General paresis

General paresis is an impairment of mental function caused by damage to the brain from untreated syphilis.


General paresis is one form of neurosyphilis. Today it is very rare.

The syphilis infection can appear in many different ways and damages many different nerves of the brain. This damage can cause:

  • Abnormal mental function including hallucinations and false ideas (delusions)
  • Brief, sharp, "lightning" pains that occur with tabes dorsalis
  • Decreased mental function
  • Eye changes and abnormal pupil response
  • Mood changes
  • Overactive reflexes
  • Personality changes
  • Speech changes

General paresis usually begins about 15 - 20 years after the syphilis infection. Risks include syphilis infection and infection with other sexually transmitted diseases, such as gonorrhea (which may hide symptoms of syphilis infection).

Syphilis infections are passed through sexual contact with an infected person, but may also be transmitted by nonsexual contact.


  • Decreased language ability (aphasia)
  • Decreased motivation
  • Impaired judgment
  • Loss of ability to calculate
  • Loss of long-term memory (long-past events)
  • Loss of short-term memory (recent events)
  • Muscle weakness (difficulty using legs, arms, or other parts of the body)
  • Personality changes
    • Delusions, hallucinations
    • Irritability, anger
    • Inappropriate moods
    • Low mood
  • Seizures

Exams and Tests

Signs include:

  • Change in the response of the pupil in the eye
  • Irregular shape of the pupil
  • Inability to stand with the eyes closed (Romberg test)
  • Loss of sense of vibration and position
  • Muscle weakness
  • Problems with walking (gait)
  • Slowly worsening dementia, with loss of many brain functions

The doctor may do the following tests:

  • Eye exam
  • Muscle exam
  • Nervous system (neurologic) exam

Blood and urine tests to detect syphilis in the body include:

Tests of the nervous system may include:


The goals of treatment are to cure the infection and slow the disorder from getting worse. The doctor will prescribe penicillin or other antibiotics, such as doxycycline, to treat the infection. Treatment may continue until the infection has completely cleared.

Treating the infection will reduce new nerve damage, but it will not cure damage that has already occurred. A follow-up examination of the cerebrospinal fluid is needed to see whether the antibiotic therapy worked.

Treatment of symptoms is needed for existing nervous system damage. Seizures rarely occur, but emergency treatment may be needed if they do. Anticonvulsants (such as phenytoin) can help control seizures.

Patients who are unable to care for themselves may need help with such activities as eating and dressing. Those with muscle weakness may need occupational therapy or physical therapy.

Outlook (Prognosis)

Without treatment, people can become disabled. People with late syphilis infections are more likely to get other infections and diseases.

Possible Complications

  • Inability to care for yourself
  • Inability to communicate or interact with others
  • Injury due to seizures or falls

When to Contact a Medical Professional

Call your health care provider if you know you have been exposed to syphilis or other venereal disease in the past, and have not already been treated.

Call your health care provider if you have symptoms of general paresis, especially if you know you've been infected with syphilis.

Go to the emergency room or call the local emergency number (such as 911) if you have seizures.


Treating primary syphilis and secondary syphilis infections will prevent general paresis.

Practicing safe sex, such as limiting partners and using protection, may reduce the risk of getting infected with syphilis. Avoid direct skin contact with patients who have secondary syphilis by wearing gloves.


Beck BJ. Mental disorders due to a general medical condition. In: Stern TA, Rosenbaum JF, Fava M, Biederman J, Rauch SL, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry. 1st ed. Philadelphia, Pa: Mosby Elsevier; 2008:chap 21.

Verma A. Infections of the nervous system. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann; 2008:chap 57.

Update Date: 3/9/2012

Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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