Further construct validity of the Timed Up-and-Go Test as a measure of ambulation in multiple sclerosis patients

Abstract:Background:Damage to the central nervous system by Multiple Sclerosis (MS) leads to multiple symptoms, including weakness, ambulatory dysfunction, visual disturbances and fatigue. Heat can exacerbate the symptoms of MS whereas cooling can provide symptomatic relief. Since the head and neck areas are particularly sensitive to cold and cooling interventions, we investigated the effects of cooling the head and neck for 60 minutes on the symptoms of MS.Methods:We used a double blinded, placebo controlled, cross-over study design to evaluate the effects of head and neck cooling on six heat-sensitive, stable, ambulatory females with MS (Extended Disability Status Scale 2.5-6.5). To isolate the effects of perceived versus physiological cooling, a sham cooling condition was incorporated, where subjects perceived the sensation of being cooled without any actual physiological cooling. Participants visited the clinic three times for 60 minutes of true, sham, or no cooling using a custom head and neck cooling hood, followed by evaluation of ambulation, visual acuity, and muscle strength. Rectal and skin temperature, heart rate, and thermal sensation were measured throughout cooling and testing.Results:Both the true and sham cooling elicited significant sensations of thermal cooling, but only the true cooling condition decreased core temperature by 0.37°C (36.97±0.21 to 36.60±0.23°C). True cooling improved performance in the six minute walk test and the timed up-and-go test but not visual acuity or hand grip strength.Conclusions:Head and neck cooling may be an effective tool in increasing ambulatory capacity in individuals with MS and heat sensitivity.

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Cognitive Processing Speed Impairment Does Not Influence the Construct Validity of Six-Spot Step Test Performance in People With Multiple Sclerosis

Physical Therapy ◽

10.1093/ptj/pzaa227 ◽

2020 ◽

Author(s):

Brian M Sandroff ◽

Stephanie L Silveira ◽

Jessica F Baird ◽

Trinh Huynh ◽

Robert W Motl

Keyword(s):

Multiple Sclerosis ◽

Construct Validity ◽

Cognitive Processing ◽

Processing Speed ◽

Test Performance ◽

Functional Mobility ◽

Step Test ◽

Timed Up And Go ◽

Cognitive Processing Speed ◽

Mobility Measure

Abstract Objective There is evidence supporting the construct validity of Six-Spot Step Test (SSST) performance as a functional mobility measure in people with multiple sclerosis (MS); however, it is unknown if cognitive processing speed (CPS) impairment confounds the construct validity of SSST performance in MS, as this test seemingly requires intact cognitive processing. The objective of this study was to examine the influence of CPS impairment on the construct validity and precision of SSST performance as a functional mobility measure in MS. Methods Participants (N = 213) completed the SSST, timed 25-foot walk, Six-Minute Walk Test, Timed “Up and Go” Test, Multiple Sclerosis Walking Scale-12, device-measured steps/day, and Late-Life Function and Disability Inventory, Patient-Determined Disease Steps, and the Symbol-Digit Modalities Test (SDMT) as a CPS measure. The overall sample was divided into subsamples with (n = 75) and without (n = 138) CPS impairment based on normative SDMT data. Correlations between SSST performance with other mobility outcomes in the overall sample and CPS impairment subsamples were examined and compared. SSST performance was compared relative to other mobility measures for differentiating MS walking function levels in people with and without CPS impairment. Results SSST performance was significantly and strongly correlated with most mobility outcomes in the overall sample and CPS impairment subsamples. The magnitudes of correlations between SSST performance with most mobility outcomes were not statistically different among subsamples. CPS impairment did not diminish the relative precision of SSST performance for differentiating walking function levels. Conclusions The presence of CPS impairment is not a source of invalidity or imprecision when interpreting SSST performance as a functional mobility measure among people with MS. Impact The SSST is a high-quality endpoint for inclusion in interventions targeting mobility in MS, regardless of CPS status. This information is critical for rehabilitation research and clinical practice given that mobility and cognitive impairment are highly prevalent, co-occurring, and disabling in MS.

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Myelin status is associated with change in functional mobility following slope walking in people with multiple sclerosis

Multiple Sclerosis Journal - Experimental Translational and Clinical ◽

10.1177/2055217318773540 ◽

2018 ◽

Vol 4 (2) ◽

pp. 205521731877354 ◽

Cited By ~ 1

Author(s):

EM King ◽

MJ Sabatier ◽

M Hoque ◽

TM Kesar ◽

D Backus ◽

...

Keyword(s):

Multiple Sclerosis ◽

Water Content ◽

Therapeutic Response ◽

Functional Mobility ◽

Functional Impairments ◽

Timed Up And Go ◽

Water Fraction ◽

Walking Intervention ◽

Myelin Water Fraction ◽

Multiple Sclerosis Patients

Background The level of myelin disruption in multiple sclerosis patients may impact the capacity for training-induced neuroplasticity and the magnitude of therapeutic response to rehabilitation interventions. Downslope walking has been shown to increase functional mobility in individuals with multiple sclerosis, but it is unclear if myelin status influences therapeutic response. Objective The current study aimed to examine the relationship between baseline myelin status and change in functional mobility after a walking intervention. Methods The Timed Up and Go test was used to measure functional mobility before and after completion of a repeated, six-session slope walking intervention in 16 participants with relapsing–remitting multiple sclerosis. Multi-component T2 relaxation imaging was used to index myelin water fraction of overall water content in brain tissue compartments. Results Results demonstrated that the ratio of the myelin water fraction in lesion to normal-appearing white matter (myelin water fraction ratio) significantly predicted 31% of the variance in change in Timed Up and Go score after the downslope walking intervention, where less myelin disruption was associated with greater intervention response. Conclusions Myelin water content fraction ratio may offer a neural biomarker of myelin to identify potential responders to interventions targeting functional impairments in multiple sclerosis.

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