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Effects of Somatosensory Impairment on Participation After Stroke

Leeanne M. Carey, Thomas A. Matyas, Carolyn Baum

Leeanne M. Carey, PhD, BAppSc(OT), FAOTA,

FOTARA, is Professor of Occupational Therapy,

Discipline Lead, Occupational Therapy, School of Allied

Health, College of Science, Health, and Engineering, La

Trobe University, Melbourne, Victoria, Australia, and

Head, Neurorehabilitation and Recovery, Stroke Division,

Florey Institute of Neuroscience and Mental Health,

Heidelberg, Victoria, Australia; [email protected]

Thomas A. Matyas, PhD, is Adjunct Professor, School

of Allied Health and School of Psychology and Public

Health, College of Science, Health, and Engineering, La

Trobe University, Melbourne, Victoria, Australia, and

Honorary Professorial Fellow, Neurorehabilitation and

Recovery, Stroke Division, Florey Institute of Neuroscience

and Mental Health, Heidelberg, Victoria, Australia.

Carolyn Baum, PhD, OTR/L, FAOTA, is Professor,

Occupational Therapy and Neurology and Social Work,

Elias Michael Director, Program in Occupational Therapy,

Washington University School of Medicine, St. Louis, MO.

OBJECTIVE. Our objective was to determine the effect of loss of body sensation on activity participation in stroke survivors.

METHOD. Participants (N 5 268) were assessed at hospital admission for somatosensory and motor impairment using the National Institutes of Health Stroke Scale. Participation was assessed using the

Activity Card Sort (ACS) in the postacute phase. Between-group differences in activity participation were

analyzed for participants with and without somatosensory impairment and with or without paresis.

RESULTS. Somatosensory impairment was experienced in 33.6% of the sample and paresis in 42.9%. ACS profiles were obtained at a median of 222 days poststroke. Somatosensory loss alone (z 5 1.96, p 5 .048) and

paresis in upper and lower limbs without sensory loss (z 5 4.62, p < .001) influenced activity participation.

CONCLUSION. Somatosensory impairment is associated with reduced activity participation; however, paresis of upper and lower limbs can mask the contribution of sensory loss.

Carey, L. M., Matyas, T. A., & Baum, C. (2018). Effects of somatosensory impairment on participation after stroke. American

Journal of Occupational Therapy, 72, 7203205100. https://doi.org/10.5014/ajot.2018.025114

One in 2 people experience loss of body sensation, or somatosensation, afterstroke (Carey, 2012; Carey & Matyas, 2011; Winward, Halligan, & Wade, 2002). They typically have difficulty sensing touch, pressure, and temperature;

perceiving own limb position; discriminating textures; and recognizing objects

through the sense of touch (Carey, 1995). They may also experience reduced or

altered pain sensation (Klit, Finnerup, Andersen, & Jensen, 2011). People who

experience somatosensory loss after stroke report problems such as communi-

cating through a handshake, using utensils, dressing, and holding objects

without crushing or dropping them. They also report problems with personal,

family, and work roles. Despite the high prevalence and apparent importance of

somatosensation in daily activities, there is limited empirical evidence to

quantify the presence and nature of a relationship between impaired somato-

sensation and participation in daily activities, as highlighted in two recent re-

views (Carey, Lamp, & Turville, 2016; Meyer, Karttunen, Thijs, Feys, &

Verheyden, 2014). The impact of somatosensory loss on participation is

therefore critical to address to understand the factors that affect participation

and to improve client-centered care planning.

Somatosensory impairment after stroke has been associated with impaired

daily actions and activities, according to clinical and laboratory studies (Borstad

& Nichols-Larsen, 2014; Carey et al., 2016; Kessner, Bingel, & Thomalla,

2016; Meyer et al., 2014). Somatosensory loss reduces control of hand

movements (Jeannerod, Michel, & Prablanc, 1984) and of the fundamental

pinch-grip-lift-and-hold task (Blennerhassett, Matyas, & Carey, 2007) and

limits grip force control during object manipulation (Nowak & Hermsdörfer,

2005). A relationship has also been demonstrated between clinical measures of

7203205100p1 May/June 2018, Volume 72, Number 3

hand function and dexterity (Blennerhassett, Carey, &

Matyas, 2008; Kong, Chua, & Lee, 2011; Park, Wolf,

Blanton, Winstein, & Nichols-Larsen, 2008).

Studies have demonstrated that the affected limb may

not be used spontaneously, despite adequate movement

abilities. This lack of use may contribute to a learned nonuse

of the limb and to further deterioration of motor function

after stroke (Carey, 1995; Dannenbaum & Dykes, 1988).

Moreover, stroke survivors have expressed uncertainty about

whether to use their sensory-impaired arm for task perfor-

mance (Connell, McMahon, & Adams, 2013). A predictive

relationship between somatosensory loss and independence

in activities of daily living (ADLs) and mobility has also

been demonstrated, for example, in a prospective sample of

102 stroke survivors (Tyson, Hanley, Chillala, Selley, &

Tallis, 2008) and using a life table analysis (N 5 95; Reding & Potes, 1988). It is therefore plausible that sensory im-

pairment may also be associated with reduced participation

in daily activities and life roles; yet our understanding of its

impact on participation is limited.

The International Classification of Functioning, Dis- ability and Health (ICF) defines participation as “a per- son’s involvement in a life situation,” for example, in

leisure, social, and work activities (World Health Orga-

nization, 2001, p. 10). A major knowledge gap about the

impact of somatosensory impairment after stroke on par-

ticipation in life activities has been recently identified in a

scoping review (Carey et al., 2016) and in a systematic re-

view (Meyer et al., 2014). Hill, Fisher, Schmid, Crabtree,

and Page (2014) reported a good to excellent relationship

between performance of and satisfaction with valued ac-

tivities, assessed using the Canadian Occupational Per-

formance Measure (Law et al., 2014), and intact sensation

of the hand in 50 stroke survivors. Desrosiers, Noreau,

Rochette, Bravo, and Boutin (2002) found a low but

significant association between light touch of the upper

limb and proprioception assessed at discharge and ADLs

and social roles assessed 6 mo later (N 5 102). Somatosensory impairment is commonly experienced

in association with motor impairment, and degree of

weakness has been significantly associated with sensory

impairment (Tyson et al., 2008). Upper limb motor

impairment is reported in 77% of stroke survivors

(Lawrence et al., 2001) and is likely to have an impact on

participation. Paresis may affect participation in its own

right and in addition to somatosensory impairment. We

therefore investigated the impact of somatosensory impair-

ment on participation in stroke survivors with and without

motor impairment. This approach is important because re-

habilitation traditionally targets motor problems, often

without attending to somatosensory deficits known to affect

performance (Carey, 2015; Kalra, 2010), despite the avail-

ability of interventions to remediate somatosensory deficits

(Carey et al., 2016; Carey, Macdonell, & Matyas, 2011).

Given the high prevalence of somatosensory loss in

stroke survivors and evidence of its relationship with daily

actions and activities, we investigated the effect of so-

matosensory impairment on activity participation in a

longitudinal stroke cohort. We were particularly interested

to learn whether the presence of sensory impairment soon

after stroke affected the number and type of activities

(instrumental, leisure, social) in which survivors retained

participation after they had returned home and completed

rehabilitation (at least 3 mo after stroke). Because sensory

impairment is often experienced concurrently with motor

impairment, which may have an effect on participation,

we investigated the impact of both motor and somato-

sensory impairment on activity participation in our analyses.

Specifically, our objectives were as follows:

• Characterize activity participation outcomes of stroke survivors with and without somatosensory impairment

after stroke

• Determine whether sensory impairment, identified during the acute stroke phase (at or within a few days

of hospital admission after stroke) using the National

Institutes of Health Stroke Scale (NIHSS; Brott et al.,

1989), predicts activity participation in the postacute

phase, that is, after the survivor has returned home and

completed rehabilitation

• Determine the effects of somatosensory loss on partic- ipation in stroke survivors with or without paresis

• Explore the effects of somatosensory loss on participation in stroke survivors with and without paresis across the do-

mains of the Activity Card Sort (ACS; Baum & Edwards,

2001).

Method

Participants

The sample comprised a subset of participants from an

existing large stroke cohort (Wolf, Baum, & Connor, 2009).

Inclusion criteria were first clinical stroke; no history of

schizophrenia or dementia; and availability of required data,

which included the acute NIHSS individual item scores,

obtained on hospital admission, and the ACS construct

scores, collected after the participant had returned home

and completed rehabilitation.

A sample of 268 cases was obtained from a search

sample of 375 after an examination of missing data,

aphasia, neglect, pattern of paresis, and latency of the ACS

test. Cases with severe aphasia or neglect, defined as scores

The American Journal of Occupational Therapy 7203205100p2

greater than 1 on the relevant NIHSS scales, were excluded

because these conditions have the potential to confound

sensory deficit test results. Cases in which the ACS was

performed before 92 days poststroke were excluded. Because

sensory impairment of the upper limb is most likely associated

with activity participation restrictions, based on prior literature

(Desrosiers et al., 2002; Hill et al., 2014), and no separate

sensory assessment data were available for the lower limb, 36

cases with paresis in only the lower limb were also excluded.

Measures

The primary outcome was percentage of retained activity

participation, measured using the ACS. The ACS is a

reliable and valid instrument (Edwards, Hahn, Baum, &

Dromerick, 2006; Everard, Lach, Fisher, & Baum, 2000;

Tse, Douglas, Lentin, & Carey, 2013). A recent review

indicated that the ACS covers the most domains of the

ICF Activities and Participation domains, relative to

other measures, and meets the most psychometric prop-

erties (Tse et al., 2013). The version used to collect the

data in a telephone interview was the 55-item measure.

Participants reported on instrumental activities (e.g.,

shopping, household maintenance), social activities (e.g.,

visiting, studying), and high-demand (e.g., swimming,

running) and low-demand (e.g., reading, table games)

physical leisure activities. For each activity, participants re-

sponded to the following descriptors: never done, given up due to stroke, doing less often due to stroke, and doing now.

The previous activity score was calculated by adding the

doing now, doing less, and given up scores. The current

activity score was the total of the doing now and doing less scores. The retained participation score was obtained by

dividing the sum total of current activities by the total of

previous activities. Higher scores indicate higher retention

of prestroke activity. The primary score was the percentage

of retained overall activity participation, with additional

scores for the domains of Instrumental Activities, Social

Activities, High-Demand Leisure Activities, and Low-Demand

Leisure Activities.

The presence or absence of somatosensory impair-

ment and motor impairment was assessed by trained

nurses within a couple of days of hospital admission using

the NIHSS. The NIHSS is widely used early poststroke to

quantify the neurological impairment caused by stroke. It has

been repeatedly validated as a tool for assessing stroke severity

and as an excellent predictor for patient outcomes (Muir,

Weir, Murray, Povey, & Lees, 1996). Only somatosensory

loss attributed to stroke is scored as abnormal, and the ex-

aminer is required to test as many body areas (arms [not

hands], legs, trunk, face) as needed to accurately check for

hemisensory loss. Sensory loss is scored as 0 5 normal; no

sensory loss, 1 5 mild to moderate sensory loss, and 2 5 severe to total sensory loss. Motor impairment is tested separately for the arm and leg and is scored from 0 (no drift; limb

holds 90 [or 45] degrees for full 10 s) to 4 (no movement).

Procedure

Participants (N 5 268) were assessed at admission for somatosensory and motor impairment using the NIHSS.

The activity participation profile was assessed using the

ACS at least 3 mo poststroke.

Data Analysis

The NIHSS somatosensory loss variable was dichotomized

(unimpaired, impaired). Because paresis is known to have

a major impact on functionality and may interact with

somatosensation, particularly in upper limb function, the

sample was also split according to presence and distribution

of paresis. Degree of paresis was dichotomized (unimpaired,

impaired). The ACS scores were obtained in the postacute

phase, that is, after participants had completed rehabili-

tation, returned home, and were experiencing the impact of

stroke on their activity participation. If participants were

tested on the ACS on more than one occasion, we selected

the ACS scores closest to 182 days (6 mo) poststroke for

analysis. Analyses were performed with IBM SPSS Statistics

(Version 23; IBM Corp., Armonk, NY).

Between-group differences in participation were

tested for participants with and without somatosensory

impairment and with or without paresis. The primary

analysis focused on the total retained activity participation

scores. A set of five pairwise comparisons was planned to

evaluate contrasts of interest across the six independent

groups (2 levels of sensory loss · 3 levels of paresis). A primary family of three comparisons investigated the

impact of sensory loss in samples with different paresis

patterns (none, upper limb only, both upper and lower

limbs). To provide an interpretative framework for the

somatosensory loss effects, we used a secondary family of

two comparisons to investigate the effects of each of the

two paresis patterns in samples without sensory loss. The

ACS percentage of retained activity score was the out-

come variable. Because the total activity score is the total

of the four activity domains (Instrumental Activities,

Social Activities, High-Demand Leisure Activities, and

Low-Demand Leisure Activities), each of the four do-

mains of the ACS was used in exploratory secondary

analyses. The same set of comparisons as for the total

ACS retained activity score was used for each of these

secondary analyses.

7203205100p3 May/June 2018, Volume 72, Number 3

Results

The 268 cases included yielded a sample with a gender

distribution that slightly favored women (53.5%). Age

was normally distributed with a mean (M) of 62.8 yr and a standard deviation (SD) of 13.1 yr. There were 239 right dominant cases, 16 left dominant, and 3 ambi-

dextrous, with the remainder unknown. The median

NIHSS score for the sample was 3.00, with an

interquartile range of 1.00–5.00 (5th percentile 5 0.00; 95th percentile 5 9.95; range 5 0–15). The mean score was 3.71 (SD 5 3.11). The distribution of somato- sensory impairment and motor impairment in the

sample is summarized in Table 1. Activity participation

was measured at a median of 222 days poststroke. A

skewed distribution (M 5 279; median 5 222; interquartile range 5 184–303 days) with wide dispersion and long tail was noted for the latency of the ACS per-

formed closest to 182 days after admission.

Effects of Somatosensory Impairment on Overall Retained Activity Participation

Activity Participation Outcome With and Without Somatosensory Impairment. Stroke survivors with somato-

sensory loss and no paresis showed a significantly reduced

percentage of retained activity participation compared with

those with no sensory loss (z 5 1.96, p 5 .048, two-tailed). Compared with the median retained activity of 89.6%

observed in the comparison group without either paresis or

sensory impairments, the group with somatosensory im-

pairment uncomplicated by paresis had a lower median

retained activity of 81.6% (Figure 1). Because these samples

exhibited significant skew (skew parameters were 5.4 and

3.6 times their respective standard errors), Mann–Whitney

U tests were used to compare participation scores. These tests revealed that the 78.0% greater activity loss in the

group with sensory impairment (18.4% loss from pre-

stroke) was significantly higher than that of the comparison

group (10.4% loss) without either sensory or motor im-

pairment. Thus, somatosensory impairment, identified at

hospital admission using the NIHSS, significantly predicts

overall percentage of retained activity participation at a

median of 222 days poststroke in stroke survivors with

somatosensory impairment but no paresis.

Activity Participation Outcome With Paresis. Both so-

matosensory loss and paresis appear to be associated with

lower total ACS retained activity scores (Figure 1), al-

though all subgroups demonstrated a wide distribution

of individual differences in retained activity scores. Despite

the wide dispersion, several trends can be identified. Paresis

had the typically expected marked effect on reducing

activity participation (Figure 1). Paresis of the upper limb

alone virtually doubled the median activity loss. Whereas

this difference was more than comparable to the effect of

sensory loss alone, the paresis effect only approached ac-

cepted standards of statistical significance (z 5 1.90, p 5 .057, two-tailed), a result that needs to be interpreted in

the context of the very small sample size. Paresis in both

upper and lower limbs (without sensory loss) approxi-

mately tripled the activity loss in groups without sensory

impairment. This effect was both large and statistically

significant (z 5 4.62, p < .001, two-tailed). The effect of sensory loss in cases with upper limb

paresis was of smaller median magnitude (an additional

Table 1. Distribution of Paresis and Somatosensory Loss

Paresis

Somatosensory Loss

TotalUnimpaired Impaired

Unimpaired 119 34 153

Upper limb only 16 11 27

Upper and lower limbs 43 45 88

Total 178 90 268

Figure 1. Box plots showing overall percentage of retained activity scores poststroke as measured by the Activity Card Sort (ACS) in six groups of stroke survivors classified according to somatosen- sory impairment and paresis. Boxes indicate the 25th and 75th percentiles (i.e., the interquartile range [IQR]). The median (50th percentile) is represented by a line across and within the box. The whiskers extend from the upper and lower edges of the box to the highest and lowest values that are not greater than 1.5 times the IQR above or below the box limits. Outliers, represented by open circles, locate cases with values that deviate more than 1.5 times the IQR above or below the box limits.

The American Journal of Occupational Therapy 7203205100p4

4.6% loss) compared with that observed in the group

without paresis (additional 7.1% loss) and estimated with

lower power from smaller samples. The effect was not

significant. The expected strong influence of paresis on

activity loss appeared to mask any additional effect from

the presence of sensory loss (Figure 1). The median ac-

tivity losses in the two subgroups with upper limb and

lower limb paresis were the strongest of all six subgroups

but comparable to each other (Figure 1) and their dif-

ference not statistically significant.

Figure 2. Box plots illustrating distributions of percentage of retained activity scores of the Activity Card Sort (ACS) domains. Light gray bars represent groups without somatosensory loss; dark gray bars indicate groups with sensory loss. Median values are rounded to the nearest integer value. Outliers, represented by open circles, indicate cases with values that deviate from the median by more than 1.5 to 3 times the IQR. Extreme outliers (values >3 times the IQR) are indicated by solid circles.

7203205100p5 May/June 2018, Volume 72, Number 3

Effects of Somatosensory Impairment on Activity Card Sort Domains Investigation of the four domains of the total ACS sug-

gested that the pattern revealed in the total score tended to

repeat within each domain (Figure 2), the most parsi-

monious hypothesis given that the four domains sum to

the total ACS. In the absence of paresis, the ACS scores

generally suggest that somatosensory impairment reduced

participation recovery. Paresis tended to reduce recovery

of participation, particularly for those with paresis in both

upper and lower limbs. The effect of paresis in both limbs

masked the effect of somatosensory loss. However, dif-

ferences in the dispersions within groups for some do-

mains, some variations in the magnitude of the median

differences, and the small group sizes for those with upper

limb paresis alone resulted in somewhat different results

for the formal pairwise comparison sets.

The adverse effect of somatosensory loss on recovery

of activity was statistically significant for participants

without paresis in low-demand leisure and social activities,

but not in the other two domains (Table 2). An effect of

somatosensory loss was not detected for samples with

upper limb paresis (Table 2) in any of the domains, de-

spite the suggestion of such an effect in Figure 2 for low-

demand leisure, instrumental, and social activities. However,

the sample sizes for these comparisons were small, re-

sulting in lower statistical power. Paresis of the upper

limb alone did not significantly lower activity recovery in

any of the domains (Table 2), despite the suggestion of

such an effect in Figure 2. The stronger adverse effect on

activity caused by paresis of both limbs emerged clearly in

all ACS domains, all of which showed statistically sig-

nificant effects (Table 2).

Comparability of Subgroups on Age, Gender, and Handedness

Subgroups, divided according to paresis and somatosen-

sory loss, were compared on age, gender, and hemispheric

dominance. No statistically significant differences were

noted. In particular, cross-tabulation of gender distribu-

tion across sensory status revealed no statistically signifi-

cant difference for the subsamples without paresis (for

those with sensory loss, the female:male ratio was

50%:50%, whereas for those without sensory loss, the

ratio was 52.1%:47.9%). The overwhelming pre-

ponderance of right handers in the sample made domi-

nance an unlikely potential confounder of the sensory loss

effect found for cases without paresis. The obtained dis-

tributions were very skewed for both subsamples without

paresis (for those without sensory loss, the right:left

ratio was 92%:8%, whereas for those with sensory loss, it

was 97%:3%). Finally, age was very comparable for these

subgroups, with means of 63.8 yr (SD 5 12.8) and 61.9 yr

(SD 5 10.9), a difference that was not significant when

evaluated by a t test. To further verify that age and gender did not con-

found the observed relationship between sensory loss and

recovery of participation, we conducted several multiple

regressions using age, gender, latency of ACS tests, and di-

chotomized sensory impairment scores as conjoint predictors

of participation recovery measured by the ACS. Because the

ACS distributions were significantly skewed, the IBM SPSS

Statistics Generalized Linear Models subroutine was used to

fit the data several times, making a variety of distributional

assumptions. The regression model demonstrated that in the

group without paresis, the association between somatosen-

sory loss and the ACS score was statistically significant (p 5

.016), even after statistically controlling for the influence

of age, gender, and latency of ACS. In contrast, multiple

Table 2. Effects of Somatosensory and Motor Impairment on Activity Card Sort Domains Between Comparison Groups

Comparison Groups

Group A Group B

High-Demand Leisure Activities

Low-Demand Leisure Activities

Instrumental Activities Social Activities

Paresis Sensory Loss Paresis Sensory Loss z p z p z p z p

No No No Yes 0.896 .371 2.567* .010* 1.564 .118 2.112* .035*

Upper limb only No Upper limb only Yes 0.645 .557 1.559 .134 0.901 .904 0.687 .716

Upper and lower limbs No Upper and lower limbs Yes 0.143 .886 0.806 .420 0.698 .485 0.205 .837

No No Upper limb only No 1.420 .155 0.388 .698 1.615 .106 1.500 .133

No No Upper and lower limbs No 4.410* .000* 4.600* .000* 4.230* .000* 4.020* .000*

Note. Summary of key statistics obtained from Mann–Whitney pairwise tests conducted for four sets of five comparisons that replicated the primary analysis for each of the four domains of the ACS. The first three comparisons present the effects of somatosensory loss for each paretic status (no paresis, upper limb only, upper and lower limbs). The last two comparisons present the effects of paresis when there is no measured somatosensory loss. *p < .05.

The American Journal of Occupational Therapy 7203205100p6

regressions showed that the relationship between sensory loss

and ACS scores was not significant (p 5 .49) in the group with paresis of an upper limb or in the group with paresis of

both upper and lower limbs (p 5 .89). These results support the conclusions reached through nonparametric analyses,

reported earlier in this article.

Discussion

Somatosensory impairment at hospital admission after

stroke is associated with more activity participation loss

compared with survivors without somatosensory loss,

when there is no concomitant paresis. This predictive

association was identified in a longitudinal cohort (N 5

268) of stroke survivors with mild impairment (median

NIHSS score 5 3.00; interquartile range 5 1.00–5.00). It

is based on a dichotomous measure of somatosensory

impairment (NIHSS) obtained early poststroke, at the

time of hospitalization, and on quantitative measurement

of retained activity participation (ACS) in instrumental,

leisure, and social activities at a median time of 222 days

poststroke. This study addresses an identified gap in the

literature, highlighted recently in two reviews (Carey et al.,

2016; Meyer et al., 2014). Our finding is consistent with

and advances the current literature on the effect of somato-

sensory impairment on activity participation (Desrosiers

et al., 2002; Hill et al., 2014; Morris, van Wijck, Joice, &

Donaghy, 2013). It demonstrates a predictive relation-

ship between somatosensory loss identified during the

acute phase after stroke, using an acute screening mea-

sure, and actual retained activities during the postacute

phase, when people had completed rehabilitation, re-

turned home, and were experiencing the impact of stroke

on their activity participation (median 5 7.4 mo post- stroke). Previous studies have been cross-sectional (Hill

et al., 2014) or have shown a predictive relationship from

2 to 4 wk after stroke or from hospital discharge to 6 mo

poststroke (Desrosiers et al., 2002; Morris et al., 2013).

Paresis affecting both upper and lower limbs, as

expected, also caused a major reduction in the percentage of

retained activity participation, an effect larger than that

resulting from somatosensory deficit alone. Paresis with the

addition of sensory deficit does not appear to further in-

crease loss in participation when there is paresis of both

upper and lower limbs, though a larger sample is needed to

clarify whether paresis of the upper limb only has as del-

eterious an effect on participation as when paresis is ac-

companied by sensory loss. In other words, the data suggest

that motor impairment in both upper and lower limbs is

sufficient to cause loss of activity participation over a wide

enough range of activities so that the addition of sensory

impairment may be insufficient to compromise additional

activity participation.

Results suggest that the presence of loss of activity

participation associated with paresis of both upper and

lower limbs can mask the contribution of somatosensory

loss and may promote an impression that somatosensory

loss can be left untreated. However, as the group with

sensory impairment unaccompanied by paresis shows,

sensory impairment alone does significantly affect par-

ticipation in everyday activities. Although an empirical

investigation using interventions to manipulate motor and

sensory impairments is ultimately necessary, the results

raise the risk that if motor impairment only, and not

sensory impairment, is addressed by intervention, the

reduction in activity participation as a result of sensory loss

will be unmasked. Addressing only motor impairment

may lead to suboptimal therapeutic effects in patients

whose somatosensory deficit has remained.

Unless motor rehabilitation training addresses sensory

deficits (indirectly), or perhaps the survivors’ confidence to

engage in activities, outcomes for stroke survivors will likely

be diminished. Historically, clinicians and researchers have

given precedence to the motor sequelae of stroke, ne-

glecting somatosensation (Kalra, 2010), but despite good

movement capacity, survivors with sensory loss learn to not

use their limb for task performance (Carey, 1995; Connell

et al., 2013; Dannenbaum & Dykes, 1988). Therefore,

according to our findings, sensory deficit alone has suffi-

cient impact on retained activity participation to include a

somatosensory intervention focus in therapeutic programs.

Exploration of the effect of somatosensory impair-

ment on the ACS domains revealed a significant impact on

low-demand leisure and social activities but not on high-

demand leisure and instrumental activities. The association

with social and low-demand leisure activities is consistent

with findings for social roles, as assessed with the Assess-

ment of Life Habits (Desrosiers et al., 2002) and the social

isolation and perceived physical activity subscales of the

Nottingham Health Profile (Morris et al., 2013). Although

the reduced statistical sensitivity resulting from small sample

sizes must be noted, we did not find a significant association

with instrumental activities, potentially at variance with the

low but significant association between somatosensation at

discharge and ADLs (Desrosiers et al., 2002).

The data confirm clinical impressions that the range of

individual differences in retained activity participation is large

after stroke, even when there is neither sensory nor paretic

impairment nor neglect or aphasia. Clearly, much remains to

be added to predict activity participation poststroke beyond

the measures used here. However, it is possible to anticipate

7203205100p7 May/June 2018, Volume 72, Number 3

that these large individual differences cause strategic decisions

about approach to therapy (e.g., ignore somatosensory im-

pairment) difficult to make on the basis of clinical impres-

sions and individual assessment alone. Population-wide,

epidemiologically informed reasoning using empirical mea-

surement of impairment is indicated by these results.

Limitations and Recommendations for Future Research

The sensory subscale of the NIHSS was used to identify

the presence of somatosensory loss. Although this tool is

commonly used to assess the presence and severity of acute

neurological impairment and involves standardized ad-

ministration, testing of somatosensation is not quantitative

or supported by psychometric data. Studies using quanti-

tative somatosensory measures with strong psychometric

properties to better assess the nature and extent of the

predictive relationship are indicated. A further benefit

would be assessment of the ability of this commonly used

clinical measure to predict quantitative somatosensory im-

pairment tests with evaluated reliability and validity.

The NIHSS was administered only once, at or within

a few days of hospital admission after stroke. Therefore,

when sensory loss, aphasia, neglect, or other NIHSS var-

iables were involved, the analyses indicate a predictive re-

lationship based on the patient status on these variables at

admission. The level of sensory loss, neglect, aphasia, and so

forth at the time of ACS administration is unknown.

To protect against the possibility that an earlier ACS

may have influenced the data, we conducted a post hoc

analysis excluding participants from the sample with ACS

scores obtained in the 92–155 days range. Findings from

this trimmed sample (N 5 240) essentially remained the

same: There was a somatosensory loss effect in the ab-

sence of paresis (total retained activity participation: z 5

2.50, p 5 .012; low-demand leisure: z 5 2.90, p 5

.004; social: z 5 2.75, p 5 .006; instrumental z 5 2.04,

p 5 .042) and a highly significant effect of paresis in both

limbs for total retained activities and all subcategories

(z 5 3.88–4.26, p < .001). Finally, use of existing data from the prospective

cohort limited choice of measures and the demographic and

organismic covariates that might be studied. Our initial

findings of a predictive association does however encourage

future studies to verify the observation. A design is rec-

ommended that uses superior measurement tools for so-

matosensory deficit and paresis and considers demographic

or organismic variables that might arguably influence

participation recovery or the strength of the relationship

between somatosensory impairment and participation in a

sufficiently large sample.

Implications for Occupational Therapy Practice

Our findings have the following implications for occu-

pational therapy practice:

• Practitioners should assess for the presence of somato- sensory impairment in stroke survivors, given its impact

on participation, especially in those without concomitant

paresis.

• Rehabilitation directed at upper limb function and return to participation in previous life activities should

consider investigation of the effect of interventions

with a specific focus on somatosensory phenomena.

• Therapeutic program planning should consider that the impact of somatosensory impairment may be un-

masked when rehabilitation has been directed only at

motor impairment recovery and the result has been

below expectation.

• Clinical evaluation and treatment in stroke have tradition- ally focused on addressing motor impairment without

considering the impact of somatosensory functions. Our

findings suggest that additional gain may be obtained in

participation outcomes by augmenting motor-based inter-

ventions with a somatosensory rehabilitation component.

Investigations of this possibility are supported by the pre-

sent findings.

Conclusion

Somatosensory impairment is associated with reduced

activity participation. On the basis of evidence that so-

matosensory improvements are obtained, a focus on so-

matosensory intervention in rehabilitation is recommended

for people with somatosensory impairment (Carey et al.,

2011). Monitoring participation outcomes may yield evi-

dence of additional improvements in participation asso-

ciated with somatosensory intervention. Such investigation

will be important in furthering evidence not only of the

relationship between somatosensory impairment and par-

ticipation but also the potential impact of somatosensory-

focused interventions on participation outcomes. Our

findings also indicate that paresis of the upper and lower

limbs can mask the contribution of sensory loss. This

finding suggests that the potential impact of somatosensa-

tion on participation when movement returns should not be

ignored. s

The American Journal of Occupational Therapy 7203205100p8

Acknowledgments

We acknowledge financial support for this research from

the James S. McDonnell Foundation (JSMF Grants

21002032 and 220020087, awarded to CB) and National

Health and Medical Research Council (NHMRC) Grants

307902 and 1022694 (awarded to LMC) and support

for analysis, write-up, and researchers from the James S.

McDonnell Foundation 21st Century Science Initiative

in Cognitive Rehabilitation Collaborative Award (JSMF

Grant 220020413), the Victorian Government’s Opera-

tional Infrastructure Support Program, an Australian

Research Council Future Fellowship (FT0992299), and an

NHMRC Career Development Award (307905) awarded

to LMC. We acknowledge the contribution of Lisa Tabor

Connor to an earlier presentation of preliminary data re-

lated to this study and to Tamara Tse for assistance with

data compilation and checking.

References Baum, C. M., & Edwards, D. F. (2001). Activity Card Sort

(ACS): Test manual. St. Louis: Program in Occupational Therapy, Washington University School of Medicine.

Blennerhassett, J. M., Carey, L. M., & Matyas, T. A. (2008).

Clinical measures of handgrip limitation relate to impaired

pinch grip force control after stroke. Journal of Hand Ther- apy, 21, 245–253. https://doi.org/10.1197/j.jht.2007.10.021

Blennerhassett, J. M., Matyas, T. A., & Carey, L. M. (2007).

Impaired discrimination of surface friction contributes

to pinch grip deficit after stroke. Neurorehabilitation and Neural Repair, 21, 263–272. https://doi.org/10.1177/ 1545968306295560

Borstad, A. L., & Nichols-Larsen, D. S. (2014). Assessing and

treating higher level somatosensory impairments post

stroke. Topics in Stroke Rehabilitation, 21, 290–295. https:// doi.org/10.1310/tsr2104-290

Brott, T., Adams, H. P., Jr., Olinger, C. P., Marler, J. R.,

Barsan, W. G., Biller, J., . . . Hertzberg, V. (1989). Mea-

surements of acute cerebral infarction: A clinical examina-

tion scale. Stroke, 20, 864–870. https://doi.org/10.1161/ 01.STR.20.7.864

Carey, L. M. (1995). Somatosensory loss after stroke. Critical Reviews in Physical and Rehabilitation Medicine, 7, 51–91. https://doi.org/10.1615/CritRevPhysRehabilMed.v7.i1.40

Carey, L. M. (2012). Touch and body sensations. In L. M.

Carey (Ed.), Stroke rehabilitation: Insights from neuroscience and imaging (pp. 157–172). New York: Oxford University Press. https://doi.org/10.1093/med/9780199797882.003.0012

Carey, L. M. (2015). Person factors. In C. H. Christiansen,

C. M. Baum, & J. Bass (Eds.), Occupational therapy: En- abling performance, participation and well-being (4th ed., pp. 249–265). Thorofare, NJ: Slack.

Carey, L. M., Lamp, G., & Turville, M. (2016). The state-of-

the-science of somatosensory function and its impact on

daily life in adults and older adults, and following stroke: A

scoping review. OTJR: Occupation, Participation and Health, 36, 27S–41S. https://doi.org/10.1177/1539449216643941

Carey, L., Macdonell, R., & Matyas, T. A. (2011). SENSe:

Study of the Effectiveness of Neurorehabilitation on Sen-

sation: A randomized controlled trial. Neurorehabilitation and Neural Repair, 25, 304–313. https://doi.org/10.1177/ 1545968310397705

Carey, L. M., & Matyas, T. A. (2011). Frequency of discrim-

inative sensory loss in the hand after stroke in a rehabili-

tation setting. Journal of Rehabilitation Medicine, 43, 257–263. https://doi.org/10.2340/16501977-0662

Connell, L. A., McMahon, N. E., & Adams, N. (2013). Stroke

survivors’ experiences of somatosensory impairment after

stroke: An interpretive phenomenological analysis. Physio- therapy, 100, 150–155. https://doi.org/10.1016/j.physio.2013. 09.003

Dannenbaum, R. M., & Dykes, R. W. (1988). Sensory loss

in the hand after sensory stroke: Therapeutic rationale.

Archives of Physical Medicine and Rehabilitation, 69, 833–839.

Desrosiers, J., Noreau, L., Rochette, A., Bravo, G., & Boutin, C.

(2002). Predictors of handicap situations following post-

stroke rehabilitation. Disability and Rehabilitation, 24, 774–785. https://doi.org/10.1080/09638280210125814

Edwards, D. F., Hahn, M., Baum, C., & Dromerick, A. W.

(2006). The impact of mild stroke on meaningful activity and

life satisfaction. Journal of Stroke and Cerebrovascular Diseases, 15, 151–157. https://doi.org/10.1016/j.jstrokecerebrovasdis. 2006.04.001

Everard, K. M., Lach, H. W., Fisher, E. B., & Baum, M. C.

(2000). Relationship of activity and social support to the

functional health of older adults. Journals of Gerontology, Series B: Psychological Sciences and Social Sciences, 55, S208–S212. https://doi.org/10.1093/geronb/55.4.S208

Hill, V. A., Fisher, T., Schmid, A. A., Crabtree, J., & Page,

S. J. (2014). Relationship between touch sensation of the

affected hand and performance of valued activities in in-

dividuals with chronic stroke. Topics in Stroke Rehabilita- tion, 21, 339–346. https://doi.org/10.1310/tsr2104-339

Jeannerod, M., Michel, F., & Prablanc, C. (1984). The control

of hand movements in a case of hemianaesthesia following

a parietal lesion. Brain, 107, 899–920. https://doi.org/ 10.1093/brain/107.3.899

Kalra, L. (2010). Stroke rehabilitation 2009: Old chestnuts and

new insights. Stroke, 41, e88–e90. https://doi.org/10.1161/ STROKEAHA.109.572297

Kessner, S. S., Bingel, U., & Thomalla, G. (2016). Somato-

sensory deficits after stroke: A scoping review. Topics in Stroke Rehabilitation, 23, 136–146. https://doi.org/10.1080/ 10749357.2015.1116822

Klit, H., Finnerup, N. B., Andersen, G., & Jensen, T. S. (2011).

Central poststroke pain: A population-based study. Pain, 152, 818–824. https://doi.org/10.1016/j.pain.2010.12.030

Kong, K. H., Chua, K. S., & Lee, J. (2011). Recovery of upper

limb dexterity in patients more than 1 year after stroke: Fre-

quency, clinical correlates and predictors. NeuroRehabilita- tion, 28, 105–111. https://doi.org/10.3233/NRE-2011-0639

7203205100p9 May/June 2018, Volume 72, Number 3

Law, M., Baptiste, S., Carswell, A., McColl, M. A., Polatajko, H., & Pollock, N. (2014). Canadian Occupational Performance Measure (5th ed.). Ottawa: CAOT Publications.

Lawrence, E. S., Coshall, C., Dundas, R., Stewart, J., Rudd, A. G., Howard, R., & Wolfe, C. D. A. (2001). Estimates of the prevalence of acute stroke impairments and disabil- ity in a multiethnic population. Stroke, 32, 1279–1284. https://doi.org/10.1161/01.STR.32.6.1279

Meyer, S., Karttunen, A. H., Thijs, V., Feys, H., & Verheyden, G. (2014). How do somatosensory deficits in the arm and hand relate to upper limb impairment, activity, and participation problems after stroke? A systematic review. Physical Therapy, 94, 1220–1231. https://doi.org/10.2522/ptj.20130271

Morris, J. H., van Wijck, F., Joice, S., & Donaghy, M. (2013). Predicting health related quality of life 6 months after stroke: The role of anxiety and upper limb dysfunction. Disability and Rehabilitation, 35, 291–299. https://doi. org/10.3109/09638288.2012.691942

Muir, K. W., Weir, C. J., Murray, G. D., Povey, C., & Lees, K. R. (1996). Comparison of neurological scales and scor- ing systems for acute stroke prognosis. Stroke, 27, 1817–1820. https://doi.org/10.1161/01.STR.27.10.1817

Nowak, D. A., & Hermsdörfer, J. (2005). Grip force behavior during object manipulation in neurological disorders: To- ward an objective evaluation of manual performance def- icits. Movement Disorders, 20, 11–25. https://doi.org/ 10.1002/mds.20299

Park, S. W., Wolf, S. L., Blanton, S., Winstein, C., & Nichols- Larsen, D. S. (2008). The EXCITE trial: Predicting a

clinically meaningful motor activity log outcome. Neuro- rehabilitation and Neural Repair, 22, 486–493. https://doi. org/10.1177/1545968308316906

Reding, M. J., & Potes, E. (1988). Rehabilitation outcome

following initial unilateral hemispheric stroke: Life table

analysis approach. Stroke, 19, 1354–1358. https://doi.org/ 10.1161/01.STR.19.11.1354

Tse, T., Douglas, J., Lentin, P., & Carey, L. (2013). Measuring

participation after stroke: A review of frequently used

tools. Archives of Physical Medicine and Rehabilitation, 94, 177–192. https://doi.org/10.1016/j.apmr.2012.09.002

Tyson, S. F., Hanley, M., Chillala, J., Selley, A. B., & Tallis,

R. C. (2008). Sensory loss in hospital-admitted people

with stroke: Characteristics, associated factors, and

relationship with function. Neurorehabilitation and Neural Repair, 22, 166–172. https://doi.org/10.1177/ 1545968307305523

Winward, C. E., Halligan, P. W., & Wade, D. T. (2002). The

Rivermead Assessment of Somatosensory Performance

(RASP): Standardization and reliability data. Clinical Rehabilitation, 16, 523–533. https://doi.org/10.1191/ 0269215502cr522oa

Wolf, T. J., Baum, C., & Connor, L. T. (2009). Changing face

of stroke: Implications for occupational therapy practice.

American Journal of Occupational Therapy, 63, 621–625. https://doi.org/10.5014/ajot.63.5.621

World Health Organization. (2001). International classification of functioning, disability and health. Geneva: Author.

The American Journal of Occupational Therapy 7203205100p10

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