Neurosyphilis: Late-Stage CNS Infection – Symptoms, Diagnosis, Treatment

Neurosyphilis is Treponema pallidum invasion of the CNS, occurring in untreated syphilis (months to decades after primary infection).

Clinical Syndromes

Form	Features
Asymptomatic	CSF abnormalities only (↑ WBC, protein, VDRL+)
Meningeal	Headache, stiff neck, cranial nerve palsies (II, VI, VIII)
Meningovascular	Stroke (endarteritis obliterans), seizures, hemiparesis
General paresis	Dementia, personality change, grandiose delusions, Argyll Robertson pupils
Tabes dorsalis	Lightning pains, ataxia, areflexia, bladder dysfunction, Charcot joints

Diagnosis

• Serum RPR/VDRL + treponemal test (FTA-ABS, TP-PA).
• CSF: cell count, protein, VDRL (specific but insensitive), PCR (sensitive).

Treatment

• Aqueous penicillin G 18–24 million units/day IV × 10–14 days (gold standard).
• Alternative: Ceftriaxone 2 g IV daily × 10–14 days.
• Penicillin allergic: desensitize → penicillin. Doxycycline less proven.
• Follow-up: CSF q6mo until normal.

Prognosis

Early treatment reverses meningeal/meningovascular; paresis/tabes often leave residual deficits. HIV co-infection accelerates progression and increases treatment failure.