Syphilis; ,meningovascular syphilis, and Tabes dorsalis

Описание: Neurosyphilis is a manifestation of the tertiary stage of syphilis.Occurs in only about 10% of individuals with untreated infection.
Individuals infected with HIV are at increased risk for neurosyphilis,
Particularly as an acute syphilitic meningitis or meningovascular disease.
This is because of impaired cell-mediated immunity.
The severity and rate of progression of the disease seem to be accelerated
Possibly for the same reason.
Chronic meningitis
Involves the base of the brain and more variably the cerebral convexities and the spinal leptomeninges.
Cranial and peripheral nerve compression
B-Obliterative endarteritis (Heubner arteritis)
Is accompanied by a distinctive perivascular inflammatory reaction rich in plasma cells and lymphocytes.
Luminal narrowing lead to tissue ischemia.
It also predisposes to cerebrovascular thrombosis, vessel occlusion, and infarction.

Meningovascular
syphilis
Occurs, on average, 7 yrs. after the initial infection.
The most common presentation is a stroke syndrome in a relatively young adult. The stroke syndrome involves the middle cerebral artery (most common)or the branches of the basilar artery (second most common). 90% of all stroks
Largest of the brain arteries
Supplies most of the outer surface of the frontal, Parietal and temporal lobes.
Tabes dorsalis is the result of damage by the spirochetes to the sensory nerves in the dorsal roots and dorsal root ganglia with corresponding atrophy in the dorsal columns of the spinal cord.
Locomotor ataxia is the inability to precisely control one’s own bodily movements.
Persons affected with this disease may appear to walk like defective robots or otherwise move like malfunctioning machinery;
that is to say, in a herky-jerky, up-and-down kind of rhythmical but non-fluid manner
The Romberg test is a test of the body's sense of positioning (proprioception), which requires healthy functioning of the dorsal columns of the spinal cord
loss of pain sensation, lead to skin and joint damage (Charcot’s joints)Tabes dorsalisIs characterized by a triad of clinical symptoms namely:
Gait unsteadiness,
Lightning pains
and Urinary Incontinence.
Argyll-Robertson Pupils is a classical eye finding in Tabes dorsalis & G.P.I.
Bilateral asymmetrical involvement
Small irregular pupils
Preserved vision
-ve light +ve to near reflexes
Site of the lesion :dorsal midbrain, Pre-aqidactal.

Microscopic picture.Tabes dorsalisThere is loss of both axons and myelin in the dorsal roots (arrows) and ganglia with corresponding pallor and atrophy in the dorsal columns of the spinal cord. stained for myelin.