Page 191 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

The Clinical Approach to Patients with Vasculitis 167

group of disorders, the reversible cerebral vasoconstriction syndromes (RCVS) [29] deserved
further attention. Although both present with headache and typical beading of arterial vessels
on cerebral angiography, the clinical presentation of RCVS is dominated by a thunderclap
headache of short duration, typically one to three hours, with associated agitation, confusion,
nausea, vomiting, phonophobia, photophobia, and occasional collapse. The thunderclap
headache, which can recur over one to two weeks, can be triggered by sexual activity, sudden
emotion, urination, bathing, showering, and bending, many of which are Valsalva maneuver-
related. The cerebrospinal fluid is typically normal, and headaches and angiographic
abnormalities resolve in days to weeks with symptomatic management without the need of
cytotoxic medication.

Diagnostic Imaging

Imaging studies employing color-Doppler sonography (CDS), and magnetic resonance
imaging (MRI) or computed tomography (CT) combined with angiography (MRA and CTA),
are the mainstays of the assessment of LVV [30] to visualize the vessel wall and lumen.
Vessel wall thickening and mural inflammation correlate with early inflammation while
vascular stenoses and aneurysm formation are indicative of late complications.
18Fluorodeoxyglucose (FDG) positron emission tomography (PET) can be used to detect
metabolically active, inflammatory cells that infiltrate vessel walls while digital subtraction
angiography (DSA) can identify luminal changes. The extent of disease and monitoring of
luminal changes is best appreciated by employing a combination of techniques. The benefit of
high resolution MRI to depict cranial and extracranial involvement and the highly operator-
dependent nature of temporal artery CDS have led to reduced enthusiasm for the latter in
GCA [31].

Clinicopathologic Correlation

ANCA-Associated Vasculitis

Guided tissue biopsy of suspected organs is important in defining the type, extent and
character of the inflammatory process and categorizing the vasculitic disorder. The clinical
presentation should dictate the biopsy location with the overall aim of performing the
simplest, safest procedure with the highest potential yield. Later in the disease course, it may
have therapeutic implications such as in distinguishing active disease from chronic cicatricial
damage that requires additional immunosuppressive therapy. In AAV, histologic evidence of
necrotizing SVV with accompanying granulomatous inflammation noted in GPA can be used
to support the diagnosis in conjunction with clinical and serologic information. Although
nasal, sinus and upper airway involvement in GPA was noted overall in 92% of patients at
onset of disease [32], tissue biopsy of these regions was associated with vasculitis and
necrosis in only 23% of upper airway biopsy specimens; vasculitis and granulomatous
inflammation in 21%; and vasculitis together with necrosis and granulomatous inflammation
in only 16%. The small amount of tissue available in biopsy specimens from areas of the head

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