[Gait disturbances in neurology]

Gait disorders in adults and the elderly : A clinical guide

Human gait depends on a complex interplay of major parts of the nervous, musculoskeletal and cardiorespiratory systems. The individual gait pattern is influenced by age, personality, mood and sociocultural factors. The preferred walking speed in older adults is a sensitive marker of general health and survival. Safe walking requires intact cognition and executive control. Gait disorders lead to a loss of personal freedom, falls and injuries and result in a marked reduction in the quality of life. Acute onset of a gait disorder may indicate a cerebrovascular or other acute lesion in the nervous system but also systemic diseases or adverse effects of medication, in particular polypharmacy including sedatives. The prevalence of gait disorders increases from 10 % in people aged 60–69 years to more than 60 % in community dwelling subjects aged over 80 years. Sensory ataxia due to polyneuropathy, parkinsonism and frontal gait disorders due to subcortical vascular encephalopathy or disorders associated with dementia are among the most common neurological causes. Hip and knee osteoarthritis are common non-neurological causes of gait disorders. With advancing age the proportion of patients with multiple causes or combinations of neurological and non-neurological gait disorders increases. Thorough clinical observation of gait, taking a focused patient history and physical, neurological and orthopedic examinations are basic steps in the categorization of gait disorders and serve as a guide for ancillary investigations and therapeutic interventions. This clinically oriented review provides an overview on the phenotypic spectrum, work-up and treatment of gait disorders.

Postural stability in cigarette smokers and during abstinence from alcohol

BACKGROUND

Static postural instability is common in alcohol-dependent individuals (ALC). Chronic alcohol consumption has deleterious effects on the neural and perceptual systems subserving postural stability. However, little is known about the effects of chronic cigarette smoking on postural stability and its changes during abstinence from alcohol.

METHODS

A modified Fregly ataxia battery was administered to a total of 115 smoking (sALC) and nonsmoking ALC (nsALC) and to 71 smoking (sCON) and nonsmoking light/nondrinking controls (nsCON). Subgroups of abstinent ALC were assessed at 3 time points (TPs; approximately 1, 5, 34 weeks of abstinence from alcohol); a subset of nsCON was retested at 40 weeks. We tested whether cigarette smoking affects postural stability in CON and in ALC during extended abstinence from alcohol, and we used linear mixed effects modeling to measure change across TPs within ALC.

RESULTS

Chronic smoking was associated with reduced performance on the Sharpened Romberg eyes-closed task in abstinent ALC at all 3 TPs and in CON. The test performance of nsALC increased significantly between 1 and 32 weeks of abstinence, whereas the corresponding increases for sALC between 1 and 35 weeks were nonsignificant. With long-term abstinence from alcohol, nsALC recovered into the range of nsCON and sALC recovered into the range of sCON. Static postural stability decreased with age and correlated with smoking variables but not with drinking measures.

CONCLUSIONS

Chronic smoking was associated with reduced static postural stability with eyes closed and with lower increases of postural stability during abstinence from alcohol. Smoking cessation in alcohol dependence treatment may facilitate recovery from static postural instability during abstinence.

Biometric and mobile gait analysis for early diagnosis and therapy monitoring in Parkinson's disease

Parkinson's disease (PD) is the most frequent neurodegenerative movement disorder. Early diagnosis and effective therapy monitoring is an important prerequisite to treat patients and reduce health care costs. Objective and non-invasive assessment strategies are an urgent need in order to achieve this goal. In this study we apply a mobile, lightweight and easy applicable sensor based gait analysis system to measure gait patterns in PD and to distinguish mild and severe impairment of gait. Examinations of 16 healthy controls, 14 PD patients in an early stage, and 13 PD patients in an intermediate stage were included. Subjects performed standardized gait tests while wearing sport shoes equipped with inertial sensors (gyroscopes and accelerometers). Signals were recorded wirelessly, features were extracted, and distinct subpopulations classified using different classification algorithms. The presented system is able to classify patients and controls (for early diagnosis) with a sensitivity of 88% and a specificity of 86%. In addition it is possible to distinguish mild from severe gait impairment (for therapy monitoring) with 100% sensitivity and 100% specificity. This system may be able to objectively classify PD gait patterns providing important and complementary information for patients, caregivers and therapists.

[Gait changes as an early indicator of dementia]

Gait disorders are more common in dementia than in the context of the physiological aging process. Prevalence of dementia-associated gait disturbances depends on the type of dementia and the severity of cognitive impairment. While in vascular dementia gait abnormalities are often clinically apparent at early disease stages, Alzheimer's disease patients usually have stable gait until late disease stages. With up-to-date ''brain-imaging" methods, it has been demonstrated that people suffering from dementia are more dependent on cortical activity in order to maintain gait stability in complex situations. When dysfunction of the frontal or temporal lobes occurs, allocation of these resources may no longer be sufficient. Dual-task paradigms are useful to test such resources. It has been shown in early Alzheimer's disease patients that, if the demand of attention exceeds available capacities, quantitative gait changes occur. Relevant parameters seem to be, e.g., walking speed and stride-time variability. Quantitative assessment of gait dysfunction in dementia may, thus, have the potential to serve as a trait marker.

Gait disturbances in old age: classification, diagnosis, and treatment from a neurological perspective

BACKGROUND

Gait disturbances are among the more common symptoms in the elderly. Reduced mobility markedly impairs quality of life, and the associated falls increase morbidity and mortality.

METHODS

Review of the literature based on a selective search (PubMed) on the terms "gait," "gait disorder," "locomotion," "elderly," "geriatric" and "ageing" (2000-11/2009) and the findings of the authors' own studies on gait changes in old age and on the functional brain imaging of gait control.

RESULTS

Gait disturbances in the elderly are often of multifactorial origin. The relevant pathogenetic factors include sensory deficits (visual, vestibular, somatosensory), neurodegenerative processes (cortical, extrapyramidal motor, cerebellar), toxic factors (medications, alcohol), and anxiety (primary or concerning falls). A clinically oriented classification of gait disorders is proposed, which, on the basis of the characterization of gait and the accompanying clinical findings, enables identification of the etiological factors and points the way to rational therapy. Current research topics in the study of gait disturbances are also discussed, including quantitative gait analysis, interactions between locomotion and cognition (dual tasking), and functional imaging approaches.

CONCLUSIONS

The evaluation of elderly patients whose chief complaint is a gait disturbance should be directed toward the identification of specific deficits. This is the prerequisite for rational therapy, even when the problem is of multifactorial origin. The preservation of mobility is important in itself, and also because the ability to walk is closely correlated with cognitive performance.