Abstract
Cognitive impairment is present in neurodegenerative disease, usually as part of a spectrum of symptoms that includes different domains of cognitive function. While the nature of the cognitive impairment tends to be diseasespecific, the aspects of cognitive impairment seen in different disease entities overlap considerably. This overlap makes distinctions among them difficult and, when considered with accumulating insights from molecular genetic and neuropathological analyses, increasingly suggests that different neurodegenerative diseases share not only aspects of their symptomatology but also their pathogenesis. This realization has prompted a reconsideration of the classification of these diseases. Reexamination of the clinical phenotypes of different neurodegenerative diseases has revealed that cognitive impairment is more commonly present than previously thought. Thus, the comparison of the patterns of cognitive impairment in different neurodegenerative diseases, when combined with molecular genetic, neuropathological, and imaging analyses, has considerable heuristic value.
This review focuses on cognitive impairment in Alzheimers disease (AD), Parkinsons disease (PD), and amyotrophic lateral sclerosis (ALS), which can be considered “pure neurodegenerative diseases”, and in multiple sclerosis (MS), whose pathogenesis includes both neurodegenerative and autoimmune processes. Rather than presenting an exhaustive description of studies addressing cognitive impairment in these diseases, it attempts to highlight the emerging patterns of cognitive impairment associated with the temporal and spatial context of their neurodegenerative processes.
Keywords: Cognitive impairment, neuropathology, imaging, neurodegenerative disease, molecular genetic analysis, cognitive domains, attention, language, memory, perception, function, testing methods, focal motor, sensory deficits, hemiparesis, hemineglat, hemianopoia, Mini Mental Status Examination (MMSE), Paced Auditory Serial Addition Test, Wechsler Memory Scale, California Verbal Learning test, Rey Auditory Verbal Test, agnosias, auditory, Space Perception Battery, Montreal Cognitive Assessment, ALZHEIMER'S DISEASE, dementia, Alzheimer's Disease Centers' Uniform Data Set, amyloid plaques, neurofibrillary tangles, pathology, myotonic dystrophy, entorrhinal cortex, synaptic loss, grey matter loss, sporadic, Brain atrophy, in vivo, transitional state, ubiquitin-immunoreactive changes, qualitative, quantitative, meta-analysis, orientation, visuomotor function, AMYOTROPHIC LATERAL SCLEROSIS, motor system disorder, depression, psychomotor, cortical atrophy, genetic loci, chromosome, mutations, progranulin gene, DNA-binding protein, cerebellum, PARKINSON'S DISEASE, idiopathic, nosological entities, late-developing dementia, axial impairment, postural and gait disorder, subcortical profile, hypometabolism, forebrain nuclei, limbic, tyrosine hydroxylase, phenotype, MULTIPLE SCLEROSIS, relapsing-remitting, cognitive dysfunction, disease parameters, episodic, perfusion, magnetization transfer, diffusion-weighted imaging, pathogenesis, systemic lupus erythematosus
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