707. Thalamic and Basal Ganglia Neuro-Imaging Abnormalities - An Important Etiologic Clue for Encephalitis Patients?
Session: Abstracts: Virology
Friday, October 22, 2010

Background: Encephalitis is a severe neurological syndrome and in many cases no etiology is identified.  Thalamic and/ or basal ganglia lesions are reported only occasionally in patients' neuro-imaging studies. When observed, these lesions may be an important etiological clue. Patients enrolled in the California Encephalitis Project (CEP) with such lesions were reviewed for the purpose of highlighting etiological agents and distinguishing clinical characteristics associated with such brain abnormalities.

Methods: Data gathered on cases enrolled in CEP with reported thalamic or basal ganglia abnormalities was retrospectively reviewed. Imaging reports and presumed etiologies were compared and analyzed. Medical records were also reviewed, in particular to identify non-infectious etiologies. Cases with known etiologies were broken into 3 groups: (1) para/post infectious, (2) infectious, and (3) non-infectious.  

Results: Of 3299 cases enrolled in the encephalitis project 226 (7%) were reported to have thalamic and/ or basal ganglia abnormalities on neuro-imaging studies. The median age was 15 years [9 months - 84 years] and 118 (52%) were male. Of 102 cases reviewed an infectious agent was identified in 33 cases (32%), a para/post infectious process was identified in 20 cases (20%), and a non-infectious etiology was found in17 cases (17%). The most commonly identified infectious agents include 15 cases (45%) with a respiratory virus identified, 6 cases (18%) Mycobacterium tuberculosis, and 4 cases (12%) of West Nile virus. Leading non-infectious etiologies included 7 cases (41%) of neoplasm and 4 cases (24%) of ischemic events. Infectious and para-infectious cases were younger (median 9 years) compared with non-infectious cases (median 43 years)(p=.01).  Infectious or para-infectious etiologies had a higher median CSF WBC (69 WBC/ml) compared with non-infectious etiologies (4 WBC/ml), though this finding was of borderline statistical non-significance (p=0.05).

Conclusion: A broad range of infectious and non-infectious etiologies need to be examined in encephalitis patients with thalamic or basal ganglia lesions identified on neuro-imaging. Patient age and CSF formula may help prioritize testing for infectious versus non-infectious agents.

 


Subject Category: V. Virology including clinical and basic studies of viral infections, including hepatitis

Speakers:
Genna Beattie, BA , Communicable Disease Emergency Response Branch, California Department of Public Health, Richmond, CA
Shilpa Gavali, MPH , Communicable Disease Emergency Response Branch, California Department of Public Health, Richmond, CA
Heather Sheriff, BA , Communicable Disease Emergency Response Branch, California Department of Public Health, Richmond, CA
Carol Glaser, MD , Communicable Disease Emergency Response Branch, California Department of Public Health, Richmond, CA

Disclosures:

G. Beattie, None

S. Gavali, None

H. Sheriff, None

C. Glaser, None

See more of: Virology
See more of: Abstracts

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 21 with the exception of research findings presented at IDSA press conferences.

 
 
   
 

Copyright IDSA 2009 Infectious Diseases Society of America 1300 Wilson Boulevard, Suite 300 Arlington, VA 22209 info@idsociety.org