was admitted to hospital for investigation and treatment of severe back pain after the start of a continuous infusion of chemotherapy for an inoperable cholangiocarcinoma. The patient went on to develop a right quadriceps weakness before the investigations could reveal the cause of the problem.

RESULTS

the pain and weakness resolved after cessation of the infusion and removal of the Hickman line.

CONCLUSIONS

The principles of clinical medicine involve careful history taking and examination and considering all the differential diagnoses fully. Also, the possibility of multiple pathology and iatrogenic causes should be assessed. This patient was receiving palliative treatment only, and this unfortunately led to additional disability, which may have been avoidable or less severe.

Decreased senile plaque density in Alzheimer neocortex adjacent to an omental transposition

Post-mortem studies of the brain of an Alzheimer patient indicate fewer senile plaques in the crests of cortical gyri underneath an omental transposition than in neighboring cortical areas.

Thoracoscapular fusion in facioscapulohumeral dystrophy: clinical review of a new surgical method

A new method of scapulothoracic fusion is described for patients with facioscapulohumeral dystrophy. To improve upper limb function by abolishing scapula winging, bilateral procedures were performed in six patients with an average age of 30 years (range 17 to 44 years). The average follow-up was 49 months (range 1 to 7 years). A good functional and cosmetic result was obtained in all patients. An average postoperative increase in shoulder abduction of 28 degrees and flexion of 40 degrees was seen. Only a small diminution in respiratory function occurred (mean decrease in forced expiratory volume in 1 second of 14% and forced vital capacity of 21%).

MRI OF ‘IDIOPATHIC’ JUVENILE SCOLIOSIS

In a prospective trial we performed MRI of the spine and hind brain in 31 patients with scoliosis of onset between the ages of four and 12 years.

In eight patients (26%) there was a significant neuroanatomical abnormality; there were six cases of Chiari-1 malformation associated with a syrinx, one isolated Chiari-1 malformation and one astrocytoma of the cervical spine. Four of these patients had left-sided curves.

There were no clinical features which could reliably identify those patients with abnormalities on MRI. In particular, the unilateral absence of abdominal reflexes was found to be non-specific (1 of 8 of patients with neuroanatomical abnormalities (12.5%) v 2 of 23 with normal scans (8.7%)).

In view of the established risks of surgical correction of scoliosis in the presence of undecompressed syringomyelia and the possible improvement that may follow decompression of the foramen magnum, we feel that MRI of all patients with scoliosis of juvenile onset should be obligatory.

MRI of 'idiopathic' juvenile scoliosis. A prospective study

In a prospective trial we performed MRI of the spine and hind brain in 31 patients with scoliosis of onset between the ages of four and 12 years. In eight patients (26%) there was a significant neuroanatomical abnormality; there were six cases of Chiari-1 malformation associated with a syrinx, one isolated Chiari-1 malformation and one astrocytoma of the cervical spine. Four of these patients had left-sided curves. There were no clinical features which could reliably identify those patients with abnormalities on MRI. In particular, the unilateral absence of abdominal reflexes was found to be non-specific (1 of 8 of patients with neuroanatomical abnormalities (12.5%) v 2 of 23 with normal scans (8.7%). In view of the established risks of surgical correction of scoliosis in the presence of undecompressed syringomyelia and the possible improvement that may follow decompression of the foramen magnum, we feel that MRI of all patients with scoliosis of juvenile onset should be obligatory.

Symptomatic salivary-rest cyst of the sella turcica

Although ectopic salivary tissue in the posterior pituitary is frequently observed in microscopic examination at autopsy, this tissue is considered clinically insignificant. The authors report a case of sella turcica mass causing progressive menstrual irregularities and mild hyperprolactinemia in a 22-year-old woman. Magnetic resonance imaging revealed a 1.2 x 0.9 cm non-enhancing mass of the postero-inferior sella turcica. The lesion was isointense to brain on T1-weighted images and hypo- to iso-intense on T2-weighted images. Transsphenoidal exploration revealed that the cyst wall consisted entirely of normal appearing salivary gland. The clinical, radiographic, and pathologic features of this unique entity are discussed.

Syringomyelia. A potential risk factor in scoliosis surgery

STUDY DESIGN

An 18-year-old patient with "idiopathic" adolescent scoliosis is presented. A thoracic syrinx was detected as an incidental finding during magnetic resonance imaging of the spine.

OBJECTIVES

Syringomyelia may be a risk factor for neurologic injury during correction of scoliosis, and in these cases, spinal cord monitoring may be of particular value.

BACKGROUND DATA

Spinal distraction and instrumentation carry a risk of neurologic damage in patients with scoliosis and associated syringomyelia. Syringomyelia is a cause of scoliosis, and although neurologic problems are the usual symptom, scoliosis may be the only sign at initial examination. A higher risk of neurologic injury has been reported in corrective surgical treatment of patients with syringomyelia. The mechanism of cord damage is unclear. Monitoring of spinal cord function is recommended to detect intraoperative neurological injury, which may be reversed on removing distraction and implants.

RESULTS

Intraoperative somatosensory-evoked potential (SSEP) spinal cord monitoring detected possible cord damage during outrigger distraction. Reduction of distraction led to a recovery of SSEPs and a satisfactory operative outcome.

CONCLUSION

Syringomyelia may be a risk factor for neurologic injury during correction of scoliosis, and SSEP spinal cord monitoring may identify and prevent intraoperative spinal cord injury.

Costoplasty in adolescent idiopathic scoliosis. Objective results in 55 patients

Costoplasty can reduce the important cosmetic deformity of rib prominence in scoliosis but there are few objective reports of correction. We recorded the results of three objective methods of assessing back shape before and after short-segment costoplasty in 55 patients. We showed that significant improvement was maintained over a two-year follow-up period. Primary costoplasty at the time of scoliosis surgery (n = 35) achieved greater proportional correction than secondary costoplasty performed after fusion of the spine (n = 20). The rib segments removed at primary surgery provided enough bone for the autogenous graft; harvesting from the pelvis was unnecessary. We report a new classification of rib morphology which helps in planning the site and extent of costoplasty, and in predicting the possible correction.

Spinal cord monitoring in scoliosis surgery. Experience with 1168 cases

Since 1981, during operations for spinal deformity, we have routinely used electrophysiological monitoring of the spinal cord by the epidural measurement of somatosensory evoked potentials (SEPs) in response to stimulation of the posterior tibial nerve. We present the results in 1168 consecutive cases. Decreases in SEP amplitude of more than 50% occurred in 119 patients, of whom 32 had clinically detectable neurological changes postoperatively. In 35 cases the SEP amplitude was rapidly restored, either spontaneously or by repositioning of the recording electrode; they had no postoperative neurological changes. One patient had delayed onset of postoperative symptoms referrable to nerve root lesions without evidence of spinal cord involvement, but there were no false negative cases of intra-operative spinal cord damage. In 52 patients persistent, significant, SEP changes were noted without clinically detectable neurological sequelae. None of the many cases which showed falls in SEP amplitude of less than 50% experienced neurological problems. Neuromuscular scoliosis, the use of sublaminar wires, the magnitude of SEP decrement, and a limited or absent intra-operative recovery of SEP amplitude were identified as factors which increased the risk of postoperative neurological deficit.

Multi-level epidural recordings of spinal SEPs during scoliosis surgery

Spinal somatosensory evoked potentials were recorded in 35 neurologically normal patients undergoing surgery for scoliosis. The recording electrodes were placed in the dorsal epidural space. Stimulation was of the tibial nerve in the popliteal fossa and the posterior tibial and sural nerves at the ankle. At thoracic levels the response consisted of at least 3 components with different peripheral excitation thresholds and spinal conduction velocities (range 35-85 m/sec). All components were conducted mainly in tracts ipsilateral to the stimulus, component 1 being most laterally located. At low stimulus intensity only the fastest activity was recorded but higher intensities elicited additional, slower conducting components. Component 1 was much less prominent when the posterior tibial nerve was stimulated at the ankle and absent from the (cutaneous) sural nerve response. Component 1 is likely to be due to the stimulation of group 1 muscle afferents which terminate in the dorsal horn and activate second-order neurones, many of whose axons go to form the ipsilateral dorsal spinocerebellar tract. Components 2 and 3 are believed to be largely cutaneous in origin and to be conducted mainly in the dorsal columns.

Conduction properties of epidurally recorded spinal cord potentials following lower limb stimulation in man

Spinal somatosensory evoked potentials were recorded in 35 neurologically normal patients undergoing surgery for scoliosis. During posterior procedures the recording electrodes were placed in the dorsal epidural space and during anterior operations in the intervertebral discs. Stimulation was of the tibial nerve in the popliteal fossa and the posterior tibial and sural nerves at the ankle. At thoracic levels the response consisted of at least 3 components with different peripheral excitation thresholds and spinal conduction velocities (range 35-85 m/sec). All components were conducted mainly in tracts ipsilateral to the stimulus, component 1 being most laterally located. At low stimulus intensity only the fastest activity was recorded but this was markedly delayed over low thoracic segments and was recorded as a repetitive discharge rostrally. Higher intensities elicited additional components which were conducted at a slower but relatively uniform velocity; consequently they might overlap with or even overtake the fast activity at mid-to-low thoracic levels. Component 1 was much less prominent when the posterior tibial nerve was stimulated at the ankle and absent from the (cutaneous) sural nerve response; remaining potentials were conducted at velocities similar to those of components 2 and 3 following tibial nerve stimulation at the knee. Small 'stationary' potentials were recorded at all thoracic levels, probably due to the change in conductivity as the volley entered the spinal cord. Efferent activity was recorded at and below the thoraco-lumbar junction, possibly related to the H-reflex or F-wave. Similar, although smaller, afferent potentials were recorded from the anterior side of the vertebral column. Component 1 is likely to be due to the stimulation of group 1 muscle afferents which terminate in the dorsal horn and activate second order neurones, many of whose axons go to form the ipsilateral dorsal spinocerebellar tract. Components 2 and 3 are believed to be largely cutaneous in origin and to be conducted mainly in the dorsal columns.

Scoliosis in neurofibromatosis. The natural history with and without operation

We reviewed 47 patients with neurofibromatosis and dystrophic spinal deformities; 32 of these patients had been untreated for an average of 3.6 years and in them the natural history was studied. The commonest pattern of deformity at the time of presentation was a short angular thoracic scoliosis, but with progression the angle of kyphosis also increased. Deterioration during childhood was usual but its rate was variable. Severe dystrophic changes in the apical vertebrae and in particular anterior scalloping have a poor prognosis for deterioration. The dystrophic spinal deformity of neurofibromatosis requires early surgical stabilisation which should be by combined anterior and posterior fusion if there is an abnormal angle of kyphosis or severely dystrophic apical vertebrae. Some carefully selected patients can be treated by posterior fusion and instrumentation alone.

The economics of mild hypertension programmes

The recently reported results from several controlled randomised trials of the drug treatment of mild hypertension suggest that such treatment may be expected to exert a small effect toward the primary prevention of stroke disease. In order that the economic implications of these results might be examined, two hypothetical programmes of anticipatory care are considered according to the principles of cost-effectiveness analysis. Each notional 5 year programme is set in a defined population, residents of Stockport, Greater Manchester, aged between 35 and 64 years, and each is addressed toward the detection and treatment of mild hypertension in the community. The programmes differ with respect to their detection processes: one programme is based upon the screening method conducted under the aegis of health visitor staff employed by a District Health Authority, the other upon opportunistic case finding conducted by general practitioners. It is likely that the screening programme would prevent about 13 strokes over a 5 year period; if set in leisure time total programme costs are estimated to be 309,500 pounds at 1986 prices. Discounting future costs and future prevented strokes provides for the development of a present value total cost per prevented stroke of 25,000 pounds. Alternately, the 5 year opportunistic programme, costing 252,650 pounds, would be expected to prevent about 15 strokes at a present value of 17,050 pounds per prevented stroke. The prevention of stroke disease attributable to these programmes can only be achieved in the presence of group compliance to drug treatment. This clearly depends upon the perception of the value of treating hypertension according to each individual subject. The respective merits of the two programmes are examined with particular reference to their sensitivity to this issue, as well as to their likely feasibility and practicability.

Long-term follow-up of fused and unfused idiopathic scoliosis

We reviewed 77 unfused and 91 fused patients with idiopathic scoliosis who first attended between 1949 and 1965. Both groups were re-examined at least 10 years after reaching skeletal maturity, with attention to progression of the Cobb angle, increased in vertebral rotation, back pain and psychosocial problems. We found that spinal fusion protects the scoliotic spine from further deterioration during adult life except for those with severe curves and marked rotation. Fusion also significantly reduced the incidence of severe pain and allowed patients to carry out heavy physical work, but did not confer complete immunity from backache. Surgery improved the appearance, but patients were not always completely satisfied with the cosmetic result.

The natural history of unfused scoliosis

Seventy-eight unfused patients with idiopathic scoliosis were followed from skeletal maturity over a mean period of 17 years (range 10 to 27 years) with a mean age at follow up of 33.7 years. The following aspects were investigated: curve deterioration, back pain incidence, and psychosocial details. There was considerable variation in the progression rate of similar deformities but on average significant deterioration occurred when the Cobb angle was over 55 degrees with a maximum deterioration approaching 1.5 degrees per year in the thoracic curves between 90 degrees and 100 degrees mature Cobb angle. Thoracolumbar and lumbar curves were slightly more benign with a maximum progression rate of about 1 degree when the mature angle was 80 degrees to 90 degrees. The thoracic component of double curves progressed least. Rotation increased in proportion to the Cobb angle progression except in some lumbar curves where lateral subluxation occurred with a disproportionate amount of rotation. The incidence of back pain in relation to pain in the general population and in fused patients remains uncertain. Eighty-two percent of patients had married and 87% had job satisfaction; 10% received treatment for depression.

Scoliosis in juvenile chronic arthritis

Structural scoliosis occurs more commonly in patients with juvenile chronic arthritis than in the normal population. We have reviewed 32 patients with both juvenile arthritis and a scoliosis and suggest that structural curves may arise from postural curves associated with asymmetrical involvement of lower limb joints.

Observations on the current and future surgical management of hydatid disease affecting the vertebrae

Five cases of hydatid disease affecting the vertebrae are described. Clinical features, radiologic appearance, and poor prognosis are emphasized. Four patients had some degree of neurologic deficit at the time of presentation and in three cases there was an increasing kyphosis. In two patients, spinal instrumentation with Harrington apparatus supplemented removal of hydatid material, and its use improved the previous neurologic deficit with stabilization of kyphosis. The antihelmintic drug mebendazole was used in two cases.

Posterior spinal fusion and instrumentation in the treatment of adolescent idiopathic scoliosis

Three hundred and nineteen patients with adolescent idiopathic scoliosis were treated by posterior spinal fusion over an eight year period. The changes in preoperative correction and surgical techniques are reviewed. The anaesthetic technique using induced hypotension and the postoperative routine are described. The amount of deformity and its correction at operation and postoperatively is discussed by reference to Cobb angles. The early and late complications are reviewed.

Backache

If a poll were taken of the conditions the average doctor finds most difficult and depressing to treat, backache would undoubtedly be near the top of the list. Yet a clear understanding of the anatomy and mechanism of injury, a thorough examination, and a logical plan of management would help alleviate the patient's and doctor's symptoms.

Intramedullary spinal cord tumours presenting as scoliosis

Intramedullary spinal cord tumours may present as scoliosis without neurological signs. Those treating spinal deformities should be alert to this possible aetiology. The clinical features of 12 such cases are discussed with reference to early diagnosis and treatment. Patients with a painful scoliosis should be investigated with myelography as well as bone scintigraphy. Many intrinsic spinal cord tumours are now amenable to surgical removal. The prognosis for neurological recovery is poor once a severe deficit becomes established. The importance of early diagnosis and joint orthopaedic and neurosurgical management is emphasised.

A system for the electrophysiological monitoring of the spinal cord during operations for scoliosis

An electrophysiological system for monitoring the spinal cord during operations for scoliosis is described. During the development of the technique the recording of cortical somatosensory evoked potentials from the scalp and spinal somatosensory evoked potentials from the laminae or spines was superseded by the positioning of recording electrodes in the epidural space cephalad to the area to be fused. All recordings were made in response to stimulation of the posterior tibial nerve at the knee. Results in 138 patients are presented and the findings in three patients who exhibited neurological deficits after operation are described. It is concluded that spinal somatosensory evoked potentials are sensitive to minor spinal cord impairment, possible due to ischaemia, and that these changes may be reversed when the cause is quickly remedied. The monitoring system interferes minimally with anaesthetic and surgical procedures and is now performed as a routine.

Pre-operative correction in adolescent idiopathic scoliosis

One hundred and sixty-seven patients with adolescent idiopathic scoliosis were allocated prospectively to one of three different groups for correction before undergoing posterior spinal fusion and Harrington instrumentation, In group 1 single curves were corrected by a Risser turnbuckle plaster jacket and double curves by halo-pelvic traction. In Group 2 patients performed Cotrel dynamic traction for three weeks and this was followed by correction in a plaster cast. In Group 3 patients were given Cotrel dynamic traction for one week only and the operation was performed without a plaster cast. There was no significant difference in the overall correction achieved among the patients in the three groups except that double curves corrected slightly better in Group 2. The correction achieved by Cotrel dynamic traction after three weeks was not significantly different from that obtained at 48 hours. An anteroposterior radiograph of the spine taken during Cotrel dynamic traction was a valuable guide to the mobility of the curve and is preferable to radiographs of the patients bending laterally, particularly with respect to curves over 70 degrees. The paper concludes that correction before operation is not required routinely in adolescent idiopathic curves unless the deformity is a severe and rigid one in which case a radiograph during Cotrel traction is a useful assessment.