It has been postulated that in steady-state
SCA the brain is normally oxygenated due to
a compensatory increase in cerebral blood flow
(CBF) 5. However, some recent studies did not
detect increased CBF in some patients at high
risk for stroke 6. An inverse relationship between
intracranial blood flow velocity 7 or cerebral
perfusion (Arkuszewski M. and Krejza J
- unpublished data) with the occurrence of SCI
has been observed. The high risk of CVA can be
related therefore to both high and low values of
CBF, hence reference tolerance limits of CBF
can be useful to estimate the risk. These tolerance
limits can inform an investigator what
CBF values may occur in relatively “healthy”
children with SCA, who are without hyperemia
or evidence of arterial narrowing.