Neurosyphilis

Neurosyphilis is nervous-system infection by T. pallidum, divided into congenital and acquired forms. Transmission is mainly by unclean sex, also mucosal contact or infected blood. Clinical types: (1) asymptomatic; (2) meningeal; (3) vascular; (4) tabes dorsalis; (5) general paresis; (6) congenital.

Common Symptoms

Genitourinary crisis; weakness; sensory ataxia; station doctor; tremor; dementia; nausea; sensory disturbance

Causes and Pathogenesis

(1) Etiology: congenital via placenta; acquired via sex. (2) Pathogenesis: treponemes enter blood and reach CSF/CNS within 1-3 months. 1. Asymptomatic neurosyphilis: autopsy data limited; probably mainly meningeal, some parenchymal/vascular. 2. Meningeal neurosyphilis: diffuse leptomeningeal inflammation with mild cortical damage; miliary gummas mimic miliary TB but are distinguished microscopically. Lymphocyte/plasma cell infiltration, Virchow-Robin spaces filled; basal meningitis damages cranial nerves (III/IV/VII/VI/VIII), obstructs CSF flow causing hydrocephalus, granular ependymitis. Gummas contain fibroblasts/multinucleated giant cells/plasma cells with central necrosis and reticulin (distinguishing from tubercles, which lack reticulin). Large gummas compress adjacent nerves. Vascular endo-/periarteritis may cause softening. Spinal leptomeningitis = syphilitic arachnoiditis; pachymeningitis = spinal pachymeningitis. 3. Vascular neurosyphilis: medium/small arteries (Heubner arteritis) causing endarteritis obliterans and focal brain/spinal cord softening; recurrent artery (Heubner), middle cerebral, vertebral/basilar, anterior spinal arteries may be involved; adventitial thickening, intimal fibroplasia, thrombosis/organization/recanalization; Nissl-Alzheimer arteritis (intimal hyperplasia without inflammation); aneurysms rare. 4. Tabes dorsalis: selective degeneration of posterior roots/columns (lumbar/sacral/lower thoracic), thickened opaque leptomeninges (especially dorsal), thinned flattened dorsal roots, narrowed atrophic posterior columns; microscopy: lymphoplasmacytic leptomeningitis, interstitial radiculoneuritis, demyelination of posterior columns (fasciculus gracilis worst), late astrogliosis without necrosis; cranial nerves (III/IV/VIII) similarly affected; optic atrophy. Cervical tabes is rare. Mechanism thought toxic-degenerative with reactive inflammation. 5. General paresis: cortical atrophy, frontal/temporal worst, granular ependymitis; perivascular lymphoplasmacytic infiltration, neuronal loss, microglial nodules, iron deposition; treated cases show reduced inflammation. 6. Congenital neurosyphilis: stillbirth, hydrocephalus/developmental anomalies, early meningovascular disease, juvenile paresis/tabes.

Treatment

Drug therapy, supportive therapy

Preventive Measures

China essentially eliminated syphilis by the late 1950s through prohibition and mass campaigns; Western rates fell with penicillin. Recent resurgence (often HIV-associated) requires health education and systemic control. 1. Treat early syphilis promptly, preferably with penicillin. 2. Follow-up: if non-treponemal titers do not fall or drop <2 dilutions in 6 months (especially non-penicillin treatment), do CSF exam. 3. Any patient with prior syphilis plus hearing/cranial-nerve/meningeal/visual damage should be evaluated for neurosyphilis. 4. Treponemal-positive patients with unexplained neuropsychiatric disease need neurosyphilis workup/treatment.

Department to Visit

It is recommended to visit the Neurology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.