Incidental white matter lesions identified on magnetic resonance images of normal Japanese individuals--correlation with age and hypertension

Dual-task gait performance among community-dwelling senior women: the role of balance confidence and executive functions

BACKGROUND

Exploring factors that contribute to dual-task gait performance among seniors is of particular interest in falls prevention because dual-task-related gait changes are associated with increased falls risk. It is unclear currently which specific executive processes are most relevant to dual-task gait performance and whether "balance confidence" is independently associated with dual-task gait performance.

METHODS

A cross-sectional analysis of 140 senior women aged 65-75 years old. Balance confidence was assessed by the Activities-Specific Balance Confidence scale. Three key executive processes were assessed by standard neuropsychological tests: (i) set shifting, (ii) working memory, and (iii) response inhibition. Dual-task gait performance was assessed by the simple and complex versions of the walking while talking (WWT) test. Two linear regression models were constructed to determine the independent association of executive functions and balance confidence with: (i) simple WWT completion time and (ii) complex WWT completion time.

RESULTS

Balance confidence was independently associated with both simple and complex WWT completion times after accounting for age, time to walk 40 ft without talking, and global cognition. Set shifting was independently associated with complex WWT completion time; no executive processes were independently associated with simple WWT completion time.

CONCLUSIONS

This study highlights that balance confidence is independently associated with dual-task gait performance. Furthermore, executive functions do not play a significant role in dual-task gait performance when the concurrent cognitive load is low. Clinicians may need to consider balance confidence and executive functions in the assessment and rehabilitation of dual-task gait performance among community-dwelling seniors.

Migraine and white matter hyperintensities

Patients with migraine are at increased risk for white matter hyperintensities detected on magnetic resonance imaging. The presence of nonspecific white matter hyperintensities may cause uncertainty for physicians and anxiety for patients. The pathophysiology and long-term consequences of these lesions are unknown. Occasionally, white matter lesions in a migraineur may indicate an underlying disease such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS), or central nervous system vasculitis. The ability to distinguish between nonspecific and disease-specific patterns of white matter hyperintensities in migraine sufferers is important for the practicing clinician.

Migraine and Cerebral White Matter Lesions

BACKGROUND

Patients with migraine are at an increased risk for white matter lesions, typically multiple, small, punctate hyperintensities in the deep or periventricular white matter, best observed on magnetic resonance imaging utilizing T2-weighted or FLAIR sequences. The underlying pathogenesis of white matter lesions in migraineurs is unknown, and the lesions are usually nonspecific and of unclear clinical significance.

REVIEW SUMMARY

Often the presence of white matter lesions causes uncertainty for physicians and anxiety for patients and may lead to a variety of diagnostic tests and treatments. Occasionally, white matter lesions may represent a secondary cause for headaches such as CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). CADASIL is underrecognized and underdiagnosed; it should be suggested by (i) 1 or more of recurrent subcortical ischemic strokes (especially before age 60 and in the absence of vascular risk factors), migraine (especially with aura, including atypical or prolonged auras) and/or early cognitive decline or subcortical dementia; (ii) bilateral, multifocal, T2/FLAIR hyperintensities in the deep white matter and periventricular white matter with lesions involving the anterior temporal pole, external capsule, basal ganglia, and/or pons; and (iii) an autosomal-dominant family history of migraine, early-onset stroke, or dementia. The clinical spectrum of CADASIL is broad, and there is a poor genotype-phenotype correlation. In certain individuals or families, migraine may be the only clinical manifestation.

CONCLUSIONS

While the prevalence of nonspecific white matter lesions in migraineurs is increased, the white matter lesions may occasionally represent a secondary cause for headache such as CADASIL. Greater awareness of the unique clinical, neuroimaging, and pathologic features, as well as the availability of diagnostic genetic testing, should enhance the recognition and diagnosis of this fascinating condition.

Emergence and progress of white matter lesion in brain check-up

White matter lesion (WML) is thought to emerge and progress with increasing age but has not yet been well investigated. In this study of WML, risk factors and prevalence added to emergence rate (%/person year) and progress speed [increase of leukoencephalopathy score (LES)/person year] were investigated in 1674 brain check-up subjects from August 1993 to August 2001. Significant (P < 0.01) risk factors were aging and hypertension. Prevalence rate (%) was 0 in 20-29 years, 1.4 in 30-39 years, 4.2 in 40-49 years, 20.9 in 50-59 years, 42.6 in 60-69 years, and 73.9 in 70-years. Emergence rate was 0 in 20-29 years, 0.7 in 30-39 years, 1.5 in 40-49 years, 3.4 in 50-59 years, 6.0 in 60-69 years, and 20 in 70-years. And progress speed was 0.12 in 40-49 years, 0.15 in 50-59 years, 0.21 in 60-69 years, and 0.21 in 70-years. WML begins to emerge early in middle age and both prevalence and severity increase with age.

Interactive effects of age and hypertension on volumes of brain structures

BACKGROUND AND PURPOSE

Advanced age and hypertension have each been associated with changes in brain morphology and cognitive function. To investigate the interaction of age and hypertension with structural brain changes and neuropsychological performance in otherwise healthy patients with essential hypertension, we compared young-old (ages 56 to 69 years) and old-old (ages 70 to 84 years) hypertensive patients (n = 27) with 20 age-matched normotensive healthy control subjects, using quantitative volumetric MRI and a battery of neuropsychological tests.

METHODS

Quantitative regions of interest and segmentation analyses were applied to MRI scans of brain to measure volumes of different brain structures and of cerebrospinal fluid (CSF). Severity of white matter hyperintensities (WMHs) was qualitatively rated in the MRI scans. A battery of neuropsychological tests was administered to each subject.

RESULTS

The combined hypertensive group (young-old and old-old) had smaller volumes of thalamic nuclei and larger volumes of CSF in the cerebellum and temporal lobes and showed poorer performance in memory and language tests than did the control subjects. Main effects for age were significant in multiple brain regions of interest. The old-old hypertensive patients and age-matched control subjects demonstrated volume reductions in brain structures and increases in ventricular and peripheral CSF volumes compared with the younger subjects. There was a significant group x age-group interaction in temporal and occipital CSF, not related to WMH, with the old-old hypertensive patients having significantly larger CSF volumes in these regions than the young-old hypertensives and both healthy control groups.

CONCLUSIONS

Hypertension exacerbates the morphological changes accompanying advanced age. Temporal and occipital regions appear most vulnerable to brain atrophy due to the interactive effects of age and hypertension.

White matter hyperintensity in neurologically asymptomatic subjects

Recent advances in magnetic resonance imaging (MRI) technology have had a great impact on the delectability of minute, asymptomatic lesions of the central nervous system. The clinical significance and treatment modes of these lesions, such as white matter hyperintensity (WMH) lesions detected by T2 MRI, remain controversial. To address these problems, we retrospectively evaluated WMH lesions in relation to clinical parameters for 240 neurologically asymptomatic persons who had visited a hospital for a medical check-up of the brain. Proton and T2-weighted MRI were obtained using a 0.5 T superconducting MR imager using the spin echo technique with a repetition time (TR) of 2800 msec. An echo delay times (TE) of 40 msec was used for the proton MRI, and a TE of 100 msec was used for the T2-weighted MRI. The images were visually analyzed according to a four-point grading system. The MRI findings were correlated with clinical parameters including age, gender, presenting symptoms, and hypertension. The overall frequency of WMH increased with age. Grades 2 and 3 of WMH were more frequent in aged persons, whereas the occurrence of grade 1 WMH remained relatively constant across age groups. Based on multiple regression analysis, age was the most significant variable influencing the frequency of WMH, followed by hypertension. These results imply that WMH lesions may simply be a phenomenon of aging, or may be an indicator of prepathologic state in an ischemic brain.