The Fazekas scale is used to simply quantify the amount of white matter T2 hyperintense lesions usually attributed to chronic small vessel ischemia, although clearly, not all such lesions are due to this.
This classification was proposed by Fazekas et al. in 1987 1 and remains a very widely used system for describing white matter disease severity in publications. It is also not infrequently used in clinical practice, although terms such as 'mild', 'moderate' and 'severe' are generally favored.
Classification
The scale divides the white matter into periventricular and deep white matter, and each region is given a grade depending on the size and confluence of lesions 1.
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periventricular white matter (PVWM)
0 = absent
1 = “caps” or pencil-thin lining
2 = smooth “halo”
3 = irregular periventricular signal extending into the deep white matter
-
deep white matter (DWM)
0 = absent
1 = punctate foci
2 = beginning confluence
3 = large confluent areas
Importantly the etiology of PVWM and DWM changes differ. The latter is chronic small vessel ischemia in nature, whereas the former (periventricular) relates to a combination of demyelination, ependymitis granularis, and subependymal gliosis, as well as small vessel ischemia 2.
Additionally, it is important to note that it is the deep white matter component score which is useful in the assessment of patients with possible dementia (see neurodegenerative MRI brain (an approach)) and it is this component that is usually reported (e.g. "Fazekas grade 2").
History and etymology
The scale is named after Franz Fazekas (b. 1956), an Austrian neurologist and the author of the original article co-published in 1987 in the American Journal of Roentgenology and American Journal of Neuroradiology 1. At the time, he was training in research in radiology at the University of Pennsylvania 3.