In a recent study of the brain in thirteen cases of paresis and in three cases of cerebral syphilis I found Spirochaeta pallida in nine cases of the former disease. The tissues had been fixed in formaldehyde, and some of the brains had remained in this solution for years. The Jahnel method,1 slightly modified, was used and in most cases seventeen regions of the brain were examined: gyrus rectus, gyrus frontalis inferior, gyrus frontalis superior, gyrus temporalis superior, gyrus temporalis inferior, gyrus centralis anterior, gyrus centralis posterior, cornu ammonis, lobus parietalis, gyrus occipitalis, thalamus, insula, medulla oblongata, pons varolii, substantia nigra, corpus striatum and cerebellum.
Spirochetes were found in nearly all the regions named; I did not find them in the medulla oblongata, pons varolii or cerebellum, though they have been observed in these regions,2 nor did I observe them in the meninges as reported by Jahnel, Carp
AARS CG. PARALYTIC DEMENTIATHE LOCALIZATION OF SPIROCHAETA PALLIDA IN THE BRAIN. Arch NeurPsych. 1930;23(3):512-520. doi:10.1001/archneurpsyc.1930.02220090103006