An evaluation of the camino ventricular bolt system in clinical practice.

The camino ventricular bolt system has been used to monitor intracranial pressure in patients after severe head injury. The correlation between the ventricular pressure measured with the Camino device and an external transducer showed that the Camino accurately measured intracranial pressure over a wide range, but that it read an average of 1.15 mm Hg higher than that obtained by the external transducer. The technique has the advantage over a remote transducer because it is sited within the ventricle. This may be of value in wave-form analysis.

99Tcm-HMPAO SPET and cerebral blood flow: a study of CO2 reactivity.

Single photon emission tomography (SPET) studies using 99Tcm-HMPAO are in widespread use in the functional imaging of cerebral blood flow (CBF). While qualitatively the images correlate well with other imaging modalities, there are doubts as to the quantitative accuracy of this method. In particular, the uptake and subsequent retention of 99Tcm-HMPAO in conditions of high flow is known to be nonlinear. In this study, we compared the quantitative retention of 99Tcm-HMPAO in eight subjects under conditions of normo- and hypercapnia. There was no significant increase, despite a mean rise of the end tidal pCO2 from 5.06 to 7.06 kPa, a stimulus that is known to provoke an 80-100% rise in CBF. We conclude that SPET studies with 99Tcm-HMPAO provide excellent qualitative images of the distribution of CBF, but that quantitative data in ml hg-1 min-1 must be interpreted with caution.

Lumbar canal stenosis presenting with acute bilateral foot drop.

We present a case of bilateral foot drop of acute onset related to lumbar canal stenosis in the absence of an acute disc prolapse, either on imaging or at surgery. The clinical and radiological findings in this case are discussed. Possible mechanisms for this occurrence are discussed and the relevant literature is reviewed.

Solitary calvarial myofibroma presenting in adolescence.

Myofibroma is a benign fibrous tumour that may be found in the soft tissues, skeleton, and internal organs. It is a rare lesion but is the commonest fibrous tumour in infancy. Involvement of the skull has been reported in some 21 cases in the English-language literature. None of these, however, has arisen outside infancy. Here, we report a myofibroma arising from the temporal bone in a 17-year-old girl.

Tumoural calcinosis of the cervical spine: case report, pathogenesis and differential diagnosis.

A rare case of tumoural calcinosis of the cervical spine is presented. Tumoural calcinosis presents with masses of dystrophic calcification in juxta-articular areas. It is very rare in the cervical spine with few cases described in the literature so far. It remains part of the differential diagnosis for any calcified spinal compressive lesion.

Cortical thermal clearance as a predictor of imminent neurological deterioration.

Cerebral blood flow (CBF) is vital for the perfusion of brain tissue. It is frequently deranged in acute neurosurgical disorders, particularly subarachnoid haemorrhage and head injury. Despite its importance, in clinical practice the routine measurement of CBF is uncommon, as changes in CBF can occur abruptly. However, a method of CBF monitoring may be potentially useful, particularly if warning could be obtained of impending ischaemia before neurological deterioration. Measurement of tissue thermal clearance has been used as an estimate of local tissue blood flow since 1933. Its history is full of controversy, mostly centred around quantification. The ability of perfused tissues to clear heat is, as a first approximation, the sum of two components: a fixed component related to the constituents of the tissue, primarily the water content, and a variable convective component, related to the local blood flow. The mathematical relationship between flow and the observed increment in thermal clearance is still debatable. Here, the history of thermal clearance is reviewed, and the results of our work with a relatively simple device are described. It consisted of an implantable probe, designed to measure the thermal clearance of the cortical surface in arbitrary clearance units (CU), ranging from 27 CU (cadaveric) to 69 CU (well perfused brain). Pre- and postoperative studies showed that the system was capable of following changes in blood flow rapidly. The cortical thermal clearance (CTC) was monitored postoperatively in 24 patients after aneurysm surgery. Most remained clinically stable and had thermal clearances over 50 CU. In others, however, it was seen that a low-or falling-thermal clearance was associated with development of a neurological deficit. Analysis using receiver operating characteristics curves established that the method had a sensitivity of 0.86 and a specificity of 0.82 in the detection of a contralateral ischaemic motor deficit. No patient in whom the CTC remained above 50 CU ever developed a new neurological deficit, whereas all patients with a CTC below 35 did. The evidence-historical, mathematical, practical, and theoretical-that CTC is closely related to local blood flow is discussed. Changes in thermal clearance have been observed prior to the development of ischaemic neurological deterioration. Detection of imminent ischaemia may become increasingly important as means of improving cortical blood flow become more widely available. Whether such early detection- and subsequent treatment-of ischaemia will result in better patient outcome remains to be established. I believe it will.

Parafalcine meningioma presenting with facial pain: evidence for cortical theory of pain?

Intracranial tumours causing facial pain are very rare. All previously reported tumours have been located in either the posterior or middle fossa. We present a unique case of a bilateral parasagittal meningioma located in the parietal-occipital cortex presenting with right-sided facial pain.

Zero tolerance to shunt infections: can it be achieved?

OBJECTIVE: To evaluate the rigid application of a technique of shunt placement aimed at the eradication of postoperative shunt infection in neurosurgical practice. METHOD: All shunt procedures were performed or closely supervised by the senior author (MSC). The essentials were the use of intravenous peri- and postoperative antimicrobials, rigid adherence to classical aseptic technique, liberal use of topical antiseptic (Betadine), and avoidance of haematomas. RESULTS: Of 176 operations, 93 were primary procedures; 33 patients underwent revisions, some multiple. Only one infection occurred, seven months postoperatively, secondary to appendicitis with peritonitis. The infecting Streptococcus faecalis appeared to ascend from the abdominal cavity. CONCLUSION: A rigidly applied protocol and strict adherence to sterile technique can reduce shunt infections to a very low level.

Will increased awareness among physicians of the significance of sudden agonizing headache affect the outcome of subarachnoid hemorrhage? Coventry and Warwickshire Study: audit of subarachnoid hemorrhage (establishing historical controls), hypothesis, campaign layout, and cost estimation.

BACKGROUND AND PURPOSE: The most common symptom associated with aneurysmal minor bleed ("warning leak") is a sudden agonizing headache. Early screening of these patients may improve the outcome of subarachnoid hemorrhage and may be highly cost-effective. METHODS: We conducted an extensive retrospective audit of subarachnoid hemorrhage over the last 10 years in the region of Coventry and Warwickshire, England, and initiated a continuous campaign among all physicians in the region for early neurosurgical referral of patients with sudden agonizing headache. RESULTS: Over the last 10 years the incidence of subarachnoid hemorrhage in the region was 8.7/100 000 per year. Surgical activity was 34% and early mortality 45.2%. Functional outcome, both overall and by grade on admission, was within internationally accepted levels. Warning leak symptoms before admission were experienced by 20% of patients. These patients sought medical advice but were not referred immediately to the neurosurgical unit. CONCLUSIONS: We have established our population as valid historical controls and outlined our campaign strategy. Lowering the clinical threshold at which patients with sudden agonizing headache are screened for aneurysms or arteriovenous malformations will undoubtedly increase diagnostic costs. However, for reasons given in the text, we estimated the cost per quality-adjusted life year gain to be 1000 pounds ($1500).

Anterior cervical discectomy: an improvement in donor site operative technique.

Bone graft harvest from the iliac crest for anterior cervical discectomy is common surgical practice. Its rate of complication remains far higher than that of the cervical operation. We describe a method of harvest that we believe reduces post-operative complications and pain, facilitating early patient mobilization and discharge.

99TCm-HMPAO SPECT studies in traumatic intracerebral haematoma.

Traumatic intracerebral haematomas are a common neurosurgical emergency. Their management, particularly the role of surgical removal, is controversial. Deterioration often occurs late, and is unpredictable. Eight patients with traumatic intracerebral haematomas were admitted to the neurosurgical unit to monitor their clinical state. All were studied within 48 hours of admission with single photon emission computerised tomography (SPECT), using the recently introduced radionuclide 99Technetiumm-Hexamethyl propylene amine oxime (99Tcm-HMPAO). At the time of the SPECT study, all the patients had been clinically stable. Three patients remained so; in the other five, the conscious level deteriorated, necessitating craniotomy and evacuation of the haematoma. In all the patients, the SPECT studies demonstrated perfusion defects that corresponded to the location of the haematoma, as demonstrated by computerised tomography (CT). However, in the five patients who subsequently deteriorated, the perfusion defects seen on the SPECT scan appeared larger than the haematoma, as seen on the CT scan. In addition, there was widespread poor retention of 99Tcm-HMPAO in the ipsilateral hemisphere. These differences were quantifiable. Interestingly, these differences were present at a time when the patients were clinically stable, before their deterioration. It is concluded that SPECT studies with 99Tcm-HMPAO are of possible use as predictors of late deterioration in the management of traumatic intracerebral haematomas.

Cortical thermal clearance monitoring in surgery for a giant middle cerebral artery aneurysm.

Cortical thermal clearance was used during surgery for clipping of a giant middle cerebral artery (MCA) aneurysm. During prolonged continuous proximal MCA occlusion thermal clearance remained normal, indicating sufficient collateral blood supply. Postoperatively the patient had no neurological deficit. This monitoring technique is a useful guide to the safety of temporary clipping during aneurysm surgery.

A conus tuberculoma mimicking an intramedullary tumour: a case report and review of the literature.

Tuberculomas of the spinal cord are rare. They usually present as mass lesions with little evidence of systemic illness. We report a case where the diagnosis was only made histologically, emphasising the need to consider infection as a cause of neurological illness in patients from under-developed countries.

Measurement of in vivo cortical thermal clearance in man during complete circulatory standstill.

The cortical thermal clearance (CTC) was recorded continuously during surgery for a giant basilar aneurysm under cardio-pulmonary bypass. The changes observed mirrored the fall and rise in cardiac output. CTC at zero flow corresponded closely to the established cadaveric value, supporting the principle that the conductive component of thermal clearance is constant.

Multiple cerebral aneurysms, multiple meningiomas and multiple subcutaneous angiolipomas: a case report.

The simultaneous occurrence of multiple meningiomas, multiple distally located cerebral aneurysms and numerous subcutaneous lipomata in a 48-year-old man is reported. There was no evidence of neurofibromatosis, connective tissue disease or abnormality of collagen synthesis. We propose a possible genetic link between these three disparate conditions in our patient.

Computed tomography in the diagnosis of malignant brain tumours: do all patients require biopsy?

A proportion of patients with computed tomographic (CT) scan appearances of malignant brain tumour undergo conservative management, despite the absence of histological confirmation of the diagnosis. Concern that this policy risked misdiagnosing a benign tumour prompted us to examine the accuracy of CT scanning in diagnosing malignant lesions. The study was designed to determine whether within a group of 300 patients with intracerebral mass lesions of known pathology, two sub-groups existed: one with appearances so specific for malignant glioma that biopsy was unnecessary, and the other in which the appearances were characteristic of malignancy, though not specific for glioma. Three neuroradiologists independently reviewed the CT scans, together with brief clinical details. When diagnosing malignant tumours, all made errors: nine benign lesions were considered to be malignant. When diagnosing malignant glioma, one neuroradiologist made errors, but the other two adopted a more cautious approach and were accurate. The restricted a "certain" diagnosis to about one in five scans considered to show malignant tumour. Those diagnosed specifically as malignant glioma were intrinsic, irregular, mixed density lesions, exhibiting variable enhancement and infiltrating the peri-ventricular tissues, especially the corpus callosum. Using these criteria, they could correctly identify a small proportion of patients with malignant gliomas. In all other patients, biopsy remains the only means of obtaining a definitive diagnosis.

A thermal clearance probe for continuous monitoring of cerebral blood flow.

Cortical thermal clearance provides a practical means of continuous assessment of cerebral blood flow. A probe which can be used to monitor cerebral cortical thermal clearance is described. It has proved a reliable method of predicting oligaemia, showing good correlation between measured thermal clearance and the onset of clinical signs of ischaemia. The limitations are its size, invasiveness, small sample volume and difficulty with quantification. It is a useful additional tool in the management of patients suffering from acute neurosurgical disorders.

A thermal clearance probe for continuous monitoring of cerebral blood flow.

Thermal clearance has been used as a measure of tissue blood flow for over 60 years. We have developed a probe which can be used to monitor cerebral cortical thermal clearance in patients suffering from acute neurosurgical disorders. Despite its limitations of size, invasiveness, small sample volume, and difficult quantification it has proved a reliable method, showing a good correlation between measured thermal clearance and the onset of clinical signs of ischaemia.