COWAT Performance of Persons with Alzheimer Dementia, Vascular Dementia, and Parkinson Disease Dementia According to Stage of Cognitive Impairment

Abstract

Background The Controlled Oral Word Association Test (COWAT) evaluates frontal lobe and executive function. Therefore, it can be helpful in differentiating cognitive deficits. However, there are no studies comparing the COWAT performance according to the type and stage of cognitive impairment. Objective To compare performance among persons with Alzheimer dementia (AD), vascular dementia (VaD), and Parkinson disease dementia (PDD) on the COWAT according to stage of cognitive impairment. Design Retrospective chart review. Settings University hospital rehabilitation psychology center. Patients We reviewed the medical records of 246 persons diagnosed with mild cognitive impairment (MCI) or dementia using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM‐5) and the Korean‐Instrumental Activities of Daily Living (K‐IADL). Patients were divided into a control group, Alzheimer groups (amnestic mild cognitive impairment [aMCI] + AD), Vascular groups (vascular mild cognitive impairment [VaMCI] + VaD), and Parkinson groups (Parkinson disease‐mild cognitive impairment [PD‐MCI] + PDD). Methods Total scores (ie, total number of words produced in 60 seconds on the semantic and phonemic fluency tests of the COWAT) were analyzed. Secondary analysis included calculating percentage scores of words produced during each of the four, 15‐second segments from the total number of words produced in each trial. Results All MCI groups scored significantly lower than the control group on both semantic and phonemic fluency tests. Among the dementia groups, the VaD (mean ± SD, 5.6 ± 5.1) and PDD (5.5 ± 5.5) groups' scores were significantly lower and worse than that of the AD (11.0 ± 8.8) group on the phonemic test (P < .001). The difference in percentage scores was most marked between the PD‐MCI (17.0 ± 2.2) and PDD (1.2 ± 3.1) groups, followed by the VaMCI (13.3 ± 1.9) and VaD (5.6 ± 1.8) groups on the latter phonemic test (P = .007). Conclusions The COWAT is a sensitive test of frontal‐lobe and executive function impairment in persons with MCI. Decreased verbal output in the last 15 seconds of phonemic fluency test is significantly decreased and impaired in persons with VaMCI and PD‐MCI compared to persons with aMCI as they progress to dementia. Level of Evidence III.

Lexical-semantic Properties in Parkinson's Disease with and without Dementia

“…The present findings showed that although patients with dementia performed worse than those without dementia on all neuropsychological tests, significant differences were found only on the semantic fluency test and Frontal assessment battery. These findings are in line with previous studies that found demented PD patients had impaired performance on the semantic fluency test (5,34) and in executive function as assessed by the Frontal assessment battery [22,23]. The current results suggest that demented PD patients may have more impairment in semantic fluency than in phonemic fluency, which implies that those patients could have specific difficulties with the retrieval of semantic information.…”

“…Other researchers found that left frontal lesions resulted in lower word production than right frontal ones. Similarly, regional cerebral blood flow findings have shown left-sided frontal activation during the performance of verbal fluency tasks [5]. Thirteen of the 159 patients scored below 24 on the MMSE, 30 patients scored below 16 on the recognition memory task and 14 patients who scored normally on the MMSE and recognition memory tasks performed poorly on the tower of London test, indicating that 57 out of the 159 patients studied (36%) had cognitive impairments.…”

Sequencing and Detection of Two Missense Variants at Chromosome 7 as Potential Azole Resistance Markers in Saccharomyces Cerevisiae

“…Semantic fluency was found to be more impaired in AD compared to VaD [45][46]. Some researchers [47][48] also found that individuals with VaD performed worse on phonemic fluency measures compared to those with AD, and HCs performed significantly better than the dementia groups. However, others found no significant differences in semantic [25,36,[48][49] and phonemic fluency [25,[45][46] between individuals with AD and those with VaD.…”

“…al [52] found that semantic fluency was less impaired in AD compared to PDD. However, most researchers found that semantic fluency is similarly impaired in AD compared to PDD [48,[53][54] and DLB [22,26,55]. Phonemic fluency was found to be less impaired in AD relative to PDD [48] and DLB [26] as measured using the COWAT.…”

“…Some researchers [47][48] also found that individuals with VaD performed worse on phonemic fluency measures compared to those with AD, and HCs performed significantly better than the dementia groups. However, others found no significant differences in semantic [25,36,[48][49] and phonemic fluency [25,[45][46] between individuals with AD and those with VaD. On the BNT, a test of naming, many researchers found that individuals with AD performed worse than those with VaD [34,46,[49][50].…”