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 damages the nerves of the brain. This damage causes:

• 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 non-sexual 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
  • No mood
• Seizures

Signs include:

• Change in the response of the pupil in the eye
• 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 tests to detect syphilis in the body include:

• FTA-ABS
• RPR
• VDRL

Tests of the nervous system may include:

• Cerebrospinal fluid (CSF)
• Head CT scan and MRI
• Nerve conduction tests