Bacterial Meningitis Imaging


The epidemiology of bacterial meningitis in the United States has changed dramatically in the past 20 years.Since the introduction of the Haemophilus influenzae type b vaccine in 1988, the incidence of H. influenzae type b meningitis has decreased by at least 97% and has Streptococcus pneumoniae highlighted as the most common aetiological agent. The PCV7 vaccine (7-valent pneumococcal conjugate [Prevnar]; Wyeth Pharmaceuticals), which targets 7 pneumococcal serotypes, was introduced in 2000 and has had a major impact on both the incidence and epidemiology of meningitis. PCV7 vaccine and the most current evidence to diagnose and empirically treat suspected bacterial meningitis.

The first clinical manifestations of bacterial meningitis are non-specific and include fever, malaise, and headache; and later meningism (stiff neck), photophobia, phonophobia and vomiting develop as signs of meningeal irritation. Headache and meningism indicate inflammatory activation of the sensory nerve fibers of the trigeminal nerve in the meninges and can be blocked experimentally by 5HT1B/D/F receptor (triptan) agonists. Headache in patients with bacterial meningitis has yet to be clarified.

Severe bacterial meningitis can be associated with an increased ICP, which can be reduced with the Lund concept. The high survival rate, the low frequency of sequelae and the reversal of the signs of an impending brainstem hernia in these high-risk patients indicated positive effects of the intervention. The study confirms previous observations that lumbar dura puncture is potentially dangerous in patients with intracranial hypertension as it can trigger a brainstem prolapse. A normal CT scan of the brain does not rule out intracranial hypertension.

An ICP monitor was implanted over a four-year period in patients admitted to our hospital with severe bacterial meningitis and suspected intracranial hypertension

Best Regards

Rachael Mora

Assistant Managing Editor

Journal of Clinical Radiology and Case Reports