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Fig. 6.17A-F Cerebral nocardiosis. A-C CT or MR scanning will show one or more cerebral abscesses, all of which will show a central cavity with ring enhancement after intravenous contrast. There is likely to be a "mass effect", with displacement due to the abscess and the surrounding edema. D The wall of a cerebral abscess is shown along the top of the picture. The contents were soft and purulent. (Gross specimen, x0.9, by Daniel H. Connor, MD; specimen contributed by Glen Wilhite, MD, Florida). E, F There may be small subependymal nodules (abscesses) which result from the marked inflammatory reaction in the ventricular ependyma and extending to form the subependymal nodule. F is the histophathology of the nodule shown in E (see arrow). Meningitis may be found at surgery or autopsy, particularly in patients who have developed hydrocephalus. This correlates with the CSF findings of increased white blood cells, decreased glucose, and increased protein. Only a few CSF cultures will be positive for Nocardia. The majority of chest radiographs in patients with CNS involvement will show evidence of lung infection, and sputum culture will often confirm the diagnosis. The patients shown in this figure were HIV-seropositive. (Courtesy of S.D. LeBlang et al and J Comput Assist Tomogr 1995)

 

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CEREBRAL NOCARDIOSIS

Cerebral nocardiosis is uncommon, and is always evidence of dissemination except for very rare cases of direct implantation following trauma. Clinically, CNS nocardiosis may be silent, but eventually most patients develop symptoms related to the raised intracranial pressure from the space-occupying inflammatory mass. Brain abscesses may be multiloculated and are often multiple, but of different sizes (Fig. 6.17). Meningeal infections are uncommon. It is not possible to make an accurate etiological diagnosis by imaging alone.

Differential Diagnosis of Nocardial and Other Infections

The basic differences between infections due to Nocardia, Actinomadura pelletieri, and Actinomadura madurae are shown in Table 6.2. In nocardial infections the clinical finding of multiple sinuses is very significant, together with any bone destruction and periosteal new bone formation. Figure 6.18 C-E illustrates the difference between pyogenic, fungal, and nocardial osteomyelitis; both the fungi and nocardia easily perforate the periosteum (Fig. 6.18 A, B), whereas in pyogenic osteomyelitis, the periosteum usually remains intact and forms a barrier, being elevated by the pus and lifted off the cortex.

Madura Foot; Mycetoma; Maduromycosis

Progressive swelling of the foot (or occasionally both feet) in those who work without shoes in the fields has been recognized for centuries. It was known that the feet would become lumpy, and there would eventually be draining sinuses with pus containing different colored grains. In the early and mid 19th century the condition was recorded by doctors in small hospitals in India and missionary doctors in East Africa. It was thought to be a manifestation of tuberculosis: the name "Madura foot" followed the first description in 1846 of four cases in Madras, followed in 1859 by another 40 cases from the same area. The bone destruction was soon recognized, and then the "fungus particles." The history and recognition of the multiple organisms which cause the same features is described in "Mycetoma" by E.S. Mahgoub and I. G. Murray (1973).

Synonyms

Mycetoma. Madura foot. Maduromycosis. Carter's foot. Actinomyces foot. Pseudotumors of bone. Fr. Madura mycose. Ger: Madurafug. Sp: Pie de Madura.

Definition

Madura foot is, strictly, only one form of mycetoma: a true eumycetoma localized to the foot. By common usage for over hundred years, mycetoma and Madura foot became synonymous. Even now, however, Madura foot is not an accurate nomenclature because it describes but one type of mycetoma and, of course, does not only occur in Madras: more over, mycetomas do not only occur in the foot.

Maduromycosis is an indolent infection, most commonly of the foot but occurring also in the upper or lower arm, and rarely in the neck, calvarium, and elsewhere. It is caused by fungi or false fungi of many varieties. The infection slowly spreads through the soft tissues and bone. Multiple sinus tracts drain pus to the skin surface. Madura foot and maduromycosis have become generic names, unrelated to any specific fungus or false fungus.

 

 

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