Behavioural change: a rare presentation of leptospirosis

Abstract

Neurological manifestations of leptospirosis without severe multiorgan involvement are a rare clinical entity. Despite the increasing prevalence of the disease in many tropical countries, its protean clinical presentations make its timely diagnosis challenging. We report the case of a 44-year-old Filipino man presenting with fever, myalgia, behavioural changes and altered sensorium. Neurological examination did not show any focal neurological deficits or clear signs of meningoencephalitis. Lumbar tap, cranial CT scan and cranial MRI were inconclusive. The diagnosis of leptospirosis with acute encephalitis relied heavily on the patient's clinical clues, appropriate exposure history and patterns in ancillary laboratory tests. Empiric antibiotic therapy with ceftriaxone was initiated. Seroconversion and fourfold increase in serological antibody titres by leptospirosis microagglutination test later confirmed the diagnosis. The patient was successfully treated, and all neurological complications were reversed.

Keywords: infection (neurology); tropical medicine (infectious disease).

Figure 1

(A) Plain cranial CT image showing a suspicious hypodense focus in the midbrain (circle). (B) Repeat plain cranial CT no longer shows the suspicious hypodense focus with no other significant findings.

Figure 2

MRI with gadolinium contrast showing (A) T2WI bright signals in the subcortical deep white matter region of both frontal lobes (arrows). (B) T2 FLAIR sequence showing non-suppression of the bright signals (arrows) in the said regions. (C) T2WI bright signal in the left external capsule (circle), (D) which exhibits non-suppression in T2-FLAIR sequence (circle).