Leprosy may so closely resemble syringomyelia that a differential diagnosis is not always possible.1 Zambaco-Pacha2 and others even consider these two morbid conditions one disease process, while Pestana and Bettencourt3 claimed to have seen lepra bacilli in the syringomyelic cavities of the spinal cord. On the other hand, cases are on record in which cavities of the spinal cord were found in leprosy, as in the cases of Steudener,4 Langhans,5 and Gerber and Matzenauer.6 In Steudener's case (lepra mutilans), a cavity extended from the medulla oblongata to the lumbar region, and was surrounded by greatly thickened blood vessels. Steudener thought that the cavity was not caused by leprosy but was the result of colloid degeneration. In contrast, Langhans considered the cavity in his case, in which it involved the gray matter of the lower cervical and all the thoracic segments, a product of leprosy.
N. Piatnizky, R. A. Schakhnovitch. A CLINICAL AND NEUROPATHOLOGIC REPORT OF A CASE OF LEPRA MIXTA. Arch NeurPsych. 1928;20(3):602–606. doi:10.1001/archneurpsyc.1928.02210150162012