A n A pplic at ion o f Co n s traint - In du c e d T h e rapy in P at ie nt s W ith Chron ic H e m ipare s i s
A ft e r B rain Injury
P ar k Ji- w on , M .S c ., P .T . Dept . of Rehabilit ation Medicine
College of Medicine, Ch onbuk National Univ er sity K im J on g - m an , P h .D ., P .T ., O .T .
Dept . of Phy sical T her apy , Division of Health , S eon am Univ er sity K im Yu n - h ee, Ph .D ., M .D .
Dept . of Reh abilitation Medicin e, College of Medicine
Resear ch In stitution of Clinical Medicin e, Chonbuk National Univ er sity
국 문 요 약
뇌 손 상 후 편 부 전 마 비 환 자 에 서 의 억 제 - 유 도 치 료 의 적 용
박지원
전북대학교 대학원 의학과 재활의학교실 김종만
서남대학교 보건학부 물리치료학과 김연희
전북대학교 의과대학 재활의학교실
뇌 손상 후 급성기에 기능의 자발적인 회복이 일어나지만 환자들은 환측의 상지를 잘 사용하지 못하게 된다. 그 결과 원하는 움직임을 억제하는 상황을 발생시키는데 이것을 학습 무사용 증후군(learned nonu se syndrome)이라 한다. 이러한 학습 무사용 증후군을 치료하기 위해 억제- 유도 치료(constraint - induced therapy )가 고안되었다. 억제- 유도 치 료는 연속되는 몇 주간에 걸쳐 매일 많은 시간 동안 건측의 상지를 묶어두고 환측 상지 를 사용하게 하여 기능을 반복 학습하게 함으로써 기능을 증진시키는 방법이다. 이미 여 러 연구자들이 경두개 자기자극(transcranial magnetic stimulation), 움직임 관련 피질전 위(movement - related cortical potential), 기능적 자기공명 영상기법(functional magnetic r esonan ce im aging ) 등을 통하여 억제- 유도 치료 후 운동피질영역에서의 재조직화를 보 고함으로써 기능 증진과 관련된 회복 기전을 뒷받침하고 있다. 억제- 유도 치료의 영역은 확대되어 뇌졸중, 척수손상, 고관절 치환술 후로 하지에서의 기능증진을 위하여 연구가 진행되고 있으며 특히 뇌졸중 후 실어증 환자에서 새로운 방법으로 제시되고 있다. 따라 서, 억제- 유도 치료는 신경학적인 손상 후 움직임의 재활에 있어서 치료- 유도를 통한 중 추신경계의 회복에 효과적으로 작용할 수 있다.
핵심단어: 경두개 자기자극; 기능적자기공명 영상기법; 억제-유도 치료; 움직임 관련 피질전위; 학
습 무사용 증후군.
In t ro du c t i o n
Con str aint - Induced ther apy (CI ther apy ) is a new int erv ention th at has been u sed for the tr eatm ent of upper extr emities of str oke patient s (Miltner et al, 1999). It is estim at ed that patient s am enable t o sub st antial impr ov em ent as a r esult of CI ther apy r epr esent at least 50% of the t ot al str oke population (T aub et al, 1998).
At pr esent , ther e is little experim ental eviden ce av ailable indicating that phy sical and occupational ther apy is effectiv e for patients with chronic cerebrovascular accident (CVA ). T he liter atur e is ev en equiv ocal on the v alue of phy sical r ehabilit ation for subacute patient s fr om the past 10 y ear s (T aub et al, 1999). In the Wint er 1998 issue of the j ourn al "T opics in Str oke Rehabilitation" devoted to Functional Implica - tion s of Upper Extr emity Manag ement , there was a discussion on specific ther apeutic approaches to improving upper limb function . Aft er the confer ence, CI ther apy has been support ed with evidence fr om contr olled r andomized studies , and hav e been sh own to be effective for the upper limb. Mor eov er , CI theapy does not inv olv e m edication s or side effect s, and th er e ar e no significant risk s (T aub et al, 1999).
Now , CI ther apy has been studied by v ariou s inv estigat or s ev er sin ce th at discu ssion (Blant on an d W olf, 1999; Kim et al, 2001; Kunkel, 1999; Levy et al, 2001;
Miltn er et al, 1999; S abari et al, 2001).
T hey had to make u se of th e m or e- affect ed limb for a t ar get of 90% of w aking h our s by employin g one of sev er al m eth ods for con str ainin g or r educin g u se
of the les s - affect ed limb for 2 or 3 w eek s.
T he r esult s r educed the m ot or deficit s of the m or e- affect ed limb s of m any patient s with chr onic CVA . T he th er apeutic effect has also been dem on str at ed t o tr an sfer fr om the clinic t o the r eal w orld.
Recently , CI ther apy becom e t o st art and expan d t o other r egion s such as the tr eatment of upper limb deficit s in tr aum atic br ain injury and low er limb deficit s in patient s with CVA , spin al cor d injury , an d hip fr actur e. Another issue is possible of th e cortical r eor g anization a s a r ecov ery mechanism that account s for the ther apeutic effect of int erv ention (T aub et al, 1999). T his article describes hist orical backgr ound, application s, and new tr end of CI ther apy and br ain im aging study finding m ot or r ecov ery mechanism aft er CI ther apy .
H i s t o ri c a l B a c k g ro u n d
T he principle of CI ther apy ar e based on earlier ba sic r esear ch with m onkey s in whom som atic sen sation w as sur gically abolished fr om a sin gle upper extr emity by dor sal rhizot omy (T aub , 1977; 1980). When a single for elimb is deaffer ent ed in a m onkey , the anim al does not make u se of it in the fr ee situation (Knapp et al, 1958).
How ev er , Kn app et al (1963) and T aub and Berm an (1968) found th at m onkey s can be induced t o u se the deafferented limb by restricting m ov ement of int act limb for sev er al day s. A u seless limb is ther eby conv erted int o a limb capable of ext en siv e m ov em ent (T aub , 1980).
Experiment al evidence in dicat ed th at the
loss of motor function due t o deaffer ent ation r esult s in a learned behavior al supr ession t ermed learned nonu se (T aub , 1977;
1980). As a background for this explanation , one should not e that subst antial neur ological injury u sually leads t o a depr es sion in m ot or and/ or per ceptual function that is con sider ably gr eat er than will ev entually be the case after spontaneou s r ecov ery of function has taken place. T he pr ocess r espon sible for the initial depr ession of function an d the lat er gr adu al r ecov ery of function , which occur s at the lev el of both the spinal cor d and the br ain , is, at pr esent , in complet ely under st ood. How ev er , r egar dles s of the m ech anism , r ecov ery pr oces ses com e int o oper ation following deaffer ent ation so that aft er a period of time m ov ement s can , at least pot entially , be ex pr essed (T aub et al, 1999).
T he sam e m echanism is thou ght t o apply t o patient s who suffer mild t o m oder ate hemipar esis aft er str oke. It w as felt that the t echniques that ov er com e learned n onu se in m onkey s aft er unilat er al deaffer ent ation might also uncov er lat ent m ot or pot entials of m any str oke patient s and ther eby con stitut e a pot ential tr eatm ent t o incr ease upper limb u se (Miltn er et al, 1999). Mutiple experim ent s th at hav e applied the unaffect ed arm con str aint and affect ed arm tr aining t echniques t o str oke patient s h av e support ed this hypothesis (T aub et al, 1993; T aub et al, 1996; T aub et al, 1998; W olf et al, 1989)
Clin i c a l A ppli c a t i o n s
S e le c t ion c rit e ria
T aub et al (1993) began with a pilot experim ent that inv olv ed application of both component s of the published pr ot ocol (ie, par etic arm tr ainin g and contr alat er al arm r estr aint ) t o th e r ehabilit ation of patient s with chr onic CVA with r esidual hemipar esis. T hey u sed minimum m ot or crit erion defining at least 20 ex tention at wrist an d 10 at each of the fin ger s in affect ed arm . W olf et al (1989) stu died patient s who w er e mor e than one- year post - injury and who possessed a minimum of 10 ext en sion at the m et acapophalang eal (MP ) and interphalangeal (IP ) joint s and 20 ext en sion at the wrist of the affect ed arm . Miltn er et al (1999) studied each patient who either m et or ex ceed a minimum m ot or crit erion of at least 20 ex t en sion of the affected wrist and 10 of each fing er . Levy et al (2001) u sed following crit eria :
⑴ age between 21 and 80 year s, with an upper limb hemipar esis secondary t o th e fir st str oke; ⑵ the ability t o ext end their par etic wrist 20 and at least t w o of their finger s and th eir thumb s 10 at the MP joint ; ⑶ 3 m onth s dur ation fr om the on set of th e str oke.
A s s e s s m e nt t o ol s
Many inv estigat or s (Blant on an d W olf, 1999; Kopp et al, 1999; Kunkel et al, 1999;
Levy et al, 2001; Miltn er et al, 1999) hav e
been u sed th e W olf Mot or F un ction T est
(WMF T ) and Mot or A ctivity Log (MAL) t o
compar e m ot or function befor e and aft er CI
ther apy . T he WMFT w a s dev eloped t o
qu antify m ot or fun ction aft er str oke and tr aum atic br ain injury (W olf et al, 1989).
T he WMF T con sist s of 14 tim e- r elat ed activities an d 2 str en gth t est s m easurin g in a clinical envir onm ent (Morris et al, 1997).
T he t est st art s pr oxim ally and m ov es dist ally , then combin es all the j oint m otion s within th e cont ext of function al t ask s. T he MAL is a structured interview that identifies perform ance on 30 daily activities an d an or dinal scale that m easur es how subject s per ceiv e th eir function in the hom e environment . For instance, the MAL ev aluat es how much”(quantity ) and how w ell”(quality ) the affected extr emity w as u sed in specific daily activities, such as turning on a light swit ch or donning shoes (Blant on an d W olf, 1999). Int err at er r eliability for the WMF T w as .97 or gr eat er for perform ance tim e and .88 or gr eat er for functional ability (Morris et al, 2001). T he how w ell portion of the MAL has been sh own t o hav e an int err at er r eliability of .94 (Miltner et al, 1999).
T he F ugl- Mey er A ssessm ent (F MA ) scale has also been u sed t o compar e ther apeutic effect (Kim et al, 2001; v an der Lee et al, 1999). T he upper ex tr emity m ot or section of the F MA scale w as applied t o m easur e th e ability t o m ov e the hemipar etic arm out side th e syner gistic patt ern on 3- point scale (m aximum scor e, 66 point s ). T he F MA scale h as been foun d t o be v alid (Fu gl- Mey er et al, 1975), r eliable (Duncan et al, 1983), and r espon siv e in the fir st 6 m onth s after str oke (De W eer dt et al, 1985).
Int erv ent ion
T r eatm ent in most study con sisted of 2
m ain elem ent s : ⑴ r estriction of m ov em ent of the unaffect ed upper ex tr emity by placing it in a r estin g hand splint/ slin g en semble for 90% of th e h our s spent aw ake for a period of 12 day s an d ⑵ int en siv e tr ainin g of the affect ed arm (Kim et al, 2001; Levy et al, 2001; Lipert et al, 1998; Miltn er et al, 1999). T hey u sed t ask orient ed activities such as r eachin g , gr aspin g , m oving block s fr om on e cont ain er t o another , turnin g the pages of a m agazine, car d activities, writing activities, food pr epar ation , ir oning , v accuming , and ball activities.
Co rt i c a l R e o rg a n i z a t i o n
Recent focal tr an scr anial m agn etic stimulation (T MS ), neur oelectric sour ces im aging , m agn etic sour ce imaging studies with hum an s, carried out by v ariou s inv estigat or s and sug gest that cortical r eor ganization m ay be associat ed with the ther apeutic effect of CI ther apy (Elbert et al, 1995; Jenkin s et al, 1990; Recanzone et al, 1992; St err et al, 1998). P on s (1991) found that m assiv e cortical r eor ganization takes place after somat osensory deaffer enta - tion of an entir e for elimb in m onkey s . Elbert et al (1994) and Yang et al (1994) also report ed that massive cortical r eor gani- zation t akes place in hum an s aft er CNS injury. These result s, especially those r elatin g t o u se- dependent cortical r eor ganization , suggest that the size of the cortical r epr esent ation of a body part in adult hum an s depends on the am ount of u se of that part (T aub et al, 1999).
T he hypothesis that CI ther apy pr oduces
a lar ge u se- dependent cortical r eor ganiza - tion in hum an s with str oke- r elat ed par esis of an upper limb w a s r ecently confirmed in sev er al stu dies. Liepert et al (1998) u sed T MS t o m ap th e ar eas of the br ain th at contr ol arm m ov em ent in 6 patient s w ith a chr onic upper limb hemipar esis befor e and aft er CI T h er apy . T hey r eport ed that chan ge in the size of cortical mot or ar ea and shift of m ean cent er of gr avity of m ot or output m aps in the dam aged hemispher e elicit ed aft er CI ther apy .
Con str aint - in duced ther apy h ad led t o a r ecruitm ent of lar ge number of neur on s adj acent t o those originally inv olv ed in contr ol of the limb by m ov em ent of th e CVA - affect ed limb . Kopp et al (1999) applied dipole m odelin g of st eady - st at e m ov em ent - r elated cortical pot entials (MRCP ) befor e and aft er tr aining an d 3 m onth s lat er . T he sour ce location s associat ed with affect ed hand m ov em ent w er e unu sual at follow - up becau se activ ation of the ipsilat er al hemispher e w as found in th e ab sence of mirr or m ov ement s
of the un affect ed hand. T his lon g - term chan ge m ay be con sider ed as an initial dem on str ation of lar ge- scale neur oplasticity associat ed with in cr eased u se of the par etic limb aft er application of CI th er apy .
Experiment al eviden ce of CI T her apy is associat ed w ith a u se- dependent incr ea se in cortical r eor g anization . It has been confirm ed by neur oimaging studies u sing function al m agn etic r eson ance im aging (fMRI) t echniques. Levy et al (2001) report ed that CI ther apy produced significant function al impr ov em ent and r esult ed in plasticity as dem on str at ed by fMRI. Aft er tr aining , 2 patient s show ed activ ation bor dering the lesion , bilat er al activ ation in the association cortex , and ipsilat er al acti- v ation in the prim ary mot or cort ex . In anoth er study , Kim et al (2001) inv esti- gat ed that CI th er apy is r elat ed to a u se- depen dent r eor g anization in cortical net w ork . P atient s show ed incr eased acti- v ation on contr alat er al an d ipsilat er al mot or cortex (Fig 1) and act iv ation on ot h er ar ea s su ch a s p ar iet al lobes.
F ig 1. Comparion of activ ation before (A ) an d aft er (B) CI therapy by fMRI. Aft er CI therapy , activ at ion of contr alat er al and ipsilat eral m ot or cort ex w as n oticed w hile only sm all activ ation focus w as seen in the contralat eral m ot or cort ex before CI theapy .
A . B .
