document: deficits of motor and sensory functions after stroke on the side contralateral to the 
   damaged hemisphere are often evident1 , 
   whereas the ipsilateral side may be primarily regarded as normal or unaffected . however , 
   there is increasing evidence of the presence of subtle motor deficits in motor performance 
   on the ipsilateral side as well2 , 3 . 
   ipsilateral motor deficits emerge during 
   the acute phase and demonstrate chronic persistence3,4,5 ; the reasons for ipsilateral motor deficits are still unclear . 
   clinical assessment tools may not be sufficient for differentiating ipsilateral motor 
   deficits ; however , deficits in dexterous motor and coordination function on the ipsilateral 
   side have been identified in laboratory testing2 , 
   6,7,8 . 
   however , kinematic deficits in the ipsilateral upper limb in performance of various specific 
   motor tasks requiring dexterity and coordination , such as a tracking task , a goal - direction 
   movement , and a tapping task , have been found in recent studies2 , 6 , 8 , 11 . on the basis of these 
   observations , several possible mechanisms for ipsilateral motor deficits 
   have been 
   suggested , such as disrupted counterbalance of each hemisphere , dysfunction of the uncrossed 
   corticospinal track , or the different roles of both sides in hemispheric functions6 , 7 , 11,12,13,14,15 . 
   as mentioned above , patients with brain damage suffer from ipsilateral motor deficits in 
   performance of the ipsilateral upper limb . 
   until now , most studies of ipsilateral deficits 
   in stroke patients have concentrated on the motor , rather than sensory deficits . 
   therefore , the purpose of 
   the current study was to investigate the presence of motor and sensory deficits in the 
   ipsilateral upper limb , and to examine the correlation between the two variables in patients 
   with stroke using a tracking and reposition sense test . 
   fifty hemiparetic stroke patients ( 25 patients with right brain injury and 25 patients with 
   left brain injury ) referred to a local rehabilitation hospital were consecutively recruited 
   in the order of their registration . 
   the inclusion criteria were ; first ever stroke confirmed 
   by medical history and brain mri ; right handed individual verified by the edinburg 
   handedness inventory ; no symptoms of unilateral neglect or hemianopsia ; no cognitive problem 
   ( mini - mental state examination>24 points ) ; no apraxic behavior ( ideomotor apraxia score 
   developed by ambosoni et al . 
   ( > 11 points)16 ; and no musculoskeletal dysfunction in the unaffected upper limb . 
   we recruited 40 sex- and age - matched normal control subjects . to control the known effects 
   of hand asymmetry , the accuracy and proprioceptive tests were performed by the 20 control 
   subjects using their dominant right hand , and the remaining subjects used their non - dominant 
   left hand . 
   all subjects gave their written informed consent prior to participation , and this 
   study was approved by the local ethics committee . 
   tracking and joint position sense tests were conducted for the hand ipsilateral to the 
   damaged hemisphere of the patients , and with the corresponding hand of the same side of the 
   control subjects . 
   all subjects were seated in front of a table , with the forearm comfortably 
   supported and the elbow flexed at 90. a plastic frame with an embedded potentiometer was 
   used to measure the accuracy of movement and proprioceptive sense in the metacarpophalangeal 
   ( mp ) joints . 
   the potentiometer detected flexion / extension motion of the mp joint , and 
   transmitted the analog signal to a computer with analog - to - digital data acquisition 
   software , that sampled the signal at a frequency of 200  hz . in the tracking task , the subject was instructed to track the red target sine wave 
   displayed for 15 seconds on the computer screen as accurately as possible . 
   the response sine 
   wave made by the subject was displayed as a black solid line , which tracked up as the mp 
   joint was extended , and tracked down as the mp joint was flexed . 
   accuracy of the motor performance was 
   analyzed by an accuracy index ( ai ) , which was normalized to the range of motion of the mp 
   joint of each individual subject , and takes into account the differences between subjects in 
   the excursion of the target and response waves17.ai = 100(p  e)/p where e is the root mean square ( rms ) error between the target line and the response line , 
   and p is the size of the subject s target pattern , calculated as the rms difference between 
   the sine wave and the midline dividing the upper and lower phases of the sine wave . 
   the 
   degree of p is determined by the scale of the vertical axis of the range of subject s mp 
   joint motion . 
   prior to the evaluation , three practice trials were provided after one demonstration , using 
   sine waves which were different from the sine waves used in the actual test to prevent a 
   learning effect . 
   the joint position sense was evaluated on the mp joint ipsilateral to the 
   damaged brain hemisphere of the patients , and the joint on the corresponding side of the 
   control subjects . 
   in addition , the same experimental apparatus and environment used for the 
   performance of the tracking task were used . 
   the subjects were instructed to actively 
   reproduce the position of the mp joint which was passively positioned by the examiner . 
   three 
   different passively - positioned angles were randomly presented , in terms of 50% , 70% , and 90% 
   flexion of the total range of motion of the mp joint . 
   the mean value of three trials of the 
   joint reposition errors between the passively - positioned angles and the actively - positioned 
   angles was calculated . 
   the  test was performed to analyze the differences in sex distribution between 
   the patient and control groups . 
   the independent t - test was performed to determine the 
   significance of differences in age and accuracy of the tracking task / joint position sense . 
   in addition , correlation between the ai and joint position sense was investigated using 
   pearson s correlation coefficient . 
   chicago , il , usa ) was used for the 
   statistical analysis of all data , and statistical significance was accepted for p values 
   < 0.05 . 
   no significant differences were observed between the two 
   groups in terms of distribution of sex and age . 
   the meanssd of the accuracy index and 
   reposition error score of both groups are shown in table 2 . in terms of motor function , 
   the stroke group showed a lower accuracy 
   index in the mp joint than the control group . 
   a higher score of reposition errors in the 
   joint reposition test in relation to sensory function was observed in the stroke group , 
   compared to the control group . 
   the results of the statistical analysis indicate that both 
   measures in the stroke group were significantly different from the control group 
   ( p<0.05 ) . 
   ipsilateral sensory deficits showed significant correlation with motor deficits 
   ( r= 0.549 ) ( p<0.001 ) ( table 2 ) . 
   in the current study , we attempted to assess motor function using a tracking task for 
   visuomotor coordination , and proprioceptive sense using a joint reposition test for the 
   ipsilateral upper limb . 
   our findings reveal a lower accuracy index in the tracking task , and 
   higher error scores in the joint reposition test in the stroke group , compared to sex- and 
   age - matched normal subjects . 
   in addition , there was a negative correlation between the motor 
   and sensory deficits , indicating stroke patients would have difficulty in performing 
   complicated motor tasks requiring delicate sensoriomotor functions using pure integrity of 
   movement accuracy and proprioceptive sense . 
   our present results are in accordance with those of several previous studies2 , 8 , 
   suggesting the presence of motor deficits in upper limbs ipsilateral to the damaged 
   hemisphere in the visuomotor tracking task . 
   a possible mechanism for the motor dysfunction 
   in the ipsilateral hemisphere of stroke patients has been suggested by previous studies , 
   which reported bilateral hemisphere activation when normal subjects executed a unilateral 
   upper limb task18,19,20,21 . 
   if functional integrity of both the right and left brain cortex is 
   necessary for normal motor control of the upper limb , it is expected that the ipsilateral 
   upper limb would be affected after stroke . in the present study , 
   ipsilateral sensory 
   deficits related to proprioceptive sense were also observed . according to our findings 
   , 
   ipsilateral sensory deficits may be connected with bilateral hemisphere activation during 
   performance of motor tasks . 
   the primary sensory cortex ( s1 ) conveys efferent projection to 
   the posterior parietal cortex ( brodmann s area 5 and 7 ) , which is connected bilaterally 
   through the corpus callsosum . 
   therefore , as suggested by our results , it is possible that 
   disturbance of transcallosal transfer after unilateral brain damage may lead to ipsilateral 
   sensory deficits . 
   in addition , there is a close relationship between sensory and motor 
   function , because the posterior parietal cortex is connected with the frontal motor areas . 
   thus , the posterior parietal cortex would have an effect on the initial movement and sensory 
   feedback during performance of a complex motor task22 . on this basis , 
   the correlation shown in our study between 
   ipsilateral motor deficits and sensory deficits can be explained . 
   these findings imply that interest in the ipsilateral side of stroke patients should focus 
   on ipsilateral sensory deficits as well as ipsilateral motor deficits . 
   motor deficits of the 
   ipsilateral limbs of individuals with stroke have been reported in many studies ; besides , 
   our study showed sensory deficits related to proprioceptive sense . on the basis of these 
   results 
   , we think that the difficultly stroke patients experience in task performance using 
   the ipsilateral upper limb may be affected by both motor and sensory deficits . 
   studies on 
   recovery of motor deficits on the ipsilateral side after stroke are in progress . 
   jung et 
   al.14 reported that motor deficits in 
   the ipsilateral upper limb show maximal recovery within one month after onset of stroke , but 
   the deficits do not completely recover . 
   thus , it will be necessary to study the recovery of 
   ipsilateral sensory deficits after stroke onset , and we will be investigating this . 
   we 
   acknowledge that our study had some limitations , in that the effects of specific lesion 
   location and the extent of the damage were not identified . 
   therefore , future studies will be 
   required in order to determine more detailed mechanisms of other movement and sensory 
   deficits , other than proprioceptive sense , in the ipsilateral upper limb of patients with 
   unilateral brain injury .
summary: [ purpose ] previous studies have reported on motor deficits in the ipsilateral upper 
   limbs ( ul ) of a damaged brain hemisphere in motor tasks . however , little is known about 
   sensory deficits on the ipsilateral side . 
   therefore , we investigated whether both motor 
   and sensory function of the ipsilateral ul are affected in patients with stroke . 
   [ subjects 
   and methods ] fifty patients with unilateral stroke and 40 age- and sex- matched normal 
   subjects participated in this study . 
   subjects were evaluated on performance of a tracking 
   task for motor function , and by the joint reposition test for integrity of proprioceptive 
   sense in the ipsilateral ul . [ result ] the comparison of the stroke group and the control 
   group showed significant differences in performance of the tracking task and the joint 
   reposition test . 
   the accuracy index for the tracking task showed significant correlation 
   with the error score for the joint reposition test in the stroke group . 
   [ conclusion ] these 
   results suggest that the ipsilateral ul of stroke patients has impairment in sensory 
   function which is related to proprioceptive sense , along with motor deficits . 
   therefore , 
   we think that the difficulty stroke patients experience with motor tasks for the 
   ipsilateral ul is induced by diminished integrity of sensorimotor function due to both 
   sensory and motor deficits .