Neurosyphilis is an infectious lesion of the central nervous system caused by the penetration of syphilis pathogens into it. It can occur in any period of syphilis. Disease is manifested by symptoms of meningitis, meningovascular pathology, meningomyelitis, lesions of the posterior cord and spinal cord roots, progressive paralysis or focal brain damage due to the formation of syphilitic gum in it. The diagnosis of neurosyphilis is based on the clinical picture, neurological and ophthalmological examination data, MRI and CT scans of the brain, positive serological reactions to syphilis and the results of the cerebrospinal fluid examination. Treatment of neurosyphilis is carried out intravenously with large doses of penicillin preparations.
A few decades ago, neurosyphilis was a very common complication of syphilis. However, mass examinations of patients for syphilis, timely detection and treatment of infected persons have led to the fact that modern venereology is less likely to encounter such a form of the disease as neurosyphilis, despite the fact that the incidence of syphilis is steadily increasing. Many authors also believe that the decrease in cases of neurosyphilis is associated with a change in the pathogenic characteristics of its causative agent — pale treponema — including a decrease in its neurotropicity.
Latent neurosyphilis has no clinical manifestations, but the examination of the patient’s cerebrospinal fluid reveals pathological changes.
Early neurosyphilis develops against the background of primary or secondary syphilis, mainly in the first 2 years of the disease. But it can occur within 5 years from the time of infection. It proceeds with damage mainly to the vessels and membranes of the brain. The manifestations of early neurosyphilis include acute syphilitic meningitis, meningovascular neurosyphilis and syphilitic meningomyelitis.
Late neurosyphilis occurs no earlier than 7-8 years after infection and corresponds to the period of tertiary syphilis. It is characterized by an inflammatory-dystrophic lesion of the brain parenchyma: nerve cells and fibers, glia. The late forms of neurosyphilis include spinal dryness, progressive paralysis and syphilitic gum of the brain.
Symptoms of neurosyphilis
Acute syphilitic meningitis is characterized by symptoms of acute meningitis: severe headache, tinnitus, nausea and vomiting regardless of food intake, dizziness. Often occurs without an increase in body temperature. Positive meningial symptoms are noted: rigidity of the occipital muscles, lower Brudzinsky symptom and Kernig symptoms. There may be an increase in intracranial pressure. Neurosyphilis in the form of acute meningitis develops most often in the first few years of syphilis disease, during its relapse. It may be accompanied by skin rashes or be the only manifestation of a relapse of secondary syphilis.
Meningovascular neurosyphilis develops with syphilitic lesions of the cerebral vessels of the type of endarteritis. It is manifested by an acute violation of the blood circulation of the brain in the form of an ischemic or hemorrhagic stroke, a few weeks before which the patient begins to worry about headaches, sleep disorders, dizziness, personality changes appear. Possible course of meningovascular neurosyphilis with impaired cerebrospinal circulation and the development of lower paraparesis, sensitivity disorders and pelvic organ disorders.
Syphilitic meningomyelitis occurs with damage to the membranes and the substance of the spinal cord. There is a slowly increasing spastic lower paraparesis, accompanied by loss of deep sensitivity and dysfunction of the pelvic organs.
Spinal dryness occurs as a result of syphilitic inflammatory lesions and degeneration of the posterior roots and cord cords of the spinal cord. This form of neurosyphilis appears on average after 20 years from the moment of infection. It is characterized by radiculitis with severe pain syndrome, loss of deep reflexes and deep types of sensitivity, sensitive ataxia, neuro-trophic disorders. With neurosyphilis in the form of spinal dryness, impotence may develop. Neurogenic trophic ulcers on the legs and arthropathy are observed. Argyle-Robertson syndrome is characteristic — irregularly shaped narrowed pupils that do not respond to light. The above symptoms may persist even after specific therapy of neurosyphilis.
Progressive paralysis may appear in patients with a 10-20-year-old disease. This variant of neurosyphilis is associated with the direct penetration of pale treponemas into brain cells with their subsequent destruction. It is manifested by gradually increasing personality changes, memory deterioration, impaired thinking up to the onset of dementia. Mental abnormalities such as depressive or manic states, hallucinatory syndrome, delusional ideas are often observed. Neurosyphilis in the form of progressive paralysis can be accompanied by epileptic seizures, dysarthria, pelvic dysfunction, intentional tremor, decreased muscle strength and tone. A combination with manifestations of spinal dryness is possible. As a rule, patients with similar symptoms of neurosyphilis die within a few years.
Syphilitic gumma is localized most often at the base of the brain, which leads to compression of the roots of cranial nerves with the development of oculomotor nerve paresis, optic nerve atrophy, hearing loss, etc. As the gumma grows in size, intracranial pressure increases and signs of compression of the brain matter increase. Less often, gumma in neurosyphilis is located in the spinal cord, leading to the development of lower paraparesis and pelvic organ dysfunction.
Diagnosis of neurosyphilis
The diagnosis is made taking into account 3 main criteria: the clinical picture, positive results of studies on syphilis and detected changes in the cerebrospinal fluid. A correct assessment of the neurosyphilis clinic is possible only after a neurologist conducts a complete neurological examination of the patient. An important additional information for the diagnosis is provided by the examination of vision and examination of the fundus, which is carried out by an optometrist.
Laboratory tests for syphilis are applied comprehensively and, if necessary, repeatedly. These include the RPR test, RIF, RIBT, detection of pale treponema with the contents of skin elements (if any). In the absence of symptoms of brain compression, a lumbar puncture is performed in a patient with neurosyphilis. Examination of cerebrospinal fluid in neurosyphilis reveals pale treponema, increased protein content, inflammatory cytosis over 20 µl. Conducting RIF with liquor, as a rule, gives a positive result.
MRI of the brain and CT of the brain (or spinal cord) with neurosyphilis reveal mainly nonspecific pathological changes in the form of thickening of the meninges, hydrocephalus, atrophy of the brain substance, heart attacks. With their help, it is possible to identify the localization of gumma and differentiate neurosyphilis from other clinically similar diseases.
Differential diagnosis is performed with meningitis of other genesis, vasculitis, brucellosis, sarcoidosis, borreliosis, brain and spinal cord tumors, etc.
Treatment of neurosyphilis
Neurosyphilis therapy is carried out in stationary conditions by intravenous administration of large doses of penicillin preparations for 2 weeks. Intramuscular penicillin therapy does not provide sufficient concentration of the antibiotic in the cerebrospinal fluid. Therefore, if intravenous therapy is not possible, intramuscular administration of penicillins is combined with taking probenicide, which inhibits the excretion of penicillin by the kidneys. Ceftriaxone is used in patients with neurosyphilis who are allergic to penicillin.
During the first day of treatment, a temporary aggravation of neurological symptoms may occur, accompanied by an increase in body temperature, intense headache, tachycardia, arterial hypotension, arthralgia. In such cases, penicillin therapy of neurosyphilis is supplemented with the appointment of anti-inflammatory and corticosteroid medications.
The effectiveness of treatment is assessed by regression of symptoms of neurosyphilis and improvement of cerebrospinal fluid parameters. The control of the cure of patients with neurosyphilis is carried out for 2 years by examining the cerebrospinal fluid every six months. The appearance of new neurological symptoms or the increase of old ones, as well as persistent cytosis in the cerebrospinal fluid, are indications for a repeated course of treatment for neurosyphilis.