Mild cognitive impairment in Parkinson's disease: Subtypes and motor characteristics

Abstract

The aims of this project were to determine the risk factors for and clinical characteristics of mild cognitive impairment (MCI) in Parkinson’s disease (PD). We performed a retrospective record review of 72 non-demented PD patients (age: 57.79 ± 10.57, duration of PD: 7.32 ± 4.97) who completed a standardized neurological assessment, including a full neuropsychological battery, as part of their diagnostic work-up. Of these participants, 47.2% were cognitively normal and 52.8% met criteria for MCI. The majority of MCI patients had single domain MCI (23/38), the affected domains being memory (n = 9), executive function (n = 6), visuospatial skills (n = 6), and language (n = 2). The MCI group had longer duration of disease and higher postural instability and gait disorder subscale scores than the cognitively normal group. This report provides further support for use of the concept of MCI in PD research. There may be certain disease characteristics that could alert practitioners to the emergence of cognitive changes in patients. Future studies should focus on additional risk factors for MCI subtypes and their possible progression to frank dementia.

Utility and Limitations of Addenbrooke’s Cognitive Examination-Revised for Detecting Mild Cognitive Impairment in Parkinson’s Disease

“…In brief, 63% of the sample met the criteria for PD-MCI, which is a considerably large proportion, though is in accordance with other studies examining PD patients with longer disease durations [14]. Consistent with the literature, a greater proportion of PD-MCI cases were non-amnestic, reflecting the characteristic pattern of cognitive impairment in PD-MCI [2,14,18,19,20]. A slightly greater proportion of PD-MCI cases displayed multiple-domain MCI, which is inconsistent with general findings elsewhere that indicated that single-domain MCI is the most common phenotype in PD [2,14,18,20,21].…”

“…In brief, 63% of the sample met the criteria for PD-MCI, which is a considerably large proportion, though is in accordance with other studies examining PD patients with longer disease durations [14]. Consistent with the literature, a greater proportion of PD-MCI cases were non-amnestic, reflecting the characteristic pattern of cognitive impairment in PD-MCI [2,14,18,19,20].…”

“…It is important to note, however, that the profile of PD-MCI is different to that observed in other neurodegenerative diseases. Indeed, studies in PD suggest that deficits are most commonly observed in non-amnestic functions and may be limited to a single cognitive domain [2,14,18,19,20,21]. This pattern is in accordance with the neuropsychological profile of PD, whereby ‘fronto-subcortical’ deficits, affecting executive functioning and processing speed, may predominate [22,23].…”

“…Therefore, epidemiological findings for PD-MCI vary between investigators due to differences in the diagnostic criteria, the instruments used for assessment, sample size, sampling procedure and study design [12,13]. However, where the MCI diagnostic criteria of Petersen [9] have been applied, approximately half of all PD patients appear to have PD-MCI [14], although prevalence rates have varied widely [2,14,15,16,17,18,19]. It is important to note, however, that the profile of PD-MCI is different to that observed in other neurodegenerative diseases.…”

Cognitive Impairment in Parkinson s Disease

“…Similar observations were documented in a study by Sollinger et al the visuospatial, operational, verbal, and memory impairment appear among non-demented PD patients [32]. Cognitive function impairment not meeting the PD-D criteria may be relevant to 18% to 52% of the patients in the early disease stage [33].…”