unilateral neglect ( un ) refers to the neuropsychological condition in which patients 
 experience reduced orientation and concentration and response to stimuli on the 
 contralesional side owing to behavioral problems that occur after brain injury , although 
 these patients having sensorimotor abilities1 .
un is caused by various forms of brain damage and has an especially 
 high incidence in patients with stroke in the right inferior parietal lobe2 .
it is 
 negatively associated with the rehabilitation period because patients with un show 
 relatively poor functional recovery compared with those without un3 .
in addition , these patients experience difficulties in 
 activities of daily living ( adl ) , including maintaining personal hygiene , eating , and 
 dressing , and also are at increased risk of falling because of gait disturbance4 . therefore , having an appropriate treatment 
 and strategy are important while treating this condition because it is essential to reduce 
 un to achieve effective rehabilitation in these patients .
we proposed a new treatment method for un by modifying current treatment methods and 
 combining them with mental practice and electromyogram - triggered electrical stimulation 
 ( mp - emg es ) .
mp - emg es is a new , state - of - the - art rehabilitation treatment technology based 
 on neurologic theories .
mp - emg es involves only repetitive mental practice ( for example , 
 imagination of intense movement of the upper limbs on the neglected side ) , not voluntary 
 muscular contraction . when the generated electric potential reaches a preset threshold , an 
 electric stimulus is generated , resulting in actual muscular contraction and cortical 
 activation5 .
in other words , mp - emg es 
 can produce a synergistic effect by combining two treatments ( mental practice plus 
 electrical stimulation ) with proven efficacy in the alleviation of neglect .
the purpose of 
 this study was to identify the effects of this novel training method 
mp combined with emg 
 es  over a 6-week period of daily training in patients showing right brain damage with 
 un .
the participants for this study were recruited from the rehabilitation center of a local 
 university hospital .
the inclusion criteria for participation were : ( 1 ) onset duration of 
 > 6 months , ( 2 ) right hemisphere stroke with un , ( 3 ) mini - mental status 
 examination score > 24 , ( 4 ) ability to imagine ( average score on the 
 vividness of movement imagery questionnaire < 3 ) , and ( 5 ) active wrist muscle strength 
 > 2 on the medical research council ( mrc ) scale .
exclusion criteria were : ( 1 ) an implanted 
 cardiac pacemaker , ( 2 ) skin lesion on the affected side or hypersensitivity at the electrode 
 site , ( 3 ) a history of seizure or epilepsy , and ( 4 ) unstable medical conditions . in total , 
 thirty - three stroke patients with neglect were eligible for this study .
all participants 
 provided written informed consent , and this study was approved by the inje university 
 institution review board .
this study was designed as a single - blind randomized control study and was scheduled to 
 last for a total 6 weeks .
eligible participants were randomly allocated to the two groups by 
 block randomization using opaque envelopes containing a code specifying the group .
the 
 experimental group ( n=16 ) received mp - emg es in addition to conventional rehabilitation 
 therapy ( crt : physical therapy and occupational therapy ) , whereas the control group ( n=17 ) 
 received cyclic es in addition to the same crt .
mentamove ( mentamove deutschland gmbh , 
 munich , germany ) was used to apply mp - emg es in the experimental group .
surface electrodes 
 were attached to the wrist extensor muscle and a reference electrode was attached at the 
 lateral side of the forearm .
the site of electrode placement was marked using a permanent 
 marker throughout the intervention . during motor imagery training ,
when the potentials reached 
 a preset threshold , the induced electrical stimulation would contract the targeted 
 muscle .
the mentamove process consisted of three stages : ( 1 ) motor imagery ( approximately 12  s ) , 
 ( 2 ) electrical stimulation ( approximately 6  s ) , and ( 3 ) relaxation ( approximately 12  s ) .
the 
 motor imagery used in this study was a vigorous waving of the affected whole arm .
this 
 imagery was selected because the emg was not able to detect electrical stimulation induced 
 by motor imagery of simple extension of the wrist or elbow .
the emg pick - up threshold was 
 set afresh for each subject in every session .
if the subject repeatedly reached the 
 threshold during the mp - emges , the threshold was automatically increased slightly .
imagine that your left 
 arm moves rapidly and intensely when you see  motor imagery  in the tool window .
if your 
 performance is successful , you will experience an electrical stimulation in your forearm .
cyclic es ( mendel gmbh , germany ) without the emg function was used to apply electrical 
 stimulation in the control group .
electrodes also were attached to the wrist extensor 
 muscle . in either instrument , biphasic pulses with a frequency of 35  hz and pulse width of 

200 s were applied for 12 s. stimulation intensity led to a clear extension of the wrist 
 ( average 2030 ma ) . over a period of 6 weeks , both groups were treated 30 times in two 
 30-min sessions . the line bisection test ( lbt ) , star cancellation test ( sct ) , and catherine bergego scale 
 ( cbs ) were used to quantify the severity of un .
twenty lines were drawn on an 
 a4 sheet parallel to the long axis , and 18 of these lines were organized into 3 set of 6 : 1 
 set lay primarily on the left , 1 at the center , and 1 on the right side of the sheet .
the 
 evaluator initially demonstrated the procedure by marking the 2,150-mm lines at the top and 
 bottom of the sheet .
patients were asked to mark the center points of each of the 18 lines 
 in order .
distances from the left of each line to patient s marks and to true line centers 
 were measured .
deviations were measured using the formula : percent deviation ( % ) = [ ( marked 
 left side distance - true half length)/true half length ]  100 . in sct ,
the left and right halves 
 of the sheet each contained 27 stars , and patients were asked to mark all of the stars .
the 
 scores range from 0 to 27 , with lower scores indicating more severe un .
assessment using cbs 
 involved evaluating the performance of patients by directly observing them perform 
 activities ( e.g. , dressing , grooming ) in real - life situations , and consisted of 10 items . 

each item was scored on a four - point scale as follows : 0 : no neglect 110 : mild neglect , 
 1120 : moderate neglect , and 2130 : severe neglect7 .
participant characteristics were analyzed using a statistical software program ( spss 
 statistics 20 ) and descriptive statistics were presented as mean  sd . the shapiro - wilk test 
 was used to check normality of the outcome variables . to evaluate the intervention effects , 
 measures before and after the intervention in each group
an independent t - test was used to compare changes in outcome measures between the 
 two groups .
all demographic and clinical characteristics of the participants were comparable and are 
 summarized in table 1table 1.baseline characteristics of the subjects included in the studyexperimental group ( n=16)control group ( n=17)gendermale10 8 female69age ( years)67.510.362.210.2time post stroke ( months)3.31.33.51.6stroke typehemorrhage45infarction1212 .
the experimental group showed a significant improvement in the lbt ( p<0.01 ) , cbs , and sct 
 ( p<0.05 ) scores after the intervention compared with the values obtained before the 
 intervention ( table 
 2table 2.clinical parameters before and after the treatment ( n=33)experimental group control groupbeforeafterbeforeaftercbs12.14.210.14.612.63.811.24.1lbt30.58.924.110.332.69.127.710.6sct10.65.213.05.5 9.25.211.04.6the values are mean  standard deviation .
cbs : catherine bergego scale , lbt : line 
 bisection test , sct : star cancellation test .
* p<0.05 by paired t test between the 
 initial and final scores in the group .
on the other hand , no significant difference was observed in the control 
 group , except in the lbt score ( p<0.05 ) .
no significant differences were observed in the 
 lbt , cbs , and sct scores between the two groups after treatment .
cbs : catherine bergego scale , lbt : line 
 bisection test , sct : star cancellation test .
* p<0.05 by paired t test between the 
 initial and final scores in the group .
mp - emg es is a recently developed method that produces tiny electrical signals in the brain 
 through mental practice , rather than through actual physical movements , and this method is 
 used to induce muscle contraction in the upper extremity ( u / e ) on the neglected side . in 
 other words ,
the aim of mp - emg es is to form sensorimotor circuits for movement through a 
 repeated cycle of brain signal  transmission  muscle movement , which can be used to 
 produce functional changes in the central nervous system and the body .
the continual 
 activation of these circuits helps reorganize the damaged areas of the cerebral cortex8 .
it is thought that mp - emg es works by 
 inducing neural and peripheral changes through activation of the cerebral cortex via mental 
 practice and afferent stimulation of the neglected u / e via electrical stimulation .
hong et al.5 reported mp - emg es is more 
 effective than cyclic es for improving motor function on the affected side and improves 
 cerebral glucose metabolism in supplementary motor , precentral and postcentral gyri on the 
 contralesional side .
however , there is little evidence about the effects of this treatment 
 in cases of un . in this study
, we investigated the effects of mp - emg es on neglect in 
 comparison with those of cyclic es .
cbs , lbt and sct scores significantly improved after 
 treatment in the experimental group .
the control group received various crt interventions 
 that were the same as the experimental group .
this control treatment was important because 
 cyclic es has been proven to alleviate neglect to some extent by applying afferent 
 stimulation to the neglected side .
therefore , while the control group only showed a 
 significant improvement in lbt , they also showed a slight improvement in scores for cbs and 
 sct , and as a result , no significant differences were demonstrated between the two groups in 
 any assessments .
some studies 
 reported that mental practice is effective for rehabilitation in patients with 
 contralesional neglect , but it is difficult to verify whether patients imagine the specific 
 movement well9 .
mp - emg es seems to remedy 
 the deficiencies of mental practice alone . in this study , patients were instructed to imagine a large and powerful movement of the 
 neglected u / e during the mental practice stage of mp - emg es treatment . when imagining the 
 movement of the neglected u / e , the muscles in the u / e show dynamic regulation and 
 changes5 .
in this regard , when a 
 participant imagined a complex and powerful movement instead of a simple movement , the 
 motor - evoked potential and the excitation in the corticospinal tract increased10 .
this study showed that mp - emg es is an effective method for reducing unilateral neglect in 
 stroke patients .
however , several factors need to be considered when applying this method . 
 because mp - emg es requires the patient to be capable of imaging movement of the body on the 
 neglect side
 [ purpose ] the aim of this study was to investigate the effect of mental practice combined 
 with electromyogram - triggered electrical stimulation on neglect and activities of daily 
 living in stroke patients with unilateral neglect . [ subjects and methods ] thirty - three 
 stroke patients with unilateral neglect were recruited from a local university hospital , 
 and were divided into two groups . 
 the experimental group received an intervention 
 consisting of mental practice combined with electromyogram - triggered electrical 
 stimulation on the neglected side , while the control group received cyclic electrical 
 stimulation at the same site . 
 in addition , both groups received an identical intervention 
 of conventional occupational and physical therapy . 
 [ results ] after the intervention , the 
 experimental group showed a statistically significant improvement in the line bisection 
 test result , star cancellation test result , and catherine bergego scale scores . 
 the 
 control group showed a significant improvement only in the line bisection test result . 
 
 [ conclusion ] these data suggest that mental practice combined with 
 electromyogram - triggered electrical stimulation is an effective , novel treatment for 
 reducing unilateral neglect in stroke patients . 