INTRODUCTION Granulomatous inflammation is a distinctive ...

granulomatous angiitis (Duna and Calabrese, 1995).
The ESR is elevated in 66% of patients, and CSF should be examined if PACNS is suspected. CNS
examinations show nonspecific abnormalities, in 81% of patients, in the form of pleocytosis, and
elevated protein levels. CT scan may show infarcts, low density lesions and giriform enhancement,
while MRI may show focal areas of infarctions in multiple vascular territories (Duna and
Calabrese, 1995).
As angiography is less invasive than brain biopsy, this test is often performed before biopsy. The
classic angiographic findings in granulomatous angiitis include “beading” (alternating dilatations
and narrowings of blood vessels), aneurysms, and other irregularities within blood vessels (Figure
25). It must be recognized, however, that many conditions not caused by vasculitis (e.g., spasm of
the blood vessels) can cause an angiographic appearance that is impossible to distinguish from
true vasculitis (Heiserman et al., 1994).
Because the diagnosis cannot be proven with 100% certainty by angiography, consideration is
often given to performing a brain biopsy before initiating treatment with the combination of
cyclophosphamide and steroids. If non–invasive imaging studies such as an MRI indicate a site of
probable pathology within the brain, the neurosurgeon may opt to perform the biopsy at that site
if it is surgically accessible. If no obvious site for biopsy is identified by non–invasive studies or by
angiography, the brain biopsy is usually performed on the non–dominant side of the patient’s
brain. Biopsy of the meninges is usually performed at the same time (this increases the chance that
the procedure will yield a piece of tissue containing pathology). Although brain biopsy remains the
“gold standard” in the diagnosis of CNSV, 25% of the time a brain biopsy will be negative even in
the setting of true vasculitis; i.e., the likelihood of a “false–negative” biopsy is unfortunately rather
high (Lie, 1992).
Treatment
Figure 25. Intracranial Granulomatous
Angiitis. Cerebral angiograms showing
diffuse irregular segmental arterial
narrowing (arrows) involving peripheral
distribution of anterior, middle, and
posterior cerebral arteries Note
asymmetric depression of right posterior
cerebral artery (Micheal et al., 1977)
Until recently, PACNS was a fatal condition in a high percentage of cases, with death following
diagnosis in a mean of 45 days after diagnosis. The availability of powerful immunosuppressive
therapy, however, has significantly improved the prognosis for people with this condition. Some
patients with PACNS respond well to treatment with high doses of steroids alone. Others require
the addition of cyclophosphamide to the steroid regimen. In many cases, a reasonable approach is
to attempt to control the disease with high doses of steroids first (e.g., for one month), adding
cyclophosphamide only if steroids fail or if patients begin to develop unacceptable side–effects of
steroid treatment (Scolding et al., 1997).