Emergency resuscitation and diagnosis

Patients who are rapidly deteriorating or already are unconscious require immediate resuscitation followed by a diagnostic CT scan. In head-injured patients it is recommended to keep systolic blood pressure higher than 90 mmHg and arterial partial pressure of oxygen (Pao2) higher than 8 kPa or arterial oxygen saturation greater than 90 . Patients with a Glasgow Coma Score (GCS) of 8 or less need to be intubated and ventilated to protect their airways prior to scanning. An intravenous bolus of...

Pathogenesis

Ischaemic optic neuropathy occurs in two forms, non-arteritic (median age 56 years) and arteritic (median age 74 years). Non-arteritic ischaemic optic neuropathy The non-arteritic form, AION or PION, may occur in patients with carotid artery disease and may be the initial manifestation of an ICA occlusion.76 Rarely, patients with ICA disease experience the simultaneous occurrence of cerebral infarction and ipsilateral ischaemic optic neuropathy. This combination is called the opticocerebral...

Nonaneurysmal subarachnoid haemorrhage

Approximately 75 of patients who suffer a non-traumatic, spontaneous SAH will be found to have a cerebral aneurysm.83 An AVM will be discovered in another 5 . Twenty per cent of SAH patients will have various other causes to which the haemorrhage is attributed. When the initial angiogram does not demonstrate an aetiology, further investigation with MRI and CT angiography is warranted. While past studies have found that a significant number of patients with initially negative arteriograms had an...

Varicella zoster virus

Encephalitis accounts for 90 of the neurological complications of varicella, which are in themselves rare, affecting only 01 of cases.24,25 In half, the encephalitis is of the cerebellar type with ataxia, dysarthria, headache, and drowsiness coming on about a week after the rash begins, but the neurological onset may precede the rash. Convulsions are common26 and progression to hemiplegia, cranial nerve palsies, aphasia, and coma may ensue. Patients with the cerebellar form usually recover...

Box 92 Bacterial meningitis causal organisms

Neonates Gram negative bacilli Streptococci (usually group B) Listeria monocytogenes Adults Pneumococci Meningococci Staphylococci Listeria monocytogenes Streptococci Mycobacterium tuberculosis can affect children and adults Table 9.1 Bacteria linked to underlying causes of meningitis Cell mediated immune defect Humoral immune defect organisms with particular virulence properties, which allow access to the CNS, cause most cases. The epidemiology of meningitis is complex and varies with the age...

Peripheral neuropathy

Peripheral neuropathy causing respiratory failure can usually be identified clinically from the gradual evolution of ascending, or sometimes descending, weakness associated with paraesthesiae, sensory deficit, and reduced or absent tendon reflexes. Difficulties in diagnosis arise in rapidly evolving pure motor neuropathies, especially in the earliest stages when the tendon reflexes may be preserved. Also paraesthesiae occur in occasional cases of toxic neuromuscular conduction block, including...

Circulation

Hypotension is relatively uncommon in stroke patients if it does occur, it is usually secondary to coexistent heart disease (arrhythmias, heart failure, or acute myocardial infarction), dehydration, or sepsis. As cerebral autoregulation is disturbed following stroke, with the result that cerebral blood flow becomes directly dependent upon systemic blood pressure, urgent correction is required. By contrast, hypertension is extremely common following stroke, even in patients without pre-existing...

References

Management of head injuries. Philadelphia FA Davies, 1981. 2 Miller JD, Jones PA, Dearden NM, Tocher JL. Progress in the management of head injury. Br J Surg 1992 79 60-4. 3 Pickard JD, Bailey S, Sanderson H, Rees M, Garfield JS. Steps towards cost-benefit analysis of regional neurosurgical care. Br Med J 1990 301 629-35. 4 Minns RA. Problems of intracranial pressure in childhood. Clinics in developmental medicine, 113 114. London MacKeith Press, 1991. 5 Marmarou A,...

Stage I prevention of intracranial hypertension general medical and nursing care avoidable factors

This section lists simple preventive measures and interventions that should be used in all patients who are either at risk of developing intracranial hypertension or have raised ICP (Box 7.4).965 The position of the patients' head should minimise any obstruction to cerebral venous drainage. Many units use head up tilt to improve venous drainage from the head. Relevant obstruction to venous outflow can also be caused by lateral head tilt, neck collars used for stabilisation of the cervical...

Box 33 Suggested guidelines for the use of intravenous rTPA in ischaemic stroke108

Intravenous r-TPA should be considered in all patients with a proven ischaemic stroke presenting within three hours of onset. Recommended dose is 0-9 mg kg, up to a maximum of 90 mg, the first 10 as a bolus, the rest as an infusion over 60 minutes. Thrombolysis should be avoided in cases where the CT suggests early changes of major infarction (for example, sulcal effacement, mass effect, or oedema). Thrombolytic therapy should only be administered by physicians with expertise in stroke...

Herpes simplex virus

Herpes simplex virus (HSV) is the most common cause of non-epidemic acute focal viral encephalitis in Europe and North America, with an incidence of up to 0 5 per 100 000 population per year.19 This is almost certainly an underestimate as many milder cases pass unrecognised. It occurs throughout the year and except for neonatal infections, almost all cases are caused by HSV type 1. Using serological studies, it is estimated that one-third of these infections occur during primary HSV1 infection...

Box 51 Symptoms of depression

Core symptoms of depression Depressed mood Loss of interest and enjoyment Reduced energy leading to increased fatiguability and diminished activity Common symptoms of depression Reduced concentration and attention Reduced self-esteem and self-confidence Ideas of guilt and unworthiness Bleak and pessimistic views of the future Ideas or acts of self-harm or suicide Disturbed sleep Diminished appetite Fitzpatrick and Hopkins6 assessed a series of patients referred to a neurologist with headaches...

Mannitol and hypertonic saline

Intravenous mannitol is invaluable as a first aid measure in a patient with brain herniation as a result of raised ICP. In practice, mannitol tends to be given as an intermittent bolus (2 ml kg of a 20 solution over 15-20 minutes) whenever the individual patient's ICP rises significantly above the threshold of 20-25 mmHg. Effects last for up to four hours. As osmotic diuresis may lead to hypovolaemia it is crucial to avoid dehydration and latent hypotension with careful attention to fluid...

Management of raised intracranial pressure

Nccu Medical Icp

Based on data from head-injured patients showing worse outcome in patients with ICP greater than 20-25 mmHg,66,67 raised ICP should be treated above this threshold. However, ICP therapy has side effects and needs to be selectively targeted if it is not to be counterproductive. As clinical signs, particularly in unconscious patients on a ventilator, are not reliable, ICP should be monitored when it is expected to be high or when active treatment is instigated in unconscious patients. For...

Indirect monitoring consequences of raised intracranial pressure

The cerebral arteriovenous oxygen content difference should normally be 5-7 ml dl. Values below 4 ml dl indicate cerebral hyperaemia, whereas values above 9 ml dl indicate global cerebral ischaemia. Jugular bulb oxygen saturation may be monitored, preferably continuously, with an indwelling catheter. Single measurements of jugular venous oxygen are of little value given the many fluctuations during the day. Overenthusiastic treatment, which on occasion may induce cerebral ischaemia, may be...

Pathophysiology

Respiratory failure is particularly dangerous when it is caused by neuromuscular rather than lung disease because its development may be insidious and unrecognised until sudden decompensation causes life threatening hypoxia. The arterial hypoxaemia of these patients is the result of both hypoventilation and also microatelectasis arising from the retention of secretions.1 Hypercapnia occurs only as a late feature in this form of respiratory failure, usually when respiratory muscle strength has...

Viral meningitis

Wallgren coined the term acute aseptic meningitis in 19251 to describe acute meningeal irritation, benign and self-limiting, with complete recovery and sterile pleocytic cerebrospinal fluid (CSF). It has become evident that viruses cause at least 70 of such cases. Viral infections of the central nervous system (CNS) are complications of systemic viral infections and the virus gains access to the brain via the bloodstream or, less commonly, by travelling up peripheral nerves.2 Viral meningitis...

Invasive methods of intracranial pressure monitoring including infusion tests

The gold standard of ICP monitoring, which was first introduced before 1951,12,27 still remains the measurement of intraventricular fluid pressure either directly or via a CSF reservoir, with the opportunity to exclude zero drift. Subdural fluid filled catheters are reasonably accurate below 30 mmHg. Risk of infection, epilepsy, and haemorrhage is less with subdural than with intraventricular catheters, but even the latter should be less than 5 overall. Catheter tip transducers are useful...

References Staut 1991

Trans Chadwick J, Mann WN. Oxford Blackwell, 1950. 2 Celsus. De Medicina. Trans. Spencer WG. London Heinemann, 1938. 3 Jackson SW. Galen - on mental disorders. J Hist Behav Sci 1969 5 365-84. 4 Lipowski ZJ. Delirium acute brain failure in man. Springfield, IL Charles C Thomas, 1980. 5 Perez EL, Silverman M. Delirium the often overlooked diagnosis. Int J Psychiatry Med 1984 14 181-9. 6 Trzepacz PT, Teague GB, Lipowski ZJ. Delirium and other organic mental...

Mechanisms of secondary brain injury after trauma

Secondary brain injury follows after primary damage, either as a consequence of the TBI itself, or due to systemic injury or insult. TBI can be responsible for the development of an intracranial haematoma, brain swelling, raised intracranial pressure, and ischaemia, all of which may be worsened by systemic hypoxia, hypotension, or pyrexia. Since Douglas Miller14,15 and others showed the strong relationship between deranged physiology, which would likely reduce brain oxygen delivery, and...

Box 93 Bacterial meningitis empirical treatment

Neonates ampicillin and a third generation cephalosporin Children and adults a third generation cephalosporin Adults over age 50 years ampicillin and a third generation cephalosporin History of beta-lactam anaphylaxis chloramphenicol and vancomycin (plus co-trimoxazole if Listeria is thought possible) practice because meningeal inflammation disrupts the barrier and allows sufficient penetration. It should be active within purulent and acidic CSF and the rate at which it is metabolised and...

Clinical classification

After the diagnosis of SAH has been established, patients are assigned a clinical grade based on one of the accepted grading systems. Grading systems for SAH have been reported since the 1930s, when Bramwell labelled patients either apoplectic or paralytic.76 Botterell and coworkers introduced a useful scale in 1956 which has undergone several modifications, including one in 1973 by Lougheed and Marshall.77,78 One of the more universally accepted grading systems is that of Hunt and Hess...

Myasthenia gravis

After establishing that a patient has respiratory failure due to myasthenia gravis the dose of anticholinesterase drugs should be optimised. The vital capacity should be monitored before and after small (2 mg) doses of intravenous edrophonium. Swallowing is usually impaired and a nasogastric tube is often needed. Pyridostigmine should be given orally or via the nasogastric tube. Doses more than 90 mg three hourly are rarely necessary. When enteral fluids cannot be absorbed, neostigmine should...