Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 30
Spatial neglect and cognitive impairment
Thus, the association between USN and recovery of
gait independence remains controversial.
Other cognitive impairments (CIs), such as memory
deficits and non-spatial attention deficits, are common
symptoms in stroke survivors, and they negatively in-
fluence their functional outcome (15, 16). In addition,
previous studies have reported that, compared with
stroke survivors without USN, those with USN are
more likely to have other cognitive dysfunctions (17,
18). Thus, it is important to consider other cognitive
functions in addition to USN in the prediction of gait
ability in stroke survivors.
The Mini-Mental State Examination (MMSE) is an
easily applicable and most widely used instrument in
screening for CIs in stroke survivors. Several studies
have reported acceptable validity of the MMSE as a
screening tool and its relationship with functional re-
covery in stroke survivors (19–21). In addition, another
previous study reported that the MMSE score reflects
the number of disturbed cognitive domains, such as
memory, mental speed, and non-spatial attention, in
subacute stroke survivors (22). Although the value of
the MMSE in screening for cognitive dysfunctions in
stroke survivors remains controversial (23), it is con-
sidered a useful indicator for conveniently evaluating
other cognitive dysfunctions.
This study aimed to investigate the impact of USN
with or without other CIs on the recovery of independent
gait in subacute stroke survivors. We hypothesized that
the presence of USN without other CIs would be less
negatively associated with the recovery of independent
gait, and that it might be a strong negative factor when
combined with other CIs. Clarification of these rela-
tionships would help in considering the prognostic pre-
diction and interventions for regaining independent gait.
METHODS
Participants
This prospective cohort study was conducted on stroke survivors
admitted to the 37-bed convalescent inpatient rehabilitation
ward of our hospital from April 2011 to March 2017. Diagnosis
of stroke was based on clinical examination by a physiatrist and
an imaging test (computed tomography or magnetic resonance
imaging) by a radiologist. Inclusion criteria were: first stroke in
the right brain hemisphere; diagnosis of cerebral haemorrhage
or cerebral infarction; independence in performing ADL prior
to stroke; and requirement for a wheelchair for locomotion on
admission. Exclusion criteria were: presence of neuromuscular
diseases or severe musculoskeletal diseases, worsening medical
conditions during hospitalization (such as a recurrence of stroke
or severe infection that would contraindicate rehabilitation), and
inability to complete the assessment. In addition, participants
who had a diagnosis of dementia prior to stroke, and those who
had a pharmacological intervention on cognitive impairments
prior to stroke were excluded. The study was conducted in
27
accordance with the principles of the Declaration of Helsinki,
and it was reviewed and approved by the ethics committees of
our hospital (approval number: 27–20).
Evaluation of unilateral spatial neglect
The presence of USN was assessed by the visuospatial percep-
tion score of the Stroke Impairment Assessment Set (SIAS) (24).
The visuospatial perception score of the SIAS was evaluated
on admission and at discharge. A 50-cm long tape measure was
used for evaluation, and the central point method was adopted.
Participants were asked to touch the midpoint of a tape held
horizontally 50 cm in front of them, using the unaffected thumb
and index finger. Two trials were allowed, and the worst error
was used for the scoring value. If there was more than a 15-cm
deviation from the midpoint, the score was 0. An error between
15 cm and 5 cm was scored as 1, while an error between 5 cm
and 2 cm was scored as 2. A score of 3 meant deviation from
the midpoint by less than 2 cm. We defined the presence of USN
as a visuospatial perception score of 2 or less. This method was
confirmed to have good inter-rater reliability and concurrent
validity, assessed via 20-cm line bisection and flower-and-cube
copying tasks in stroke survivors (24).
Other cognitive functions
Other cognitive functions were assessed on admission by using
the MMSE, which consists of the following 5 areas of cognitive
functions: orientation, memory, attention and calculation, langu-
age, and construction. The total scores vary from 0 to 30, with
higher scores indicating better cognitive functions. In this study,
other CIs were defined as a score of less than 24 in the MMSE (the
cut-off value was defined by referring to previous studies) (10, 21).
Outcome variable
We investigated the gait dependency of the participants upon
discharge, with the walking score of the Functional Indepen-
dence Measure (FIM) (25) as the outcome measure. A FIM
walking score of 7 corresponds to complete independence,
wherein the participant can safely walk a minimum of 150 ft (50
m) without using assistive devices. A FIM walking score of 6
corresponds to modified independence, wherein the participant
can walk a minimum of 150 ft (50 m) without supervision, but
with the support of a brace (orthosis) or cane. FIM walking
scores of 1–5 correspond to requiring help or supervision and
are determined by the level of physical assistance required for
walking. In this study, gait independence was defined as a FIM
walking score of 6 or more, according to a previous study (26).
Other variables
Demographic characteristics and stroke-related information
including age, sex, stroke type (cerebral infarction or cerebral
haemorrhage), number of days from onset of stroke to admis-
sion, length of stay, body mass index, comorbidity, use of medi-
cation (antidepressants and anxiolytics), severity of hemiplegia
of the lower limb, and ability to perform ADL were investigated
on admission to our rehabilitation ward. Comorbidity was asses-
sed using the Charlson comorbidity index (CCI) (27). The CCI
is an evaluation index with 1 to 6 points for 19 comorbidities,
with a higher score indicating greater comorbidity. The seve-
rity of hemiplegia was determined in terms of the Brunnstrom
recovery stages (BRS) (28). The BRS classifies voluntariness
in paralysed limbs into 6 ordinal stages, with the lower stages
J Rehabil Med 51, 2019