Oxygen Cost During Walking in Individuals With Stroke: Hemiparesis Versus Cerebellar Ataxia

Useless. You describe a problem, give NO SOLUTION.  Not even any mention of normobaric oxygen. Does anybody in stroke have any clue at all in what they are doing?

• Normobaric oxygen (9)

Possible solutions: Obviously not vetted coming from me. Don't do them.

How to Improve Your Brain Function with An Oxygen Concentrator April 2018 

Or is it more important to increase the loading ability of red blood cells to carry more oxygen? 

Like this?

University of Glasgow Study Demonstrates the Ability of Oxycyte® to Supply Oxygen to Critical Penumbral Tissue in Acute Ischemic Stroke  August 2012

Or like this?

chronic cannabis users have higher cerebral blood flow and extract more oxygen from brain blood flow than nonusers. August 2017

 

The latest here:

Oxygen Cost During Walking in Individuals With Stroke: Hemiparesis Versus Cerebellar Ataxia

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Maxence Compagnat, Jean-Christophe Daviet, Charles Batcho, ...

First Published February 24, 2020 Research Article Find in PubMed

https://doi.org/10.1177/1545968320907076

Article information

Abstract

Background.
Understanding the factors that limit mobility in stroke patients is fundamental for proposing appropriate rehabilitation strategies. A high oxygen cost during walking (Cw) has a strong impact on the community ambulation of hemiparetic patients. The Cw in poststroke cerebellar ataxia is poorly evaluated, unlike hemiparetic gait.  
Objective.
To compare the oxygen cost/self-selected walking speed (S) relationship in stroke individuals with cerebellar ataxia or hemiparetic gait.  
Methods. Thirty-three subjects were included (14 cerebellar stroke, 19 hemispheric stroke), with stroke confirmed by brain imaging and able to walk without human assistance. We measured Cw using the Metamax3B. The relationship between Cw and self-selected walking speed was modelled by logistic regression and then compared between the cerebellar and hemispheric groups.  
Results.
No significant difference was found between the 2 groups for all characteristics of the population, except motor impairments, spasticity, and ataxia (P < .01). We identified 2 separate Cw/S relationships with different logistic regression equations for the 2 groups. Faster than 0.4 m s⁻¹, Cw was 30.6% to 39.9% higher in patients with cerebellar stroke in comparison with hemispheric stroke individuals. The Cw was correlated with ataxia (r = 0.88; P < .001) in the cerebellar group, whereas there was a correlation with motor impairments (r = −0.61; P < .01), spasticity (r = 0.59; P < .01), and ataxia (r = 0.81; P < .01) in hemispheric stroke individuals.  
Conclusion.
The Cw in poststroke cerebellar ataxia is significantly higher compared with hemiparetic patients at an equivalent walking speed. The impact on community walking needs to be explored in stroke survivors with cerebellar stroke.

Keywords oxygen cost, walking, cerebellar stroke, hemispheric stroke, energy expenditure

Introduction

Walking is a meaningful activity in view of social participation and quality of life in individuals with poststroke sequelae.¹ Unfortunately, at 6 months after stroke, less than 30% of patients have regained the ability to walk independently, and almost 50% believe they have restricted mobility in the community.² The limitation of walking activity may be due to metabolic factors, because individuals with stroke suffer from significant cardiorespiratory deconditioning. The VO₂ peak in these patients was found to be 26% to 87% lower than that of age- and sex-matched healthy control subjects.³ In addition, secondary to their neurological impairments, stroke individuals consume between 1.5 and 2 times more oxygen when walking than healthy subjects, which causes intense metabolic strain, leading to an increase in fatigability and consequently to limitation of activity.⁴ The walking efficiency of an individual can be quantified by measuring the oxygen cost of walking (Cw), which is the consumption of oxygen per meter expressed in mL kg⁻¹ m⁻¹.⁵ The Cw is of crucial importance in stroke individuals, because this parameter is associated with walking ability⁴ and social participation.⁶ Franceschini et al reported that stroke individuals with a Cw greater than 0.55 mL kg⁻¹ m⁻¹ have walking restrictions for community activities.⁶
Neurological impairments following stroke depend on the damaged neurological structure. Thus, after a hemispheric stroke, damage to the pyramidal pathway is classically responsible for spastic hemiparesis, associated or not with cognitive, sensory, and neuro-vegetative impairments, depending on the extent of the injury. These impairments lead to a stiff knee gait and circumduction of the impaired lower limb.⁷ After a cerebellar stroke, individuals typically have coordination and balance disorders, resulting in characteristic ataxic walking.⁸
Among these 2 types of clinical conditions, several deficiencies may induce an increase in Cw. The presence of co-contractions related to spasticity are associated with an increase in Cw.^9,10 The increase in the variability of the trajectories of the limb segments due to the loss of selectivity of the central control¹¹ is also associated with the increase in Cw.^9,12
The gait patterns of cerebellar stroke and hemispheric stroke patients are very different. Cerebellar ataxic gait is typically characterized by an increased step width, variable foot placement, irregular foot trajectories, and a resulting unstable, stumbling walking path with very high movement variability and a high risk of falling. This type of gait is clinically recognizable and is easily differentiated from the gait pattern of hemiparetic individuals, who have a loss of symmetry, with a tendency for increased stance time on the unaffected limb. The affected lower limb appears stiff-legged, demonstrating a synergy pattern with extension, adduction, internal rotation of the hip, extension of the knee, and plantarflexion/inversion of the foot/ankle. This extended limb posture leads to an impairment of limb clearance during the swing phase, and compensatory maneuvers include hip hiking, lateral trunk sway, circumduction, and, less commonly, contralateral vaulting (Olney and Richards, 1996)¹³. In a previous study, we showed that the relationship between the Cw and self-selected walking speed (S) was strong in individuals with poststroke hemispheric sequelae (r = −0.94; R² = 0.97, P < .001).¹⁴ We assumed from this work and our clinical experience that this strong relationship is explained by the fact that the walking pattern was similar from one hemiparetic individual to another. In addition, Zamparo et al, in a similar study, compared the Cw of 20 hemiparesis patients and 17 healthy subjects. The authors found different Cw/S relationships between the groups of subjects (P < .001 in the covariance analysis).¹⁵
The Cw/S relationship seems to be a characteristic of the walking efficiency of individuals that would be specific to the individual’s walking pattern. To support this hypothesis, it must be compared with a very different gait pattern, that of ataxic individuals with post–cerebellar stroke. To our knowledge, no studies have explored the Cw of cerebellar stroke individuals or the Cw/S relationship.
The objective of this study was to compare the relationship between Cw and S in individuals with cerebellar and hemispheric stroke. Our hypothesis is that individuals with cerebellar stroke sequelae do not have the same Cw/S relationship as hemiparetic stroke individuals, due to the differences in impairments and gait patterns between these 2 stroke types. If this hypothesis is confirmed, this would imply that a specific Cw/S relationship could be identified for patients, depending on the stroke location.

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