Page 157 - The Vasculitides Volumes 2

Central Nervous System Vasculitis Due to Infection 133

causes Lyme disease and its neurological complications in North America; the Borrelia
garinii and afzelii species are predominantly outside North America. Virtually all cases result
from an infected Ixodes tick bite. Lyme disease is a systemic infection with most patients
manifesting the prototypical expanding skin lesion at the bite site termed erythema migrans.
Both the CNS and peripheral nervous system (PNS) are targeted body organs. CNS vasculitis
while exceedingly uncommon, accounted for 0.3% of all Lyme disease cases in a Lyme
endemic area according to Back and coworkers [24]. Patients with Lyme neuroborreliosis
may present with cerebral infarction, intracerebral or subarachnoid hemorrhage, and TIA [25-
30].

There are rare instances of cerebral venous sinus thrombosis. B. burgdorferi infection in
the CNS may be associated with lymphocytic cerebral vasculitis [31] preceding clues of
which include, headache, arthralgia, myalgia, peripheral facial nerve palsy, and flu-like illness
during the summer months. Laboratory evaluation may demonstrate meningeal enhancement
on brain MRI although there appears to be a propensity of vasculitis to involve the posterior
circulation. Lumbar CSF analysis typically reveals pleocytosis, increased protein, and
intrathecal Lyme antibody production. CNS vasculitis due to Lyme neuroborreliosis should
be treated with IV ceftriaxone 2 grams daily for four weeks via midline or permanent
intravenous catheter (PIC) line with daily acidophilus to lower risk of Clostridium difficile
colitis.

Leptospirosis
Leptospirosis is a worldwide zoonotic infection due to a spirochete from the genus

Leptospira. It is transmitted by the urine of infected animals, and to people exposed to the
pathogenic organism through contact with contaminated water, blood or soil. Infection is
biphasic, with flu-like symptoms, followed by a second immune phase that can involve
meningitis, jaundice with liver injury, and renal failure. Infection can be asymptomatic. About
90% of symptomatic infections manifest a benign biphasic febrile illness with 10% involving
icteric Weil disease, and a fatality rate of 10%. Spirochetes are found in blood and CSF early
in the course of the illness, and in the urine later in the disease. Leptospirosis more commonly
causes meningitis or meningoencephalitis. Clinically apparent CNS vascular involvement is
unusual but can result in stroke, hemorrhage and venous sinus thrombosis [32-34]. Diagnostic
tests include screening serology via enzyme linked immunosorbant assay (ELISA),
microscopic agglutination test, and polymerase chain reaction (PCR). Vasculitis is a
recognized feature of this infection involving capillaries, with consequent edema, necrosis,
and lymphocytic infiltration. Therapy involves primarily doxycycline however other effective
antibiotics include cefotaxime, penicillin, ampicillin, and amoxicillin.

Relapsing Fever
Relapsing fever is spread by tick or lice bites. Louse-borne relapsing fever is due to

Borrelia recurrentis. Tick-borne relapsing fever is due to at least 15 different Borrelia
species. Clinical illness is characterized by febrile episodes accompanied by prominent
headache and myalgia. Neurologic involvement is characterized by meningitis, facial palsy,
myelitis, radiculitis, and focal or diffuse CNS dysfunction [35]. Neuropathologic changes
involve edema, subarachnoid, and parenchymal hemorrhage, with perivascular mononuclear
infiltrates. Spirochetes can be found in the cerebral microvasculature and interstitial spaces.

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