To the Editor.
—Dr Weintraub's1 series of five patients with beauty parlor stroke syndrome postulates a plausible causal mechanism for such arterial injury. Although well documented clinically, I have some epidemiologic concerns about his observations.Since this report reflects a new syndrome, it is critical to describe the nature of the hypothetical causal variable or risk factor in a rigorous fashion.2 Unfortunately, no precise descriptions of these five clients' salon visits are given. The presumed risk factor (alternatively termed shampooing or shampoo treatment) is not described either in the same manner or in operational terms for all cases. These details are essential to delineate "exposure" to the potential causal variable.2Weintraub does not take sufficient account of several factors unique to beauty salons. The hanging, hyperextended position, with the head cradled in a contour sink, and the body reclining in a chair applies to situations other than