Elements of muscle's pathology in pediatrics

(1)

Muscles in

Muscles in movementsmovements: : applied

applied physiologyphysiology to infants andto infants and theirtheir clinicalclinical conditionsconditions

(2)

Concerned

Concerned items:items: from

from fetalfetal live to 7 yearslive to 7 years

MuscularMuscular activitiesactivities: : tonus, posture, muscle contraction, tonus, posture, muscle contraction, metabolicmetabolic aspects, aspects, general

general movementsmovements, , archaicarchaic reflexesreflexes, , paroxysmsparoxysms, convulsions, , convulsions,

DevelopmentalDevelopmental aspects:aspects:

TheThe healthyhealthy musclesmuscles

TheThe perturbedperturbed muscle muscle activityactivity

(3)

Muscular

activities

: states, attitudes

and

movements

The

tonus:

basic state basic state ofof contraction contraction leadingleadingto to resistanceresistance to stretch, to stretch, andand thisthis is

is dependentdependentofof efferentefferentinnervation.innervation.

The

posture

The

muscle contraction

The

metabolic

aspects

The

general

movements

as as describeddescribed by by thethegroup group ofof Groningen;Groningen;

The

archaic

reflexes

The

paroxysms

: tonic,

clonic

,

myoclonic

,

myokimy

,

fasciculation,

dystonia

(4)

Developmental

aspects

and

the

«

final

results

»

:

a strict distribution

a strict distribution withwith vertical hierachyvertical hierachy andand parallelparallel connectionsconnections

Motor cortex: UMN *

Rostral midbrain: LMN *

Py EPy

Cerebellum *

Associative cortex *

Basal ganglia *

Reflex motor prog Premotor cort Cerebellum Limbus Amygdala thalamus

Cranial nerve M nuclei

Muscles, and gamma N Alpha N( ant horn )

(5)

Strict distribution

In In thethemotormotorcortexcortex: : with

with6 layers6 layers, , fromfromfeetfeetto to mouthmouth, , togethertogetherwithwithotherotherstructures ofstructures ofmotormotorlearninglearningor reflexesor reflexesmotormotor programs

programs; ;

In In thetheinternalinternalcapsula, 40 % ofcapsula, 40 % of fibersfibersare fromare fromsomatosensorysomatosensoryareas, 31 % fromareas, 31 % frommotormotorcortex, cortex, andand20 % 20 % from

frompe-pe-motormotorcortex;cortex; In the cerebellum:

with 3 layers, with lateral part for planing movements, intermediate part for adjusting limb movements, with central part for postural adjustment, with flocculus for eye movements

In the basal ganglia:

these are the putamen ( 1 ) with the globus pallidus (2) forming lenticular nucleus, and with caudate nucleus (3) forming the striatum, the subthalamic nucleus ( 4), the substantia nigra ( 5 ), the thalamus (6) wich is the obligatory passage for all these pathways of modulation and treatments of cortical inputs/outputs

In the midbrain nuclei:

mainly the red nucleus, the locus coeruleus, the cranial nerve motor nuclei, In the spine:

with anterior and posterior horn, and alpha MN together with gamma MN to maitain possible the stretching/destretching reflex

In the motor units: with the fibers

(6)

Topographic anatomy

Level

Level ofof orbitsorbits

Upper: CN Middle: TH

Lower: Pu,GP _Level_Level _of_of _nose_nose

Rostral midbrain

Blood supply is mainly from Heubner’ artery

(7)

The histology of muscles

The motor unit= 1 LMN + = 1 LMN + severalseveral muscle muscle fibersfibers;;

3 3 kindskinds ofof muscles fibers ( ( RedRed slow, White slow, White fastfast, , IntermediateIntermediate slowslow--fastfast ) ) and

and motormotor unitsunits in in allall muscles but muscles but withwith a variable distribution; a variable distribution; thethe adultadult pattern

pattern isis obtainedobtained atat 30 w 30 w afterafter an important an important differentiationdifferentiation fromfrom 26 w;26 w;

TheThe recruitementrecruitement isis made in a made in a orderorder sizesize; CNS ; CNS hashas more control on more control on thethe redred slow

slow fibersfibers;;

TheThe myotubesmyotubes( or ( or myocitesmyocites ) are ) are thethe resultsresults ofof fusion fusion ofof myoblastsmyoblasts andand contain

contain myoglobinmyoglobin, contractiles , contractiles proteinsproteins ( actine ( actine withwith tropininetropinine, , tropomyosine

tropomyosine; myosine ; myosine withwith titininetitinine, , actimineactimine, , myonesinemyonesine, , proteinprotein C; C; desmine

desmine, , dystrophinedystrophine, , merosinemerosine, , proteicproteic triadtriad ), ), mitochondriamitochondria, , severalseveral nucleus

nucleus nearnear membrane [ note membrane [ note thethe differencesdifferences withwith myocardiummyocardium ]. ]. TheseThese cells

cells are are fullyfully donedone atat 20 20 weeksweeks GA, GA, andand the contractile system isis presentpresent atat 16

16 weeksweeks andand endsends itsits developmentdevelopment afterafter 40 w;40 w;

Innervation isis presentpresent atat 10 w, 10 w, firstlyfirstly multi multi thenthen monomono--fiberfiber atat 43 w;43 w;

(8)

Developmental

aspects

Muscles

cells

division, fusion

ended

at

20

20 weeks

weeks

fetal

life;

Fibers

differentiation

and

distribution

ended

at

30

30 weeks

weeks

fl

;

Contractile

and

sarcotubular

system

ended

at

43

43 weeks

weeks

;

Innervation

from

a multi to a

mono

-

innervation

at

43

43 weeks

weeks

;

Before

3

3 -

-

4

4 months

months

of

age,

motor

behavior

depens

from

globus

pallidus

;

Afters

3

3 -

-

4

4 months

months

,

motor

behavior

is

depending

of

motor

cortex +

putamen

+

caudate

nucleus +

learning

areas;

Full control

of

spinal motoneurones by locus

niger

and

Extra

Pyramidal structures

is

obtained

at

3

3 -

-

4

4 years

years

;

(9)

Muscles contraction: relevant

anatomy

Cortex primary motor area

Basal ganglia

Bulbar reticular structure

cerebellum

-Adjacent structures

+

Alpha / gamma motoneurons of anterior horn

+

muscles

Sensory receptors:

Muscles, tendons, bones,

-Posterior horn

+

(10)

The

so

called

archaic

reflexes

12 12--1616 37 37 < 34 < 34 Neck

Neck rightingrighting

12 12--1616 37 37 < 28 < 28 Stepping Stepping 12 12--1616 37 37 < 33 < 33 Traction Traction 12 12--1616 34 34 < 28 < 28 Rooting Rooting 10 10--1212 33 33 < 28 < 28 Recoil Recoil 12 12--1616 32 32 <28 <28 MORO MORO 8 8--1010 32 32 < 28 < 28 Palmar

Palmar graspgrasp

8 8--1010 < 28 < 28 < 28 < 28 withdrawal withdrawal

(11)

Metabolic

aspects

of

muscles tissue

Biochemical

reactions

are

the

glycolysis

,

the

Kreb

’

s cycle,

the

P

-

creatine

cycle,

the

purine cycle,

the

lipid

oxydation,

the

glucose

-

fatty

acids

cycle

At

«

rest

»

:

mainly

use

of

FFA;

At

«

exercise

»

:

1

1 hr

hr

: glucose (

even

anaerobic

glycolysis

if

intense ),

with

a shift to

glycogenolysis

or

neoglucogenesis

,

but

also

FFA;

1

1 -

-

3

3 hr

hr

: FFA;

> 4

hr

:

lipid

(

beta

and

omega

) oxydation

In

fetus

and

till 6

months

,

mass

of

muscles

is

22

22 -

-

24 %

of

body

weight

(12)

Activities

in non

healthy

muscles

(

( thethe incidence ofincidence of neuromyopathiesneuromyopathies isis about 0.3/1000 birthsabout 0.3/1000 births ))

EvenEven if if bloodblood flowflow cancan bebe adaptedadapted to effort, to effort, abnormalitiesabnormalities in adaptation in adaptation cancan be

be observedobserved due to due to

defects in metabolism

ofof glucose ( glucose ( seesee glycogenglycogen ), ), of

of lipidslipids ( ( seesee betabeta--oxydationoxydation, , carnitinecarnitine, FA transport ). , FA transport ).

DefectsDefects in contractile in contractile proteinsproteins;;

DefectsDefects in contraction ( i e in contraction ( i e spasticityspasticity ););

Infection, Infection, fastingfasting, , exerciseexercise ( short or long ), cold, ( short or long ), cold, narcosisnarcosis mightmight induceinduce abnormalities

abnormalities;;

If If myoglobinuriamyoglobinuria, , thinkthink on on disordersdisorders ofof glycolysisglycolysis or or glycogenolysisglycogenolysis;;

If 3If 3--5 5 foldfold increaseincrease in lactate, NH3 in lactate, NH3 andand pyruvatepyruvate, , thinkthink on on lipidlipid metabolismmetabolism (

(13)

Testing

muscles in

spastic

muscles

MeasureMeasure in in anklesankles ( ( goniometrygoniometry or or radiologyradiology ););

SpecialSpecial clinicalclinical teststests

AnalysisAnalysis ofof walkwalk or or movementsmovements

MuscleMuscle’’s s scalesscales: : AshworthAshworth, Tardieu, Duncan Ely, , Tardieu, Duncan Ely, SelectiveSelective motormotor control control test,

test, ModofiedModofied selectiveselective motormotor control test;control test;

Muscles Muscles echographyechography

OtherOther methodsmethods are are mainlymainly devoteddevoted to neuromyopathiesto : EMG, VC, : EMG, VC, biopsy

biopsy withwith enzymologyenzymology andand morphometrymorphometry; In ; In thisthis case, case, thinkthink on on makingmaking studies

(14)

Testing

the

muscles

activities

during

efforts: the

efforts:

the

rationale

« Exercise »

local local increaseincrease ofof VO2 VO2 input input fromfrom muscles to muscles to motormotor

area

area andand recticulorecticulo--endothelialendothelial systemsystem increaseincrease ofof heartheart rate, rate, cardiaccardiac output

output andand bloodblood pressure AND pressure AND increaseincrease ofof RR RR andand tidal volume;tidal volume;

LacticLactic acidacid production arrives if HR > 0.8 ( 220 production arrives if HR > 0.8 ( 220 –– age in age in yearsyears ););

ExcentricExcentric contraction contraction ofof muscles ( muscles ( thethe lengthlength ofof fibersfibers changes changes andand therethere isis a

a movementmovement ) ) isis betterbetter supportedsupported thanthan concentricconcentric contraction: contraction: lessless VO2, VO2, lower

lower CardiacCardiac output, output, lessless lacticlactic acidosisacidosis; ;

HoweverHowever, , exageratedexagerated excentricexcentric contraction contraction leadsleads to to ofof pain due to release pain due to release of

of ( ( fromfrom myocytesmyocytes ) ) hydroxylasehydroxylase, , andand moreovermoreover whenwhen myofibroblastsmyofibroblasts are are stimulated

stimulated collagencollagen mightmight bebe excessivelyexcessively secretedsecreted. .

Stretching Stretching andand destretchingdestretching reflex ( by gamma MN reflex ( by gamma MN spindlespindle withwith alpha MN alpha MN )

(15)

Testing

the

muscles

activities

by «

by

«

efforts

»

Walking

for 6

-

9

9 -

-

12 minutes or running for 9

-

10

10 -

-

12 minutes;

Forearm

exercise

with

aerobic

mode or

ischemic

mode;

These

modes are

difficult

to

perform

before

7

7 years

years

; but

imaginative techniques are

being

built

up

: to

improve

methods

of

(16)

Biochemical

data in

several

tissue

23 %

6

0.18

25.7

11.3

11.3 exercise

exercise

23 %

6

0.13

0.23

0.14

0.14 Muscles

Muscles

At

rest

4 %

6

0.19

7

2.8

2.8 liver

liver

1 %

6

0.15

25.7

12.5

12.5 kidneys

kidneys

0.4 %

6

0.16

16.3

23

23 heart

heart

15 %

6

0.18

7

3

3 brain

brain

Tissue/body Tissue/body Weigth Weigthratioratio ATP/O2 ratio

ATP/O2 ratio Glucose/O2

Glucose/O2 Molar Molarratioratio Glucose Glucose Mg/100g/min Mg/100g/min O2/100g/min O2/100g/min tissue tissue

(17)

Definitions

of

several

movements

AtaxiaAtaxia: : impairementimpairement ofof smoothsmooth voluntaryvoluntary coordination coordination ofof movementsmovements;;

AthetosisAthetosis: slow flexion/extension : slow flexion/extension ofof face face andand limbslimbs;;

ChoreaChorea: : fastfast movementsmovements ofof face, face, shouldershoulder or drop;or drop;

Convulsion: Convulsion: suddensudden sustainedsustained ( tonic ) or ( tonic ) or briefbrief ( ( clonicclonic ) contraction ) contraction ofof a or a or several

several wholewhole muscles;muscles;

DystoniaDystonia: : extremeextreme sustainedsustained coco--contraction ( contraction ( agonistsagonists andand antagonistsantagonists) ) ofof any

any body part;;body part;;

Fasciculation: single contraction Fasciculation: single contraction ofof oneone MotorMotor Unit;Unit;

MyokimyMyokimy: : repetitiverepetitive cotractioncotraction ofof oneone MU in MU in oneone muscle;muscle;

MyoclonusMyoclonus: : briefbrief andand suddensudden contraction contraction ofof severalseveral MU, in MU, in oneone or or severalseveral muscles;

muscles;

(18)

Cerebral

palsy

in

children

:

a

necessary

multidisciplinary

approach

We hope a as good as possible physical and mental

health for the children, future adults.

(19)

Diapositive 18

(20)

Cerebral

palsy

_palsy

in

_in

children

_children

Prevalence

:

3

3 -

-

4 / 1000;

Clinical

forms

:

following

evident

motor

involvement

:

spastic

:

diplegia;quadriparesia;Hemiplegia

;

triplegia

;

ataxic

;

dyskynetic

:

dystonic

;

athetoid

;

(21)

Etiologies

or

circumstances

of

cerebral

palsy

Leucomalacia

Meningitis

/

encephalitis

Asphyxia

Occlusive

vascular

disorder

Malformation

unknown

(22)

Muscles contraction (1 ): structures

Interventions of

the

pyramidal and

extrapyramidal

tracts, of

the

eye

function

, of

the

red

nucleus, of

the

cerebellum

,

the

caudate

,

subthalamus

and

putamen

nuclei

,

all

the

tracts

making

relays

between

these

structures,

and

(23)

Muscles contraction ( 2 ): relevant

anatomy

Cortex primary motor area

Basal ganglia

Bulbar reticular structure

cerebellum

-Adjacent structures

+

Alpha / gamma motoneurons of anterior horn

+

muscles

Sensory receptors:

Muscles, tendons, bones,

-Posterior horn

+

(24)

Muscles contractions ( 3 ):

molecular

aspects (

1 1 nerve

nerve per per motormotor unit, unit, componedcomponed of 3of 3--15 15 interlacedinterlaced muscles muscles fibersfibers thatthat canncann’’tt bebe individualized

individualized ))

D membrane Pot

Release of Ac Cho

Na+

influx

SRE

Ca++ efflux Troponin ( actin+myosin ) overlap=

Muscles contraction

nicotin

Curare, Ach esterase

(25)

Clinical

presentation

Motor

involvement

:

spasticity

,

ataxia

,

dyskinesia

,

hypotonia

;

Vision

impairement

and

disorder

of

communication

Feeding

disorder

Epilepsy

Orthopedic

disorder

(26)

Relevant

motor

items for

the

practitioner

An

ability

to

progress

smoothly

from

one

movement

to

the

in

orderly

succession (

i.e.

walking

progress

)

A cognitive

control

of

sequences

of

motor

pattern (

from

about

one

to

six

years

)

A

ability

to

change

the

timing and

scale

intensity

(27)

Therapeutics

in CP

_{in CP}

Physiotherapy

«

castings

»

Botulinum

toxin

Intrathecal

baclofen

Improve

daily

life

function

Mental pattern

Self

-

esteem

Nutrition

Pain

convulsions

Increase

in force

Increase

in

dexterity

Better

movements

Better

equilibrium

Better

self

-

concept

(28)

Cellular organisation:

from brain to muscles

(29)

points of action for

btx

-

a

Loss

of balance

between

muscles;

Excessive

activity

of

acetyl

-

choline

;

Blocking

action on

acetyl

-

choline

in muscle

plate;

(30)

Cellular

(31)

Professionals

around

the

child

with

CP

Pediatrician, physiotherapist, orthopedist, Social worker, family doctor, nurse,…

(32)

Links

between

the

CNS and

the

skeletal

muscles activities

muscles

activities

(33)

Bot

(34)

Muscles

concerned

by

the

injections:

example

for

one

side

…

Iliopsoas

: 2 sites;

Hamstrings

: 4 sites;

Adductors

: 2 sites;

Gastrecnomius

: 4 sites;

Tibialis

: 2 sites;

(35)

Castings

: a

complex

word

and

world

…

Maintain

good

ankles

;

(36)

hospital

phase

Re

-

pay

attention;

Explain

pa

t

hology

;

Re

-

assessment

;

Make

injections;

Initiate

physiotherapy

;

Recalibrate

mental of

infant and

family

;

(37)

Assessment

before

injections

Type ad

severity

of

palsy

;

Muscles

to

be

injected

and

number

of

units

;

Walking

analysis

;

Orthopedic

analysis

and type of

castings

;

Muscles

analysis

:

quality

and

quantity

;

Nutrition

analysis

;

(38)

The

special

physiotherapy

program

after

the

injections: 3 + 3

weeks

Special

casting

;

Special

physiotherapy

;

Special

distribution of

activities

during

day

;

Stretching

muscles;

(39)

Then normal

program

of

physiotherapy

But

with

another

energy

and motivation

…

More interaction

between

infant,

family

,

physio

,

doctor

,

friends

and

(40)

The

follow

-

up

program

after

the

injections

First

visit

after

4

4 -

-

6

6 weeks

weeks

;

Then

visits

every

3

3 -

-

4

4 months

months

;

Centered

upon

walking

,

ankles

, muscles

’

health

,

emotions

;

Feed

-

back

from

infant, parents and

physiotherapist

;

(41)

Special

hopes

and

improvements

for

the

near

future

Better

administrative

procedures

;

Better

interaction

between

different

disciplines

around

cerebral

palsy

;

Better

casting

methods

;

Special

and

specific

pediatric

revalidation

;

Early

in

group

integration

(

garden

and

elementary

(42)

Some

words

about

the

intra

-

thecal

baclofen

injection

What

is

baclofen

Why

intrathecal

This

is

by

neurosurgery

and

pediatrics

;

The

4

4 different

different

phases: 1.

selection; 2.installing

catheter

and

finding

the

right

dosage; 3.installing

the

pump

;

4.follow

-

up,

including

the

maintenance and replacement of

the

pump

;

(43)

This

(44)

This