Binswanger disease, a type of vascular dementia, is characterized by atherosclerosis of blood vessels supplying the deep white matter of the brain. Hypertension, being the principal risk factor, is universally present, and a variable degree of cognitive impairment, gait disturbances and other neurological deficits are encountered in patients. A thorough physical examination and magnetic resonance imaging (MRI) of the brain are necessary to make the diagnosis.
Binswanger disease (BD) is a distinct form of vascular dementia in which atherosclerosis and hypertension affecting the smaller blood vessels in the white matter cause a slowly progressive ischemia of the subcortical areas of the brain[1] [2] [3]. Hypertensive vascular disease is, by far, the single most important risk factor for the development of BD, and many individuals report prior episodes of stroke or transient ischemic attacks (TIAs), whereas diabetes mellitus, pre-diabetic states, cigarette smoking, hyperlipidemia and sleep apnea are mentioned in certain reports as well [1] [4]. Progressive reduction of blood flow through these areas explains the gradual course of BD, and the initial symptoms are related to alterations in cognitive status - decline in executive functions, reduction in the speed of processing information and memory dysfunction [1] [2] [5] [6]. Moreover, deficits in attention, behavioral changes and emotional lability are clinical hallmarks of BD and other forms of dementia [3] [5]. In addition, focal neurological deficits are commonly observed, most prominent being those involving the upper motor neurons (UMNs) - muscle rigidity, hyperreflexia (often asymmetric), signs of parkinsonism, ataxia and gait disturbances [1] [2] [3] [6]. Urinary incontinence is reported in many individuals as well [4] [6].
To diagnose BD, a detailed patient history is the first step in the workup. The course and progression of symptoms are noted in the history. If patients give unreliable data regarding their illness, a heterogeneous anamnesis from either family members of close friends can be highly useful in obtaining an objective view about the condition of the patient. History of cardiovascular disease and the presence of additional risk factors and comorbidities is integral in order to make a presumptive diagnosis. The second step is a meticulous physical examination, with an emphasis on cognitive assessment and neurological examination, both equally important procedures when there is a clinical suspicion of any type of dementia. The Montreal Cognitive Assessment (MOCA), preferred over the mini-mental status examination (MMSE) is recommended for evaluation of cognitive function [1] [7]. Once valid clinical criteria for dementia are noted, the diagnosis of BD can be confirmed with imaging studies, especially magnetic resonance imaging (MRI) [1] [2] [3] [5] [7]. One of the most important features of BD on MRI are 5-10 mm lacunar infarcts, principally located in the brain stem and the majority of the white matter with signs of atrophy [1] [4]. Together with lacunar infarcts, hyperintensity of the white matter (known as leukoaraiosis), usually in the periventricular space, is diagnostic for BD [1] [4] [6]. In addition to MRI, computed tomography (CT) can also identify leukoaraiosis, and is preferred over MRI in certain circumstances [1] [4] [6].