Effectiveness of Lumbar Puncture in the Diagnosis of Central Nervous System Infection for the Elderly Patients Presenting with Acute Confusional State

Objective: To evaluate the effectiveness of lumbar puncture (LP) as a diagnostic procedure for central nervous system infection in cases of acute confusional states in elderly patients.

Patients and Methods: This is an observational prospective study as a short research article that enrolled 50 elderly patients with acute confusional state to assess lumbar puncture results as a diagnostic procedure for central nervous system infections in Al-Fallujah Teaching Hospital in Al-Anbar, Iraq, between January 2011 and January 2013. All of the patients have been subjected to lumbar puncture (LP), as well as laboratory investigations.

Results: This study reveals slight female predominance (54%) in cases of acute confusional state. The mean age was 68 years. Acute confusional state in 92% of our cases was due to systemic disease, and central nervous system infection (meningitis and encephalitis) represented only 8% of cases. Most LPs were negative (normal). Fifty per cent of CNS infections were in pre-LP cases presenting systemic diseases. Central nervous system infections were mostly bacterial meningitis.

Conclusions: This study reveals that positive LP results were low in elderly patients presenting with acute confusional state. This gives an idea about the LP effectiveness that should be suspected. Since the causes of such presentation are life threatening diseases, so LP remain the best useful procedure in spite of its low positive results.