MRI findings in RCVS can be normal or showing ischemic lesions, especially in posterior circulation and watershed areas.
For example, middle cerebral artery (MCA) stroke (a primary source of information that underpins models of language and aphasia) typically does not damage the inferior-to-middle aspects of the ATL, because it is in the posterior cerebral artery-MCA watershed territory (Phan et al. 2005, 2009).
However, PRES can be found in a non-posterior distribution, occurring at watershed areas of vascular territories, including the frontal, inferior temporal, cerebellar and brainstem areas.
Tendons are metabolically active tissues requiring vascular supply but, in some (Achilles tendon, tibialis posterior and supraspinatus), hypovascular or watershed areas have been identified.
They might even, Benson speculated, have vascular rather than degenerative disease, an accumulation of small blockages in the watershed zone between the posterior and carotid circulations of the brain.
These blocks are harvested at the preoccipital notch (BA37), where the watershed territory of the anterior, middle, and posterior cerebral arteries is located.
23 This is a watershed region lying between the areas supplied by the middle and posterior cerebral arteries, which is vulnerable to hypoxia.
6 However, despite the complex drainage pathways, head and neck melanomas usually seem to follow a somewhat predictable pattern, with preferred drainage to the parotid and levels I V for lesions located anterior of the so-called watershed line and to the suboccipital region and level II V for tumors located posterior of this line.
