Leslie Wolfson

The Relationship of Knee and Ankle Weakness to Falls in Nursing Home Residents: An Isokinetic Study

The strength of the knees and ankles of a group of nursing home residents with a history of falls was compared to age‐matched controls. Peak torque (PT) and power (POW) were recorded at two limb velocities (60°/s and 220°s) on a Cybex II Isokinetic dynamometer for four muscle groups: knee extensors, knee flexors, ankle plantar flexors and ankle dorsiflexors. The PT and POW of falters were significantly decreased for all four muscle groups in comparison to controls, with the ankles showing the greatest decrements. Although POW in fullers was significantly lower at the higher velocity in both joints, the decrease was most prominent in the ankles. Dorsiflexion POW production in falters was the most affected of all the motions (7.5 times less than the control value). At the higher, more functional limb velocities, ankle weakness particularly involving the dorsiflexors appears to be an important factor underlying poor balance.

Clinico‐pathologic studies in dementia: Nondemented subjects with pathologically confirmed Alzheimer's disease

We compared neuropsychological findings in 28 longitudinally evaluated elderly subjects with their postmortem neuropathology, including senile plaque and neurofibrillary tangle counts from standardized sections. Nine of the subjects were not demented when evaluated just prior to their death. Numerous cortical senile plaques and other changes of Alzheimers disease (AD) occurred in six of nine nondemented old-old subjects. Five of these six subjects had shown decline on yearly neuropsychological tests but their cognitive impairment was too mild to meet clinical criteria for dementia. Whereas cortical senile plaque count did not distinguish well between demented and nondemented subjects, every subject with numerous cortical neurofibrillary tangles was demented. The nondemented subjects with Alzheimer pathology may have had “preclinical” AD, or numerous cortical plaques may occur in some elderly subjects who would never develop clinical dementia.

Balance and Strength Training in Older Adults: Intervention Gains and Tai Chi Maintenance

OBJECTIVE: To determine the effect on balance and strength of 3 months of intensive balance and/or weight training followed by 6 months of low intensity Tai Chi training for maintenance of gains.

Stressing the postural response: a quantitative method for testing balance

Using a series of graded destabilizing forces, we have developed a simple quantitative test of the postural response: the Postural Stress Test (PST). Suitable for widespread testing of elderly subjects, the test evaluates the subjects ability to avoid a fall as well as the appropriateness of the response. We have determined that by comparison with young subjects, the elderly controls have compromised although functionally effective balance. On the other hand, the balance response was severely compromised in half of the individuals with a history of falls. Experience with the Postural Stress Test suggests it will predict those elderly individuals with a tendency to fall as well as provide a simple mechanism for studying the balance response in the elderly.

A dynamic posturography study of balance in healthy elderly

Using dynamic posturography, we studied the balance of 234 community-dwelling elderly subjects (mean age, 76 ± 5 years) as well as 34 young controls (mean age, 34 ± 12 years). Almost all measures of balance were worse in elderly subjects compared with young controls. The decrements in older persons indicate a diminished capacity to process conflicting sensory input as well as a possible narrowing of the limit of stability (or, alternatively, an increase in sway). We propose that this occurs most likely as a result of biomechanical or central processing changes as opposed to diminished sensory or vestibular input. Furthermore, with difficult tasks sequentially presented, the performance of the older subjects improved, suggesting that balance, at least in the short term, adapts to stressful conditions. In these elderly subjects screened for age-related diseases affecting balance, only small decrements of balance occurred between the ages of 70 and 85 years. This nominal decrease over a 15-year span suggests that clinically significant balance impairment is the result of age-related disease rather than an inevitable consequence of aging and is therefore potentially treatable.

Effects of Resistive and Balance Exercises on Isokinetic Strength in Older Persons

OBJECTIVE: To determine the safety and efficacy of 3 months of resistive training of multiple lower extremity muscle groups compared with balance training in persons over 75 years.

White matter abnormalities in mobility-impaired older persons

Objective: To investigate the relationship between white matter abnormalities and impairment of gait and balance in older persons. Methods: Quantitative MRI was used to evaluate the brain tissue compartments of 28 older individuals separated into normal and impaired groups on the basis of mobility performance testing using the Short Physical Performance Battery. In addition, individuals were tested on six indices of gait and balance. For imaging data, segmentation of intracranial volume into four tissue classes was performed using template-driven segmentation, in which signal-intensity–based statistical tissue classification is refined using a digital brain atlas as anatomic template. Results: Both decreased white matter volume, which was age-related, and increased white matter signal abnormalities, which were not age-related, were observed in the mobility-impaired group compared with the control subjects. The average volume of white matter signal abnormalities for impaired individuals was nearly double that of control subjects. Conclusions: This cross-sectional study suggests that decreased white matter volume is age-related, whereas increased white matter signal abnormalities are most likely to occur as a result of disease. Both of these changes are independently associated with impaired mobility in older persons and therefore likely to be additive factors of motor disability.

Antemortem diagnosis of diffuse Lewy body disease

Using the presence of widespread cortical Lewy bodies (LB) as the pathologic criteria of diffuse Lewy body disease (DLBD), we describe serial neurologic and mental status examinations in 6 patients with DLBD, 3 patients with Alzheimers disease (AD), and 1 patient with Parkinsons disease (PD). The 6 patients with DLBD included 3 with neocortical neurofibrillary tangles (NFT) consistent with coincident AD. Most patients with DLBD had gait impairment concurrent with mild to moderate dementia. Abnormalities of tone or resting tremor were also prominent early symptoms in the subjects with DLBD, but not AD. Patients with DLBD frequently had abnormal EEGs with background posterior slowing and a frontally dominant burst pattern at the time of mild to moderate dementia. Agitation, hallucinations, and delusions were frequent early symptoms in DLBD patients. Patients with DLBD without concomitant AD had numerous Alz-50 negative cortical plaques. Patients with DLBD have a distinct clinical syndrome that can be differentiated from AD. Pathologic features, including the absence of Alz-50 immunoreactivity, also differentiate DLBD from AD.

Alterations of regional cerebral blood flow and oxygen metabolism in Parkinson's disease.

Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO,) were determined in six normals, six unilateral Parkinsons disease (PD) patients, and eight bilateral PD patients. In the unilateral patients, rCBF and rCMRO2 in the basal ganglia contralateral to the symptomatic limbs was 13% higher than on the other side (p < 0.01); in the frontal cortex it was 8% lower than the other side, suggesting abnormal neuronal function in both regions. The bilateral PD patients had a widespread decrease (20%) in rCBF unaccompanied by comparable changes in rCMRO2, suggesting vasoconstriction due to loss of dopaminergic innervation of blood vessels in more advanced PD patients.

Older people with impaired mobility have specific loci of periventricular abnormality on MRI.

Background: Recent investigations using MRI suggest that older persons with mobility impairment have a greater volume of abnormal cerebral white matter compared with persons with normal mobility, thus raising the possibility that those with impairment have lesions in areas critical for the control of mobility. Objective: To utilize automated image analysis methods to localize the specific regions of abnormal white matter that distinguish subjects with lower mobility from subjects with higher mobility. Methods: Tissue classification was performed on subjects’ dual-echo long repetition time spin-echo MRI using computer algorithms operating on intensity criteria integrated with anatomic information. Statistical analysis of group differences was obtained after spatially normalizing each brain to a standard reference brain. Results: Four discrete periventricular regions, including bilaterally symmetric frontal and bilateral occipitoparietal regions, were identified as being sensitive (frontal) or specific (occipitoparietal) in discriminating the subjects with lower mobility from subjects with higher mobility. The symmetry of these lesions in individual subjects suggested pathology other than arteriolar infarction. Conclusions: These results suggest that damage to discrete frontal and occipitoparietal periventricular white matter locations may be associated with a mobility disorder of aging.