Frontal-Subcortical Dementias

Abstract

Frontal-subcortical dementias are a heterogeneous group of disorders that share primary pathology in subcortical structure and a characteristic pattern of neuropsychologic impairment. Their clinical presentation is characterized by memory disorders, an impaired ability to manipulate acquired knowledge, important changes of personality (apathy, inertia, or depression), and slowed thought processes (or bradyphrenia). It also has marked frontal dysfunction. Classic frontal-subcortical dementias include Huntington chorea, Parkinson disease dementia, progressive supranuclear palsy, thalamic degeneration, subcortical vascular dementia, multiple sclerosis, the acquired immunodeficiency syndrome dementia complex, depressive pseudodementia, and some other rare dementias like spinocerebellar degenerative syndromes, Hallervorden-Spatz disease, choreoacanthocytosis, idiopathic basal ganglia calcification, Guamanian parkinsonism-dementia complex, corticobasal degeneration multiple system atrophy, Wilson disease, metachromatic leukodystrophy, adrenoleukodystrophy, hypoparathyroidism, sarcoidosis, and other CNS inflammatory disorders. Anatomic data suggest that the frontal signs result from a disconnection of the frontal cortex from the basal ganglia. However, most frontal-subcortical dementias show cortical atrophy in later stages, and cortical dementias have subcortical pathology at some point. In fact, the concept might be seen as a continuum, and only the 2 extremes would be represented by pure cortical or subcortical pathology. Anyway, subcortical disorders may still be more similar to one another than they are to AD. Possibly, frontal-subcortical and cortical dementias are the description of the prior main target of the disease process, ending up in both cases in a global dementia. Although the dichotomy cortical versus frontal-subcortical dementia is not strict, the 2 concepts still seem to have advantages.

Impaired Ideomotor Limb Apraxia in Cortical and Subcortical Dementia: A Comparison of Alzheimer’s and Huntington’s Disease

“…Arango-Lasprilla et al [44] suggested that the distinction between cortical and subcortical manifestation might not be clinically meaningful because patients with AD and HD appear to have similar neuropsychological profiles, especially in later stages. Bonelli and Cummings [7] suggested the establishment of the concept of frontal-subcortical dementia, as subcortical dementia shows frontal signs due to the close interconnections between basal ganglia and frontal cortex. Furthermore, as most subcortical dementias also develop cortical degeneration during the progression of disease and many cortical dementias show subcortical atrophy at later stages [45] , Bonelli and Cummings argue that cortical and subcortical dementia should be regarded as a continuum between 2 extremes.…”

“…In addition, there are close interconnections between subcortical structures and the frontal lobes; for instance, it is well known that the basal ganglia communicates with the cortex via a series of corticostriatal loops [6] . So, it is possible that patients with subcortical dementia and patients with lesions confined to the frontal lobe may experience similar symptoms [7] .…”

"Frontal" Behaviors Before the Diagnosis of Huntington's Disease and Their Relationship to Markers of Disease Progression: Evidence of Early Lack of Awareness

“…Although some of these symptoms have been attributed to subcortical dysfunction (e.g., striatum) and the connecting circuitry with the frontal lobes (2,3), most studies have examined the relationships with cognitive and motor symptoms. For example, executive dysfunction on cognitive tasks (i.e., set shifting, response inhibition) has been linked with the dorsolateralsubcortical circuit (4) and dorsolateral prefrontal cortex deficits (5).…”

Alteraciones neuropsicológicas asociadas en pacientes con infarto lacunar.

“…Con respecto a la alteración de la función ejecutiva, se explica probablemente por la interrupción de circuitos frontocortico-subcorticales que participan activamente en el correcto funcionamiento de este proceso cognoscitivo, ya que al ocurrir una lesión en dichos circuitos puede presentarse un bajo desempeño de este dominio (Bonelli & Cummings, 2008;Cummings, 1993), el cual ha sido también descrito por otros autores como causa de un síndrome disejecutivo (Junqué & Mercé, 1990;Mungas, 2005) o sindrome frontalsubcortical (Young, 2011).…”

“…Además de estos síndromes neurológicos, y dependiendo de su localización, los infartos lacunares pueden ocasionar un deterioro cognoscitivo y de la conducta (Bonelli & Cummings, 2008). Este deterioro cognoscitivo relacionado con el infarto pertenece a la amplia gama de patología vascular que cubre el concepto propuesto por Hachinski & Bowler (1993) llamado Deterioro Cognoscitivo Vascular (DCV).…”