Cause: disease of small cerebral arteries that affects the watershed perfusion areas in the deep white matter
Risk factors include:
(1) hypertension
(2) recurrent episodes of hypoperfusion (overtreatment of hypertension, cardiac arrhythmia, cardiac arrest, heart failure, autonomic failure, etc)
(3) amyloid angiopathy
(4) multiple small strokes
(5) diabetes
Pathologic and imaging findings:
(1) periventricular leukoencephalopathy with symmetrical hypodense areas in the white matter (leukamalacia) and lacunae
(2) dilatation of the lateral ventricles with nonobstructive hydrocephalus
(3) absence of contrast enhancement
Clinical findings:
(1) dementia in a person >= 50 years of age
(2) focal neurological deficits
(3) frontal signs
(4) pseudobulbar palsy
(5) gait difficulties (gait apraxia, small step gait, frequent falls)
(6) urinary incontinence
Differential diagnosis:
(1) dementia associated with multiple strokes (with large infarcts)
(2) normal pressure hydrocephalus
