A prospective study of cerebral white matter abnormalities in older people with gait dysfunction

OBJECTIVES: The authors previously reported cross-sectional data suggesting a relationship between cerebral white matter hyperintensities (WMH) and gait and balance dysfunction in older people. There have been no longitudinal MRI studies to address this issue. The current study compared progression of WMH in subjects with gait and balance dysfunction with that in healthy subjects. METHODS: Two brain MRI were performed on 70 healthy, ambulatory subjects (mean baseline age 79, range 74 to 88) with no identifiable neurologic disease. The mean time between MRI was 4 years. Gait and balance were quantified using the Tinetti Balance and Mobility Scale, and falls were documented each year. On T2-weighted MRI, total hyperintense volume (HV) within three periventricular levels was estimated using the Cavalieri principle, and WMH were graded (0 to 4) using an established semiquantitative scale. RESULTS: Compared with those with normal gait and balance, subjects whose Tinetti scores dropped markedly (> 4 points) between first and second MRI showed a significantly greater mean increase in HV during follow-up. The larger group of subjects with an abnormal Tinetti score (< 24) at the time of second MRI showed a significantly greater mean increase in HV, compared with those with normal gait and balance at follow-up. Subjects with marked WMH at baseline showed significantly greater increase in HV over time. Subjects with abnormal Tinetti scores had significantly more falls than subjects with normal Tinetti scores. CONCLUSIONS: Some older people develop gait and balance dysfunction that is associated with gradual onset of cerebral white matter disease.     

High incidence of falls in patients with myotonic dystrophy type 1 and 2: A prospective study

We aimed to examine the incidence as well as the circumstances and the consequences of falling in adult patients with myotonic dystrophy type 1 and 2 (DM1/DM2). We performed a prospective cohort study in 209 subjects, of which 102 had DM1, 42 had DM2 and 65 healthy controls. An assessment of their falls was carried out during 100 consecutive days. In addition, falls during the previous year were reported. The primary outcome measure was the number of self-reported falls per participant during these 100 days. The secondary outcome measures included self-reported causes, circumstances and consequences of the falls. Mean (SD) falls per participant in 100 days was seven- to eightfold higher in patients with DM1 (0.74 (0.14)) and DM2 (0.62 (0.20)) compared to the controls (0.09 (0.04); p < 0.001)). Sixteen percent of DM1 and 17% of DM2 patients fell at least twice. Two-thirds of the falls occurred inside. Fifty percent of falls resulted in an injury, including a head trauma in four patients. Compared to non-fallers, those patients who fell were older (DM1/DM2), had a lower DM1-Activ score (DM1), had more muscle weakness (DM1), and reported less confidence in balance (DM1). This study demonstrates a high incidence and clinical relevance of falling in patients with DM1 and DM2. Fall prevention strategies in both DM1 and DM2 should focus on adaptations of the home environment and the patient's interaction in this environment.     

Quantified measurement of activity provides insight into motor function and recovery in neurological disease

BACKGROUND: A direct quantitative measurement of locomotor activity in an individual's own environment over an extended period may help in evaluating the impact of impairments in neurological disorders. OBJECTIVE: To investigate the reliability and validity of activity monitoring in neurological patients and healthy subjects. METHODS: Initial reliability studies were completed on 10 healthy subjects and 10 mobility restricted neurological patients. Validity was investigated using 7 days of ambulatory monitoring with the Step Watch( step activity monitor, laboratory based measures of gait and the Rivermead Mobility Index (RMI) in 10 patients with multiple sclerosis, 10 with Parkinson's disease, and 10 with a primary muscle disorder. Additionally, 30 healthy subjects participated in the study. Two clinical illustrations of ambulatory monitoring are provided. RESULTS: The mean (range) right step count of 7 days of monitoring in both healthy and neurological patients proved a reliable measure of activity (intra-class correlations 0.89 and 0.86 respectively). The 7 day mean (range) right step count was 5951 (2886-9955) in healthy subjects, 3818 (1611-5391) in patients with Parkinson's disease, 3003 (716-5302) in those with muscular disorders, and 2985 (689-5340) in those with multiple sclerosis. A moderate correlation was noted between 7 day mean step count and gait speed (r = 0.45, p = 0.01) in the grouped neurological patients but not the RMI (r(s) = 0.3, p = 0.11). CONCLUSION: Ambulatory monitoring provides a reliable and valid measure of activity levels. Neurological patients, living independently, demonstrate lower activity levels than healthy matched controls. Ambulatory monitoring as an outcome measure has potential for improving the evaluation of ambulation and providing insight into participation.     

Characterizing cognitive-motor impairments in patients with myotonic dystrophy type 1

Myotonic Dystrophy Type 1 (DM1) is the most frequent hereditary, adult-onset muscular dystrophy. Nevertheless, DM1-associated cognitive-motor impairments have not been fully characterized so far. This study aimed at profiling cognitive and locomotor dysfunctions in these patients. In addition, cognitive-motor interactions were assessed using a dual-task paradigm. Comprehensive cognitive-motor impairment profiles were generated for 19 patients with DM1 and 19 healthy subjects by thorough clinical, biomechanical and neuropsychological examinations. Detailed gait analysis was performed using a 3D motion capture system, whereas cognitive function was assessed using a standardized neuropsychological test battery. Patients with DM1 showed impaired functional mobility, gait velocity and endurance. DM1-related gait pathology was mainly characterized by enhanced dynamic instability, gait variability, and restricted ankle dorsiflexion. Patients’ cognitive impairments particularly concerned attentional functions. Dual-task conditions induced gait deviations that slightly differed between patients and controls. DM1-associated cognitive impairments correlated with reduced functional mobility and impaired ankle dorsiflexion. Patients with DM1 revealed significant impairments of walking function, balance and cognitive performance. Differential cognitive-motor interference and significant interactions between cognitive and motor dysfunctions point towards a prominent role of cognition in gait performance of patients with DM1.     

Hypogonadism in DM1 and its relationship to erectile dysfunction

Myotonic dystrophy type 1 (DM1) is characterized by both a premature appearance of age-related phenotypes and multiple organ involvement, which affects skeletal and smooth muscle as well as the eye, heart, central nervous system, and endocrine system. Although erectile dysfunction (ED) is a frequent complaint in patients with DM1, it has not been investigated in great depth. Hypogonadism, which is reported to be one of the physical causes of ED in the general population, frequently occurs in DM1. We planned this case-control study to evaluate the relationship between hypogonadism, as defined by the sexual hormone profile (FSH, LH, testosterone (T) and prolactin) and ED, as assessed by means of an internationally validated self-administered questionnaire (IIEF). DM1 patients had significantly increased mean levels of both gonadotropins (FSH and LH) (p < 0.0001) and a reduced mean level of T (p < 0.0001) when compared to controls. Twelve patients were eugonadic (normal LH, T, and FSH), while 18 displayed hormonal evidence of hypogonadism, characterized by tubular failure (increased FSH) in all the subjects and associated with interstitial failure in 14 subjects: seven with primary hypogonadism (increased LH and reduced T) and seven with compensated hypogonadism (increased LH and normal T). Patients with hormonal evidence of interstitial failure had a larger CTG expansion (p = 0.008), longer disease duration (p = 0.013), higher grade of disease (p = 0.004) and lower erectile function score (p = 0.02) than eugonadic patients. Impotence occurred in 13/14 hypogonadic patients with interstitial failure and in 5/12 eugonadic patients (p = 0.017, OR = 18.2).     

Factors of importance for dynamic balance impairment and frequency of falls in individuals with myotonic dystrophy type 1 – A cross-sectional study – Including reference values of Timed Up & Go, 10 m walk and step test

Patients with myotonic dystrophy type 1 suffer from gait difficulties including stumbles and falls. To identify factors of importance for balance impairment and fall-risk a mapping of functional balance was performed, in a cross-sectional study of 51 adults. Walking, balance, falls and muscle force were self-assessed and measured. Reference values of balance were established through measurements of 220 healthy subjects. Falls were more frequently observed in the patients who were more severely affected of muscle weakness than in mildly affected patients, p = 0.014. The number of falls showed negative correlation with balance confidence (r_s = −0.516, p < 0.001). The ankle dorsiflexor force together with the time difference between comfortable and maximum speed in 10 m-walk proved to be significant factors for fall frequency. A ten Newton muscle force decrease showed 15% increase in odds ratio for frequent falls. One-second increase in time difference between comfortable and maximum walking speed showed 42% increase in odds ratio for frequent falls. In conclusion, assessing the ankle muscle force and the time difference in different walking speeds is important to detect risk of falling. The activities-specific balance confidence score reflects the consequences of the muscle force decrease. Certain patient strategies to diminish risk of falling could be due.     

Parkinson's disease as a model of aging: prospective analysis of gait discorders

Falls are a dramatic consequence of the age-related gait disorders. There are few prospective studies on falls predictive of the biomechanical features of gait. According to the literature, there are similarities between the gait observed in older people and in parkinsonian subjects. The objective of this study was to apply multiparametric gait analysis to demonstrate changes of the neuromotor gait pattern connected with falls. This prospective study included two groups of 16 subjects aged more than 60 years, who had not fallen during the previous year. One group included 16 minimally disabled parkinsonian patients off drugs, and the other group 16 healthy people. Gait recordings were obtained with a three-dimensional optoelectronic movement analysis system coupled with 2 force platforms in all persons who were followed for 1 year to collect data on all new events, particularly falls. Data analysis concerned spatiotemporal stride and three-dimensional power peaks developed in each lower limb joint. Cluster analysis of the 32 persons was used to determine various infraclinic neuromotor gait patterns. A post hoc analysis of variance was then applied to identify discriminating parameters. Three groups of subjects were identified with 3 different neuromotor gait patterns, independently of the presence of Parkinson disease. There were no fallers in first group (n=18). The second group (n=8) had 20 p.cent fallers and the third group (n=4) 100 p.cent fallers. The groups differed by 4 spatiotemporal parameters and 3 joint power peaks in the sagittal plane. Functional capacity was good in the first group with no falls recorded. This group of subjects had characteristics reported in the literature corresponding to a category of persons who compensate well for the phenomena of aging. Functional capacity was intermediary in the second group (20 p. cent were fallers). The kinematic pattern appeared to be less successful, revealing a tendency for stiff posture. The third group (100 p. cent fallers) exhibited inferior functional capacity. In this group, the kinematic pattern appeared to be disrupted. The subjects were unable to adapt satisfactorily to situations other than by stereotypical neuromotor reactions. In conclusion this study demonstrated a close determinism between physiological neuromotor aging and Parkinson's disease. The prospective follow-up demonstrated that falls that occurred were related to changes in neuromotor gait patterns. Three phases of gait pattern were also identified from minimal to major risk of falls.     

Steady or not following thalamic deep brain stimulation for essential tremor

Deep brain stimulation (DBS) has become an important option for medication-refractory essential tremor (ET), but may contribute to worsened gait and falling. This study evaluates impaired gait in a cohort of patients treated with DBS with a retrospective review of ET patients before and after DBS implantation. Factors examined included: age, duration of symptoms, pre-morbid gait difficulties/falls, Fahn-Tolosa-Marin tremorrating scale (TRS) scores at baseline, 6 months post-unilateral DBS implantation, and 6 or 12 months post-bilateral implantation. All implantations targeted the nucleus ventralis intermediate (Vim). Thirty-eight patients (25 males, 13 females) were included. Twenty-five patients (65.8%) underwent unilateral DBS implantation and 13 (34.2%) bilateral. The mean age at surgery was 67.1 years ± 11.4 (range 34-81). The mean disease duration was 31 years ± 18.3 (range 6-67). Fifty-eight percent of patients had worsened gait post-operatively. Seventy percent of patients with unilateral Vim DBS experienced gait worsening while 55% of bilateral DBS patients experienced gait worsening. Patients with worsened gait post-DBS had higher baseline pre-operative TRS scores than those without worsened gait (43.1 points ± 8.4 vs. 33.1 points ± 10.1, p = 0.002) (odds ratio 2.5, p = 0.02). Gait/balance may worsen following DBS for medication refractory ET. Higher baseline TRS score may factor into these issues, although a larger prospective study will be required with a control population. The larger percentage of difficulties observed in unilateral versus bilateral cases likely reflected the bias not to proceed to second-sided surgery if gait/balance problems were encountered.     

Community walking activity in neurological disorders with leg weakness

BACKGROUND: The aims of this study were to determine walking mobility in the community in individuals with lower limb weakness and to establish the extent to which some clinic based measures predict such activity. METHODS: Five groups (n = 12-18) of independently ambulant patients with lower limb weakness due to neurological conditions and a matched healthy control group were recruited. Measures of isometric knee extension/flexion muscle strength, time to stand up (sit-to-stand, STS), gait speed, and daily step counts (recorded over 7 days) were obtained. The Rivermead Mobility Index (RMI) provided a measure of functional ability. Between group differences and associations were explored. Backward stepwise regression analysis was used to identify variables influencing daily step count in individuals with neurological impairment. RESULTS: Patients were significantly weaker (mean (SD) quadriceps strength 69+/-34% v 102+/-37% predicted), slower to stand up (2.9+/-1.3 v 2.0+/-0.6 s), and had slower self selected gait speed (0.74+/-0.3 v 1.2+/-0.2 m/s) than controls. Mean daily step count was also lower (3090+/-1902 v 6374+/-1819) than in controls. In neurology patients step count was correlated with RMI score (r(s) = 0.49, p<0.01) and STS (r = -0.19, p<0.05). However, self selected gait speed was the only significant predictor in the regression analysis (p<0.01) of daily mean step count. CONCLUSIONS: Measures of muscle strength, timed STS, and RMI do not appear to closely reflect community walking activity in these patient groups. Self selected gait speed was partially predictive. Measurement of community walking activity may add a new dimension to evaluating the impact of interventions in neurological disorders.     

Energy expenditure of ambulation in paraplegics: effects of long term use of bracing

Energy metabolism data were collected in a series of seven male paraplegic patients with complete spinal cord lesions (T9 to L1). Among these four had just been rehabilitated and three had been using their bilateral long leg braces for more than 4 years. A group of five healthy volunteers was used as a control. All the subjects ambulated on a treadmill between parallel bars and in a second trial they ambulated on the floor using forearm crutches. Mean O2 consumption was 1.46 ml O2/kg/m for the unaccustomed paraplegics who had never used long-leg braces before, 0.61 for paraplegics used to walking with braces, and 0.83 for the healthy subjects walking between parallel bars with a swing-through gait. The second trial (on the floor), showed a mean O2 consumption of 0.73 ml O2/kg/m for the paraplegic brace-user with a high heart rate (156/min). This mean O2 consumption was much lower than the values of the paraplegic non-user and slightly higher than the normal subjects.     

Energy cost of spontaneous walking in Parkinson’s disease patients

In healthy subjects, comfortable walking minimizes the energy cost (E (c)) of locomotion. In Parkinson's disease (PD) patients walking is slower than in healthy subjects: this may increase E (c). Our aims were to analyze gait and E (c) in PD patients during walking, particularly at self-selected speed, and the possible pathological, mechanical, and cardiorespiratory limitations. Fourteen mild-to-moderate PD and 14 control subjects were enrolled. Subjects underwent 5-min walking tests at two speeds: self-selected and as-fast-as-possible speeds. Cardiopulmonary and gait parameters (heart rate, ventilation, gas exchanges, step count) were recorded. Velocity was reduced in PD compared to control subjects at both speeds (P < 0.05), and PD patients had shorter strides (P < 0.05) at both speeds and reduced cadence (P = 0.01) at fastest speed. No significant difference was found in E (c) at self-selected (0.12 ± 0.04 versus 0.11 ± 0.02 mLO(2) kg(-1) m(-1) in PD and control subjects, respectively) and maximal (0.14 ± 0.03 versus 0.15 ± 0.02 mLO(2) kg(-1) m(-1) in PD and control subjects, respectively) speed. However, the E (c) increment from self-selected to fastest velocity was significantly lower (P = 0.02) in PD patients. PD patients failed to walk at a self-selected speed, which minimizes the E (c). This could be mainly due to the inability to develop a wider stride. Cardiorespiratory adaptation was not affected, except for the possible reduced cardiac adaptation observed in some (28%) cases. Presumably, rehabilitation procedures that improve flexibility and step length may help maintain walking ability.     

Brain structural abnormalities in psychotropic drug-naive pediatric patients with obsessive-compulsive disorder

OBJECTIVE: The authors investigated structural abnormalities in brain regions comprising cortical-striatal-thalamic-cortical loops in pediatric patients with obsessive-compulsive disorder (OCD). METHOD: Volumes of the caudate nucleus, putamen, and globus pallidus and gray and white matter volumes of the anterior cingulate gyrus and superior frontal gyrus were computed from contiguous 1.5-mm magnetic resonance images from 23 psychotropic drug-naive pediatric patients with OCD (seven male patients and 16 female patients) and 27 healthy volunteers (12 male subjects and 15 female subjects). RESULTS: Patients had smaller globus pallidus volumes than healthy volunteers, but the two groups did not differ in volumes of the caudate nucleus, putamen, or frontal white matter regions. Compared to healthy volunteers, patients had more total gray matter in the anterior cingulate gyrus but not the superior frontal gyrus. Total anterior cingulate gyrus volume correlated significantly and positively with globus pallidus volume in the healthy volunteers but not in patients. CONCLUSIONS: These findings provide evidence of smaller globus pallidus volume in patients with OCD without the potentially confounding effects of prior psychotropic drug exposure. Volumetric abnormalities in the anterior cingulate gyrus appear specific to the gray matter in OCD, at least at the gross anatomic level, and are consistent with findings of functional neuroimaging studies that have reported anterior cingulate hypermetabolism in the disorder.     

Cognitive impairment is associated with gait variability and fall risk in amyotrophic lateral sclerosis

Background

In amyotrophic lateral sclerosis (ALS), gait abnormalities contribute to poor mobility and represent a relevant risk for falls. To date, gait studies in ALS patients have focused on the motor dimension of the disease, underestimating the cognitive aspects.

Methods

Using a wearable gait analysis device, we compared gait patterns in ambulatory ALS patients with mild cognitive impairment (ALS MCI+; n = 18), and without MCI (ALS MCI−; n = 24), and healthy subjects (HS; n = 16) under two conditions: (1) normal gait (single task) and (2) walking while counting backward (dual task). Finally, we examined if the occurrence and number of falls in the 3 months following the baseline test were related to cognition.

Results

In the single task condition, ALS patients, regardless of cognition, displayed higher gait variability than HS, especially for stance and swing time (p < 0.001). The dual task condition revealed additional differences in gait variability parameters between ALS MCI+ and ALS MCI− for cadence (p = 0.005), stance time (p = 0.04), swing time (p = 0.04) and stability index (p = 0.02). Moreover, ALS MCI+ showed a higher occurrence (p = 0.001) and number of falls (p < 0.001) at the follow-up. Regression analyses demonstrated that MCI condition predicted the occurrence of future falls (β = 3.649; p = 0.01) and, together with executive dysfunction, was associated with the number of falls (cognitive impairment: β = 0.63; p < 0.001; executive dysfunction: β = 0.39; p = 0.03), regardless of motor impairment at clinical examination.

Conclusion

In ALS, MCI is associated with exaggerated gait variability and predicts the occurrence and number of short-term falls.     

Pain in multiple sclerosis: a clinical and instrumental approach

BACKGROUND: Pain is a frequent and disabling symptom in multiple sclerosis (MS) patients. In this study we assess the frequency and intensity of pain, as well as its impact on the quality of life and activities of daily living, in a sample of MS patients. METHODS: One hundred and twenty eight MS patients underwent a neurological examination, a structured interview designed to assess pain, and a Medical Outcome 36-item Short Form Health Survey. Functional status was assessed by means of the Barthel Index (BI) and Rivermead Mobility Index. We also assessed the presence of depression, by means of the Montgomery and Asberg Depression Rating Scale, and fatigue, by means of the Fatigue Severity Scale. An algometer was used to measure thermal and discomfort thresholds in all of the patients and a group of 61 age- and sex-matched healthy subjects. RESULTS: Pain was present in 61 patients. No differences were found between patients with and those without pain in disease duration, disease form or Expanded Disability Status Scale and its functional systems. Patients with pain had a lower vitality score (p = 0.008), mental health score (p = 0.03) and physical (p < 0.001) and mental composite scores (p = 0.01) than patients without pain. Furthermore, there was a significant difference between patients with and those without pain in the BI (p = 0.04). Both thermal and discomfort thresholds, as assessed by means of the algometer, were statistically lower in MS patients than in controls, whereas no difference was observed between patients with and those without pain. There was a statistically significant improvement in the thermal threshold in patients with pain who were treated pharmacologically when compared with those who were not treated (p = 0.049). CONCLUSION: The results of this study provide further evidence of the negative impact that the presence of pain has on both the quality of life and activities of daily living in MS patients. The lower thermal and discomfort thresholds observed in our MS patients, compared with controls, may represent a predisposition to develop pain during the course of the disease.     

Cognitive and gait decrements among non-demented older adults with Type 2 diabetes or hypertension: a systematic review

Abstract

Objective: Older adults with Type 2 diabetes (DM2) and hypertension (HTN) often experience cognitive weaknesses. Growing evidence suggests that such weaknesses place patients at risk for gait disturbance and falls. The current systematic review evaluated (a) the impact of DM2 and HTN on cognition and gait and (b) the association between cognition and gait in the context of DM2 and HTN. Methods: PubMed was searched to identify studies published in English before 15 April 2017 that evaluated both cognition and gait among non-demented older adults either as a function of DM2 or HTN status or as a function of continuous variables that indicate disease severity and/or management (e.g. blood pressure, HbA1C). Risk of bias was assessed by examining the method of verifying HTN/DM2 and excluding dementia as well as included covariates. Results: In the majority of studies reviewed (n = 17), both DM2 and HTN status were associated with poorer cognitive and/or gait functioning (8 out of 10 studies). In addition, in 10 out of 11 studies cognition was reliably associated with gait. For continuous variables, higher systolic blood pressure (measured with ambulatory methods) was consistently related to poorer cognition and slower gait, but other continuous variables (e.g. HbA1C) were studied inconsistently with inconclusive results. Conclusions: Cognitive and gait decrements are not only common in the context of HTN and DM2, but also are related to each other. This suggests that clinical neuropsychologists should address cognitive contributions to gait disturbance and falls in their clinical work and research with these patient populations.     

Falls in peripheral neuropathy]

Falling accidents are predisposing factors in worsening the quality of life. Causes of falls included gait and balance problems, visual disorder, cognitive impairment and drugs. However, falls in neuropathic patients are not often investigated. We studied the actual condition and causes of falls associated with neuropathy. One hundred and ninety-three patients (122 males and 71 females, ages 57 +/- 15 years) with neuropathy were selected for evaluation. In all patients, more than half a year had passed since the onset of symptoms and the present condition was considered comparatively stable. We divided the patients into 2 groups: falling or non-falling. Patients experiencing accident accompanied by external injury once or more in the past year, or patients who answered "often fell" (1 time or more per month) on flat ground or in their residence comprised the fall group. The severity of disease was evaluated by modified Rankin Scale (0 to 5). The relationship between falls and neuropathic symptoms (proximal muscle weakness, distal muscle weakness, aching or numbness, and the position and vibration sensory loss) was statistically examined. The distribution of patients in the fall group according to modified Rankin Scale of neuropathy was scale 5: 0/0 (0%), scale 4: 5/36 (14%), scale 3: 24/72 (33%), scale 2: 7/56 (13%), and scale 1: 1/19 (5%). There were six fractures among all patients. Regarding the etiology, the fall group showed a high level of axonal neuropathies (44%). On analysis according to condition and symptoms in the patients with a score of 2, 3, or 4 who demonstrated a high rate of falls, there was a strong correlation between deep sensory loss and fall (p < 0.05). However, as independent factors, there were no correlations between falling and proximal muscle weakness, distal muscle weakness or aching numbness, respectively. We thought it necessary to add ataxic gait resulting from deep sensory loss to one of the fall risks.     

Falls and gait disturbances in Huntington's disease

Falls are common in patients with Huntington's disease, but the incidence, falling circumstances and contributing factors have never been examined. We recorded falls in 45 early to midstage Huntington's disease patients, both retrospectively (12 months) and prospectively (3 months). Fall rates were related to relevant baseline measures, including the Unified Huntington's Disease Rating Scale (UHDRS) and quantitative measures of balance (using angular velocity sensors) and gait (using a pressure‐sensitive walkway). Balance and gait measures were compared between patients and 27 healthy age‐matched controls. Twenty‐seven patients (60%) reported two or more falls in the previous year and were classified as fallers. During prospective follow‐up 40% reported at least one fall. A high proportion of falls (72.5%) caused minor injuries. Compared to nonfallers, fallers showed significantly higher scores for chorea, bradykinesia and aggression, as well as lower cognitive scores. Compared to controls, Huntington patients had a decreased gait velocity (1.15 m/s versus 1.45 m/s, P < 0.001) and a decreased stride length (1.29 m versus 1.52 m, P < 0.001). These abnormalities were all significantly greater in fallers compared to nonfallers. In addition, fallers had an increased stride length variability and a significantly greater trunk sway in medio‐lateral direction compared to nonfallers. We conclude that falls are common in Huntington's disease. Contributing factors include a combination of “motor” deficits (mainly gait bradykinesia, stride variability and chorea, leading to excessive trunk sway), as well as cognitive decline and perhaps behavioral changes. These factors should be considered as future targets for therapies that aim to reduce falls in Huntington's disease. © 2008 Movement Disorder Society     

Frail elderly patients with dementia go too fast

The reason why patients with dementia fall more often and sustain more fractures than patients without dementia remains unclear. Therefore, the relationship between dementia and gait velocity as a marker for mobility and falls in a cohort of frail elderly (mean age of 77.3 years) inpatients was assessed. Patients with dementia were expected to walk slower than patients without dementia. A trend was indeed observed: absolute gait velocity of 0.59 m/s in patients with dementia (n = 63) versus 0.65 m/s in patients without dementia (n = 62; p = 0.19). After adjustment for parkinsonism and walking aids, however, patients with dementia walked 0.44 m/s faster than patients without dementia (p = 0.02). Probable explanations are frontal lobe disinhibition and lack of insight, causing patients with dementia to walk relatively too fast in the context of their frailty. Therefore, the high risk of falls in dementia may be partially explained by the loss of control of gait velocity.     

Characteristic regional cerebral blood flow patterns in anorexia nervosa patients with binge/purge behavior

OBJECTIVE: The authors' goal was to investigate the effect of imagining food on the regional cerebral blood flow (rCBF) of anorexia nervosa patients with and without habitual binge/purge behavior. METHOD: The subjects included seven female patients with purely restrictive anorexia, seven female patients with anorexia and habitual binge/purge behavior, and seven healthy women. Single photon emission computed tomography examination was performed before and after the subjects were asked to imagine food. Changes in rCBF count ratios (percent change) were then calculated and compared. The subjects were also asked to assess their degree of fear regarding their control of food intake. RESULTS: The anorexia nervosa patients with habitual binge/purge behavior had a significantly higher percent change in the inferior, superior, prefrontal, and parietal regions of the right brain than the patients with purely restrictive anorexia and the healthy volunteers. The patients with habitual binge/purge behavior also had the highest level of apprehension in regard to food intake. CONCLUSIONS: Specific activation in cortical regions suggests an association between habitual binge/purge behavior and the food recognition process linked to anxiety in patients with anorexia nervosa.     

Falls in Parkinson's disease: Kinematic evidence for impaired head and trunk control

Changes in stride characteristics and gait rhythmicity characterize gait in Parkinson's disease and are widely believed to contribute to falls in this population. However, few studies have examined gait in PD patients who fall. This study reports on the complexities of walking in PD patients who reported falling during a 12‐month follow‐up. Forty‐nine patients clinically diagnosed with idiopathic PD and 34 controls had their gait assessed using three‐dimensional motion analysis. Of the PD patients, 32 (65%) reported at least one fall during the follow‐up compared with 17 (50%) controls. The results showed that PD patients had increased stride timing variability, reduced arm swing and walked with a more stooped posture than controls. Additionally, PD fallers took shorter strides, walked slower, spent more time in double‐support, had poorer gait stability ratios and did not project their center of mass as far forward of their base of support when compared with controls. These stride changes were accompanied by a reduced range of angular motion for the hip and knee joints. Relative to walking velocity, PD fallers had increased mediolateral head motion compared with PD nonfallers and controls. Therefore, head motion could exceed “normal” limits, if patients increased their walking speed to match healthy individuals. This could be a limiting factor for improving gait in PD and emphasizes the importance of clinically assessing gait to facilitate the early identification of PD patients with a higher risk of falling. © 2010 Movement Disorder Society