To the Editor:

We would like to thank Drs. Abud-Mendoza and Herrera-van Oostdam for their interest in our recent article on childhood PACNS. Their letter highlights difficulties in monitoring some of the clinical features of patients with angiography-negative childhood PACNS, including behaviour changes, cognitive dysfunction, psychiatric disturbances, and seizure activity (1). Our colleagues have suggested that the Pediatric Stroke Activity Limitation Measure (PSALM) should be used in addition to the tools that are currently used to measure disease activity in children with childhood PACNS (2). However, we would caution that the addition of the PSALM would not adequately address the limitations of existing measures, such as the validated and more widely used Pediatric Stroke Outcome Measure, in determining outcomes in children with angiography-negative PACNS (3). Even the researchers who developed the PSALM admit that this tool is likely biased toward motor and sensory deficits and may not adequately capture the cognitive and psychological challenges that affect a child's daily functioning (2). The activities listed in the PSALM are not easily transferable to all societies and age groups. We echo the PSALM researchers' proposal that cognitive and psychosocial functioning be assessed more fully through age-appropriate neuropsychiatric testing. There is emerging evidence that this type of testing provides a more accurate picture of the cognitive burden in children with PACNS (4). Unfortunately, none of the existing measures adequately capture seizure activity.

Drs. Abud-Mendoza and Herrera-van Oostdam also argue that hydroxymethylglutaryl-coenzyme A reductase inhibitors, or statins, should be added to the therapeutic regimen for patients with childhood PACNS. To date, there is no evidence demonstrating that statin therapy is effective in children with active vasculitis. The studies of patients with Kawasaki disease addressed whether statins could be used to treat endothelial dysfunction and vascular remodeling late after acute inflammation (5, 6). These children were unlikely to have active vasculitis since they had been diagnosed as having Kawasaki disease between 5 and 22 years prior to initiation of statin therapy (5, 6). The only other study of statin therapy in rheumatic diseases included 1 child diagnosed as having granulomatosis with polyangiitis (Wegener's) and significant renal involvement, while the remaining 9 patients were adults (7). Therapy for adults with vasculitis may be different from therapy for children given the higher prevalence of atherosclerosis in older patients. Further studies of statins in children with vasculitis are necessary before recommending the addition of this unproven therapy to the immunosuppressive treatment regimen for childhood PACNS.

Tania Cellucci MD, BScHons, FRCPC*, Susanne M. Benseler MD, PhD*, * Hospital for Sick Children, and University of Toronto, Toronto, Ontario, Canada.