Neurology through history: Syphilis from scourge to cure

Syphilis, caused by the bacterium Treponema pallidum, first made its notorious appearance in Europe in the late 15th century, following Columbus's return from the Americas. This timing led many to speculate that it was brought back from the New World, although this theory remains debated. The disease rapidly became endemic in Europe, with its first recorded outbreak in Naples in 1495.

Initially, syphilis was a highly aggressive disease, leading to quick deaths. However, over the centuries, its manifestations became less severe, though no less serious. The disease progresses in stages, initially presenting with sores, followed by a latent period where symptoms can disappear, only to re-emerge years later.

Neurological implications

For neurologists, syphilis holds particular interest due to its neurologic manifestations, particularly in its tertiary stage. Neurosyphilis, which can occur years to decades after the initial infection, can lead to a plethora of neurologic symptoms. These range from meningitis, stroke, and cranial nerve dysfunction to more insidious forms like general paresis and tabes dorsalis. The latter is particularly notorious for its effects on proprioception and gait, leading to the characteristic "tabetic gait." Given the great variety of its presenting manifestations, syphilis has been dubbed “the great imitator” or “the great masquerader.”

The study of neurosyphilis greatly advanced our understanding of the nervous system. It highlighted the connection between infection, the immune system, and neurologic function. Moreover, it provided invaluable insights into the workings of the brain and spinal cord, aiding in the development of modern neurology.

Societal impact and stigma

Syphilis was not just a medical issue but a societal one, steeped in stigma and moral judgment. It became synonymous with promiscuity and immorality, leading to the social ostracization of sufferers. This stigma hindered public health efforts and contributed to the disease's spread because many avoided seeking treatment.

The turn of the 20th century

As we entered the 20th century, syphilis remained a significant public health problem. The Wassermann test, developed in 1906, was a breakthrough, providing the first reliable diagnostic test for the disease. However, treatment options were limited and largely ineffective.

Mercury, arsenic-based compounds, and even malaria therapy (introducing malaria to induce fever, which was thought to kill the syphilis bacterium) were among the treatments used. These treatments were often as harmful as the disease itself, leading to a dire need for an effective and safe treatment.

The discovery of penicillin

The landscape of syphilis treatment changed dramatically with the discovery of penicillin by Alexander Fleming in 1928. However, it wasn't until the 1940s that penicillin was used to treat syphilis, following the work of scientists like Howard Florey and Ernst Chain, who developed methods for mass-producing the drug.

Penicillin, being highly effective against T. pallidum, transformed syphilis from a chronic, debilitating disease into a curable infection. This not only had profound implications for individual patients but also changed the course of public health. The availability of penicillin led to a dramatic decline in syphilis rates and the virtual elimination of congenital syphilis in developed countries.

MedLink acknowledges the use of GPT-4 in drafting this blog entry.