carpal tunnel syndrome ( cts ) is the most common entrapment neuropathy1,2,3 , caused by compression and traction of the median nerve at the level 
 of the carpal tunnel , which is a cylindrical , inelastic cavity , delimitated by the carpal 
 bones and transverse carpal ligament4 , 5.the compression results in impaired nerve 
 conduction , paresthesia , and pain , which worsen at night and often wake the patient6 , 7 .
the treatment for cts can be broadly divided into surgical and non - surgical approaches . 
 according to the findings of several important randomized controlled trials ,
carpal tunnel - release surgery is 
 effective in 7075% of patients , but is relatively invasive and can be accompanied by 
 complications10 .
furthermore , 
 recurrence after surgery , although uncommon , can be difficult to treat11 . moreover , surgical decompression leaves 8% of patients in 
 a worse condition than they were previously12 , and persistent pain in the scar or proximal palm 5  years after 

numerous non - surgical , less - invasive treatment options are available , including oral 
 medication , splinting , exercise , corticosteroid injections , and mobilization 
 interventions14,15,16,17 .
only a few complications result from non - surgical approaches in 
 those with mild - to - moderate cts .
thus , non - surgical treatment might be indicated for 
 patients with cts when surgery is not desired or for any other reason not immediately 
 indicated18 . to the best of our 
 knowledge , surgical decompression or carpal tunnel release
. however , there is currently limited evidence indicating any benefit from 
 splinting , exercise , and mobilization15 , 16 .
this study aimed at prospectively 
 assessing the effectiveness of nocturnal splinting by using clinical scores and ncs .
of the 66 consecutive outpatients to our neurological clinic , 41 patients who met the 
 inclusion criteria were finally enrolled ( fig . 

all individuals provided informed consent to participate in this study , and the 
 local ethics committee of the hospital approved this study .
the inclusion criteria of the 
 report of the quality standards subcommittee of the american academy of neurology were 
 implemented19 , whereby all the patients 
 must meet at least one of the first 2 items and one of the remaining 5 items below to be 
 included in the study:19 , 20 ( 1 ) numbness in the median nerve territory or the whole 
 hand ; ( 2 ) pain or hypesthesiain the hand ; ( 3 ) awakened from sleep by numbness or pain 
 mid - night or early in the morning ; ( 4 ) numbness relieved by shaking the hand and aggravated 
 by flexing the wrist , or numbness becoming more severe in winter than in summer ; ( 5 ) 
 weakness of the hand ; ( 6 ) atrophy of the thenar muscle ; and ( 7 ) positive phalen or tinel 
 sign . in this study , patients with the following conditions were excluded : ( 1 ) clinical or / and 
 electrophysiological findings suggesting ulnar nerve lesion , cervical radiculopathy , 
 polyneuropathy , systematic diseases ( e.g. , diabetes mellitus , hypothyroidism , and rheumatoid 
 arthritis ) , and stroke20 ; ( 2 ) cts caused 
 by wrist trauma or deformity20 ; ( 3 ) prior 
 treatment for cts through any approach , either surgical or non - surgical ; and ( 4 ) severe 
 weakness or atrophy of the hand , and no response of compound muscle action potentials ( cmap ) 
 elicited from the muscle of the abductor pollicis brevis ( mapb ) on ncs .
the follow - up was 
 completed in 20 patients with splinting ( fig . 
 1 ) .
this study had a prospective design recommended by american association of neuromuscular 
 and electrodiagnostic medicine ( aanem)21 . 

all the subjects enrolled in this study underwent electrophysiological detection after oral 
 informed consent was obtained .
electrophysiological detections were completed on keypoint 4 
 ( detec , denmark ) by one examiner .
while ncs 
 was performed , surface electrodes were used for stimulating or recording . while recording 
 cmap , the median and ulnar nerves were both stimulated at the wrist .
while recording the 
 sensory nerve action potentials ( snap ) , the median and ulnar nerves were also stimulated at 
 the wrist , and ring electrodes were placed at digits 2 and 5 , respectively .
in addition , for 
 comparing the difference in distal sensory latency ( dsl ) , the median and ulnar nerves were 
 stimulated at the wrist , recording the snap at digit 4 .
the following parameters were 
 analyzed : the distal motor latency ( dml ) from the wrist to mapb or abductor digiti minimi ; 
 the sensory conduction velocity ( scv ) from the wrist to digits 2 , 5 , and 4 ; and the dsl . 

needle electromyographic detection was performed to observe abnormal spontaneous activities 
 only when the amplitude of the cmap of mapb reduced . considering stevens ( aanem ) and our previous study20 , 22 , the following 
 electrodiagnostic criteria for cts were used in this study : ( 1 ) scv ( wristdigit 2 ) < 40.0 
 m / s or scv ( wristdigit 4 ) < 43.5 m / s ; dml ( wrist to mapb ) 3.7  ms ( distance 5.56.5  cm ) ; 
 or dsl 0.4  ms ; and ( 2 ) normal sensory or motor conduction in the ipsilateral ulnar 
 nerve .
symptom severity scale ( sss ) and functional status scale ( fss ) were used to evaluate the 
 patients at each hospital visit23 .
sss 
 consists of 11 questions with multiple - choice responses , which includes 6 critical domains 
 for the evaluation of cts : pain , paresthesia , numbness , weakness , nocturnal symptoms , and 
 over - all functional status .
fss consists of 8 functional activities , including writing , 
 buttoning of clothes , household chores , and bathing and dressing .
each question was scored 1 
 point ( mildest / no difficulty with the activity ) to 5 points ( most severe / unable to perform 
 the activity ) . the overall score was calculated as the mean of the scores for all the 
 individual items .
items that were left unanswered and if not applicable , they were not 
 included in the calculation of the overall score23 .
all the subjects were instructed to make stereoplasm splints of approximately 912  cm  
 57  cm size by themselves and bring them to us for assessment .
subsequently , they were asked 
 to wear each splint on the dorsal and palmar surface of the hand , centered at the distal 
 wrist crease , immobilizing the wrist in the neutral posture at bedtime , keeping the fingers 
 relatively free.the wrists were fixed to ensure that they were neither too tight nor too 
 loose . meanwhile ,
the subjects were instructed to avoid flexing their wrists during any 
 daytime activities such as washing clothes , riding a bicycle , working on a computer , and 
 carrying heavy grocery bags .
the follow - up was completed in 20 patients ( 31 wrists ) with splinting .
all statistical analyses were performed using statistical package for social sciences 
 ( spss ) for version 17.0 ( spss china , shanghai ) .
one - sample t - test was used to compare the values with known population means , 
 and paired - sample t - test was used to compare paired measurement data . in bivariate 
 correlations , data of normality was analyzed by person correlations , else by spearman 
 correlations .
the shapiro - wilk test was used to test the normality of the measurement data . 

values of p<0.05 were considered statistically significant ; * represents p<0.05 , * * 
 p<0.01 and * * * p<0.001 .
of the 41 patients who met the inclusion criteria , 90% were female , and the mean age of all 
 patients was approximately 50  years old .
the clinical data are presented in table 1table 1.clinical data of the subjectsall 41 patients20 patients with splintingage ( years)2072 ( 50.2  12.0)2672 ( 52.5  12.6)illness duration ( years)1.1  1.71.5  2.3male / female ( wrists)4 ( 5)/37 ( 59)1 ( 1)/19 ( 30)bilateral hands affected ( cases)2411right hand affected ( cases)114left hand affected ( cases)6 ( 4 left - handed)5 ( 4 left - handed)numbness ( or pain ) at night ( cases)216tinel sign ( wrists)1811phalen sign ( wrists)2014 . in 20 patients ( 31 wrists ) with cts treated by splinting , sss ( 1.77  0.38 , 1.55  0.38 ; 
 t=5.956 , p=0.000 ) and fss ( 1.53  0.31 , 1.40  0.27 ; 
 t=5.452 , p=0.000 ) decreased .
in addition , dml ( 4.53  1.25 , 4.14  0.76 ; 
 t=2.431 , p=0.021 ) shortened and dsl ( 1.24  0.61 , 0.97  0.60 ; 
 t=2.978 , p=0.006 ) decreased significantly after splinting ( table 2table 2.comparison of clinical scores and ncs findings of splinting in 20 patients ( 31 
 wrists)parametersbefore splintingafter splintingclinical scoressss1.77  0.381.55  0.38fss1.53  0.311.40  0.27parameters of ncsdml ( ms)4.53  1.25 4.14  0.76scv of wrist digit 2 ( m / s)42.02  8.29 42.12  7.58scv of wrist digit 4 ( m / s)38.20  6.72 38.51  6.42dsl ( ms)1.24 
0.610.97  0.60ncs : nerve conduction studies ; sss : symptom severity scale ; fss : functional status 
 scale ; dml : distal motor latency ; scv : sensory conduction velocity ; dsl : sensory 
 latency difference between median and ulnar nerve*p<0.05 , * * p<0.01 , * * * p<0.001 ) .
there was no improvement in the clinical scores in 9 patients ( 14 wrists , 
 45.8% ) after splinting .
there were significant correlations between sss and dml 
 ( r=0.420 , p=0.019 ) , scv of wrist digit 2 ( r=0.425 , 
 p=0.017 ) , and scv of wrist digit 4 ( r= 0.519 , p=0.003 ) .
no correlations 
 were noted between sss and dsl ( p>0.05 ) , and between fss and all the parameters of ncs 
 ( p>0.05 ) ( table 3table 3.correlation of clinical scores with ncs findings in 20 patients treated by 
 splinting dml scv of wristdigit2 scv of wristdigit4dslsss0.420*0.425*0.519 * 0.189fss0.1920.1750.3190.124values represent correlation coefficients*p<0.05 ) .
ncs : nerve conduction studies ; sss : symptom severity scale ; fss : functional status 
 scale ; dml : distal motor latency ; scv : sensory conduction velocity ; dsl : sensory 
 latency difference between median and ulnar nerve * p<0.05 , * * p<0.01 , * * * p<0.001 values represent correlation coefficients
in this study , 90% of patients with cts were female , and the mean age was approximately 
 50  years , which is consistent with the epidemiological data3 .
studies have shown that females with the highest body mass index 
 ( bmi ) are more likely to develop cts24 , 25 .
a bmi 30  kg / m almost doubled 
 the risk of cts , and when bmi was assessed as a continuous variable , the hazard ratio 
 increased approximately linearly with increasing bmi24 .
splinting is the most common method among the non - surgical treatments available for 
 cts7 . in this study ,
a self - administered 
 questionnaire was used to assess the severity of symptoms and functional status in cts , as 
 questionnaires are reproducible , internally consistent , valid , and responsive to clinical 
 change23 .
the questionnaire for 
 clinical evaluation was subjective , but it can be semi - quantitative .
we recommend that the 
 questionnaire should be used at least in the clinical research on cts , so that the outcome 
 of each researcher is relatively comparable . in this study ,
both sss and fss were 3 points , 
 which suggested that the condition in most patients was not severe . in a previous study
, 89% 
 of patients with severe cts experienced recurrence of the symptoms within 1  year after 
 conservative treatment , whereas only 60% of patients with mild cts experienced 
 recurrence26 .
therefore , the 
 conservative approach is more successful in patients with mild nerve lesion than with severe 
 cts .
conservative management with splinting should be initiated in patients with cts with 
 only mild symptoms12 .
splinting is an acceptable method for patients in the early phases of cts , as it is simple 
 and inexpensive and can be used at home . in this study ,
sss and fss decreased significantly , 
 dml shortened , and dsl decreased . moreover , 54.2% of patients with cts were effective after 
 neutral wrist nocturnal splinting .
neutral wrist splinting can reduce the pressure on the 
 median nerve and increase blood flow , especially when the wrist is held in a flexion 
 position at night27 . in a review 
 assessing the effectiveness of conservative therapy for cts ,
it was reported that splinting 
 is an effective therapy especially when used for the whole day28 .
no improvement was noted in the clinical scores of almost half the patients in this study . 

this could be because the splints made by the patients may not have immobilized the wrist . 

additionally , patients low compliance for the complex course of splinting may have 
 influenced the therapeutic effect , although we emphasized that the patients should follow 
 our guidelines strictly .
splinting 
 reduces latency , suggesting that the intervention may alter the underlying 
 pathophysiological course of cts4 . 

moreover , there was no correlation between sss and dsl , and between fss and the parameters 
 of ncs .
thus , there was a weak correlation between the clinical scores and ncs , which is 
 consistent with the findings of a previous study29 .
therefore , the use of both clinical scores and ncs may allow us to 
 evaluate the therapeutic effect of splinting on cts through different aspects .
overall , conservative approaches such as splinting have a negligible incidence of serious 
 complications and should be used more widely12 . providing patients the facts about their conditions and
nevertheless , patients 
 with cts who do not show satisfactory improvement with non - surgical treatment should be 
 offered surgery30 .
the therapeutic effect of combination splinting and other conservative treatments on cts 
 were not compared , and the number of patients enrolled in this study was small , which were 
 the main limitations in this study .
moreover , patients made the splints by themselves , which 
 may cause a variation in the therapeutic effect among individuals , although the splints that 
 they made were checked . in conclusion ,
neutral wrist nocturnal splinting is effective in at least the short term in 
 patients with cts .
there is a weak correlation between the clinical scores and ncs , which 
 suggests that both approaches should be used to assess the therapeutic effect of treatment 
 on cts .
 [ purpose ] to prospectively assess the effectiveness of neutral wrist nocturnal splinting 
 in patients with carpal tunnel syndrome ( cts ) by using clinical scores and nerve 
 conduction studies ( ncs ) . 
 [ subjects and methods ] forty - one patients enrolled in the study 
 were clinically evaluated by a symptom severity scale ( sss ) and functional status scale 
 ( fss ) , and were electrophysiologically evaluated by conventional ncs ; distal motor latency 
 ( dml ) , sensory conduction velocity ( scv ) , and difference in sensory latency between the 
 median and ulnar nerves ( dsl ) were measured . 
 subjects were treated with wrist splinting . 
 
 patients who showed no improvement in symptoms were treated with other conservative 
 treatments , the remaining patients continued to wear splints . 
 sss , fss , and ncs were 
 evaluated after splinting as well . 
 [ results ] the follow - up was completed in 20 patients 
 ( 31 wrists ) with splinting . 
 sss and fss decreased , the dml shortened and dsl decreased 
 significantly after splinting for 3.03  1.16 months . 
 there were significant correlations 
 between sss and dml , scv of wrist digit 2 , and scv of wrist digit 4 . 
 no correlations were 
 found between sss and dsl , and fss and the parameters of ncs . 
 [ conclusion ] neutral wrist 
 nocturnal splinting is effective in at least short term for cts patients . 
 there is a weak 
 correlation between clinical scores and ncs , which suggests that both approaches should be 
 used to effectively assess the therapeutic effect of cts treatment . 