Neurosyphilis

Definition

Neurosyphilis is an infection of the brain or spinal cord. It usually occurs in persons who have had untreated syphilis for many years.

Causes, incidence, and risk factors

Neurosyphilis is caused by Treponema pallidum, the bacteria that cause syphilis. It usually occurs about 10 - 20 years after a person is first infected with syphilis. Not everyone who has syphilis will develop this complication.

There are four different forms of neurosyphilis:

• Asymptomatic (most common form)
• General paresis
• Meningovascular
• Tabes dorsalis

Asymptomatic neurosyphilis occurs before symptomatic syphilis.

Symptoms

• Abnormal walk (gait)
• Blindness
• Confusion
• Dementia
• Depression
• Headache
• Incontinence
• Inability to walk
• Irritability
• Numbness in the toes, feet, or legs
• Poor concentration
• Seizures
• Stiff neck
• Tremors
• Visual disturbances
• Weakness

Note: There may be no symptoms

Signs and tests

Signs include:

• Abnormal reflexes
• Muscle atrophy
• Muscle contractions

Blood tests can be done to detect substances produced by the bacteria that cause syphilis. The oldest test is the VDRL test.

Other tests include:

• Fluorescent treponemal antibody absorption (FTA-ABS)
• Rapid plasma reagin (RPR)
• Treponema pallidum particle agglutination assay (TPPA)

In neurosyphilis, it is important to test the spinal fluid for signs of syphilis.

Tests to look for problems with the nervous system may include:

• Cerebral angiogram
• Head CT scan
• Lumbar puncture ("spinal tap") and a cerebrospinal fluid analysis ( CSF fluid analysis)
• MRI scan of the brain, brainstem, or spinal cord

Treatment

Penicillin is used to treat neurosyphilis. The medicine may be given in various ways.

• It may be injected into a vein several times a day for 10 - 14 days.
• You may take probenecid by mouth 4 times a day, combined with daily muscle injections -- both for 10 - 14 days.

You must have follow-up blood tests at 3, 6, 12, 24, and 36 months to make sure the infection is gone. You will need follow up lumbar punctures for CSF fluid analysis every 6 months. If you have HIV or another medical condition, your follow-up schedule may be different.

For information on treating syphilis, see the following articles:

• Primary syphilis
• Secondary syphilis
• Syphilis
• Tertiary syphilis

Expectations (prognosis)

This is considered a life-threatening complication of syphilis. How well you do depends on how severe the neurosyphilis is before treatment.

Complications

The symptoms can get slowly worse.

Calling your health care provider

Call for an appointment with your health care provider if you have had syphilis in the past and now have signs of neurological problems.

Prevention

Prompt diagnosis and treatment of the original syphilis infection can prevent neurosyphilis.

References

Hook EW. Syphilis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 340.

Tramont EC. Treponema pallidum (syphilis). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 238.