General paresis combines progressive mental deterioration with a characteristic disorder of speech, fine movement and motor control. The historical phrase “general paralysis of the insane” does not mean complete, simultaneous immobility of every muscle.
Early changes may include impaired judgment, forgetfulness, altered personality, irritability, inappropriate confidence and loss of ordinary social restraint. Expansive or grandiose delusions are characteristic in some cases, but depression, suspiciousness or less spectacular cognitive failure can occur. Increasing dementia and reduced insight are more fundamental than any one extravagant belief.
The physical examination may disclose hesitating or slurred articulation, tremulous lips and tongue, facial tremor, deteriorating handwriting and impaired coordination of the hands. Gait becomes unsteady and weakness advances. Unequal or abnormally reacting pupils, altered reflexes and seizures may occur. Later disease can bring severe cognitive incapacity, swallowing difficulty, incontinence and dependence. Mental and motor manifestations need not develop in a fixed order or with equal severity.[ref]
Neurosyphilis Guide by the California Department of Public Health. Late neurosyphilis: general paresis, psychiatric change, dysarthria, tremor, pupils and reflexes
The name general paresis was already advocated in a January 1864 pathological study to avoid the ambiguity of “general paralysis.”[ref]
The Pathology of General Paresis by William Henry Octavius Sankey. Opening, Journal of Mental Science 9, pp. 467–493, January 1864
Modern medicine recognises the classical disease as a form of neurosyphilis, involving chronic injury to the brain. This causal diagnosis should be separated from the historical clinical label; it was not securely established by the wording of an 1864 examination. Syphilis serology, relevant cerebrospinal fluid findings and exclusion of alternative causes now help establish the diagnosis.[ref]Neurosyphilis, Ocular Syphilis, and Otosyphilis treatment guidance by CDC. Neurological involvement: cognitive or motor signs and cerebrospinal-fluid examination
Several mimics deserve explicit comparison. Mania can resemble the expansive mental phase, and depression or psychotic illness can resemble other presentations, but a sustained progressive combination of cognitive decline, characteristic speech disturbance and neurological signs argues for organic disease. Alcohol intoxication can produce tremor, slurred speech and an unsteady gait; an acute time course or improvement with clearance differs from progressive general paresis, although chronic alcohol-related disease may complicate the distinction. Other dementias, chronic cerebral vascular disease, tumours and some toxic or metabolic disorders can likewise combine cognitive and motor abnormalities.
A focal stroke generally gives a more abrupt and lateralised deficit; a series of strokes can produce a stepwise course. Parkinsonism can impair speech and gait but has a different predominant motor pattern. Tabes dorsalis can produce marked sensory ataxia, absent tendon reflexes and bladder disturbance with relatively preserved intellect; it can also coexist with paretic disease. The diagnosis rests on the pattern, course and corroborating investigation, not on grandiosity or a tremulous tongue alone.[ref]
German Guidelines on the Diagnosis and Treatment of Neurosyphilis (2020). General paresis and tabes dorsalis: contrasting clinical manifestations and diagnostic framework
In 1865 Mercury was the principal systemic remedy for early constitutional syphilis, while potassium iodide was especially associated with later destructive lesions; neither is an acceptable substitute for modern penicillin therapy. Historical classifications depended chiefly on clinical appearance, before identification of Treponema pallidum and modern serology.
For a primary indurated chancre, period treatment combined cleanliness, protection from friction and irritant discharges, and, in mercurial practice, a prolonged course of a Mercury preparation. Administration could be by mouth or by rubbing an ointment into the skin; some practitioners used fumigation. Local cauterisation of a sore could not be assumed to remove infection already spread beyond it. Painful soft sores and suppurating groin swellings were often discussed among venereal diseases, but modern chancroid is distinct from syphilis; an 1865 “variety” cannot automatically be assigned the same cause or treatment.[ref]
Health of the Navy: Home Station report (1864). discussion of infecting sores, soft sores, buboes, mercurial and non-mercurial practice
In secondary disease, with generalised eruptions and mucosal lesions, Mercury was used in carefully watched courses, with food, hygiene and local care. Blue pill, grey powder and other mercurial compounds were alternative forms, not interchangeable quantities. Stomatitis, excessive salivation, bowel disturbance and constitutional deterioration were reasons to interrupt treatment, not desirable signs of cure. Relapse after apparent healing was recognised. For later gummatous syphilis, painful periosteal swellings, ulceration and some nervous manifestations, potassium iodide, sometimes combined with a mercurial, was a characteristic period choice. Apparent symptomatic improvement did not demonstrate eradication of the infection.[ref]
Remarks on Syphilis and Its Treatment (1864). pp. 17–23, secondary disease, mercurial effects and uncertainty
[ref]Clinical Commentaries on late syphilis in the British Medical Journal (1864). 3 September, p. 263, late tertiary lesions and iodide practice
Congenital disease also received mercurial treatment in the period, together with attention to feeding and the mother. That history must be separated from present management: congenital syphilis results from maternal infection, not an inherited constitutional taint. Maternal treatment, infant examination and laboratory evaluation determine modern management; an affected infant can require a full course of parenteral penicillin even without obvious external lesions.[ref]
Modern early acquired syphilis, including primary, secondary and early latent disease, is ordinarily treated with benzathine penicillin G, 2.4 million units intramuscularly once in adults. Late latent disease or disease of unknown duration ordinarily requires three weekly 2.4-million-unit injections. Neurosyphilis, ocular disease and otic disease require a regimen with appropriate tissue penetration, ordinarily aqueous crystalline penicillin G, 18–24 million units per day intravenously for 10–14 days, rather than the single early-disease injection. Pregnancy, allergy, congenital disease and other special circumstances need the corresponding specialist pathway. Clinical and quantitative serological follow-up, partner management and assessment for coexisting infections are part of treatment. The stage labels guide management, but nervous, ocular or auditory involvement can occur at more than one stage.[ref]
Primary and Secondary Syphilis treatment guidance by CDC. recommended adult regimen
[ref]Latent Syphilis treatment guidance by CDC. early and late latent regimens
[ref]Neurosyphilis, Ocular Syphilis, and Otosyphilis treatment guidance by CDC. recommended regimen and ocular/otic management