St Louis encephalitis: a review of 11 cases in a 1995 Dallas, Tex, epidemic.
OBJECTIVE
To update some of the clinical features of St Louis encephalitis (SLE), a common arboviral infection that occurs in epidemic patterns in the south-central and midwestern United States.


METHODS
Eleven patients with SLE from a 1995 epidemic in Dallas, Tex, were studied clinically, radiologically, neurophysiologically, and neuropathologically (in 1 case).


RESULTS
The electroencephalograms and magnetic resonance imaging (MRI) scans of our patients revealed features that have received little attention in previous studies. Of the 9 patients who were examined with electroencephalography, all 9 had seizures or other abnormalities, and 1 had nonconvulsive status epilepticus. Two of 6 patients who had MRIs showed substantia nigra edema. Finally, 2 (18%) of our patients had coinfection with the human immunodeficiency virus.


CONCLUSIONS
The MRI findings of substantia nigra edema in patients with SLE have not been previously reported. Nonconvulsive status epilepticus can occur in patients with SLE and should be considered in patients with prolonged encephalopathy. Finally, human immunodeficiency virus coinfection may be a risk factor for symptomatic SLE infection.
Wasay
M
M
Department of Neurology, University of Texas Southwestern Medical School, Dallas, USA.
Diaz-Arrastia
R
R
Suss
R A
RA
Kojan
S
S
Haq
A
A
Burns
D
D
Van Ness
P
P
D015526:AIDS Dementia Complex / Q000473:pathology / Q000821:virology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001929:Brain Edema / Q000473:pathology / Q000821:virology; D004196:Disease Outbreaks; D004569:Electroencephalography; D004665:Encephalitis Virus, St. Louis; D004674:Encephalitis, St. Louis / Q000453:epidemiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013378:Substantia Nigra / Q000473:pathology / Q000821:virology; D013781:Texas