wiki:neurology:meningitis

Meningitis

adults - Bacterial meningitis in the Western world is most often caused by S pneumoniae
children - infection with Neisseria meningitidis is more common
classic triad of fever, nuchal rigidity, and altered mental status in adults
The sensitivity of the classic triad in adults presenting with community-acquired acute bacterial meningitis is low, and absence of specific clinical signs is not unusual. Neonates often not febrile
Kernig'sclose flexing the hip and extending the knee to elicit pain in the back and the legs & Brudzinski'sclose passive flexion of the neck elicits flexion of the hips signs - reported to be highly specific but low sensitivity. Absence of these signs should NOT exclude entertaining meningitis as Dx
Head jolt testclose considered positive if headache accentuated by horizontal rotation of head at frequency of 2-3x per sec variously considered more sensitive
seizures occur significantly more often in patients with pneumococcal meningitis than in meningococcal infection and are associated with increased mortality

Mollaret meningitis

due to a viral infection (aseptic meningitis) that occurs multiple times. Most often herpes simplex, HSV-2 but occasionally HSV-1
known by many other names including Recurrent benign lymphocytic meningitis (RBLM), aseptic meningitis etc
characterized by repeated episodes of meningitis, typically lasting 2-5/7, occurring weeks to years apart.
spontaneous full recovery usually after 5/7
neurological signs - not unlike migraine presentation
Almost 1/2 develop long-term CNS impairment eg. memory, balance, coordination, and/or hearing.

CSF findings	Bacterial	Viral	Fungal
opening Press	↑	N	↑
WCC	1k-10k	<300	<500
Neutrophils	>80%	1-50%	1-50%
Glu	↓	N	↓
Protein	↑	N	↑
g stain	bacteria	-	-

IV ceftriaxone.
children <3/12 IV cefotaxime + amoxycillin or ampicillin
consider herpes simplex encephalitis, consider other unusual pathogens eg Listeria, TB
IV dexamethasone
PCR should be taken for bacterial and viral studies