Neurosyphilis is a stage of syphilis infection which is caused by the spirochaete Treponema pallidum. The condition usually develops as a result of long-term syphilis infection that has not been treated for around 10 or 20 years. Neurosyphilis is seen in around 25% to 40% of those not treated.
There are four forms of neurosyphilis, each of which has different manifestations. These different types of the condition include:
- Tabes dorsalis
- General paresis
Some of the symptoms that may be seen in neurosyphilis include:
- A vision disturbance called Argyll Robertson, where the pupils constrict when focussing on a near object but not when exposed to bright light.
- Abnormal gait
- Dementia and memory problems
- Confusion and disorientation
- Lack of concentration
- Irritability and mood disturbances
- Numbness in the lower limbs
- Stiffness in the neck
- Muscle weakness
To diagnose syphilis, the patient is assessed for signs and symptoms of the condition and blood tests are performed. Examples of the tests that may be performed include the Venereal Disease Research Laboratory test, the rapid plasma reagin, fluorescent treponemal antibody absorption and the treponema pallidum particle agglutination assay. The cerebrospinal fluid can also be checked for signs of the disease. Additional tests that may be performed to assess involvement of the nervous system include computed tomography (CT) scan, magnetic resonance imaging (MRI) scan and cerebral angiography.
Syphilis is a treatable condition. Early diagnosis and initiation of antibiotics such as penicillin is critical. Penicillin is administered every day over the course of 10 to 14 days, sometimes along with probenecid, which increases the blood levels of penicillin.