Neuroanatomical Correlates of Hypophonia in Subcortical Vascular Cognitive Impairment.

BACKGROUND/AIMS: Early detection and intervention may alter the disease course of subcortical vascular cognitive impairment (SVCI). Patients with SVCI have white matter ischemia that disrupts connections between the cortex and subcortical gray matter and therefore manifest various symptoms such as motor disturbances and behavioral/cognitive dysfunction. Reduced vocal loudness, or hypophonia, is one of the common motor symptoms of SVCI, but few studies have systematically investigated it in this patient population. The main purpose of this investigation was to identify neural pathways underlying hypophonia in patients with SVCI. METHODS: Eighty-eight patients with SVCI and 21 normal controls performed phonation tasks. Diffusion tensor imaging data from 73 patients were utilized to measure white matter changes associated with hypophonia. RESULTS: Correlational analyses between white matter fractional anisotropy values and the decibel level of the "sustained phonation" task identified the left midbrain cerebral peduncle (corticobulbar tract), external capsule, corona radiata/internal capsule, and bilateral frontal white matter as possible neural correlates for hypophonia. CONCLUSION: Our results support the notion that hypophonia in SVCI patients might be caused by the impairment of the pyramidal and extrapyramidal systems. This study provides a unique contribution towards understanding the neuropathology of hypophonic features in this population.

Cardiovascular risk factors cause cortical thinning in cognitively impaired patients: relationships among cardiovascular risk factors, white matter hyperintensities, and cortical atrophy.

Cardiovascular risk factors are associated with cognitive impairments. However, the effects of cardiovascular risk factors on the topography of cortical thinning have not yet been studied in patients with mild cognitive impairment (MCI) or dementia. Thus, we aimed to evaluate the topography of cortical thinning related to cardiovascular risk factors and the relationships among cardiovascular risk factors, white matter hyperintensities (WMH), and cortical atrophy. Participants included 226 patients with Alzheimer disease or subcortical vascular dementia and 135 patients with amnestic MCI or subcortical vascular MCI. We automatically measured the volume of WMH and cortical thickness. Hypertension was associated with cortical thinning in the frontal and perisylvian regions, and cortical thinning related to diabetes mellitus (DM) occurred in the frontal region. In path analyses, hypertension accounted for 0.04 of the frontal thinning with the mediation of WMH and 0.16 without the mediation of WMH. In case of DM, it accounted for 0.02 of the frontal thinning with the mediation of WMH and 0.13 without the mediation of WMH. Hypertension and DM predominantly affected frontal thinning both with and without the mediation of WMH, where the effects without the mediation of WMH were greater than those with the mediation of WMH.

The effect of ischemic cholinergic damage on cognition in patients with subcortical vascular cognitive impairment.

Prior research has shown that the total amount of white matter ischemia had no significant correlation with cognitive deficits. We compared the association of white matter hyperintensities (WMHs) of total as well as cholinergic pathways with clinical dementia severity and investigated whether cholinergic ischemic burden had an independent predictive value with respect to cognitive decline in subcortical vascular cognitive impairment (SVCI). Forty-eight patients underwent detailed neuropsychological tests and brain magnetic resonance imaging. Quantification of WMH in the total white matter and in cholinergic pathways was achieved using the visual Scheltens scale and Cholinergic Pathway HyperIntensity Scale (CHIPS), respectively. We explored the association between WMH scores and clinical dementia rating scale (CDR). To assess the relation between WMH and cognitive scores, multiple linear regression analysis was used. The CHIPS score was higher in subcortical vascular dementia compared to subcortical vascular MCI, while this difference was not found with the total TMHs (TWMH) score. The TWMH score had a positive correlation with CHIPS, however only CHIPS scores positively correlated with sum of box scores of CDR scale (CDR SB; ρ = .474, P = .001). Higher CHIPS scores were associated with lower performance on the semantic word fluency test (ß = -.447, P = .036), whereas the TWMH scores had no independent predictive value with respect to cognitive impairment, after controlling for CHIPS score. Our data confirmed the association of ischemic damage within cholinergic pathways with dementia severity, independent of TWMH in SVCI. In addition, this cholinergic deficit is clinically relevant to cognitive deterioration, especially with frontal dysfunction.

Different associations of periventricular and deep white matter lesions with cognition, neuropsychiatric symptoms, and daily activities in dementia.

We investigated the associations of periventricular white matter hyperintensities (PWMHs) and deep white matter hyperintensities (DWMHs) with cognition, activities of daily living (ADLs), and neuropsychiatric symptoms in dementia. This was a hospital-based MRI300 study. We recruited patients newly diagnosed with mild-to-moderate dementia caused either by Alzheimer's disease or subcortical ischemic vascular dementia from 13 dementia clinics at university or general hospitals in South Korea. We enrolled 289 patients aged over 50 from August 2007 to March 2008. We compared cognition, ADLs, and neuropsychiatric symptoms among 3 groups according to the severities of PWMHs and DWMHs, respectively, by adjusting for age, vascular risk factors, and level of other WMHs. A higher severity of PWMHs was related to lower cognitive function and severer neuropsychiatric symptoms, whereas basic ADLs were associated with DWMH. Both PWMHs and DWMHs exhibited different associations with cognition, neuropsychiatric symptoms, and daily activities.

Effects of medial temporal atrophy and white matter hyperintensities on the cognitive functions in patients with Alzheimer's disease.

AIMS: We conducted this study to investigate the independent association of medial temporal atrophy (MTA) and white matter hyperintensities (WMH) with cognitive impairments of Alzheimer's disease (AD) patients and the interaction between MTA and WMH. METHODS: From 13 centers, a total of 216 AD patients were consecutively recruited and their MTA and WMH were visually rated. We evaluated the association of MTA and WMH with the various cognitive domains, and the interaction between MTA and WMH. RESULTS: MTA independently correlated with scores of the Mini-Mental State Examination (MMSE), Clinical Dementia Rating scale (CDR), delayed recalls of the Seoul Verbal Learning Test (SVLT), the Boston Naming Test (BNT), and Word Fluency. WMH independently correlated with MMSE, CDR, Digit Span, and Stroop word reading, but not with delayed recall. There were interactions of WMH and MTA on CDR (p = 0.004), SVLT (p = 0.023), BNT (p = 0.002) and the semantic Word Fluency (p = 0.007). CONCLUSION: MTA and WMH independently affected cognitive deficits in AD patients, with somewhat different patterns where MTA was associated mostly with memory and language, while WMH were associated with attention and frontal executive functions. This study also showed interactions between MTA and WMH on some cognitive deficits and dementia severity, suggesting that they synergistically contribute to cognitive impairment in AD.

Defining functional SMA and pre-SMA subregions in human MFC using resting state fMRI: functional connectivity-based parcellation method.

Noninvasive parcellation of the human cerebral cortex is an important goal for understanding and examining brain functions. Recently, the patterns of anatomical connections using diffusion tensor imaging (DTI) have been used to parcellate brain regions. Here, we present a noninvasive parcellation approach that uses "functional fingerprints" obtained by correlation measures on resting state functional magnetic resonance imaging (fMRI) data to parcellate brain regions. In other terms, brain regions are parcellated based on the similarity of their connection--as reflected by correlation during resting state--to the whole brain. The proposed method was used to parcellate the medial frontal cortex (MFC) into supplementary motor areas (SMA) and pre-SMA subregions. In agreement with anatomical landmark-based parcellation, we find that functional fingerprint clustering of the MFC results in anterior and posterior clusters. The probabilistic maps from 12 subjects showed that the anterior cluster is mainly located rostral to the vertical commissure anterior (VCA) line, whereas the posterior cluster is mainly located caudal to VCA line, suggesting the homologues of pre-SMA and SMA. The functional connections from the putative pre-SMA cluster were connected to brain regions which are responsible for complex/cognitive motor control, whereas those from the putative SMA cluster were connected to brain regions which are related to the simple motor control. These findings demonstrate the feasibility of the functional connectivity-based parcellation of the human cerebral cortex using resting state fMRI.

Comparison of neuropsychological and FDG-PET findings between early- versus late-onset mild cognitive impairment: A five-year longitudinal study.

AIMS: Our purpose was to investigate differences in neuropsychological characteristics and glucose metabolism between early-onset mild cognitive impairment (EOMCI) and late onset MCI (LOMCI) patients and to determine if the baseline differences are predictive of conversion to dementia. METHODS: We enrolled 28 patients with MCI (12 EOMCI, 16 LOMCI) and 2 age-matched control groups. At the end of a 5-year follow-up, we compared the baseline neuropsychological and PET data between converters and nonconverters. RESULTS: The EOMCI patients obtained significantly higher scores in verbal recall and word fluency tests than the LOMCI patients. The EOMCI group, compared to the young controls, demonstrated hypometabolism in brain regions vulnerable in mild Alzheimer's disease. Converters were significantly more impaired in the delayed verbal recall test than nonconverters (p = 0.028) and tended to be more impaired in the semantic word fluency test (p = 0.084). The baseline PET scan of the converters demonstrated severer hypometabolism in frontal areas than that of the nonconverters both in the EOMCI and LOMCI groups. CONCLUSION: Our study suggests that EOMCI patients may differ from LOMCI in the patterns of cognitive deficits and glucose hypometabolism. In addition, baseline neuropsychological and FDG-PET findings suggest that MCI patients with poor memory or frontal dysfunction are at greater risk of conversion to dementia.

Effects of amyloid and vascular markers on cognitive decline in subcortical vascular dementia.

OBJECTIVE: To determine the independent and synergistic effects of amyloid and small vessel disease (SVD) burden on longitudinal cognitive decline in patients with subcortical vascular dementia (SVaD). METHODS: A longitudinal cohort study was conducted involving patients from outpatient clinics of 2 tertiary referral centers. Sixty-one patients with SVaD were prospectively recruited and underwent MRI, 11C-Pittsburgh compound B (PiB) PET at baseline, and a 3-year annual neuropsychological follow-up. Effects of PiB positivity and SVD markers (white matter hyperintensities [WMH], lacunes, and microbleeds) on longitudinal cognitive decline were evaluated using generalized estimation equation after controlling for age, sex, education, APOE4 allele, and follow-up interval. RESULTS: When individual neuropsychological tests were used as outcome measures, PiB positivity was associated with faster cognitive decline in attention, visuospatial, visual memory, and global cognition function. Higher WMH burden was associated with faster cognitive decline in attention, visuospatial, visual recognition memory, and semantic/phonemic fluency function, whereas lacunes and microbleeds had no significant effects. When global dementia rating (Clinical Dementia Rating sum of boxes) was considered as an outcome measure, however, only PiB positivity was associated with faster cognitive decline. Significant interactions between PiB positivity and higher SVD burden were found to affect cognitive decline in semantic word fluency (from WMH burden) and global dementia rating (from microbleed burden). CONCLUSIONS: In SVaD patients, amyloid burden, independently or interactively with SVD, contributed to longitudinal cognitive decline. Amyloid deposition was the strongest poor prognostic factor.

Effects of cerebrovascular disease and amyloid beta burden on cognition in subjects with subcortical vascular cognitive impairment.

Cerebrovascular disease (CVD) and amyloid burden are the most frequent pathologies in subjects with cognitive impairment. However, the relationship between CVD, amyloid burden, and cognition are largely unknown. We aimed to evaluate whether CVD (lacunes, white matter hyperintensities, and microbleeds) and amyloid burden (Pittsburgh compound B [PiB] retention ratio) contribute to cognitive impairment independently or interactively. We recruited 136 patients with subcortical vascular cognitive impairment who underwent magnetic resonance imaging, PiB-positron emission tomography, and neuropsychological testing. The number of lacunes was associated with memory, frontal dysfunctions, and disease severity. The volume of white matter hyperintensities and the PiB retention ratio were associated only with memory dysfunction. There was no direct correlation between CVD markers and PiB retention ratio except that the number of lacunes was negatively correlated with the PiB retention ratio. In addition, there were no interactive effects of CVD and PiB retention ratio on cognition. Our findings suggest that CVD and amyloid burden contribute independently and not interactively to specific patterns of cognitive dysfunction in patients with subcortical vascular cognitive impairment.

Neuropsychiatric predictors of conversion to dementia both in patients with amnestic mild cognitive impairment and those with subcortical vascular MCI.

OBJECTIVE: The aim of this study was to investigate whether specific neuropsychiatric domains could predict a conversion to dementia in those patients either with amnestic subtype of mild MCI (aMCI) or subcortical vascular MCI (svMCI). METHODS: At baseline, all subjects underwent neuropsychological tests, Neuropsychiatric Inventory (NPI), and MRI. We compared the baseline NPI scores between converters (CV) and non-converters (NCV) both in the aMCI and svMCI groups. RESULTS: The mean follow-up duration was 16.74±8.02 months (range: 4.2-43.9). At the second time point, about 30% of aMCI and svMCI patients converted to dementia with 7.5% of aMCI patients exhibiting improvement to normal cognitive state. In female aMCI patients, those who later improved to normal cognition exhibited higher baseline depression scores than the CV group. However, baseline depression scores were higher in the CV group than the NCV group in svMCI patients, and this difference was significant only in males. CONCLUSION: Our results suggest that depression might serve as a predictive marker of conversion to dementia in patients with svMCI, albeit only in males. On the other hand, patients who later improved to normal cognition showed higher scores of depression at baseline in female aMCI patients, suggesting that longer follow-ups are warranted in female patients with aMCI and depression.

Reversible antecollis associated with pramipexole in a patient with Parkinson's disease.

Antecollis is a frequent complication in multiple system atrophy but is rare in Parkinson's disease (PD). We report an 80-year-old patient with a four-year history of PD who developed antecollis six weeks after taking pramipexole (1 mg/day). When assessed in the outpatient clinic, she had antecollis, cogwheel rigidity on the right side, and mild bradykinesia. We found no evidence of myopathic or neurogenic changes in the neck muscles on needle electromyography. We withdrew the pramipexole immediately, and, one week later, her antecollis improved dramatically. This report emphasizes the importance of considering dopamine agonists as a possible cause of antecollis and shows that immediate withdrawal of these drugs may reverse the symptoms.

Neurobehavioral dysfunction in patients with subcortical vascular mild cognitive impairment and subcortical vascular dementia.

Amnestic mild cognitive impairment (MCI) is considered to be a prodromal stage of Alzheimer's disease. Likewise, subcortical vascular MCI (svMCI) is considered as a prodromal stage of subcortical vascular dementia (SVaD). The objective of this study was to investigate neuropsychiatric features in patients with svMCI compared to healthy controls and patients with SVaD. We evaluated 31 patients with svMCI, 42 with SVaD, and 28 healthy controls who underwent neuropsychiatric assessments using the Neuropsychiatric Inventory (NPI) and the Frontal Behavioral Inventory (FBI). On both the NPI and FBI, SVaD patients had the most severe neuropsychiatric symptoms, followed by svMCI patients and then healthy controls, suggesting that svMCI might be a prodromal stage of SVaD in terms of neuropsychiatric abnormalities. When we compared the differences of mean scores between negative and positive symptoms in FBI, negative symptoms tended to be more predominant than positive symptoms in both svMCI and SVaD patients, but the tendency was stronger in SVaD patients than in svMCI patients. These results suggest that vascular cognitive impairment with small vessel disease would start with both negative and positive neuropsychiatric symptoms and progress to present more severe negative symptoms. These behavioral ratings may be useful for early detection of vascular cognitive impairment associated with small vessel disease.

Measurements of lenticulostriate arteries using 7T MRI: new imaging markers for subcortical vascular dementia.

Recent studies have demonstrated that ultra-high resolution MRA imaging using 7 Tessla (T) MRI can be employed to noninvasively visualize the lenticulostriate arteries (LSA) that supply the basal ganglia and internal capsule. Subcortical vascular dementia (SVaD) is believed to involve these regions from an early stage. We investigated whether LSA abnormalities measured by 7T MRA correlate with MRI ischemia markers and neuropsychological/motor deficits. A total of 24 subjects (12 with SVaD, 12 normal controls (NC)) were imaged with 3T and 7T MRIs. We assessed the severity of white matter hyperintensities (WMH) and the number of lacunes and microbleeds (MB) by visually inspecting images obtained from conventional 3T MRI. We also analyzed three-dimensional models of the measured LSAs obtained from 7T MRI. Compared to the NC, the SVaD subjects had fewer branches of LSAs and greater radii of LSAs. The number of branches was correlated with the number of lacunes. The number of branches was correlated with the delayed recall scores on Rey's Complex Figure Test (RCFT). While not quite reaching statistical significance, the immediate recall, recognition scores on the RCFT, recognition scores on the Seoul Verbal Learning Test, and the word and color readings of Stroop trended in the direction of correlation with the number of branches, as well as with the extrapyramidal scores. Our findings suggest that LSA imaging using 7T MRI might be a potent candidate for the detection of SVaD.

Neurochemical alterations of the entorhinal cortex in amnestic mild cognitive impairment (aMCI): a three-year follow-up study.

The neurochemical alterations in the entorhinal cortex have not yet been measured, even though the entorhinal cortex is the earliest involved brain region in aMCI. In this study, we investigated whether brain regions including the entorhinal cortex would show early involvement of neurochemical abnormalities in aMCI, and whether magnetic resonance spectroscopy (MRS) abnormalities might be a predictive marker of conversion of aMCI to Alzheimer's disease (AD). MRS was performed on 13 aMCI patients and 11 patients with no cognitive impairment (NCI). Localizing voxels were placed within the entorhinal cortex, hippocampus, posterior cingulate gyrus, and occipital white matter in the dominant hemisphere. N-acetyl aspartate/creatinine (NAA/Cr) ratios in the entorhinal cortex were significantly lower in aMCI patients than in NCI subjects. After a three-year follow-up, seven aMCI patients converted to AD and six remained stable. Baseline NAA/Cr ratios of entorhinal cortex were decreased in converters, compared to NCI. Our study suggested the entorhinal cortex is the earliest site that is subject to neurochemical alteration in aMCI patients, and baseline MRS metabolite ratios in the entorhinal cortex can be a marker for predicting conversion of aMCI to AD.

Cortical thinning related to periventricular and deep white matter hyperintensities.

Previous studies showed that white matter hyperintensities (WMH) are related to cognitive decline in patients with mild cognitive impairment (MCI) or dementia. Moreover, periventricular WMH (periventricular white matter hyperintensities (PWMH)) and deep WMH (deep white matter hyperintensities (DWMH)) may have different effects on cognition. The purpose of this study is to investigate the contributions of PWMH and DWMH to the topography of cortical thinning and to investigate the relationship among WMH, cortical thinning, and cognitive impairments. Participants included 226 patients with Alzheimer's disease or subcortical vascular dementia, and 135 patients with amnestic MCI or subcortical vascular MCI. Cortical thickness was measured using the surface based method. The topography of cortical thinning related to WMH was distributed in the frontal and perisylvian regions, which was similar to that of PWMH. In contrast, there were only small areas of cortical thinning inversely associated with DWMH, which were distributed in medial frontal and lingual gyrus. PWMH, but not DWMH, were associated with the frontal thinning and executive dysfunction; where both PWMH and frontal thinning were independently associated with executive dysfunction. Our results suggest that PWMH are associated with frontal thinning, which is further associated with frontal executive dysfunction.

Pure word deafness in a patient with early-onset Alzheimer's disease: an unusual presentation.

BACKGROUND AND PURPOSE: The occurrence of PWD in neurodegenerative disease is very rare, and this is the first report of it being related to early-onset AD. We describe a patient with early-onset Alzheimer's disease (AD) who presented with pure word deafness (PWD). CASE REPORT: The patient had experienced PWD for 2 years, followed by other cognitive deficits suggestive of parietotemporal dysfunction. Brain imaging including (18)FDG-PET and [(11)C] PIB-PET supported the diagnosis of AD. CONCLUSIONS: Our case highlights the clinical variability that characterizes early-onset AD.

Voxel-based analysis of diffusion tensor imaging in patients with subcortical vascular cognitive impairment: correlates with cognitive and motor deficits.

BACKGROUND AND PURPOSE: Patients with small vessel disease show high-signal intensity on T2-weighted magnetic resonance (MR) images that represent ischemic cell damage. However, despite a similar degree of ischemic change, the amount and the severity of clinical presentations may vary. We investigated the clinical correlations of ischemic changes using voxel-based morphometric analyses of diffusion tensor imaging (DTI). METHODS: Twenty-seven MCI and 34 dementia patients were included who all had significant small vessel disease on magnetic resonance imaging (MRI). In all patients, neuropsychological tests, a rating on the Pyramidal and Extrapyramidal scale (PEPS) for motor deficits, and 3-Tesla MRI including DTI scans were performed. Voxel-based analysis of the fractional anisotropy and mean diffusivity maps were computed. RESULTS: Cognitive scores correlated with the DTI abnormalities in supratentorial areas with regional specificity according to each cognitive test. Unexpectedly, cognitive deficits in most neuropsychological tests, even in some frontal tasks, were associated with disruption of posterior white matter integrities. Motor deficits correlated with both supra- and infratentorial lesions. CONCLUSION: Our findings suggest that in patients with small vessel disease who show cognitive and motor impairments, a specific distribution of fiber tract damage is more related with clinical deficits than is the severity of the total ischemia.

Effects of demographic factors on cortical thickness in Alzheimer's disease.

The aim of this study was to investigate the effect of demographic factors (age of onset, sex and years of education) on the distribution of cortical thickness in a large sample of patients with Alzheimer's disease (AD). The study participants consisted of 193 AD patients and 142 controls with no cognitive impairment (NCI) that were measured with cortical thickness across the entire brain. The effects of demographic factors on cortical thickness were analyzed by applying linear regression after controlling confounding factors. Older individuals in NCI group showed more cortical thinning in frontal, temporal association cortices and insula than younger participants. Early onset AD was associated with cortical thinning in the parietal lobe, whereas late onset AD was associated with cortical thinning in the medial temporal region. The NCI group demonstrated sex-related differences in cortical thickness, although those differences were not present in the AD group. While the education effect was absent in NCI individuals, high levels of education in the AD group correlated with cortical thinning in the frontal and temporoparietal association cortices. Our results show that AD with earlier onset and higher education had suffered more pronounced cortical atrophy in specific parts of the brain than their counterparts, which may be related to cognitive reserve theory.

Pyramidal and extrapyramidal scale (PEPS): a new scale for the assessment of motor impairment in vascular cognitive impairment associated with small vessel disease.

OBJECTIVE: Vascular cognitive impairment associated with small vessel disease (sVCI) may manifest as both cognitive and motor dysfunctions. However, few instruments exist for systematically assessing motor symptoms in sVCI, even though many neuropsychological tests exist to evaluate cognitive function. We developed a new scale for assessing motor impairments and evaluated the reliability and validity of the scale in patients with sVCI. METHODS: A new motor scale, called the PEPS (Pyramidal and Extra Pyramidal Scale for sVCI), consisted of 34 items (for 60 total points) with 5 subdomains: corticospinal, corticobulbar, extrapyramidal signs, gait abnormalities, and gait severity. The PEPS was compared between 75 patients with sVCI and 73 control patients who had dementia or mild cognitive impairment (MCI) without ischemia. RESULTS: The PEPS had good interrater and test-retest reliability, and it was moderately to highly correlated with the UPDRS, NIHSS, MMSE, CDR, and ADL scales. An optimal cut-off score of PEPS to discriminate dementia or MCI patients with ischemia from those without ischemia was 6.5 with a sensitivity of 88% and a specificity of 100%. CONCLUSION: The PEPS is a reliable and valid scale that can be used to assess and monitor motor impairment in patients with vascular cognitive impairment due to small vessel disease.

Semantic dementia combined with motor neuron disease.

Up to 20% of patients with behavioural variants of frontotemporal dementia (FTD) also have motor neuron disease (MND); conversely, this comorbidity is rare in patients with language variants of FTD. A few patients have been reported with semantic dementia (SD) combined with MND. However, these patients demonstrated the clinical features of MND in the advanced stage. We report a patient with SD who also demonstrated MND symptoms in an earlier stage of the disease. A 61-year-old man visited our memory disorder clinic as a result of language disturbance and dysarthria of 8 months duration and facial recognition impairment of 3 months duration. Neuropsychological tests revealed anomic aphasia, prosopagnosia, and decreased semantic fluency. A brain MRI revealed significant atrophies localized in both anterior temporal lobes with a greater prominence on the right side. Clinical examination and electrophysiological studies confirmed a diagnosis of MND 17 months after the onset of the disease.