Background: Infections of the central nervous system are neurological emergencies requiring early recognition and efficient decision making. Clinical presentations are varied and non infective causes can also present with similar features.

Aim and Objectives: To study the causes of altered sensorium and to analyze the profile of patients presenting with CNS infection.

Methods: The study included 121 patients (73 males and 48 females) who met inclusion criteria (Age more than or equal to 18 years and suspicion of CNS infection) admitted in Sri Ramachandra Medical College Hospital from the year 2009 to 2011. Clinical presentations were analyzed by questionnaire and detailed examination including a fundoscopy done.

Results: Out of 121 patients, 90 had CNS infection. 15 patients had bacterial meningitis, 32 had tuberculous meningitis, 9 had aseptic meningitis, 30 had encephalitis and 4 had Cryptococcal meningitis. Viral encephalitis was seen more in younger age group. The most common presenting symptom was fever (105 patients), followed by altered sensorium (89), headache in (68), vomiting in (58) and seizures in 48 patients. Altered sensorium was universal in cryptococcal meningitis. 45.5% of patients with CNS infection presented with seizures while 35.5% had seizures in patients without infection. Mean duration of fever was 23 days for cryptococcal meningitis with TB meningitis having 15 days. 75% patients had neck stiffness and focal neurological deficits were seen in 9% patients. Fundus was abnormal in 28.1 % patients.

Conclusion: Clinical presentation of CNS infections is a changing scenario. Young patients had more incidence. Fever and altered sensorium were the most common symptom. Neck stiffness was not an universal feature.

Keywords- Altered sensorium, Fever, Meningitis, Neck stiffness, Seizures.

1.      Tindall SC (1990). "Level of consciousness". In Walker HK, Hall WD, Hurst JW. Clinical Methods: The History, Physical, and Laboratory Examinations. Butterworth Publishers. Retrieved 2008-07-04.

2.      Posner JB, Saper CB, Schiff ND, Plum F (2007). Plum and Posner's Diagnosis of Stupor and Coma. Oxford University Press, USA. p. 41. ISBN 0-19-532131-6.

3.      Von Koch CS, Hoff JT (2005). "Diagnosis and management of depressed states of consciousness". In Doherty GM. Current Surgical Diagnosis and Treatment. McGraw-Hill Medical. p. 863. ISBN 0-07-142315-X. Retrieved 2008-07-04.

4.      Johnson AF, Jacobson BH (1998). Medical Speech-language Pathology: A Practitio-ner's Guide. Stuttgart: Thieme. p. 142.  ISBN 0-86577-688-1. Retrieved 2008-07-04.

5.      Scheld WM, Whitley RJ, Marra CM (2004). Infections of the Central Nervous System. Hagerstown, MD: Lippincott Williams & Wilkins. p. 219. ISBN 0-7817-4327-3. Retrieved 2008-07-04.

6.      B.D. Michael, M. Sidhu, D. Stoeter et al. Acute central nervous system infections in adults-a retrospective cohort study in the NHS North West region. QJM 2010; 103:749-58.

7.      Durand ML, Calderwood SB, Weber DJ, et al. Acute bacterial meningitis in adults. A review of 493 episodes. N Engl J Med 1993; 328(1):21–8.

8.      G E Thwaites, T T H Chau, K Stepniewska, N H Phu, L V Chuong, D X Sinh, N J White, C M Parry, J J Farrar. Diagnosis of adult tuberculous meningitis by use of clinical and laboratory features. LANCET 02;360:1287-92.

9.      Abdul Majid Wani, Waleed Mohd Hussain, Mohd Fatani, Bothaina Abdul Shakour et al. Clinical Profile of Tuberculous Meningitis in Kashmir Valley The Indian Subcontinent. Infect Diseases in Clinical Practice 2008;16:360-67.

10.  Elisabeth Franzen-Rohl, Kenny Larsson, Eva Skoog. High diagnostic yield by CSF-PCR for entero- and herpes simplex viruses and TBEV serology in adults with acute aseptic meningitis in Stockholm.  Scandinavian Journal of Infectious Diseases, 2008; 40: 914921.

11.  Mailles A, Stahl JP, Steering Committee and Investigators Group. Infectious encephalitis in france in 2007: a national prospective study. Clin Infect Dis 2009; 49:1838.

12.  K. Wada-Isoe, M. Kusumi, T. Kai, E. Awaki, M. Shimoda, H. Yano, K.Nakashima. Epidemiological study of acute encephalitis in Tottori Prefecture, Japan. Europe an Journal of Neurology 2008, 15: 1075-1079.

13.  Vasant Baradkar, M Mathur, A De, S Kumar, M Rathi. Prevalance and clinical presentation of Cryptococcal meningitis among HIV seropositive patients. Indian J Sex Transm Dis & AIDS ;30:19-22

14.  Van de Beek D, de Gans J, Spanjaard L, et al. Clinical features and prognostic factors in adults with bacterial meningitis N Engl J Med 2004;351(18):1849–59.

15.  D. A. Nowak, R. Boehmer, H-H. Fuchs. A retrospective clinical, laboratory and outcome analysis in 43 cases of acute aseptic meningitis. European Journal of Neurology 2003, 10: 271–280.

16.  Carol A. Glaser,Sabrina Gilliam,David Schnurr, Bagher Forghani, In Search of Encephalitis Etiologies: Diagnostic Challenges in the California Encephalitis Project, 1998 –2000,Clinical Infectious Diseases 2003; 36:731–42.

17.  Moghtaderi A,Cuevas LE.Diagnostic risk factors to differentiate tuberculous and acute bacterial meningitis.  Scand J Infect Dis. 2009;41:188-94.

18.  R Kumar, S N Singh, Neera Kohli. A diagnostic rule for tuberculous meningitis. Arch Dis Child 1999;81:221–224.