The value of interhospital transfer and emergency MRI for suspected cauda equina syndrome: a 2-year retrospective study.

INTRODUCTION: The timing of surgery in cauda equina syndrome due to prolapsed intervertebral disc remains controversial. Assessment of these patients requires magnetic resonance imaging (MRI), which is of limited availability outside normal working hours in the UK. PATIENTS AND METHODS: We reviewed radiological results in all patients undergoing emergency MRI within our unit for suspected cauda equina syndrome over a 2-year period, and all subjects undergoing emergency lumbar discectomy for cauda equina syndrome within the same period. Outcome measures were: proportion of positive findings in symptomatic patients and proportion of patients referred with diagnostic MRI scans undergoing emergency surgery. We also assessed outcomes of patients having surgery for cauda equina syndrome in terms of improvement of pain, sensory and sphincter disturbance. RESULTS: A total of 76 patients were transferred for assessment and 'on-call' MRI; 27 were subsequently operated upon. Only 5 proceeded to emergency discectomy that night (prior to next scheduled list). This may be due to delays in timing--from referral to acceptance, to arrival in the department, to diagnostic scan and to theatre. With the second group of patients, 43 had emergency discectomy for cauda equina syndrome during the study period. Of these, 6 patients had an out-of-hours MRI at our hospital for assessment (one patient living locally). Most surgically treated patients experienced improvement in their pain syndrome, with approximately two-thirds experiencing improvement in sensory and sphincter disturbance. CONCLUSIONS: These data support a policy of advising MRI scan for cauda equina syndrome at the earliest opportunity within the next 24 h in the referring hospital, rather than emergency transfer for diagnostic imaging which has a relatively low yield in terms of patients operated on as an emergency.

Posterior approach vertebrectomy in the thoracolumbar spine with expandable cage reconstruction: indications and techniques based on eight cases.

We present a series of eight patients undergoing circumferential neural decompression and stabilization of the thoracolumbar spine via a single midline posterior approach, with complete vertebrectomy for a variety of indications. Four had primary tumours, two secondary tumours, one patient had tuberculosis and one had delayed deformity due to trauma. This single posterior approach is made possible via the use of an expandable cage that may be expanded in situ to offer anterior and middle column reconstruction. There were no major neurological complications and all patients with deficits improved postoperatively. Extensive posterior fixation was avoided with five patients undergoing a one above/one below fixation and three undergoing a two above/two below fixation. When combined with pedicle screw and rod fixation this anterior reconstruction makes a sound construct. The flexibility of this approach in the thoracolumbar spine, some of the biomechanical advantages and pitfalls are considered.

Pilocytic astrocytoma of the adult--clinical features, radiological features and management.

Pilocytic astrocytoma is a histological subtype of astrocytoma classically located in the cerebellum of children and young adults. Cases occurring over the age of 30 years are rare and have not been classified in terms of their clinical features and management. Suitable cases were identified using diagnostic coding and by reviewing a neuropathology database. Casenotes and neuroradiology were reviewed retrospectively. Ten cases were identified over a 6 year period with an incidence of 0.49 cases per million population per year. Tumours were equally distributed between the supra- and infra-tentorial spaces. The most common symptom was headache occurring in 90%. No patient suffered seizures. Total macroscopic treatment remains the treatment of choice. Pilocytic astrocytoma of the adult is a rare tumour with a favourable prognosis.

Cauda equina syndrome: outcome and implications for management.

A retrospective review of all patients who had surgery for cauda equina syndrome (CES) due to a herniated lumbar disc between January 1996 and November 1999 was undertaken. All underwent laminectomy and discectomy, and had been admitted as emergencies with cauda equina syndrome. Ten women and 10 men with a mean age of 45 years (range 33-67) had their diagnosis verified with MRI in 19 cases and CT in one case. Only half the patients had been catheterized at the time of admission to the neurosurgical unit. Nine patients had emergency decompressive surgery within 5 h of presentation to our unit. The others had surgery on the next available list, but within 24 h of admission. No difference was found between urgently operated patients and those operated on the next available list when urological outcome and quality of life assessments were made using a validated questionnaire at a mean time of 16 months after surgery (range10-48). Twenty per cent of a control group who had undergone laminectomy and discectomy for large disc herniations, but without CES had new urological symptoms when questioned postoperatively, but similar quality of life status. Emergency decompressive surgery did no significantly improve outcome in CBS compared with a delayed approach.

Syringe tip accuracy for application of Victor Horsley's bone wax.

An inexpensive way of improving the handling properties of white bone wax is described.

Posterior lumbar interbody fusion for revision disc surgery: review of 50 cases in which carbon fiber cages were implanted.

OBJECT: The authors undertook a study to assess the value of posterior lumbar interbody fusion (PLIF) in which carbon fiber cages (CFCs) were placed in patients undergoing revision disc surgery for symptoms suggesting neural compression with low-back pain. METHODS: The authors followed their first 50 patients for a maximum of 5 years and a minimum of 6 months after implantation of the CFCs. Patients in whom magnetic resonance (MR) imaging demonstrated "simple" recurrent herniation did not undergo PLIF. Surgery was performed in patients with symptoms of neural root compression, tension signs, and back pain with focal disc degeneration and nerve root distortion depicted on MR imaging compatible with clinical signs and symptoms. In 40 patients (80%) pedicle screws were not used. Clinical outcome was assessed using the Prolo Functional Economic Outcome Rating scale. Fusion outcome was assessed using an established classification. Symptoms in 46 patients (92%) improved after surgery, and given their outcomes, 45 (90%) would have undergone the same surgery again. Two thirds of patients experienced good or excellent outcomes (Prolo score > or = 8) at early and late follow up. There was no difference in clinical outcome between those in whom pedicle screws were and were not implanted (p = 0.83, Mann-Whitney U-test). The fusion rate at 2 years postsurgery was 95%. There were minimal complications, and no patients fared worse after surgery. No patient has undergone additional surgical treratment of the fused intervertebral space. CONCLUSIONS: In this difficult group of patients the aim remains to improve symptoms but not cure the disease. A high fusion rate is possible when using the CFCs. Clinical success depends on selecting patients in whom radiological and clinical criteria accord. Pedicle screws are not necessary if facet joints are preserved, and high fusion rates and clinical success are possible without them.

Screwdriver assaults and intracranial injuries.

Four patients with intracranial penetrating injuries from screwdrivers are presented. Two cases were fatal; the others were left with functional deficits. In two of the patients a penetrating injury was not suspected initially because the history was limited and the significance of the small entry wounds were not appreciated. Unless these wounds are carefully examined a penetrating injury is easily overlooked.

The relationship between pure tone thresholds and the radiological dimensions of acoustic neuromas.

A retrospective analysis of 109 consecutive patients presenting with acoustic neuromas between 1986 and 1997 were undertaken. Sufficient data were available in 104 cases for comparison. In 65 cases patients had undergone surgery and the radiological diagnosis of acoustic neuroma was confirmed histologically. In this group there were 25 large and 40 small tumors when a maximal radiological diameter of 2.5 cm was used to subdivide the groups. When pure tone thresholds were compared at specific frequencies, in those with hearing ears, there was no significant difference between the two groups. Our results are compared with recent series and the causes of hearing loss associated with acoustic neuroma are discussed.

Intrinsic brainstem tumours in childhood: a report of 35 children followed for a minimum of 5 years.

The presentation, pathology and outcome of 35 children with intrinsic brainstem tumours treated at our institution between 1980 and 1990 have been reviewed. Eight children remain alive. There were 19 girls and 16 boys. Mean age at diagnosis was 5 years. The mean duration of symptoms prior to diagnosis was 5 months. The diagnosis was made by computed tomography (CT) in all children and magnetic resonance imaging (MRI), in addition, for 24 children. Twenty-seven tumours (77%) were diffuse, three (8.6%) were predominantly cystic, three (8.6%) were exophytic and two (5.7%) were focal. Cervicomedullary tumours were not included in this study. Definitive histology was obtained in 13 children (37.1%), eight (22.9%) by biopsy alone and five (14.3%) after surgery to debulk the tumours. Eleven of these cases were astrocytomas and two were primitive neuroectodermal tumours (PNET). Twelve children (34.3%) required shunt placement for hydrocephalus. Twenty-eight children (80%) were irradiated using conventionally fractionated radiotherapy to a total dose between 50 and 55 Gy. Six children (17.1%) also received chemotherapy. The overall mean survival time was 10 months, but five of six children who had their tumours debulked survived free of progressive disease for more than 5 years following their diagnosis. The prognosis for brainstem tumours in children remains poor with only a minority falling into the surgically resectable (good prognosis) group.