A H istorical P erspective Monica Arnell P lague H ysteria T he N eurological C omponent of I nfectious D isease When a person mentions that they have been ex- posed to an infectious disease of any kind, you may have observed that the people talking to them instinc- tively use their hand to cover their mouth or lean back and avoid contact. This is not surprising, because just the words “infectious disease” tend to conjure up ideas ranging an average flu to more extreme symp- toms such as open sores or epidemics like the Black Death that swept through medieval Europe. A less common category of symptoms that often stem from these diseases are neurological complications, which can be far more serious and often deadlier than the rest if the disease is left to develop without treatment. Neurological components of infectious disease are symptoms that result when the disease attacks the brain or central nervous system. These symptoms vary in severity; they can cause headaches due to swelling of brain tissue and increased pressure, mental psy- chosis and atypical behavior, or an overall decrease in will we be able to prevent their spread and the ostra- cism of victims. T uberculosis : T he W hite P lague Although it is usually the unique and characteris- tic complications of each infectious disease that cause illness and eventually death, neurological symptoms have been historically perplexing as they are not read- ily apparent at the first signs of infection. Tuberculosis can present such seemingly unexplainable symptoms. The disease was previously and popularly known as “Consumption” because it seemed to consume the body from within, in addition to being coined the “White Plague” due to the pallor of victims’ faces. Spread through the air by coughs and sneezes, it is caused by mycobacterium and primarily affects the lungs in 75% of cases. Children or immunosuppressed individuals, however, may become infected in other areas, including the central nervous system (Golden and Vikram 2005). A common manifestation of the disease in these populations is meningitis, or inflammation of the meninges, which is the protective covering of the brain and spinal cord. The mycobacteria that cause Tubercu- losis travel to the brain and attack the tissues of the meninges, caus- ing them to swell as an inflamma- tory response. The most common symptoms are severe headache and fever, but if not treated quickly with antibiotics, epilepsy, deafness, and cognitive deficits can develop due to the pressure of the swelling inside the skull (Saez-Llorens and McCracken 2003). Tuberculosis became known as the major killer during the Industrial Revolution and was cited by fa- mous authors such as Edgar Allen Poe, who suffered many familial losses from the disease. The neurologi- cal symptoms were often overlooked during the era because the disease itself was poorly understood and no treatment had yet been discovered. Tuberculosis victims were thought to be crazed vampires, prey- B S J “Tuberculosis victims were thought to be crazed vampires, preying on their infected family members one by one and coughing up their blood. They often suffered from epileptic attacks and amnesic symptoms.” brain function due to the deterioration of brain tissue by disease-infected cells. In some cases, neurological symptoms are quite rare, as they present themselves years after infection. However, these complications are quite serious and especially prevalent in particu- lar diseases. Throughout history, there have been epi- sodes of contagious diseases causing mass hysteria not only due to their rapid spread and deadliness, but also to the resulting extreme mental and behavioral changes that were so poorly understood. Neurologi- cal symptoms continue to be a prevalent component of modern infectious diseases; only through education B erkeley S cientific J ournal • I nfectious D isease • F all 2010 • V olume 14 • I ssue 1 • 13