Incidence and effects of increased cerebral blood flow velocity after severe head injury: a transcranial Doppler ultrasound study II. Effect of vasospasm and hyperemia on outcome.

Cerebral blood flow velocities were measured in 50 severely head injured (Glasgow Coma Scale (GCS) 8 or less) patients using transcranial Doppler ultrasonography (TCD). Abnormally high TCD velocities were recorded in 35 patients; in 20 this was deemed to be due to vasospasm and in the other 15 to hyperemia. Patients who developed hyperemia also had the highest intracranial pressure (ICP) and the lowest cerebral perfusion pressure (CPP) of the three groups. Outcome was assessed at six months after injury using the Glasgow outcome scale and the disability rating scale. In the normal velocity group 87% of patients had a good outcome, compared with 47% of those with hyperemia and 40% of those with vasospasm. The highest velocity (HVEL), GCS, age, ICP and CPP were entered into a logistic regression analysis. HVEL, age and CPP were found to be the most significant predictors of outcome (chi 2 = 29.5; p < 0.0001). These factors predicted outcome with 82% accuracy, 86% sensitivity and 76% specificity. Routine monitoring of TCD velocity may be useful in detecting hyperemia and vasospasm after severe head injury, allowing appropriate treatment to be started as early as possible.

Transcutaneous carbon dioxide measurement after craniotomy in spontaneously breathing patients.

OBJECTIVE: The purpose of this study was to determine the incidence of postoperative hypercarbia in patients undergoing intracranial neurosurgery. Postoperative hypercarbia is a well-recognized cause of postoperative morbidity. METHODS: Sixty-four patients undergoing craniotomy were monitored in the first 36 postoperative hours using transcutaneous CO2 monitoring. We collected and analyzed demographic data, complete medical histories and examinations, and details of surgery, anesthesia, and postoperative progress. The accuracy of the transcutaneous CO2 monitoring was evaluated by comparison with arterial blood gas CO2. INSTRUMENTATION: The "TINA" TCM3 Transcutaneous CO2 Monitor (Radiometer, Copenhagen, Denmark) was used. RESULTS: Thirty-nine patients (61%) developed no hypercarbia. Nineteen patients (30%) developed mild to moderate hypercarbia (46-59 mm Hg) and six patients (9%) developed severe hypercarbia (60 mm Hg or greater). Statistically significant differences were observed between the severely hypercarbic group and the other two groups combined, as follows: a higher incidence of preoperative and postoperative seizures, a lower average postoperative Glasgow Coma Scale score, a higher incidence of reintubation and ventilation, and a higher degree of intraoperative brain disturbance. Analysis of transcutaneous CO2 measurements and time-matched arterial blood gas CO2 measurements revealed an acceptable accuracy of the transcutaneous method. CONCLUSION: this study demonstrates that, in routine neurosurgical practice, a subgroup of patients are at risk of developing postoperative hypercarbia, which may be more common than is generally recognized and will not usually be detected by routine postoperative monitoring. Transcutaneous CO2 monitoring is a useful technique that may impact management decisions.

An investigation with serial angiography into the evolution of cerebral arterial spasm following aneurysm surgery.

Serial postoperative angiograms were performed in 28 patients with intracranial aneurysms, 26 of whom had presented with a subarachnoid hemorrhage. The clinical state and intracranial pressure (ICP) were also measured. Angiograms were performed in the ward using a cannula, which was passed into the proximal external carotid artery via the superficial temporal artery. Measurements of the vessel diameters were made, with the preoperative angiogram as a baseline. Patients could be placed into one of five groups depending on the presence or absence of significant arterial spasm, the clinical state of the patient, and the normality or otherwise of the ICP. No patient's condition deteriorated without an elevated ICP and/or significant arterial spasm. The study shows that this spasm is usually associated with a poor clinical state if it reaches a maximum 8 to 12 hours after the operation, although the clinical deterioration is not apparent for a further 6 to 12 hours. Knowledge of the natural history of postoperative arterial spasm may allow earlier treatment of the spasm, which may be more successful than delaying treatment until clinical deterioration has occurred. The worth of the varied drugs proposed for the treatment of spasm may be assessed using this type of protocol.

Clinical course and outcome of severe head injury in Australia.

The records of 159 severely head-injured patients (all in coma for longer than 6 hours) from Sydney, Australia, were studied. The clinical course, charted over a 2-week period, indicated that 60% of deaths occur by Day 3 and that 12% of patients remain in coma (Glagow Coma Scale (GCS) score less than 7) for more than 2 weeks. Overall, at long-term follow-up review more than 2 years after injury, 51% of patients were dead, 7% were severely disabled or vegetative, and 42% had a good to moderate recovery. Outcome of the patients in prolonged coma was assessed separately, with only one-third making a good or moderate recovery; two-thirds of the severely disabled patients came from this group. The high proportion of poor outcomes associated with prolonged coma suggests that this group of patients should be specifically targeted in research. One appropriate intervention with this group would be the restructuring and intensification of early rehabilitation. However, the GCS score lacks the precision needed for this type of study, and a better measure of recovery should be developed.

Changing the old order: neurosurgery and ethics at the millennium.

The profound changes in biotechnology which have challenged established beliefs in western society over the last 30 years have resulted in ethical problems which affect neurosurgeons no less than other medical scientists. This paper examines some of these changes in the context of neurological aspects of bioethics and argues a justification for the active involvement of clinical neurosurgeons in the vigorous debates in society today. In order to adapt to these changes, neurosurgeons will need to learn about ethical systems as utilities to resolve the conflicts thrown up by biotechnology and pay particular attention to such diverse issues as the quality of training programs, continuing medical education, the establishmnt of standards of care and membership of Institutional Ethics Committees.

Management of moderate and severe head injury in neurosurgical units in Australasia.

A survey of the 31 neurosurgical units in Australia and New Zealand was undertaken by the Trauma Committee of the Neurosurgical Society of Australasia to determine areas of common practice and areas of divergence in management protocols in the treatment of moderate and severe head injury. Intracranial pressure (ICP) measurement was a fundamental component of care in the majority of units with rises in ICP being treated by sedation, mild hyperventilation (p(a)CO(2) of 30-35 mm Hg) and osmotherapy or cerebrospinal fluid drainage as first choices. Where the ICP was measured selectively following a severe head injury, the computed tomography appearance was used as the criterion for initiation of measurement. All units used at least an arterial line, a central venous pressure monitor and end-tidal CO(2) measurement routinely to monitor progress. Attention to the cerebral perfusion pressure with volume support and pressors, together with less intense hyperventilation, were the most common alterations to management protocols made over the preceding 2 years.

The Westmead head injury project: Outcome prediction in acute subdural haematoma.

A prospective two year study of a consecutive sample of patients with an acute subdural haematoma who were admitted to Westmead Hospital, New South Wales, Australia was undertaken. There were 103 patients with an acute subdural haematoma admitted in the period. Twenty-four of these scored 9 or greater on the Glasgow Coma Scale (GCS) and of these all made a functional recovery, i.e. Glasgow Outcome Scale (GOS 1 or 2). The remaining 79 patients scored 8 or less on admission and of these 30% made a functional recovery. Of the 70% remaining, 4% were moderately or severely disabled (GOS 3 or 4) while 66% died (GOS 5). Age, hypoxia, hypotension, response to intracranial pressure control and two CT scan features, midline shift as measured from the septum pellucidum and cerebral oedema, were all significant in predicting outcome. Time from injury to treatment, initial pupil response, lucid interval and compression of brainstem cisterns on CT scans statistically failed to predict outcome. The data were analysed using logistic regression which showed age and midline shift to predict death or disability with an accuracy of 80% at twelve months after the injury (sensitivity 58%, specificity 89%).

Metastatic atypical meningioma: case report and review of the literature.

Extracranial metastasis of an intracranial meningioma is rare. We discuss the clinical, radiological and histopathological presentation of an elderly man with pulmonary metastases from a recurrent meningioma of atypical histology, and review the literature pertaining to this phenomenon.

Ossification of the posterior longitudinal ligament of the cervical spine.

Although ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is an uncommon condition, its strong prevalence among the Japanese and non-Japanese Asians is well known. Genetic predisposition coupled with ageing and an imbalance in bone-seeking hormones are some actiological factors postulated in recent years. Imaging is directed at showing the calcified mass, cord compression and any attendant damage, as the latter are important prognostic factors. We describe 6 cases of OPLL of the cervical spine seen at Westmead Hospital between 1979 and 1994. Of the 4 patients presenting with disabling compressive myelopathy, 3 made significant recovery following surgical decompression. Characteristic plain film features manifesting as a dense calcified linear structure along the course of the posterior longitudinal ligament (PLL) were present in 5 patients, including 1 who was asymptomatic. Computed tomography (CT) was invaluable in demonstrating the full extent of the disease in all 5 symptomatic patients. Magnetic resonance imaging (MRI) was helpful in excluding myelomalacia in 2 patients prior to successful surgery. The myelopathy caused by cervical OPLL remains rare, affecting mainly middle aged males of Asiatic and European extraction.

Cervical cord extradural haematoma with familial cutaneous haemangiomas.

This case report confirms the link between familial cutaneous haemangiomas and haemangiomas of the spinal extradural space. Haemorrhage from a cervical extradural haemangioma may cause a haematoma resulting in an anterior cord syndrome. Recovery is possible with early diagnosis and surgical decompression at the involved level. If the diagnosis is not made the patient may die from this extradural cervical compression. Diagnosis involves myelography with spinal angiography to confirm the site and extent of both haemangioma and extradural haematoma.

The treatment of raised intracranial pressure following aneurysm surgery.

The effect of intravenous mannitol infusion and withdrawal of cerebrospinal fluid on the intracranial pressure and clinical state was studied in 26 patients with raised intracranial pressure after direct surgery for ruptured aneurysm. Each method decreased the mean intracranial pressure by about 60% of the pre-treatment level. The maximal decrease following mannitol occurred after 60-90 minutes and generally lasted between three and four hours. The effects of mannitol did not decrease when repeated infusions were necessary. Rebound increases in the intracranial pressure following infusion were not observed. Withdrawal of cerebrospinal fluid lowered the intracranial pressure immediately and the effect persisted for approximately 60 minutes. This could be repeated as often as necessary and was without systemic disturbance, although a patent intraventricular catheter was necessary. The two methods could be used simultaneously.

Tumours of the cauda equina.

A retrospective study of 70 consecutive patients with a cauda equina tumour who were admitted to Neurosurgical Department at the Radcliffe Infirmary, Oxford is presented. The diagnosis of these tumours is often difficult and delayed. The quality of life largely depends upon the neurological disability at presentation. The diagnostic features and investigations are discussed together with the treatment and prognosis.

Interhemispheric subdural haematoma following head injury.

A case of interhemispheric subdural haematoma following head injury is reported. The clinical and computerized axial tomographic (CT) features of this unusual complication are described together with the surgical management.

Post-coma disturbance and post-traumatic amnesia as nonlinear predictors of cognitive outcome following severe closed head injury: findings from the Westmead Head Injury Project.

This study sought to identify combinations of early neurological variables which best predict cognitive outcome 12 months after severe head injury. At the time of admission patients were assessed on seven neurological indices. Twelve months later a battery of neuropsychological tests examining recent memory functioning and speed of information processing was administered. Recent memory functioning was best predicted by a combination of post-coma disturbance (PCD; i.e. the duration of post-traumatic amnesia, PTA, minus the duration of coma) and presence of subarachnoid haemorrhage (multiple r = 0.54, p < 0.001). Speed of information processing was best predicted by the duration of PTA (r = 0.35, p < 0.01). However, these conclusions were based on square root transformation of PCD and PTA variables. The success of this transformation in assisting prediction confirms suggestions that the relationship between PTA and cognitive outcome is nonlinear.

The Westmead Head Injury Project. Physical and social outcomes following severe head injury.

This study reports the physical outcomes of 181 survivors of severe head injury [Glasgow Coma Score (GCS) 8 or less] following aggressive head injury management which included early triage, evacuation and resuscitation, the use of ventilation in the Intensive Care Unit and intracranial pressure (ICP) measurement and control. At the conclusion of the study period of 2 years after the head injury, 71% had achieved a Glasgow Outcome Score (GOS) of 1, 17% GOS 2, 10% GOS 3 and 2% GOS 4. Physical recovery continued during the 2 years. Locomotor independence was achieved in 93% despite a motor disorder in 59%. About 90% were considered independent for basic life functions, e.g. feeding, bathing, dressing or toileting. Speech disorders were present in 19%. A return to an occupation, either a job or studies, at or below the pre-morbid level was achieved in 68%. Most patients were cared for at home by family or relatives. The majority of patients make a reasonable physical recovery following severe head injury with independence in locomotion and basic life skills. It was our impression that the neuropsychological sequelae of cognitive and behavioural disorders were a major impediment to re-assimilation into society.

Outcome prediction in extradural haematomas.

Extradural haematoma (EDH) is generally a condition of young adult males. It represents only a small percentage of the total number of head injuries admitted to a neurosurgical service, but it must be differentiated from simple concussion, and this means that it is considered in a large number of patients. EDH has the potential for a low mortality rate because of its extraaxial location, but in practice it is approximately 10%. Our results show that about 40% of EDH present with vomiting or nausea and no focal neurological signs. Skull X-ray does not aid in the diagnosis as approximately 35% are reported as being normal. There is a place for conservative treatment of EDH but only if the shift of the midline is minimal (less than 5 mm). A score has been developed to predict accurately a patient's outcome after suffering an EDH. This score includes the Glasgow Coma Scale, pupillary reaction and initial CT scan appearance, and has an accuracy of 88%.

The Westmead Head Injury Project outcome in severe head injury. A comparative analysis of pre-hospital, clinical and CT variables.

A prospective study of 315 consecutive patients with a severe head injury was undertaken to study factors contributing to mortality and morbidity, both in the pre-hospital and hospital phases. Entry criteria were a Glasgow Coma Scale (GCS) score of 8 or less after non-surgical resuscitation within 6 h of the injury, or a deterioration to that level within 48 h. Patients with gunshot wounds or who were dead on arrival were excluded. End points of the study were either death or at 6 months after the injury. Predictors of mortality were increasing age, the presence of hypotension, a low GCS, abnormal motor responses and pupillary non-reactivity. In the 167 patients in whom intracranial pressure (ICP) was measured, raised ICP and failure to respond to treatment for raised ICP also predicted mortality. Three CT predictors of mortality were the presence of cerebral oedema, intraventricular blood and the degree of midline shift. When analysed using logistic regression, the most accurate model (accuracy 84.4%) included increasing age, abnormal motor responses and the three CT indicators. Analysis of the data for 'good' (Glasgow Outcome Score (GOS) 1 and 2) vs 'poor' (GOS 3 and 4) survival at 6 months was also performed using logistic regression. The model which provided the most accurate prediction of poor outcome included age, hypotension and three different CT characteristics, subarachnoid blood, intracerebral haematoma or intracerebral contusion (accuracy 72.5%).