ANSWER 76
This patient has bacterial meningitis. He has presented with sudden onset of severe headache,
vomiting, confusion, photophobia and neck stiffness. The presence of hypotension, leucocy-
tosis and renal impairment suggest acute bacterial infection rather than viral meningitis. The
most likely causative bacteria are Neisseria meningitidis, Haemophilus influenzae and
Streptococcus pneumonia. In patients in this age group Streptococcus pneumonia orNeisseria
meningitidisare the most likely organisms. Meningococcal meningitis (Neisseria meningi-
tidis) is usually associated with a generalized vasculitic rash.
The most severe headaches are experienced in meningitis, subarachnoid haemorrhage and
classic migraine. Meningitis and subarachnoid haemorrhage present as single episodes of
headaches. Meningitis usually presents over hours, whereas subarachnoid haemorrhage
usually presents very suddenly. Fundoscopy in patients with subarachnoid haemorrhage
may show subhyaloid haemorrhage. Meningeal irritation can be seen in many acute
febrile conditions particularly in children. Local infections of the neck/spine may cause
neck stiffness. Other causes of meningitis include viral, fungal, cryptococcal and tubercu-
lous meningitis which can be distinguished by analysis of the CSF.
When meningitis is suspected appropriate antibioic treatment should be started even before
the diagnosis is confirmed. In the absence of a history of significant penicillin allergy the
most common treatment would be intravenous ceftriaxone or cefotaxime.
Patients with no papilloedema or lateralizing neurological signs that suggest a space-
occupying lesion should be lumbar punctured immediately (even before a CT scan is
obtained). If there are localized neurological signs it is essential to perform a CT scan first
to avoid the dangers of coning which can occur when a lumbar puncture is performed in
the presence of raised intracranial pressure.
The combination of #1000 neutrophils/mL CSF, a CSF glucose!40 per cent of the simul-
taneous blood level and a CSF protein 1.4 g/L is strongly suggestive of bacterial meningi-
tis. The Gram stain and culture will give the definitive diagnosis. In this case, the Gram
stain demonstrated Gram-positive cocci consistent with Streptococcus pneumoniainfec-
tion. Intravenous antibiotics must be started immediately. The patient must be nursed in a
manner appropriate for the decreased conscious level. Adequate analgesia with opiates
should be given. The patient has mild hyponatraemia due to the syndrome of inappropri-
ate antidiuretic hormone (ADH) secretion, and fluid losses should be treated with normal
saline. Inotropes may be needed to treat hypotension.
The two children aged 3 and 4 years must be considered. It is not clear from the history
who is looking after them. They should be examined, and if meningococcal meningitis is
suspected or the organism is uncertain they should be given prophylactic treatment with
rifampicin and vaccinated against meningococcal meningitis.
- Bacterial meningitis causes severe headache, neck stiffness, drowsiness and photophobia.
- The main differential diagnoses are subarachnoid haemorrhage and migraine.
- When bacterial meningitis is strongly suspected antibiotic treatment should be started
before bacteriological confirmation is available.