To the Editor: The magnetic resonance imaging (MRI) scan shownin Figure 1 of the report by Weber et al. (Feb. 13 issue)1 showscongestion of the ethmoid sinus, not the right maxillary sinus,as the figure legend says. The scan does not show the maxillarysinuses. It is not permissible to diagnose sinusitis only onthe basis of an MRI scan, because MRI often demonstrates mucosalthickening without clinical disease.2 Was there a rhinoscopicexamination? The authors relate the observed sinus congestionto the Encephalitozoon cuniculi infection. Chronic sinusitisis very common in patients with human immunodeficiency virus(HIV) infection, and the traditional sinus pathogens are usuallyresponsible for the infection.3 Did the authors perform a sinusallavage to isolate the pathogen? As they observe, detecting E.cuniculi may be difficult in the cerebrospinal fluid or theurinary sediment.
Orlando Guntinas-Lichius, M.D. University of Cologne D-50924Cologne, Germany
References
Weber R, Deplazes P, Flepp M, et al. Cerebral microsporidiosis due to Encephalitozoon cuniculi in a patient with human immunodeficiency virus infection. N Engl J Med 1997;336:474-478. [Free Full Text]
Digre KB, Maxner CE, Crawford S, Yuh WT. Significance of CT and MR findings in sphenoid sinus disease. AJNR Am J Neuroradiol 1989;10:603-606. [Abstract]
Meiteles LZ, Lucente FE. Sinus and nasal manifestations of the acquired immunodeficiency syndrome. Ear Nose Throat J 1990;69:454-459. [Medline]
Dr. Weber and colleagues reply:
To the Editor: Dr. Guntinas-Lichius is correct that the MRIscan in our article showed congestion of the left ethmoid sinus,not the right maxillary sinus. (The MRI is read looking frombelow.) Nevertheless, the HIV-infected patient we describedwho had cerebral microsporidiosis due to E. cuniculi also hadleft maxillary sinusitis, as Figure 1A and Figure 1B shows.We did not perform a rhinoscopic examination, sinonasal lavage,or a mucosal biopsy of the maxillary sinus since sinusitis wasnot clinically relevant in our patient, who eventually died,most probably from cerebral microsporidiosis. There is, however,indirect evidence of a causal association between the E. cuniculiinfection and the sinusitis. Multiple courses of antimicrobialtherapy had not improved the patient's condition, but the administrationof albendazole alleviated his symptoms and reduced the mucosalthickening of the left maxillary and ethmoid sinuses, in additionto decreasing the urinary excretion of microsporidial spores.
Figure 1. Axial T2-Weighted MRI Scans before and after Treatment with Albendazole in an HIV-Infected Patient with Disseminated E. cuniculi Infection and Left Maxillary Sinusitis.
The scan obtained before treatment (Panel A) shows extensive mucosal thickening and subtotal obliteration of the left maxillary sinus cavity. In Panel B, showing the scan obtained after four weeks of treatment with albendazole (400 mg orally twice a day), only slightly thickened mucosa remains.
Chronic sinusitis due to bacterial pathogens is common in HIV-infectedpatients, but sinusitis due to various species of microsporidia,including E. cuniculi, E. hellem, E. intestinalis, and Enterocytozoonbieneusi, has also been described.1,2,3,4 In most patients withmicrosporidial infection of the respiratory tract, the parasitescould be detected in specimens of stool or urine. In some HIV-infectedpatients, sinonasal infection is a predominant manifestationof systemic microsporidiosis.2,4 In these patients, microsporidialparasites have been demonstrated by electron- or light-microscopicalexamination of mucosal-biopsy specimens or sinonasal washings2,3,4and also by molecular diagnostic methods,1 but the sensitivityof these techniques is not known. In our experience with patientswho have disseminated infection with an encephalitozoon species,microsporidial spores are best demonstrated by microscopicalexamination of urine sediments (obtained by the centrifugationof urine at 1500 x g).2,5
Rainer Weber, M.D. Markus Flepp, M.D. Werner Wichmann, M.D. University Hospital CH-8091 Zurich, Switzerland
References
Hartskeerl RA, Schuitema AR, van Gool T, Terpstra J. Genetic evidence for the occurrence of extra-intestinal Enterocytozoon bieneusi infections. Nucleic Acids Res 1993;21:4150-4150. [Free Full Text]
Weber R, Bryan RT, Schwartz DA, Owen RL. Human microsporidial infections. Clin Microbiol Rev 1994;7:426-461. [Free Full Text]
Molina JM, Oksenhendler E, Beauvais B, et al. Disseminated microsporidiosis due to Septata intestinalis in patients with AIDS: clinical features and response to albendazole therapy. J Infect Dis 1995;171:245-249. [Medline]
Rossi RM, Wanke C, Federman M. Microsporidian sinusitis in patients with the acquired immunodeficiency syndrome. Laryngoscope 1996;106:966-971. [CrossRef][Medline]
Weber R, Deplazes P, Flepp M, et al. Cerebral microsporidiosis due to Encephalitozoon cuniculi in a patient with human immunodeficiency virus infection. N Engl J Med 1997;336:474-478.
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