Page 112 - The Vasculitides Volumes 2

88 Aleksandra Mineyko and Adam Kirton

pleocytosis, and raised CSF protein have been described in both large and small vessel
cPACNS [14, 15, 112]. Abnormal CSF was described in 39% (9/23) patients in a single-
centre, retrospective study [41] of 62 children with cPACNS. Findings included non-specific
or lymphocyte-predominant pleocytosis in 32% and the same proportion with elevated
protein. Oligoclonal bands were absent. CSF markers were not associated with outcome or
progression of disease. However, the numbers were too small to distinguish differences
between subtypes of vasculitis.

Isolated case reports of children with PVA have shown mild CSF pleocytosis. [80] The
detection of CSF anti-VZV IgG antibodies is possibly more sensitive than VZV PCR testing
with some [117] suggesting the diagnosis can be excluded when CSF is negative for both.
The use of an antibody index (AI) to better determine significant elevations of VZV
antibodies in CSF has been proposed as more sensitive [118]. With the exact role of VZV in
childhood arteriopathy yet to be determined, these findings and other isolated cases of
infection-associated arteriopathy [89-91, 95] suggest that additional methods to define CSF
biomarkers are required [102].

Neuroimaging

The diagnosis of a child with acute focal neurological deficits is stroke until proven
otherwise. It requires urgent imaging in the form of CT or MRI depending on availability of
scan and stability of the patient. Given the high incidence of arteriopathy in childhood stroke,
angiography should be included in the initial imaging protocol [8]. For children being
evaluated for subacute or progressive neurological changes such as headaches, cognitive or
behavioral changes, MRI is the modality of choice.

Advanced cerebral vascular imaging modalities have increased the sensitivity of
detecting and defining the unique features of childhood arteriopathies. CT, MR and
conventional angiography are used to confirm arteriopathy in most children with large vessel
arteriopathy. Inflammation is considered if stenosis, narrowing, or occlusion is seen without
evidence of dissection and when associated with luminal irregularities or other indications of
arterial wall disease. However, it is important to note that there are no validated imaging
biomarkers of inflammation in childhood stroke [25]. CTA and MRA produce excellent
images of first and second order cerebral arteries but resolution of smaller vessels is limited.

The diagnosis of large-medium vessel vasculitis according to the criteria of Calabrese and
colleagues [46] requires demonstration of the angiographic findings of arteritis if brain biopsy
is not feasible. Conventional angiography is the preferred modality for demonstrating specific
vascular abnormalities. Banding or striae are key findings in large-medium vessel vasculitis
(Figure 2D). Similarly, alternating areas of stenosis and dilatation in distal arterial beds are
seen in small vessel cPACNS [24, 51]. Sensitivity is only moderate for predominantly distal,
small vessel disease [47]. Conventional angiography which is very safe in the pediatric
population [119] should be considered in children with AIS.

Less invasive vascular imaging modalities are preferable for serial surveillance of
fluctuating disease or syndromes with high recurrence risk. When comparing MRA to
conventional angiography, sensitivity and specificity for known angiographic abnormalities
identified on MRA were 70% and 98% respectively in one study [47]. MRI and MRA have
been evaluated in single centre cohort studies. All patients with abnormal conventional

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