Corticospinal tract involvement in spinocerebellar ataxia type 3: a diffusion tensor imaging study.

PURPOSE: The aim of this study was to evaluate the integrity of the corticospinal tracts (CST) in patients with SCA3 and age- and gender-matched healthy control subjects using diffusion tensor imaging (DTI). We also looked at the clinical correlates of such diffusivity abnormalities. METHODS: We assessed 2 cohorts from different Brazilian centers: cohort 1 (n = 29) scanned in a 1.5 T magnet and cohort 2 (n = 91) scanned in a 3.0 T magnet. We used Pearson's coefficients to assess the correlation of CST DTI parameters and ataxia severity (expressed by SARA scores). RESULTS: Two different results were obtained. Cohort 1 showed no significant between-group differences in DTI parameters. Cohort 2 showed significant between-group differences in the FA values in the bilateral precentral gyri (p < 0.001), bilateral superior corona radiata (p < 0.001), bilateral posterior limb of the internal capsule (p < 0.001), bilateral cerebral peduncle (p < 0.001), and bilateral basis pontis (p < 0.001). There was moderate correlation between CST diffusivity parameters and SARA scores in cohort 2 (Pearson correlation coefficient: 0.40-0.59). CONCLUSION: DTI particularly at 3 T is able to uncover and quantify CST damage in SCA3. Moreover, CST microstructural damage may contribute with ataxia severity in the disease.

Effects of APOE haplotypes and measures of cardiovascular risk over gender-dependent cognitive and functional changes in one year in Alzheimer's disease.

BACKGROUND: Illiteracy, high cerebrovascular risk and copies of APOE-ϵ4 are risk factors for Alzheimer's disease dementia (AD). We aimed to investigate the impacts of gender, education, coronary heart disease (CHD) risk and creatinine clearance variations, body mass index (BMI) and APOE haplotypes over the rates of cognitive and functional decline of AD in one year. METHODS: Consecutive outpatients with late-onset AD were assessed for gender, schooling, BMI and APOE haplotypes, variations in one year of creatinine clearance and Framingham projections of the 10-year absolute CHD risk, and prospective scores of the Mini-Mental State Examination (MMSE), the Clinical Dementia Rating Sum-of-Boxes (CDR-SOB), the Index of Independence in Activities of Daily Living (ADL) and Lawton's Scale for Instrumental Activities of Daily Living (IADL). RESULTS: For 191 patients, mean age at AD onset was 73.26 ± 6.4 years-old, earlier for APOE-ϵ4/ϵ4 carriers (p = 0.0039). For women, higher BMI led to improvements in CDR-SOB (ß = -0.091; p = 0.037) and MMSE (ß = 0.126; p = 0.017) scores, while increased creatinine clearance was associated with improvements in ADL (ß = 0.028; p = 0.012) and MMSE (ß = 0.043; p = 0.039) scores and higher schooling led to faster worsening of IADL (ß = -0.195; p = 0.022) scores. No variables impacted cognitive or functional decline for men, whereas copies of APOE-ϵ4 and the CHD risk had no significant effects whatsoever. CONCLUSIONS: Higher BMI and creatinine clearance are protective regarding cognitive and functional decline for women, whereas higher cognitive reserve may lead to faster decline in instrumental functionality. APOE haplotypes affected the age at AD onset, but not cognitive or functional decline.

Balance impairment does not necessarily coexist with gait apraxia in mild and moderate Alzheimer's disease.

OBJECTIVES: To assess correlations among gait apraxia, balance impairment and cognitive performance in mild (AD1, n = 30) and moderate (AD2, n = 30) AD. METHOD: The following evaluations were undertaken: gait apraxia (Assessment Walking Skills); balance performance (Berg Balance Scale); Clinical Dementia Rating and Mini-mental State Examination (MMSE). RESULTS: While disregarding AD subgroups, Berg Balance Scale and the MMSE correlated significantly with Assessment Walking Skills and 23% of all subjects scored below its cut-off. After stratification, Berg Balance Scale correlated significantly with Assessment Walking Skills in both AD subgroups, and with the MMSE only in AD1. CONCLUSIONS: Balance impairment does not necessarily coexist with gait apraxia. Gait apraxia is more prevalent in moderate AD when compared with mild AD.

Balance impairment does not necessarily coexist with gait apraxia in mild and moderate Alzheimer's disease / Comprometimento do equilíbrio e apraxia da marcha não necessariamente coexistem na doença de Alzheimer leve e moderada

ABSTRACT Currently, there are no studies reporting how much balance impairment coexists with gait apraxia in mild and moderate Alzheimer’s disease (AD). Objectives To assess correlations among gait apraxia, balance impairment and cognitive performance in mild (AD1, n = 30) and moderate (AD2, n = 30) AD. Method The following evaluations were undertaken: gait apraxia (Assessment Walking Skills); balance performance (Berg Balance Scale); Clinical Dementia Rating and Mini-mental State Examination (MMSE). Results While disregarding AD subgroups, Berg Balance Scale and the MMSE correlated significantly with Assessment Walking Skills and 23% of all subjects scored below its cut-off. After stratification, Berg Balance Scale correlated significantly with Assessment Walking Skills in both AD subgroups, and with the MMSE only in AD1. Conclusions Balance impairment does not necessarily coexist with gait apraxia. Gait apraxia is more prevalent in moderate AD when compared with mild AD.

RESUMO Apraxia da marcha e desequilíbrio são condições subinvestigadas na doença de Alzheimer (DA) leve e moderada. Objetivo Verificar a correlação da apraxia da marcha com desequilíbrio e cognição em 30 idosos com DA leve (DA1) e 30 idosos com DA moderada (DA2). Método Foram feitas as seguintes avaliações: apraxia da marcha (Assessment Walking Skills); equilíbrio (Berg Balance Scale); Clinical Dementia Rating e Mini-exame do estado mental – MEEM. Resultados Desconsiderando-se os grupos, Berg Balance Scale e MEEM correlacionaram-se significativamente com a Assessment Walking Skills, enquanto 23% dos participantes pontuaram abaixo da note de corte da mesma. Considerando-se os grupos, Berg Balance Scale correlacionou-se significativamente com a Assessment Walking Skills em ambos os grupos, embora o MEEM o tenha feito apenas em DA1. Conclusões Desequilíbrio e apraxia da marcha não necessariamente coexistem com apraxia da marcha. Prevalência de apraxia da marcha foi maior na DA moderada do que na DA leve.

A new quantitative method for evaluating freezing of gait and dual-attention task deficits in Parkinson's disease.

People with Parkinson's disease (PD) can exhibit disabling gait symptoms such as freezing of gait especially when distracted by a secondary task. Quantitative measurement method of this type of cognitive-motor abnormality, however, remains poorly developed. Here we examined whether stepping-in-place (SIP) with a concurrent mental task (e.g., subtraction) can be used as a simple method for evaluating cognitive-motor deficits in PD. We used a 4th generation iPod Touch sensor system to capture hip flexion data and obtain step height (SH) measurements (z axis). The accuracy of the method was compared to and validated by kinematic video analysis software. We found a general trend of reduced SH for PD subjects relative to controls under all conditions. However, the SH of PD freezers was significantly worse than PD non-freezers and controls during concurrent serial 7 subtraction and SIP tasking. During serial 7 subtraction, SH was significantly associated with whether or not a PD patient was a self-reported freezer even when controlling for disease severity. Given that this SIP-based dual-task paradigm is not limited by space requirements and can be quantified using a mobile tracking device that delivers specifically designed auditory task instructions, the method reported here may be used to standardize clinical assessment of cognitive-motor deficits under a variety of dual-task conditions in PD.

The single-leg-stance test in Parkinson's disease.

BACKGROUND: Timed single-leg-stance test (SLST) is widely used to assess postural control in the elderly. In Parkinson's disease (PD), it has been shown that an SLST around 10 seconds or below may be a sensitive indicator of future falls. However, despite its role in fall risk, whether SLST times around 10 seconds marks a clinically important stage of disease progression has largely remained unexplored. METHODS: A cross-sectional study where 27 people with PD were recruited and instructed to undertake timed SLST for both legs was conducted. Disease motor impairment was assessed with the Unified Parkinson's Disease Rating Scale Part 3 (UPDRS-III). RESULTS: This study found that: 1) the SLST in people with PD shows good test-retest reliability; 2) SLST values can be attributed to two non-overlapping clusters: a low (10.4 ± 6.3 seconds) and a high (47.6 ± 11.7 seconds) value SLST group; 3) only the low value SLST group can be considered abnormal when age-matched normative SLST data are taken into account for comparison; and 4) lower UPDRS-III motor performance, and the bradykinesia sub-score in particular, are only associated with the low SLST group. CONCLUSION: These results lend further support that a low SLST time around 10 seconds marks a clinically important stage of disease progression with significant worsening of postural stability in PD.

Use of the Gait Deviation Index and spatiotemporal variables for the assessment of dual task interference paradigm.

Three-dimensional gait analysis (3DGA) is an important element in the quantitative evaluation of gait in subjects with Parkinson's disease (PD). Indexes, such as the Gait Deviation Index (GDI), have recently been proposed as a summary measure of gait. The aim of the present study was to investigate the effectiveness of the GDI and spatiotemporal variables in the quantification of changes in gait during a dual-task (DT) exercise. Fourteen patients with idiopathic PD and nine healthy subjects (CG) participated in the study. All subjects walked under two conditions: free walking and DT walking. The GDI was computed from the 3DGA data. The results show gait impairment during DT, a significant difference between groups regarding GDI and an interaction effect involving the group, side and task factors. The CG and PDG were different independent of interference and side, but interference was only different for the PDG group. The results also demonstrate that the GDI should be an appropriate outcome measure for the evaluation of the effects of DT on patients with Parkinson's disease.