Alejandro Fuerte, MD
Focal cerebral arteriopathy (FCA) of childhood is an acute disease causing unilateral stenosis of the cerebral arteries. It appears to be caused by an inflammatory process, and corticosteroids are used in its treatment in the absence of clinical trial data. Because it is one of the most common causes of arterial ischemic stroke (AIS) in healthy children and it increases the risk of recurrent stroke, a Delphi consensus identified this issue as the highest priority for a clinical trial in the field of childhood stroke.
The main goal of Fullerton et al. was to develop a severity score for this disease (Focal Arteriopathy Childhood Severity Score; FCASS). For this they used data from the VIPS study (Vascular Effects of Infection in Pediatric Stroke), a large, international, prospective cohort study that enrolled 355 children (29 days to 18 years of age) with AIS and collected clinical, imaging data and serum samples.
After examining the neuroimaging of the 41 children affected by FCA in the VIPS study, an FCASS based on the degree of stenosis was developed. Each arterial segment was assigned a score of 0 (no involvement) to 4 (occlusion). The maximum FCASS for each case was obtained by adding the scores for the individual artery segments. This system was optimized by correlating it with the clinical data. Clinical outcomes included 1-year cumulative stroke recurrence rates and 1-year pediatric stroke outcome measures (PSOM).
Using the optimized score, the following results were obtained. The maximum FCASS among all 41 cases was a median of 7 (4–9). Among those 33 with multiple FCASS measurements, the score increased (indicating worsening arteriopathy) in 24 (73%). Maximum FCASS correlated with 1-year pediatric stroke outcome measures (P=0.037) and with relative volumes of larger strokes in neuroimaging (P=0,0008). FCASS did not correlate with recurrent arterial ischemic stroke.
In summary, the authors have developed a tool that could be useful in future clinical trials on FCA, the FCASS. It has been shown that the higher maximum FCASS scores correlated with both larger infarct size and poorer 1-year neurological outcomes. Unlike other current systems to classify childhood arteriopathies based on severity, FCASS has been created specifically for ACF and appears to be more reliable. The main limitation of this study is the small sample size, which could explain the absence of correlation between FCASS score and recurrent stroke.
The authors anticipate that in the near future, FCASS could serve as a clinically meaningful measurement and end point for FCA treatment trials. To this end, they emphasize that a validation study is needed in an independent cohort, a study that is currently underway.