CorticalControlofHandMovement:Impacton

ClinicalCareofPeoplewithCerebralPalsy

KathleenM.Friel,Ph.D.

CorticalControlofHandMovement• PrimarymethodsofevaluatingcorticalcontrolofhandmovementinpeoplewithCP– Singlepulsetranscranialmagneticstimulation(TMS)– Diffusiontensorimaging(DTI)

• Whocares?– Whatistheclinicalrelevanceofthisinformation?– Howdoescorticalwiringimpacthandfunction,responsivenesstotherapies?

• Howcanthisinformationbeassessedmeaningfullyintheclinic?

Hemiplegic(Unilateral)CerebralPalsy• Motordeficitsprimarilyononesideofthebody.

• Handfunctionismostimpactedimpairment.

• Aschildrenwithhemiplegiaage,theyoftenfailtodevelopgoodmotorskillsononesideofbody.

• Affectsabilitytoperformactivitiesofdailyliving.

CorticalControlofHandMovement• BestunderstoodinchildrenwithunilateralCP.• Moststudiedinolderchildren(age>6yr).

• Assessmentschallengingformoreseverelyimpairedchildrenandyoungerchildren.

• Muchworkstillneedstobedone:differenttypesofCP,differentpartsofbody,differentages(veryyoungchildren,adults,agerelatedchangesacrosslifespan).

MotorSystemDysfunctioninChildrenwithUnilateralCP

• Single-pulseTMStomapbraincircuits

• RepetitiveTMStochangeactivityofbraincircuits

Ingaetal.,2009 NIMH

Videosaresharedwithconsentofparticipants&theirfamilies.

TMSwithKids:ACollaborativeEffort!

• [VIDEO]

UsingTMStoStudyCPNeurophysiology• Howdoesmotorsystemdevelopafterperinatalbraininjury?

Staudt etal,2002

”Contralateral” ”Bilateral” ”Ipsilateral”

Ipsi,contra-->Samelatency

UsingTMStoStudyCPNeurophysiology• Howdoesmotorsystemdevelopafterperinatalbraininjury?

Staudt etal,2002

”Contralateral” ”Bilateral” ”Ipsilateral”

Ipsi,contra-->Samelatency

UsingTMStoStudyCPNeurophysiology• Howdoesmotorsystemdevelopafterperinatalbraininjury?

Staudt etal,2002

”Contralateral” ”Bilateral” ”Ipsilateral”

Ipsi,contra-->Samelatency

• HowdoesCSTpatternimpacthandfunction?”Contralateral” ”Bilateral” ”Ipsilateral”

Contralateral

Bilateral

Ipsilateral

0

500

1000

JTTH

F (S

EC)

Jebsen-TaylorTestofHandFunction:Timetakentocompletefinemotortasks(higherscore-->moreimpaired)

KidswithipsilateralCSThavepoorerhandfunctionthanothergroups(p<0.05).

~20%ofkids ~40%ofkids ~40%ofkids

UsingTMStoStudyCPNeurophysiology

c c Ipsilateralprojections:• Maladaptiveafterstrokeinadults.• Previouslyassumedtoonlycontrol

proximalgrossmovements.• Markerofpoorfunction/prognosis?

Contralateral

Bilateral

Ipsilateral

0

500

1000

JTTH

F (S

EC)

c

Highvariability:Why??

UsingTMStoStudyCPNeurophysiology

~40%ofkids

c cIpsilateralprojectionsinCP:• Possiblyadaptiveafterdevelopmental

braininjury.• Cancontrolfinemotor(digit/wrist)

movements.• Motormapsofbothhandssharethesame

corticalspace.• Inmanykids,themapsofthetwohands

arehighlyoverlapped.• Moreoverlapà betterhandfunction

(r=0.51,p<0.05).• “Adaptiveyoking”ofmotorcontrolofthe

twohands.

UsingTMStoStudyCPNeurophysiology

AlternativetoTMSfordeterminingCSTlaterality

• TMSequipmentisexpensive,contraindicatedforchildrenwhohaveseizuredisorders.

• DiffusionTensorImaging(DTI)canbeusedtovisualizebrainpathways.

DTI:AlternativetoTMSfordeterminingCSTlaterality

• CanbedoneonmostMRIscanners(~6min).

• IsaccuratesurrogatemeasureofCSTlaterality(Kuo etal.,2017).

Contralateral Bilateral Ipsilateral

MirrorMovements:AQuickClinicalAssessmentofCSTLateralty?

• EventhoughDTIismoreaccessibletomostkidsthanTMS,itstillrequiresanMRI,andinterpretationofscans.

• Mirrormovements(MMs)à whenchildmovesonehandvoluntarily,theotherhandinvoluntarilymirrorsthemovement.

• SevereMMsassociatedwithipsilateralCST.

• Mostkidshavemild/moderateMMs– unclearhowmildMMsrelatetoCSTlaterality.

Summary:NeurophysiologyinChildrenwithUnilateralCP

• ConnectionpatternofCSTisrelatedtoseverityofhandfunctiondeficits.

• SinglePulseTMSandDTIcanbeusedtoassessCSTlaterality.

• SeveremirrormovementsmaypointtoanipsilateralCST.

Activity-BasedTreatmentsforUnilateralCP

§ Unimanualtraining:slingover“good”arm,intensivetrainingofimpairedarm- game-playing,arts/crafts,practicingfunctionalmovements.(Gordonetal.)

§ Bimanualtraining:childrenusebothhandsintensively,efficacynotdifferentfromunimanualtraining,bettertranslatesintoimprovementoffunctionalgoals.(Hand-ArmBimanualArmTraining,HABIT)(Gordonetal.)

Unimanual Bimanual-100

-50

0

50

100

Therapy Type

Perc

ent I

mpr

ovem

ent

Affe

cted

Han

d Fu

nctio

n

High Variability in Treatment Response

High Variability in Treatment Response-

Why??

Affected Hand Affected Hand

§ Single pulse TMS -

determine corticospinal

tract (CST) organization

§ 90 hrs. of unimanual or

bimanual therapy

§ Goal: Determine if CST

organization relates to

improvements in

dexterity following

unimanual vs. bimanual

therapy

Contralateral Ipsilateral

High Variability in Treatment Response-

Why??

Affected Hand Affected Hand

§ Constraint therapy –

drives down activity in

the hemisphere

controlling the less-

affected arm.

§ If both hands are

controlled by the less-

affected hemisphere,

driving down activity

may not be best.

§ Bimanual therapy à“yoking” of both hands.

Contralateral Ipsilateral

§ Children with contralateral CST improve more

than children with ipsilateral CST in CIMT

(unimanual therapy)

§ Children with ipsilateral and contralateral improve

equally in HABIT (bimanual therapy)

§ Understanding an individual’s brain

wiring can help prescribe the most

effective therapy.

UpperLimbRehabinPeopleWithCP:LessonsandFuture

• TMSandDTIeffectivetoolsformeasuringCSTlaterality.

• CSTlateralityaffectshandfunction:– ContralateralCSTassociatedwithbetterhandfunction.

– IpsilateralCSTassociatedwithpoorerhandfunction.• CSTlateralityappearstoimpactefficacyofintensivehandtherapy:– CIMTbestforkidswithcontralateralCS.

• Muchisstillunknown!

EarlyBrainInjuryRecoveryProgram

Funding: NINDS,NICHD,BurkeFoundation,CarvelFoundation,Blythedale Children’sHospital

LabMembers:TalitaCamposKarenChin,MSClaudioFerre,PhDDisha Gupta,PhD

Collaborators:AndyGordon,PhDMarom Bikson,PhDDylanEdwards,PTPhDYannickBleyenheuft,PhDJasonCarmel,MDPhDSusanDuff,EdD PTOT/RCHTBernadetteGillick,PhDPT