Page 306 - Medicine and Surgery

P1: FAW
BLUK007-07 BLUK007-Kendall May 25, 2005 18:18 Char Count= 0

302 Chapter 7: Nervous system

Table 7.5 CSF findings in meningitis
Normal Bacterial Viral Tuberculous
Appearance Clear Cloudy Clear Opalescent
Cells/mm 3 0–5 10–100,000 15–2000 250–500
Cell type Lymphocytes Neutrophils Lymphocytes Lymphocytes
Glucose >60% blood <60% blood >60% blood <60% blood
Protein (g/L) 0.15–0.35 0.5–5 0.15–1.25 0.45–5.0

Macroscopy/microscopy reduce mortality and overall morbidity in adults and
Inflamedarachnoidmater,withexudateinthesubarach- may reduce the incidence of hearing loss in children.
noid space which is rich in neutrophils. There may be Nasopharyngeal clearance may be recommended for
oedema, focal infarction and congested vessels in the the patient and household ‘kissing contacts’, e.g. with
underlying brain tissue. aquinolone or rifampicin. Cephalosporins provide
good clearance of nasal carriage in the patient, but
penicillins do not.
Investigations
Any underlying cause may need to be treated.
If there is no evidence of intracranial mass lesion, fo-
cal neurology, papilloedema or reduced consciousness,
alumbar puncture can be performed otherwise a CT Vaccination
brain is indicated prior to LP. CSF is sent urgently for Vaccination with the H. influenzae B (HiB) vaccine has
protein, glucose, microscopy and culture (see Table 7.5). dramatically reduced this as a cause of meningitis in chil-
CSF pressure is characteristically raised. Other impor- dren. It is recommended in asplenic patients.
tant tests include blood culture (up to 50% positive, if Meningococcal meningitis is most commonly of the
taken before antibiotics given), coagulation screen and type B meningococcus, for which there is no vaccine.
blood glucose levels for comparison with CSF glucose. However, the type C vaccine is used to reduce the chance
Low inflammatory markers (CRP and ESR) and low of an epidemic when clusters occur and is now a routine
white blood counts do not exclude the diagnosis and childhood immunisation.
are associated with a worse prognosis. PCR, ELISA and Conjugate Strep. pneumoniae vaccine (Prevenar®)is
antigen testing are increasingly used. givento infants with chronic diseases, and Pneumovax®
(live attenuated) is used in at risk patients.

Management
Prognosis
Treatmentdelaymaybefatal,ifthepatientisseverelyun-
Despite the advent of antibiotics, the mortality is still as
well treatment should be commenced before perform-
high as 15–20%, with a significant proportion of sur-
ing LP/CT brain. CSF taken soon after antibiotics are
vivors having persistent neurological abnormality. Poor
givenstill demonstrates the causative organism in many
prognostic markers include hypotension, confusion and
cases.
seizures.
Abroad-spectrum antibiotic such as a cephalosporin

at high doses is initially recommended due to the
increasing emergence of penicillin-resistant strepto- Viral meningitis
cocci. Once cultures and sensitivities are available,
the course and choice of agent can be determined Definition
(ceftriaxone/cefotaxime for Haemophilus influenzae Acute viral infection of the meninges is the most com-
andStreptococcuspneumoniae,penicillinforN.menin- mon cause of meningitis. It often occurs as combined
gitidis, and ampicillin for Listeria). meningo-encephalitis and in many cases it is a diagnosis
Dexamethasone for 2–4 days which is commenced
of exclusion after investigating for bacterial or tubercu-
shortly before or at the time of giving antibiotics may lous meningitis.