David Doyle

ISCHAEMIC BRAIN DAMAGE IN FATAL NON-MISSILE HEAD INJURIES

The incidence and distribution of ischaemic brain damage in a consecutive series of 151 patients who died as a result of a non-missile head injury in the Institute of Neurological Sciences was determined on the basis of a comprehensive neuropathological and neurohistological examination. Ischaemic damage was identified in 138 cases (91%) even after excluding cases who only had necrosis and infarction related to contusions or fat embolism, and infarction in the brain stem of the type conventionally associated with raised intracranial pressure. The ischaemic damage was assessed as severe in 37 (27%), moderately severe in 59 (43%) and mild in 42 (30%), and in the 138 cases with ischaemic brain damage it was found more frequently in the hippocampus (122 cases; 81%), and in the basal ganglia (119 cases; 79%) than in the cerebral cortex (70 cases; 46%) and in the cerebellum (67 cases; 44%). There were statistically significant correlations between ischaemic brain damage and either an episode of hypoxia or of raised intracranial pressure. From the nature of the brain damage it seems likely that much of it was due to a reduction in the cerebral perfusion pressure. This study has shown that ischaemic brain damage is common after head injury, that at least a proportion of it is probably avoidable, and that it is more important as a cause of mortality and morbidity after head injury than has been hitherto realised.

Pituitary apoplexy and its effect on vision.

A series of 15 patients with a clinical diagnosis of pituitary apoplexy is reviewed. Clinical features are highlighted, with stress on the defects of visual function and ocular motility, and the associated endocrine abnormalities are described. Potential diagnostic errors and their significance are considered. The incidence of this complication in a large series of pituitary adenoma patients is measured, and the radiological and pathological findings are recorded. The results of treatment by surgery and/or radiotherapy and/or bromocriptine are assessed, particularly in relation to visual consequences, and compared with previous reports in the literature, which are reviewed.

DIFFUSE AXONAL INJURY IN HEAD INJURIES CAUSED BY A FALL

82 cases of diffuse axonal injury were found at necropsy in 635 patients with fatal nonmissile head injuries. 13 of these injuries were attributable to falls, and in all the patients fell from a considerable height. Diffuse axonal injury was not found in those with head injuries caused by a simple fall--ie, a fall from not more than the persons own height--but there was a statistically significant association between the presence of diffuse axonal injury and falls from a considerable height. These results indicate that diffuse axonal injury rarely, if ever, occurs as a result of a fall unless the patient has fallen some distance.

Anti-GM1 ganglioside antibodies cloned from autoimmune neuropathy patients show diverse binding patterns in the rodent nervous system

We have recently cloned a panel of monoclonal IgM anti-GMl ganglioside antibodies from peripheral blood lymphocytes of patients with multifocal motor neuropathy and Guillain Barr6 syndrome. In solid-phase immunoassay, the antibodies all reacted with GM1 and also reacted to different degrees with the structurally related glycolipids asialo-GMl and GDlb. These antibodies are being used to study the pathogenesis of anti-GMl antibody-mediated neuropathy in different experimental systems. In the present immunofluorescence study we report the binding patterns of 5 of these antibodies in the rodent nervous system. The antibodies demonstrated highly diverse binding patterns on tissue sections and teased fibers when compared to one another and between different species. The antibodies bound many central and peripheral nervous system structures, including neurons and myelin, motor end plate regions, and muscle spindles. The diversity of binding shown by these antibodies provides evidence that may account for the differing clinical phenotypes, including normality, associated with elevated titers of anti-GMl antibodies.

Brain Damage in Non-Missile Head Injury Secondary to High Intracranial Pressure

A comprehensive neuropathological analysis was undertaken on 434 patients who died as a result of a non-missile head injury in order to determine the frequency and extent of brain damage secondary to high intracranial pressure (ICP) in head injury. Using the criterion of pressure necrosis in the parahippocampal gyrus as evidence of high ICP due to a supratentorial expanding lesion, it was established that the ICP had been high in 324 cases. In 42 of these there was no other brain damage attributable to a high ICP. There was evidence of secondary brain stem damage in 221 cases and in 44 of these the damage could be seen only microscopically. In 54 cases there was a contralateral peduncular lesion. Other abnormalities were infarction in the territories of various arteries and in the anterior lobe of the pituitary. There was a supracallosal hernia in 80 cases and haemorrhage in the oculomotor nerves in 48 cases. These results further emphasise the frequency and range of brain damage due to secondary vascular factors brought about by high ICP in a patient who has sustained a head injury.

Microscopic Diffuse Axonal Injury in Cases of Head Injury

Diffuse axonal injury is one of the most important types of brain damage that can occur in the course of a head injury. Its presence can usually be predicted post-mortem because of the presence of focal macroscopic abnormalities in the corpus callosum and in the brain stem. This report describes nine cases where the diagnosis could only be made on the basis of histological studies.

A diagnostic quartet in leptomeningeal infiltration of the optic nerve sheath.

A rare case of optic leptomeningeal carcinomatosis secondary to a rectal adenocarcinoma is recorded. The presentation of rectal disease with blindness is unique. A diagnostic quartet of symptoms and signs of leptomeningeal infiltration of the optic nerve sheath is proposed and its value emphasized by the inability of further investigation to confirm the clinical diagnosis. The investigation and treatment of leptomeningeal carcinomatosis is reviewed.

Acute Renal Failure Due to McArdle's Disease

A 37-year-old previously fit man developed acute renal failure associated with rhabdomyolysis following a brief period of strenuous exercise. Subsequent muscle biopsy and ischaemic arm exercise confirmed the diagnosis of McArdles disease. This case illustrates that McArdles disease can present with acute renal failure in the absence of a past history of exercise-induced muscle pain and stiffness.

Chronic fatigue: electromyographic and neuropathological evaluation

Single fibre electromyography of extensor digitorum communis muscle (EDC) was performed on 35 patients with chronic fatigue, the majority of whom also had creatine kinase estimation and biopsy of EDC. The subjects were categorised as having an acute-onset post-viral fatigue syndrome, a non-specific chronic fatigue or possible muscle disease in view of pronounced myalgia. Of 11 subjects who had myalgia as a significant symptom, abnormalities in fibre density were found in 6, and 5 of these had some non-specific abnormalities on muscle biopsy, with creatine kinase levels being normal in all cases. Fibre density estimation may be a useful way of identifying a subgroup of chronic fatigue sufferers with a possible primary muscle disorder.