Upload
vuduong
View
221
Download
0
Embed Size (px)
Citation preview
AplicaAplicaçções da Neurofisiologia no ões da Neurofisiologia no estudo do controlo motor das estudo do controlo motor das
doendoençças do movimentoas do movimento
João Costa
Laboratório EMG e PE. IMM. Faculdade Medicina Lisboa
Unitat de EMG y controlo motor. Hospital Clínic. Barcelona.
SumSumááriorio
• Os “instrumentos” neurofisiológicos
• As técnicas neurofisiológicas
• As doenças do movimento
• Os resultados das técnicas aplicadas às
doenças do movimento e ao controlo motor
• Discussão
““Os instrumentosOs instrumentos””
• EMG
– de Superfície:
• Registo da actividade motora (“muscular”)
– Espontânea (ex: tremor, mioclonias, …)
– Não espontânea
» Estímulos (ex: visual, acústico, eléctrico, …)
» Experiências de Tempo de Reacção
» Reacção de Sobresalto
– Reflexa
• Acelerometria
• TMS
• Outros (Importância da biomecânica e da biofísica!)
Tri - Axial
Graphics tablets for measuring 2D planar movements which have
position sample rates of 100-225 Hz, and detection area sizes of
30 x 30 cm (12" x 12") and 45 x 30 cm (18" x 12").
Graphics tablets report the X-Y position of the pen or puck with a
resolution of 0.02 mm, at a sampling rate of up to 225 Hz, and
distances of up to 2 cm from the tablet. Contact switches on the
tip of the pens allow measuring of transit and touch-dwell times in
sequential movement such as "Fitts Tapping" experiments.
Graphics tablets
Pen computers
Simple reaction time experiment (Givler, 1920).
Group testing of complex reaction times (U.S. Air Force).
Simple Reaction TimeExperimenter and its
modulation by the startlestimulus
ImperativeSignal
IS
SRT
STR
STR + Startle
MAIN NEUROPHYSIOLOGICAL TECHNIQUES FOR THE STUDY OF MAIN NEUROPHYSIOLOGICAL TECHNIQUES FOR THE STUDY OF
MOVEMENT DISORDERS MOVEMENT DISORDERS
•• BehavioralBehavioral physiologyphysiology– EMG and study of movements– Reaction time– Startle– Conditioning– Motor learning
•• EyeEye andand eyelideyelid movementsmovements– Blink rate– Saccades
•• Brainstem Brainstem reflexesreflexes– Trigemino-facial reflexes
• Blink reflex• Perioral reflex
– Trigemino-trigeminal reflexes• Jaw-Jerk• Masseteric inhibitory reflex
– Other brainstem reflexes• Sternocleidomastoid inhibition• Facial responses to other stimuli
•• LongLong latencylatency andand spinalspinal reflexesreflexes
– Cutaneo-muscular and stretchreflexes
– Propriospinal inhibitory circuits
•• EvokedEvoked potentialspotentials
– Somatosensory, visual, auditory
– Event related potentials
•• Transcranial Transcranial magneticmagnetic stimulationstimulation
– Central conduction time
– Threshold
– Cortical excitability
•• NeedleNeedle electromyographyelectromyography
– Anal and vesical sphincter EMG
•• AutonomicAutonomic nervousnervous systemsystem
– Sympathetic skin response
– Heart beat frequency modulation
– Urodynamic/rectal pressure studies
Principais doenPrincipais doençças do movimentoas do movimento
•• SyndromesSyndromes presentingpresenting withwith hyperkinesiahyperkinesia
– Tremor
– Dystonia
– Corea
– Tics
– Myoclonus
•• SyndromesSyndromes presentingpresenting withwith hypokinesiahypokinesia
– Parkinson’s disease
– Progressive supranuclear palsy
– Multisystem atrophy
– Cortico-basal degeneration
NRL Diagnosis
syndrome
Clinicalassessment
Psychology
Radiology
Neurophysiology
Blood tests
Genetics
Pathology
ethiology
topography
pathophysiology
Some symptoms are common to diseases involving central andperipheral nervous systems
During electromyographic examination, we may be able to discoversigns that were missed by the requesting physician
more time devoted to electrophysiological examsclose clinico-electrophysiological correlation
Characterize better the pathophysiological aspects of diseasespresenting with movement disorders
Neurophysiological endophenotyipificationCorrect clinical diagnosisGood communication between clinicians and neurophysiologistsGood technical skill and neurophysiological knowledge
1
2
WHY IS IT INTERESTING TO WHY IS IT INTERESTING TO KNOWKNOW ABOUT ABOUT NEUROPHYSIOLOGICAL STUDIES NEUROPHYSIOLOGICAL STUDIES
IN PATIENTS WITH MOVEMENT DISORDERS?IN PATIENTS WITH MOVEMENT DISORDERS?
Disk electrodes attached over the muscle belly
Recording agonist-antagonist muscles
Recording many muscles along rostro-caudal axis
Avoid recording low frequency artifacts (cables)
Rest, posture, action
Accelerometer recording
Cutaneous electrical stimuli. Recording reflex
responses
Recording evoked potentials to somatosensory stimuli
EMG EMG andand accelerometeraccelerometerassessmentassessment
ofof movementmovement disordersdisorders
TremorTremorMyoclonusMyoclonus
ParkinsonParkinson’’s diseases disease
•Agate et al, 1956.
•Acelerómetros piezoresistivos uni-axiais ou tri-axiais.
(sensibilidade máxima 0.001 mV/cm/s2)
•Determinam o pico de frequênciadominante e a amplitude
TremorTremor
Movimento muscular involuntMovimento muscular involuntáário, rrio, ríítmico, tmico,
originando movimentos oscilatoriginando movimentos oscilatóórios de uma ou rios de uma ou
mais partes do corpo.mais partes do corpo.
Tremor essencialTremor essencial
Grau de Ritmicidade
• Área/integral pico / Área/integral do total (20Hz)
Grau de Ritmicidade
• Área/integral pico / Área/integral do total (20Hz)
• 0.05288 (1º) / 0.11040 = 0.5
• 0.00392 (2º) / 0.11040 = 0.03
Neurophysiological investigations in patients with head tremor.Valls-Sole J, Tolosa ES, Nobbe F, Dieguez E, Munoz E, Sanz P, Valldeoriola F.
Mov Disord 1997 Jul;12(4):576-84
Tremor cefTremor cefáálicolico
10º
1 s
CONTROL SUBJECTCONTROL SUBJECT
Visual Visual signalsignal
Tremor Tremor parkinsparkinsóóniconico, essencial e , essencial e psicogpsicogééniconico
10º
1 s
CONTROL SUBJECTCONTROL SUBJECT
PSYCHOGENIC TREMORPSYCHOGENIC TREMOR
Visual Visual signalsignal
10º
1 s
ParkinsonParkinson
Tremor Tremor essencialessencial
Visual Visual signalsignal
AplicaAplicaçções dos testes neurofisiolões dos testes neurofisiolóógicos no gicos no diagndiagnóóstico diferencial do tremorstico diferencial do tremor
Fisiológico exacerbado vs essencialVariação da frequência com peso no fisiológico exageradoReflexo de estiramento aumentado no fisiológico exagerado
Parkinsónico vs essencialPredomínio de tremor em repouso ou posturaPadrão EMG sincrónico ou alternante entre antagonistas
Tremor vs miocloniasRitmicidadeSalvas e silêncios sincrónicos nas mioclonias
Psicogénio vs orgânicoInconsistênciaExecução de movimentos balísticos
MiocloniasMiocloniasMovimentos involuntMovimentos involuntáários que se repetem, srios que se repetem, súúbitos e breves, que podem bitos e breves, que podem
envolver desde um menvolver desde um múúsculo a segmentos ou mesmo todo o corposculo a segmentos ou mesmo todo o corpo
MiocloniasMioclonias de acde acççãoãoPostural and action myoclonus in patients with parkinsonian type multiple system atrophy
Salazar G, Valls-Solé J, Martí MJ, Chang H, Tolosa ES. Mov Disord, 2000; 15: 77-83.
DistoniaDistonia
ContracContracçções musculares involuntões musculares involuntáárias, rias,
intermitentes e mantidas que originam intermitentes e mantidas que originam
movimentos repetitivos ou posturas anormaismovimentos repetitivos ou posturas anormais
Principais tipos de distoniaPrincipais tipos de distonia
• Generalizadas
• Segmentares
• Focais
– Distonia cervical
– Blefaroespasmo
– Distonias de tarefa
– …
MOV
FLEX
EXT
MOV
FLEX
EXT
CorrelaCorrelaçção ão electrofisiolelectrofisiolóógicagica da distoniada distonia
Deuschl G, Heinen F, Kleedorfer B, Wagner M, Lucking CH, Poewe W.Clinical and polymyographic investigation of spasmodic torticollis.
J Neurol 1992;239:9-15
Distonia CervicalDistonia Cervical
Pattern of movement during chewing
SindromeSindrome MeigeMeige e Distonia Cranianae Distonia Craniana
Blepharospasm
Hemifacial spasm
Control
Spontaneous blinking
Blink ReflexBlink Reflex
R OOc
L OOc
R1 R2
R2c
Blink reflex excitability recovery
Cranial dystonia
Control
Control
Test
pulse
pulse
prepulse
Prepulse Prepulse phenomenonphenomenon
A weak, innocuous stimulus, which isnot able to induce a visible reflexresponse causes effects on the response induced by a subsequent suprathresholdstimulus
SensorySensory modulationmodulation ofof thetheblinkblink reflexreflex in in patientspatientswithwith blepharospasmblepharospasm
Gómez-Wong et al. Arch Neurol., 1998; 55: 1233-1237.
100 ms
0.5 mV Um só registo
original
rectificado
0.2 mV
original
rectificado
Média 20 registos
Média do EMG rectificado
Sem contracção
Contracção ligeira
Contracção máxima
100 ms
0.2 mV
Média de 100-200 registos de EMG rectificado
Normalvolunteer
Dystonicpatient
Normal volunteer
Dystonic patient
Abnormal sensorygating in dystoniaMurase et al., 2000
Distonias de tarefa e Distonias de tarefa e caimbracaimbra de escrivãode escrivão
2 s
Esta es una muestra de mi escritura
Pressão exercida pelos dedos sobre a caneta
Correlação com a actividade electromiográfica do 1ºinterósseo
CONTROL
PATIENT
TMS inTMS inDistoniaDistonia
A) A) decreaseddecreased
corticocortico--cortical cortical
inhibitioninhibitionRidding et al.,
J N N P 1995; 59:493-498
GABA-A
B) B) decreaseddecreased
durationduration ofof thethe
silentsilent periodperiodRona et al.,
Mov Disord; 1998; 13: 118-124
TMS inTMS inDistoniaDistonia
DoenDoençça de Parkinsona de Parkinson
DoenDoençça caracterizada por a caracterizada por bradicinbradicinéésiasia, rigidez, , rigidez,
tremor e alteratremor e alteraçções dos reflexos posturaisões dos reflexos posturais
SIMPLE REACTION TIME TASKSIMPLE REACTION TIME TASK TRIPHASIC PATTERN TRIPHASIC PATTERN ofof a a BalisticBalistic movementmovementHallettHallett et al., 1975et al., 1975
WE
WE
MOV
MOV
0.2 s0.5 mV
‘go’signal
OFF
ON
0
100
200
300
400
500
600
700
800
EMG MOV TASK
off DBS
on DBS
Control
Kumru et al., Mov Dis, 2004. Effects of subthalamic nucleus stimulation on characteristics of EMG activity underlying reaction time in Parkinson's disease. Mov Disord, 2004; 19: 94-100.
SIMPLE REACTION TIME TASKSIMPLE REACTION TIME TASK
Kimura J. Disorders of interneurons
in Parkinsonism. The orbicularis
oculi reflex to paired stimuli.
Brain 1973; 96: 87-96.
Motor Motor ControlControl
Startle and Reaction Time Experiences
Arm movement
Wrist extensors
Deltoid
Sternocleidomastoid
Orbicularis oculi
S
The startle reaction to an auditory stimulus
StepsSteps ofof a a reactionreactiontime time tasktask experimentexperiment
The structure of the basic motor program is going to be significantly modified if the
descending ‘voluntary’ volley collides with that of the startle ‘involuntary’ volley.
This will not occur if the tract carrying the ‘involuntary’ volley is an essential part of
the execution of ‘voluntary’ actions.
Presenting a startling stimulus during preparation for execution of a voluntary ballistic
movement would induce the activation of the reticulospinal tract and a startle reaction
Activation of the corticospinal tract by commands related to the execution of the
voluntary ballistic movement will come on top of the activation induced by the
reticulospinal tract
Voluntary movements are executed through activation of descending cortical and
subcortical motor pathways
However, activation of subcortical motor tracts is considered accessory,
participating just in preparatory or accompanying postural adjustments
Is the response different whenthe ‘go’ signal is interferedwith a startlingstimulus?
STC – Task Specific Channel
SES – Stimulus Evaluation System
TR – Time of Recognition
TI – Time of Initiation
TD – Time of Development
RC – Response Channel
ReactionReaction time time shorteningshortening withwith TMSTMS
OOc
SCM
WExt
WFlex
OOc
SCM
WExt
WFlex
Acc
Acc
ReactionReaction time time shorteningshortening withwith a a startlestartle
‘go’+startle
‘go’
Effect of a loud auditory stimulus on the
voluntary reaction (the StartReact effect)
Valls-Solé. Patterned ballistic movements triggered by a
startle in healthy humans. J Physiol, 1999
Forewarning
‘go’
Level ofreadiness
Task
PREPARATION OF SUBCORTICAL MOTOR PATHWAYS
Forewarning
‘go’
Level ofreadiness
Forewarning
‘go’ +startle
Ben Johnson129 ms
Carl Lewis196 ms
A startle accelerates theexecution of a voluntaryaction.
At the time of the IS, thestartle is larger than in a condition of no preparation
The startle does not modifythe characteristics of thevoluntary motor command
It is possible to have a reaction time shorter thanthe established limits of a voluntary reaction
There is a preparatoryphase preceding the IS
OBSERVATIONSOBSERVATIONS CONSEQUENCESCONSEQUENCES
Motor preparation involvesenhancement of the excitabilityof the system activated in thestartle reaction
The reaction of the goal keeper to the penalty shot
RECORDING Arm: leverEye: vertical and
horizontal
ANALYSISReaction time Number of errorsLearning rate
Trying to intercept a moving targetThe goal-keeper and the penalty shot. Low target velocity
target
arm mov
verticaleye mov
horizontaleye mov
target
arm mov
verticaleye mov
horizontaleye mov
target
arm mov
verticaleye mov
horizontaleye mov
Trying to intercept a moving targetThe goal-keeper and the penalty shot. Very high target velocity
stimulusdelivery
movementrecording
evokedpotential
subjectiveawareness
0
45
3530
25
20
15
10
5
40
50
55Método de Libet para determinação da percepção temporal sensorialLibet et al., Brain 1979;102:193-224.
0
45
3530
25
20
15
10
5
40
50
55Awareness of the motoraction (Libet’s method) is not significantlyadvanced in trials withthe StartReact effect
Conscious awareness of the time of the reaction (a cortical process)is independent from
the execution of the motor task in StartReact trials
REFLEX AND VOLUNTARY REFLEX AND VOLUNTARY COMPONENTS OF THE COMPONENTS OF THE
REACTION TO PULLREACTION TO PULL--TESTTESTI. I. ColmeneroColmenero, J. Costa, J. Costa¹¹, J. Casanova, J. Casanova²², J. Valls, J. Valls--SolSoléé²²
Department of Clinical Neurophysiology, Marques de Valdecilla University Hospital, Santander.
¹Department of Neurology, Santa María University Hospital, Lisbon. ²Department ofNeurology, Clínic i
Provincial University Hospital, Barcelona.
INTRODUCTION & OBJECTIVE
BUT…
What is the pattern of muscular contraction associated with it?
TO DEFINE THIS MUSCLE TO DEFINE THIS MUSCLE ACTIVATION PATTERN IN HEALTHY ACTIVATION PATTERN IN HEALTHY
VOLUNTEERS VOLUNTEERS
PULL-TEST: Manoeuvre widely employed in clinical practice.
OUR AIM
AND THEN…
We could understand the abnormalities that can be seen in patients
METHODS
Sternocleidomastoid
Rectus abdominalis
Quadriceps
Tibialis Anterior
9 subjects Orbicularis Occuli
Soleus
Accelerometer
Synergy electromyograph
Experimenter
Pull backwards
METHODS
Volunteer
Reaction TimeVs
Disequilibrium
Signal of accelerometer
Latency
SCM
QUA
TA
SOL
OOC
ABD
QUA
TA
SOL
OOC
ABD
SCM
Reaction Time
Disequilibrium
100 ms
1 mV
1º
S
S
RESULTS
0.16121±16125±14Soleus
0.0378±17110±18*Tibialis Ant
0.0164±14191±49Quadriceps
0.1658±1264±9Abdominal
0.0272±39125±23SCM
0.1125±528±4OOc
React vs DiseqDisequilibriumReaction
* Bursts of low amplitude in reaction
ABD Reaction Time
Disequilibrium
100 ms
1 mV
OOC Reaction Time
Disequilibrium
SOL
100 ms
1 mV
Reaction Time
Disequilibrium
S
COMMENTS & CONCLUSIONS
1) The first burst of EMG activity in the condition “Disequilibrium” is compatible with a REFLEXREFLEX REACTIONREACTION. .
The latencies are shorter than in the same muscles in the condition “Reaction”.
2) The fact that bursts were observed in most muscles is compatible with a GENERALIZED REACTIONGENERALIZED REACTION.
Possible generatorsSomatosensory afferents Vestibular afferents
RETICULOSPINAL TRACT
COMMENTS & CONCLUSIONS
3) The first muscles to be activated:
•Bisdorff et al. (J Neurol Neurosurg Psychiatry. 1999) : OOC-SCM-ABD
•Our study: OOC- ABD ABD -SCM
The ABD muscles play an important role in maintaining the trunk´scenter of gravity
4) The OOC showed some activity in both manoeuvres.
The tap stimulus in the shoulder is sufficient to induce a SOMATOSENSORY BLINK REFLEXSOMATOSENSORY BLINK REFLEX (Miwa et al., 1998)
COMMENTS & CONCLUSIONS
5) The relationship between TA and SOL is different in both conditions:
The SOL is tonically active during standing AND a burst contraction of SOL while standing is preceded by a PREPRE--MOVEMENT SILENT PERIODMOVEMENT SILENT PERIOD (pmsp) (Aoki et al., 2002).
•In “Disequilibrium”: The SOL pmsp is accompanied by a burst in the TA.•In “Reaction” : The SOL and TA activity are simultaneous.
Present in most trials in our subjects
TA
SOL
1º
2º
1º No feet displacement2º Feet displacement
pmsp
burst
100 ms
1 mV
TA
SOL
S
DISEQUILIBRIUM
FINAL CONCLUSION
The latencies of the motor responses and the pattern of muscular activation recorded during the pull test maneuver is compatible with the activation of the circuit of the startle reaction through either somatosensory or vestibular inputs.
According with this hypothesis, an association can be expected between impairment of the startle reaction and abnormalities in the pull test maneuver.