Tomas Nikolai

Czech Version of the Trail Making Test: Normative Data and Clinical Utility

The Trail Making Test (TMT) comprises two psychomotor tasks that measure a wide range of visual-perceptual and executive functions. The purpose of this study was to provide Czech normative data and to examine the relationship between derived TMT indices and demographic variables. The TMT was administered to 421 healthy adults. Two clinical groups (n = 126) were evaluated to investigate the clinical utility of the TMT-derived scores: amnestic mild cognitive impairment (n = 90) and Alzheimers disease (n = 36). Statistical analyses showed that age and education, but not gender, were significantly associated with TMT completion times and derived scores. Of all the indices, only the TMT ratio score was insensitive to age. We present normative values for the Czech version of the TMT, providing a reference for measuring individual performance in native Czech speakers. Moreover, we found that accuracy on the TMT was improved with the attenuation of age.

Montreal cognitive assessment (MoCA): Normative data for old and very old Czech adults

ABSTRACT The principal aim of our study was to present norms for old and very old Czech adults on the Czech version of the Montreal Cognitive Assessment (MoCA) and investigate the influence of social and demographic factors on MoCA performance. We analyzed 540 adults aged ≥ 60 years (5-year age categories; nationally representative sample in terms of sex and educational level), who met strict inclusion criteria for the absence of neurodegenerative disorders and performed within normal range in neuropsychological assessment. Using multiple regression model, we found that MoCA performance was affected by age and education (both p < .001) but not sex. The study provides normed percentile estimates for MoCA performance stratified by age (60–74 years; ≥ 75 years) and education lower versus higher. We also present percentile equivalents for the MoCA and Mini-Mental State Examination (MMSE) for use in clinical practice. We found age- and education-related effects on MoCA performance which support the use of culturally adapted normative data.

Czech version of Rey Auditory Verbal Learning test: Normative data

ABSTRACT The present study provides normative data stratified by age for the Rey Auditory Verbal Learning test Czech version (RAVLT) derived from a sample of 306 cognitively normal subjects (20–85 years). Participants met strict inclusion criteria (absence of any active or past neurological or psychiatric disorder) and performed within normal limits on other neuropsychological measures. Our analyses revealed significant relationships between most RAVLT indices and age and education. Normative data are provided not only for basic RAVLT scores, but for the first time also for a variety of derived (gained/lost access, primacy/recency effect) and error scores. The study confirmed a logarithmic character of the learning slope and is consistent with other studies. It enables the clinician to evaluate more precisely subject’s RAVLT memory performance on a vast number of indices and can be viewed as a concrete example of Quantified Process Approach to neuropsychological assessment.

Olfactory identification in amnestic and non-amnestic mild cognitive impairment and its neuropsychological correlates

BACKGROUND Olfactory identification impairment in amnestic mild cognitive impairment (aMCI) patients is well documented and considered to be caused by underlying Alzheimers disease (AD) pathology, contrasting with less clear evidence in non-amnestic MCI (naMCI). The aim was to (a) compare the degree of olfactory identification dysfunction in aMCI, naMCI, controls and mild AD dementia and (b) assess the relation between olfactory identification and cognitive performance in aMCI compared to naMCI. METHODS 75 patients with aMCI and 32 with naMCI, 26 patients with mild AD and 27 controls underwent the multiple choice olfactory identification Motol Hospital Smell Test with 18 different odors together with a comprehensive neuropsychological examination. RESULTS Controlling for age and gender, patients with aMCI and naMCI did not differ significantly in olfactory identification and both performed significantly worse than controls (p<0.001), albeit also better than patients with mild AD (p<.001). In the aMCI group, higher scores on MMSE, verbal and non-verbal memory and visuospatial tests were significantly related to better olfactory identification ability. Conversely, no cognitive measure was significantly related to olfactory performance in naMCI. CONCLUSION Olfactory identification is similarly impaired in aMCI and naMCI. Olfactory impairment is proportional to cognitive impairment in aMCI but not in naMCI.

Validity of the Montreal Cognitive Assessment in the Detection of Cognitive Dysfunction in Huntington's Disease

The purpose of this study was to assess the convergent and discriminative validity of the Montreal Cognitive Assessment (MoCA) as a screening tool for cognitive dysfunction in Huntingtons disease (HD). Twenty HD patients with cognitive deficit and 23 normal controls (NC) without cognitive deficit were matched for age, sex, and education. The mean MoCA score was 20.5 (SD = 5.5) in HD and 27.5 (SD = 2.2) in NC. The MoCA correlated in both samples with the brief cognitive battery composite score (r = .81, p < .001). With the screening and diagnostic cutoff scores determined at <26 points, the MoCA showed a sensitivity of 94% and a specificity of 84% in the detection of cognitive dysfunction in HD. The area under the receiver-operating characteristics curve (95% confidence interval) for the MoCA was 0.90 (0.809–0.997), p < .001. Our results show that the MoCA is a suitable tool for assessing cognitive dysfunction in patients with HD.

The Prague Stroop Test: Normative standards in older Czech adults and discriminative validity for mild cognitive impairment in Parkinson’s disease

Objective. The aim of this study was to provide normative data for older and very old Czech adults on the Prague Stroop Test (PST) and to test its discriminative validity in individuals with Parkinson’s disease mild cognitive impairment (PD-MCI). Method. The construction of the PST was modeled after the Victoria Stroop Test. We examined 539 participants aged 60–96 that met strict inclusion criteria. After, we compared the PST scores for a group of 45 PD-MCI patients with a healthy adult sample (HAS) of 45 age- and education-matched individuals. Results. I. In the non-clinical sample, robust age- and education-related influences were observed on all PST scores. No gender effect was noted. II. For clinical cases, interference condition (PST–C) was able to discriminate between PD-MCI and HAS (all scores ps < .01). Area under the curve (AUC) was 77% when a screening cut-off of ≤ 27 s was used, showing sensitivity of 82% and specificity of 53%. A more conservative diagnostic cut-off of ≤ 33 s showed sensitivity of 60% and specificity of 80%. Discussion. The present study provides PST normative data for basic, interference, and error scores stratified by age (60–96 years). PST appears to be a helpful tool for the diagnostics of PD-MCI especially in research settings at Level II (Litvan et al., 2012) and for PD-MCI attention/working memory and executive function subtyping.

Grooved Pegboard Predicates More of Cognitive Than Motor Involvement in Parkinson’s Disease

The Grooved Pegboard Test (GPT) was conceived as a test of manual dexterity, upper-limb motor speed, and hand–eye coordination. The aim of our study was to test the componential structure of the GPT on an archetypal model of motor impairment, Parkinson’s disease (PD). A total of 45 PD patients (33 males, 12 females; age M = 67, range = 49-81; PD duration M = 10, range = 6-20 years; H/Y stage 2, range = 2-3) and 20 age- and education-matched controls (14 males, 6 females; age M = 66, range = 48-80) were included. All participants were investigated using the GPT, Short Falls Efficacy Scale–International, Frontal Assessment Battery (FAB), Montreal Cognitive Assessment (MoCA), and Non-Motor Symptom Scale. Patients were followed for 6 months, using fall diaries and monthly phone calls to define PD fallers (falls ≥ 1; n = 27) and PD nonfallers (falls = 0; n = 18). Using structural equation modeling, the GPT predicted performance on the MoCA (p < .001), but not on the FAB (p = .29). In conclusion, analysis of the structure of the GPT provided evidence about important cognitive features, in addition to the motor component of this test in PD.

Eye Movements in Ephedrone-Induced Parkinsonism

Patients with ephedrone parkinsonism (EP) show a complex, rapidly progressive, irreversible, and levodopa non-responsive parkinsonian and dystonic syndrome due to manganese intoxication. Eye movements may help to differentiate parkinsonian syndromes providing insights into which brain networks are affected in the underlying disease, but they have never been systematically studied in EP. Horizontal and vertical eye movements were recorded in 28 EP and compared to 21 Parkinsons disease (PD) patients, and 27 age- and gender-matched healthy subjects using standardized oculomotor tasks with infrared videooculography. EP patients showed slow and hypometric horizontal saccades, an increased occurrence of square wave jerks, long latencies of vertical antisaccades, a high error rate in the horizontal antisaccade task, and made more errors than controls when pro- and antisaccades were mixed. Based on oculomotor performance, a direct differentiation between EP and PD was possible only by the velocity of horizontal saccades. All remaining metrics were similar between both patient groups. EP patients present extensive oculomotor disturbances probably due to manganese-induced damage to the basal ganglia, reflecting their role in oculomotor system.

Neuropsychological correlates of hippocampal atrophy in memory testing in nondemented older adults.

BACKGROUND AND OBJECTIVE Cognitive deficits in older adults attributable to Alzheimers disease (AD) pathology are featured early on by hippocampal impairment. Among tests used to evaluate memory, verbal memory tests with controlled encoding and cued recall are believed to be specific for hippocampal impairment. The objective of this study was to assess the relation between left and right hippocampal volumes and several frequently used memory tests. METHODS Fifty six nondemented older adults (30 with amnestic mild cognitive impairment and 26 cognitively healthy older adults) underwent neuropsychological testing including: (1) The Enhanced Cued Recall test (ECR), a memory test with controlled encoding and recall; (2) the Auditory Verbal Learning Test (AVLT), a verbal memory test without controlled encoding and with delayed recall; and (3) The Rey-Osterrieth Complex Figure test (ROCF), a visuospatial memory test-recall condition. 1.5T brain MRI scans were used to measure estimated total intracranial volume (eTIV) along with hippocampal right and left volumes, which were measured with quantitative volumetry using FreeSurfer package (version 4.4.0). Spearman partial correlation controlled for age was used to correct for non-normal score distribution and effect of age. RESULTS We found moderate correlations of hippocampal volumes with AVLT 1-5 scores, AVLT delayed recall, ECR free and total recall, and ROCF reproduction. Total recall in ECR using cued recall was not superior to any of the free recall tests. No correlation in any memory test was achieved with eTIV. CONCLUSION Verbal memory tests, either with controlled encoding and cued delayed recall (ECR), or without it (AVLT), as well as nonverbal memory test with delayed recall (ROCF), equally reflect hippocampal atrophy in nondemented older adults.

Clinical validity of the Mattis Dementia Rating Scale in differentiating mild cognitive impairment in Parkinson's disease and normative data.

Background/Aims: The aim of the present study was to provide normative data and determine the validity of the Czech version of the Mattis Dementia Rating Scale 2 (czDRS-2) in screening for mild cognitive impairment in Parkinsons disease (PD-MCI) based on the Movement Disorder Society (MDS) Level II criteria. Methods: For validation purposes, 41 healthy controls (HC), 46 patients with PD-NI (Parkinsons disease, no impairment) and 41 patients with PD-MCI (all groups assessed by the MDS Level II criteria for PD-MCI) were matched according to age and education. Results: With screening and diagnostic cutoff scores determined at ≤139 points, the czDRS-2 showed a sensitivity of 78% and a specificity of 88% in the detection of PD-MCI versus HC and a sensitivity of 78% and a specificity of 76% in the detection of PD-MCI versus PD-NI. The AUC (95% confidence interval) for the czDRS-2 was 84% (75-93) and 82% (73-91), respectively. We report percentile values for 286 subjects from the Czech population stratified by education level. Conclusion: Our results show that the czDRS-2 is a valid instrument at Level I for screening PD-MCI and support its construct validity and diagnostic equivalence in a cross-cultural setting.