Amyloid in neurosurgical and neurological practice.

The amyloidoses are a diverse group of diseases characterized by the deposition of specific proteins with distinct affinity to the dye Congo red, collectively called amyloid. The amyloidogenic proteins have acquired an abnormal, highly ordered, beta-pleated sheet configuration with a propensity to self-aggregate. The amyloid may be distributed in different organs with a remarkable diversity. Two broad categories of amyloidoses are recognised: The systemic (consisting of the primary or light chain form, the secondary or reactive form and the familial or hereditary form) and the localised that target specific organs. A tropism of amyloid proteins to the neural tissue produces certain patterns of central nervous system diseases: cerebral amyloid angiopathy, a substrate of spontaneous intracerebral haemorrhage; mature neuritic plaques found in Alzheimer disease and a subset of prion diseases; a topographically restricted accumulation of extracellular proteins giving rise to tumour-mimicking masses, the amyloidomas; and finally, spinal extradural amyloid collections that occasionally are found in the context of rheumatoid arthritis. In this review article we present original illustrative cases of amyloid diseases of the central nervous system that may be encountered in neurosurgical and neurological practice. Molecular aspects and clinical management problems are discussed.

Cerebrospinal fluid kinetics of epidural clonidine in man.

Ten patients with deafferentation pain after spinal cord injury were given 150 micrograms clonidine epidurally. CSF and plasma samples were collected over the following 24 h, and drug concentrations were measured by radio-immunoassay. The results of only 6 patients are included in the pharmacokinetic analysis because the catheters were not in the epidural space in the remaining 4 patients. These analyses revealed a mean maximum CSF concentration of 228 ng/ml whereas the mean plasma concentration at all time points was less than 0.7 ng/ml. The elimination half-life of epidural clonidine was 66 +/- 2 min, while the absorption half-life was 31 +/- 7 min, Tmax was 60 +/- 7 min and Cmax was 228 +/- 56 ng/ml. The ratio of the area under the curve (AUC) for CSF and plasma was 52. One patient's catheter was intrathecal and 3 were not in the epidural space. The measured plasma concentrations were similar after all injections. As 4 of 6 patients with epidural catheters obtained pain relief and all 3 patients with spasms obtained relief from epidural clonidine, these data suggest that clonidine has a place in the treatment of patients with spinal cord injury.

Meningitis due to Gemella haemolysans after radiofrequency trigeminal rhizotomy.

Meningitis due to Gemella haemolysans developed in a 73 year old woman after thermolysis of the Gasserian ganglion for trigeminal neuralgia. The taxonomy of this organism is discussed, and previous cases of infection are reviewed.

Lymphomatoid granulomatosis apparently confined to one temporal lobe. Case report.

Lymphomatoid granulomatosis is of uncertain etiology and poses problems with diagnosis and treatment. A case with involvement of the right temporal lobe, but associated with cystoid macular edema of the retina, is described. The unusual mode of presentation, the radiographic, operative, and pathological findings, the response to surgery and radiotherapy, and the possible etiology are discussed.

Total removal of craniopharyngiomas. Approaches and long-term results in 144 patients.

The clinical features, perioperative course, and postoperative outcomes of 144 patients who underwent microsurgical resection of craniopharyngioma were reviewed. Overall, 90% of the tumors were completely resected and 7% recurred. Evaluation of those patients who underwent primary resection revealed much better results. The operative techniques and approaches are reviewed in detail. The results of this series suggest that primary total removal of craniopharyngiomas yields the best long-term outcome for the patient. Experience has shown that the larger the tumor the greater will be the damage, both preoperatively and intraoperatively, to vital intracranial structures. Consequently, early diagnosis, at a stage when the tumor is still small, improves the chances of accomplishing complete removal and of achieving good operative results. The early diagnosis of craniopharyngioma, before it can produce devastating neurological defects, continues to be the principal goal of our medical and pediatric colleagues.

CSF smooth-muscle constrictor activity associated with cerebral vasospasm and mortality in SAH patients.

Cerebrospinal fluid (CSF) was collected preoperatively (by lumbar puncture) or perioperatively (by lumbar or ventricular drain) from 32 patients with subarachnoid hemorrhage (SAH) from ruptured intracranial aneurysms. Samples were also obtained from six control patients without evidence of subarachnoid blood. Smooth-muscle constrictor activity in the CSF was measured by bioassay using the isolated rat stomach fundus preparation. Concentrations of unidentified smooth-muscle constrictor substances were considerably greater in CSF from a group of seven patients with evidence of severe angiographic vasospasm and/or delayed ischemic deficits who died (73.8 +/- 39.7 nmol/liter prostaglandin E2 (PGE2) equivalents), as compared to 25 other SAH patients who survived (6.5 +/- 1.4 nmol/liter PGE2 equivalents), and six control patients (1.17 +/- 0.34 nmol/liter PGE2 equivalents). The data suggest that there is a relationship between smooth-muscle constrictor substances in the CSF after SAH and both the degree of angiographic vasospasm and the outcome. It is possible that this relationship might be exploited clinically.

Mobilization of patients after spinal surgery for acute spinal cord injury.

STUDY DESIGN: A retrospective review was conducted covering records of patients who underwent spinal surgery after acute spinal cord injury. OBJECTIVE: To study the relation between time of operation and mobilization of patients. SUMMARY OF BACKGROUND DATA: No such report has existed in the literature. METHODS: Reviews were conducted for the medical records of 102 consecutive patients with acute spinal cord injury admitted to the National Spinal Injuries Center whose spines had been stabilized surgically. The surgeries had been performed either in the National Spinal Injuries Center or in hospitals of the United Kingdom or Continental Europe not specialized in comprehensive care of spinal cord injury. For the patients in three groups, the date of operation and the date of mobilization were compared. The causes for delay in mobilization were identified. RESULTS: A trend of negative correlation was found between the mean number of days from injury to operation and the mean number of days from injury to mobilization. Conversely, a trend of positive correlation was found between the mean number of days from injury to admission or transfer to the National Spinal Injuries Center and the mean number of days from injury to mobilization. Long stay in bed was associated with complications. None of the patients in Group A stayed in bed longer than 77 days, whereas 13 patients in Groups B and C combined had a longer stay. The difference was statistically significant (P = 0.02, chi2). Eight of these patients had pressure sores. CONCLUSION: To ensure early mobilization, early spinal surgery must be supported by specialized comprehensive care.

Chemodectoma of the cauda equina: case report.

Well-differentiated paragangliomas have been found in unusual sites where conspicuous paraganglions are not normally found. A patient with a chemodectoma of the cauda equina is described. The importance of differentiating such tumors from those far more commonly seen in the region of the cauda equina, namely, ependymomas, hemangioblastomas, and metastatic carcinomas is emphasised.

Clinical and pathological studies of brain injuries in horse-riding accidents: a description of cases and review with a warning to the unhelmeted.

We present a clinical and pathological study of brain injuries in horse-riding accidents. Among six fatal cases, all experienced riders varying in age and sex, two were not wearing helmets and four had inadequate protective headgear. Among five non-fatal cases, four wore adequate helmets and only one of these suffered permanent neurological damage. The fifth was not wearing a helmet and although he eventually returned to work, a CT scan following the fall showed a deep-seated perithalamic hematoma. These findings are consistent with those of virtually all other studies in that they suggest that the present type of riding helmet is inadequate and largely unable to absorb the shock of a normal fall. We hope these findings will serve as a warning to those who choose to ride unhelmeted.

Arteriovenous malformations of the spinal cord.

The operative experience in Zürich of forty-one cases of spinal AVM with major intramedullary components showed that it was possible, with the aid of precise microsurgical techniques, to remove completely 60% of these lesions with improvement, or, at least, without deterioration in neurological condition. A further 12% could be apparently effectively palliated by subtotal removal. Radical surgery may be justified in patients with irreversible neurological deficits to treat pain and to prevent fatal SAH. The best results have generally been obtained in patients with less severe neurological deficits and with lesions in the cervical region rather than the thoracolumbar region. The natural history of intramedullary spinal AVMs--that of deterioration after recurrent haemorrhage--is analogous to that of intracranial aneurysms--and the need for earlier diagnosis and for early preventive surgery is the same for both. It would, perhaps, be preferable to treat all cases of spinal AVM by transvascular occlusion to obviate the risk of open surgery and of spinal deformity, but some AVMs will remain impossible to treat by this means and the long term results of embolization still require full analysis before it can be accepted as definitive treatment. Comprehensive and exact superselective spinal angiography is a mandatory prerequisite to surgery and preoperative partial embolization may facilitate operation considerably in the future. However, even the most careful angiographic studies do not always totally define the lesion and the surgeon must be prepared to find unexpected vascular relationships at operation. A simple classification of intramedullary and mixed extra/intramedullary lesions is described. The experiences with dural arteriovenous malformations in Queen Square again show that the best results are obtained in patients who have mild or moderate neurological deficit preoperatively. There is no doubt that progressive neurological deficits finally become irreversible and it is therefore clear that once the diagnosis is suspected, it should be definitively established and operation should follow immediately. The prime, indeed the only, necessary investigation is selective spinal angiography, which demands a high degree of radiological skill and experience, but given these prerequisites, may be performed with little hazard. While embolization of these lesions is possible, the simple surgical disconnection of the nidus of the shunt from the coronal venous plexus is effective in most cases, apparently permanently, and is substantially without risk.

Surgery for paediatric thoracic outlet syndrome.

The effectiveness of operative treatment of paediatric thoracic outlet syndrome (TOS) has been analysed, and an attempt made to improve the definition of the condition in terms of presentation, aetiology and diagnosis. A retrospective review of postoperative pain, functional capability and overall outcome was carried out on 13 patients (<18 years) treated by a single surgeon. In 20 operations, 17 were scalenotomies, and three were transaxillary rib resections (TARRs). Follow-up was 6-96 months post-operatively. Surgery alleviated many TOS symptoms, especially vascular compromise, although pain resolution was inconsistent and that of motor deficit poor. Mean functional improvement was good, and overall operative outcomes excellent. Therefore, surgery was successful for paediatric TOS in this series. Anatomical anomalies and sport participation may be related to early onset of TOS in many paediatric patients.

Implants for spasticity.

In carefully selected groups of patients, intrathecal baclofen therapy offers well-proven benefits in reducing spasticity, notably in cases of spinal injury and multiple sclerosis. The initial costs of implantation are high, and there must be a long-term commitment by both patient and medical personnel to careful and proper management. Nevertheless, in suitable cases, the techniques should generally be properly considered before proceeding to any irreversible destructive neurosurgical procedure.

Cerebral arterial vasospasm following severe head injury: a transcranial Doppler study.

Transcranial Doppler ultrasound was used to determine the natural history of cerebral arterial vascular spasm following severe head injury. Doppler Flow Velocity (DFV) was measured in the anterior cerebral, middle cerebral and terminal carotid arteries. High DFVs consistent with vasospasm were identified in 68% of the 25 patients studied. They came on from between 12 h and 4 days and lasted from 12 h to 14 days. No relationship could be determined between presumed vasospasm and blood pressure, intracranial pressure or outcome. Rises in the maximum DFV value (to above 100 cm s-1) were associated with neurological deterioration in 12 instances (in 11 of these the DFV remained elevated for more than 12 h). Deterioration occurred in three instances without change in DFV. DFV rose to above 100 cm s-1 on 10 occasions without neurological change (but remained elevated for more than 12 h in only four of these). Vasospasm has been found to be more common following head injury and may be a more significant cause of deterioration than previously thought.

Malignant fibrous histocytoma producing spinal cord compression.

Three cases of malignant fibrous histiocytoma presented as primary paraspinal tumours causing extradural spinal cord compression. Study of these cases suggests that pain relief is considerable after laminectomy but pain may recur with further tumour growth. Total removal is unrealistic and diagnosis, difficult. The prognosis in terms of continuing neurological deficit after surgery followed by local radiotherapy appears poor.

A prospective trial of prophylactic antibiotics in hand lacerations.

A series of 368 patients with hand lacerations which required suturing were randomly allocated to one of three treatment groups. The incidence of infected and of imperfectly healed wounds was noted 7 days after suturing. As well as the influence of antibiotics on healing, sixteen other factors which it was considered might affect healing were analysed. The overall infection rate was 9-8 per cent, and there was no significant difference between the three groups. The imperfect healing rate (which includes the infected cases) was 24-6 per cent. There was a lower rate (P less than 0-05) of imperfect healing in the Triplopen group (15 per cent) than in either the flucloxacillin group (29-5 per cent) or the group who received no antibiotics (29-0 per cent). Other factors associated with imperfect healing found to be significant at the 1 per cent level, were wound contamination, pain and the presence of a wet or changed dressing at the second examination.

Transient global brainstem dysfunction after microvascular decompression of the trigeminal nerve.

Microvascular decompression of the trigeminal nerve root entry zone has become a standard treatment for trigeminal neuralgia. It has been widely reported with a low morbidity. This case report details an unusual and previously unreported complication of this procedure.

The treatment of trigeminal neuralgia by posterior fossa microsurgery.

Between 1972 and 1981 57 patients underwent posterior fossa exploration in Oxford by a single surgeon for the treatment of trigeminal neuralgia. Fifty-four of these had either partial or total section of the trigeminal sensory root, 2 had microvascular decompression operations and one had both a partial sensory root section and microvascular decompression. There was no mortality and no significant morbidity. Fifty-four patients were followed up for a mean period of 4 . 5 years. Fifty-two patients (96%) had either no further pain or only minor twinges requiring no further treatment. Two other patients who had partial sections suffered no further trigeminal neuralgia after subsequent total sections. One patient who had a partial root section developed anaesthesia dolorosa and one who had a microvascular decompression developed painful dysaesthesia. All patients having partial root sections retained previously intact corneal responses--the sensory impairment in the face corresponded to the appropriate part of the portio major cut. Only 11% of patients were found to have a vascular abnormality.

Metastasis of parotid acinic cell carcinoma to an internal carotid aneurysm: a case report.

Tumours related to intracranial aneurysms are rare. The authors report the metastasis of a parotid acinic cell carcinoma which spread to an intracavernous carotid aneurysm in a 51-year-old female. The tumour and aneurysm were partially excised at craniotomy with relief of the patients presenting headache.