Recommendations from the Society of British Neurological Surgeons.
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Algorithms↗
Biomedical subjects
A D Mendelow
Publications and source records attributed to A D Mendelow.
Selective impairments of mitochondrial respiratory chain activity during aging and ischemic brain damage.
Cumulative oxidative damage to mitochondrial deoxyribonucleic acid (DNA) with subsequent defects in oxidative phosphorylation may reduce the capacity of the aging brain to cope with metabolic stress. This may contribute to the age related increase in cerebral infarct size that has been documented following permanent middle cerebral artery occlusion (MCAO) in the rat. This hypothesis was evaluated by assessing mitochondrial respiratory chain complex activity in both ischemic and non ischemic brain tissue of adult (10 month) and aged (28 month) male Wistar rats, six hours after occlusion of the left middle cerebral artery. Aging was associated with a significant decline in cerebral mitochondrial function with impairment of the activities of complexes I. II and IV. The individual respiratory chain complexes also exhibited selective vulnerability to a focal cerebral ischemic lesion, with significant impairment of complex I activity in the lesioned hemisphere of both age groups. The age related decline in complex I activity may be important in the enhanced susceptibility of the aging brain to ischemic neuronal damage.
Aging↗
The effect of non-competitive N-methyl-D-aspartate receptor antagonism on cerebral oedema and cerebral infarct size in the aging ischaemic brain.
Although vulnerability to ischemic neuronal injury is enhanced with age, the aging brain may be less amenable to neuroprotection as a result of quantitative and qualitative changes in the NMDA receptor. In addition, the elderly may be less tolerant of adverse effects of neuroprotective drugs and this might ultimately limit therapeutic potential in human stroke. However, antagonism of the excitotoxic effects of glutamate by parenteral administration of the non competitive NMDA antagonist magnesium has been well tolerated and has shown to be neuroprotective in young animal models of stroke and head injury. We therefore evaluated the potential of magnesium chloride to reduce ischemic neuronal injury in aged rodents subjected to permanent occlusion of the middle cerebral artery. Treatment with magnesium chloride induced hypotension and hyperglycaemia in both adult and aged rats and did not reduce ischemic neuronal injury or cerebral edema. However, despite these adverse haemodynamic and biochemical effects, which may augment cerebral infarct size, ischemic damage was not exacerbated in the treated groups, suggesting that magnesium has the potential to salvage penumbral neurons and that inotropic support and maintenance of normoglycaemia may permit realisation of its neuroprotective potential. This may have important implications for future clinical stroke trials.
Aging↗
Delayed aneurysm formation following surgery for a giant serpentine aneurysm.
We report a case of a giant serpentine aneurysm of the right middle cerebral artery (MCA) that was treated by total excision of the aneurysm with cerebral blood flow control management. Four years later the patient presented with a three month history of headache and angiograms showed a new aneurysm on a different branch of the MCA which is thought to have been caused by the previous surgical dissection.
Adolescent↗
Microvascular reconstruction of complex craniofacial defects.
Many large vault or skull base tumours are best treated by wide surgical excision and primary reconstruction using a microvascular free tissue transfer (free flap). We report 23 patients who were reconstructed using free flaps, eight having been previously treated surgically elsewhere and seven of whom had recurrent disease after radiotherapy. There was one flap failure and a local recurrence rate of 16% (3/19). The outcome at a mean follow-up period of 29 months, was 19 patients alive and four deaths.
Adult↗
Intensive care of severely head injured patients. National research is needed.
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Attitude of Health Personnel↗
Magnetic resonance angiographic assessment after extracranial-intracranial bypass surgery.
Extracranial-intracranial (EC-IC) bypass operation may be performed to augment the distal cerebral circulation. The bypass patency is usually assessed postoperatively with conventional cerebral angiography. Six patients are reported in whom the bypass patency was assessed using magnetic resonance angiography (MRA): Two had intracavernous carotid aneurysms, three had base of skull tumours encompassing the internal carotid artery, and one had occlusion of the right internal carotid artery with poor collateral reserve as confirmed by an acetazolamide stimulation test. Postoperative conventional cerebral angiography was also obtained in three patients for comparison. The MRA correlated reasonably well with conventional cerebral angiography in showing bypass patency, although conventional cerebral angiography was superior in demonstrating small vessels; MRA has the added advantage of showing the relative flow contribution and flow direction under physiological conditions by using targeted presaturation pulses.
Adult↗
The Apache II scoring system in neurosurgical patients: a comparison with simple Glasgow coma scoring.
In order to compare the predictive value of the Apache II, the Glasgow Coma Scale and Revised Trauma Scoring systems in relation to outcome in a neurosurgical department high dependency unit (HDU), all 109 patients entering the unit under the care of one consultant were studied. All patients in the HDU were self-ventilating, so that motor responses were not suppressed by muscle relaxants or sedation. Initial Minimum and Maximum Glasgow Coma Scale Scores, Revised Trauma Score, Apache II and the Apache minus neurological weighting (Apache-NW) scores, were compared as predictors of outcome (as assessed by the Glasgow Outcome Score at 6 months). Twenty-eight patients had a bad outcome, i.e. Glasgow Outcome Scores 1-3, and 72 individuals a good outcome, i.e. scores 4 or 5. Statistical analysis was by the Spearman Ranked Correlation Test, and comparison of Receiver Operational Characteristics Curves. Data were complete on 100 patients (91.7%) and show the Maximum Glasgow Coma Score, followed by the Apache II score, as the best predictors of outcome analysed. This was also true if all patients except those with head injury were analysed as a group. All scoring systems were significantly better predictors of outcome in the head injured patient. For this group, Apache II had an outcome predictive value of 97% compared with 93% for initial and 95% for minimum GCS. Removing the neurological weighting from Apache II weakened its predictive ability in all patients, emphasizing that it is the neurological status of the patient which best predicts overall functional outcome. Apache II data are also much more time-consuming to collect than GCS data.(ABSTRACT TRUNCATED AT 250 WORDS)
Brain Injuries↗
Experimental stroke and neuroprotection in the aging rat brain.
BACKGROUND AND PURPOSE: Experimental stroke research has for the most part incorporated the use of young animals despite the importance of aging in cerebrovascular disease in humans. We hypothesized that age-related reductions in the density and function of cortical N-methyl-D-aspartate (NMDA) receptors might limit neuroprotective potential in the elderly. In this study, a model of occlusive stroke in the aging rat brain has been developed and used to establish the effects of age on cerebral infarction and to evaluate the scope for protecting the aging brain during ischemia. METHODS: Focal cerebral ischemia was produced by thermocoagulation of the left middle cerebral artery in adult (11 to 17 months) and aged (28 to 36 months) male Wistar rats. Infarcts were assessed histologically with volumetric analysis of infarct size, hemodynamically by serial cerebral blood flow measurement using the hydrogen clearance technique, and by analysis of specific gravity as an index of brain edema. Neuroprotective potential was assessed using the competitive NMDA receptor antagonist 3-(2-carboxy piperazin-4-yl)propyl-1-phosphonate (D-CPPene). RESULTS: Aging was associated with a significant increase in infarct size, with a mean infarct volume of 40.5 +/- 2.6% of the hemisphere volume in aged rats compared with 30.9 +/- 0.7% in adult rats (P < .01). D-CPPene reduced the mean infarct volume to 33 +/- 1.8% and 20.7 +/- 3.2% in aged and adult rats, respectively (P < .05). Cerebral blood flow fell markedly after infarction, but thereafter D-CPPene-pretreated rats maintained higher cerebral blood flow than untreated animals throughout the duration of the experiment (22.8 +/- 3.2 and 30.1 +/- 5.5 mL.100 g-1.min-1 in treated aged and adult rats, respectively, compared with 11.3 +/- 2.7 and 16.5 +/- 3.2 mL.100 g-1.min-1 in untreated aged and adult groups, 90 minutes after infarction [P < .05]). Pretreatment also reduced cortical edema; mean cortical specific gravity 4 hours after infarction was 1.0381 +/- 0.0013 in untreated aged rats and 1.0391 +/- 0.0014 in untreated adults compared with 1.0458 +/- 0.0031 in treated aged rats and 1.0442 +/- 0.0014 in treated adult rats (P < .05). CONCLUSIONS: Under similar experimental conditions, there was an age-related increase in cerebral infarct size. However, NMDA receptor antagonism was neuroprotective in the aging brain and resulted in a significant reduction in cerebral ischemic damage, less cortical edema, and preservation of cerebral blood flow.
Aging↗
Cerebral oedema following intracerebral haemorrhage: the effect of the NMDA receptor antagonists MK-801 and D-CPPene.
The effects of pre-treatment with the NMDA receptor antagonists MK-801 and D-CPPene on the development of brain oedema were investigated in a rodent model of intracerebral haemorrhage. In acute experiments (4 hour survival) both drugs caused significant hypotension and had significant anaesthetic effects whilst conferring no protection against oedema formation. In chronic experiments (24 hour survival) MK-801 conferred no protection against brain oedema. With D-CPPene marginal protection against cortical oedema may have been conferred but this result should be interpreted with caution.
Animals↗
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.
Blood Flow Velocity↗
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.
Basilar Artery↗
The effect of age on cerebral oedema, cerebral infarction and neuroprotective potential in experimental occlusive stroke.
A model of occlusive stroke in the aging brain has been developed and used to evaluate the effects of age upon cerebral infarction, cerebral oedema and neuroprotective potential. Focal ischaemia following left middle cerebral artery occlusion has been compared in aged (30 month) and adult (< 17 month) rats, with histological assessment of infarct volume and analysis of specific gravity as an index of cerebral oedema. Aging was associated with a significant increase in cerebral infarct size. The mean infarct volume in aged rats was 40.5% +/- 2.6% of the hemisphere volume, compared to 30.9% +/- 0.7% in adults (p < 0.01). Pre-treatment with the competitive N-Methyl-D-Aspartate (NMDA) receptor antagonist 3-(2-Carboxy Piperazin-4-yl)Propyl-l-Phosphonate (D-CPP-ene) reduced infarct volumes in both age groups to 33.0% +/- 1.8% and 20.7% +/- 3.2% in aged and adult animals, respectively (p < 0.05). There was significantly less oedema of the cerebral cortex in D-CPP-ene pre-treated rats; mean cortical specific gravity 4 hours post-infarction was 1.0381 +/- 0.0013 in untreated aged rats and 1.0391 +/- 0.0014 in untreated adults, compared to 1.0458 +/- 0.0031 in treated aged rats and 1.0442 +/- 0.0014 in treated adults (p < 0.05). At 24 hours post-infarction, D-CPP-ene pre-treated aged rats had a mean cortical specific gravity of 1.0403 +/- 0.0006 compared to 1.0361 +/- 0.0014 in untreated aged animals (p < 0.05). This study has demonstrated an age-related increase in cerebral infarct size, but has shown that the aging brain is amenable to neuroprotection by NMDA receptor antagonism.
Age Factors↗
Effect of guidelines on management of head injury on record keeping and decision making in accident and emergency departments.
OBJECTIVE: To compare record keeping and decision making in accident and emergency departments before and after distribution of guidelines on head injury management as indices of implementation. DESIGN: Before (1987) and after (1990) study of accident and emergency medical records. SETTING: Two accident and emergency departments in England. PATIENTS: 1144 adult patients with head injury in department 1 (533 in 1987, 613 in 1990) and 734 in department 2 (370, 364 respectively). MAIN MEASURES: Recording of relevant symptoms and signs as determined in the guidelines; presence of, indications for, and rates and appropriateness of skull x ray examination and admission. RESULTS: The median number of guidelines variables recorded for all study periods ranged from 7 to 9 out of a possible maximum of 27. For key decision making variables the presence or absence of penetrating injury was least likely to be recorded (< or = 1%) and that of loss of consciousness most likely (> or = 75%). Altogether, the proportion of patients receiving skull x ray examination or admitted varied from 25%-60% and 7%-23% respectively; overall, 69% (1280/1856) and 64% (1177/1851) of patients were managed appropriately. However, no consistent change occurred in the departments between the study periods. For instance, in department 1 the proportion of appropriate x ray examinations rose significantly after distribution of the guidelines (from 61% (202/330) to 73% (305/417)) and appropriate decisions on whether to x ray or not also rose (from 65% (340/522) to 72% (435/608)). There was no significant change in department 2, although the proportion of appropriate admissions fell (from 33% (55/166) to 15% (19/130)). CONCLUSIONS: Recording practice and decision making were variable and had not consistently improved after dissemination of the guidelines. Strategies are required to ensure effective implementation of guidelines.
Adult↗
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.
Bone Transplantation↗
Cerebral blood flow measurement using the hydrogen clearance technique: a microcomputer-based system for data collection and analysis.
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Cerebrovascular Circulation↗
Post-traumatic bilateral facial palsy.
Bilateral facial palsy is an uncommon condition and few clinicians have experience of more than the occasional case. Unlike its unilateral counterpart, an aetiological factor is often demonstrable. A wide variety of recognized diseases may give rise to the condition and thus thorough investigation is required. This paper presents an unusual example of this rare condition.
Adult↗
The management of carotid artery disease: application of new diagnostic techniques and their neuropathological significance.
The early management of patients with carotid artery disease was based on minimal investigative knowledge without much appreciation of its pathophysiological significance. During the last decade, however, the advent of non-invasive and functional imaging has increased our awareness and the significance of extracranial cervical vascular disease. This has led to more logical management strategies particularly for patients with carotid artery disease. Non-invasive imaging, in particular, has identified patients at risk and led to the establishment of large randomized trials of medical and surgical treatments, the recent results of which have altered management practice.
Carotid Artery Diseases↗