Legionnaire’s disease presenting with encephalitis, myoclonus, and seizures: Successful treatment with doxycycline

Abstract

Legionnaire’s disease (LD) is a non-zoonotic atypical community acquired pneumonia (CAP) with several characteristic extra-pulmonary findings. Pending diagnostic test results, selected characteristic findings when considered together are the basis of clinical syndromic diagnosis and the basis of empiric antimicrobial therapy. Of the extra-pulmonary manifestation of LD, neurologic findings are among the most common, e.g., headache, mental confusion. In LD, encephalitis is rare as are myoclonus and seizures. This is a most interesting case of LD that presented with encephalitis, myoclonus and seizures. Pulmonary infiltrates developed early after admission. LD was suspected on the basis of otherwise unexplained characteristic findings, e.g., hypophosphatemia, elevated serum transaminases, microscopic hematuria, elevated ferritin, and empiric doxycycline therapy was started. The diagnosis of LD was further supported by prominent and persistent myoclonus and seizures, rare but characteristic neurologic findings in LD. On week 12 of hospitalization, he finally seroconverted with negative urinary antigen tests indicating his LD was due to a non- L. pneumophilia (serotype 01) strain. On doxycycline, he made a slow but complete recovery. We believe this is the first reported case of LD presenting with encephalitis, myoclonus, and seizures successfully treated with doxycycline.

Legionnaires’ disease arising with hirsutism: case report of an extremely confusing event

“…The multisystem involvement includes the kidney, liver, heart, gastrointestinal tract. The mechanism involving the nervous system has not yet been well defined and a role of circulating toxins cannot be certainly excluded [ 3 ]. Among neurological findings, the most common are mental confusion, headache, irritability and aggressiveness.…”

Overview of management of infection-related movement disorders with focus on specific-infections

“…Among the bacterial infections, group A beta-haemolytic streptococcus (GABHS), Mycobacterium tuberculosis , Treponema pallidum and Tropheryma whipplei are commonly associated with MD. In addition, other bacteria such as Salmonella typhi , Orientia tsutsugamushi , Mycoplasma pneumoniae , Bordetella pertussis , Borrelia burgdorferi , Corynebacterium diphtheriae , Clostridium tetani and meningitis secondary to Neisseria meningitides , Hemophilus influenza , Streptococcus pneumoniae [6] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] have also been reported to result in MD. Viral encephalitis can result in MD either during the acute state or as a part of post-encephalitic sequelae [23] .…”