fact versus fiction..... current opinion on the early diagnosis of cerebral palsy fact versus...
Post on 18-Dec-2015
220 Views
Preview:
TRANSCRIPT
FACT VERSUS FICTION.....CURRENT OPINION ON THE
EARLY DIAGNOSIS OF CEREBRAL PALSY
Robyn SmithDepartment of PhysiotherapyUFS2012
Defining Cerebral Palsy (CP)
Always been challenge to defineOlder definitions only focussed
on the motor componentNot comprehensive and inclusive
enough
DEFINING CEREBRAL PALSY (CP)
Cerebral
Palsy (CP)
Cerebral
Motor Disturbance (CMD)
Consensus Definition (2005)“Cerebral Palsy is:
A group of disorders of the development of movement and posture,
causing activity limitation, that are attributed to a non-progressive
disturbance that occurred in the developing foetal or infant
brain. The motor disorders of CP are often
accompanied by disturbances in sensation, cognition, communication, perception, and/or behaviour and/or/by a seizure disorder”
(Developmental Medicine & Child Neurology, 2005)
6 KEY COMPONENTS:
1
•Damage to immature brain
2
•Non-progressive
3
•Disorder of movement and posture
4
•Activity/ function limitation
5
•Associated problems
6
•Epilepsy
6 KEY IMPLICATIONS:
1
•Brain still developing.....neural plasticity & myelinisation incomplete
2
•Damage dies not change ....but clinical picture can
3
•Motor component to the disorder
4
•Results in impairments, activity & participation limitation (ICF)
5
•Range of other challenges relating to communication, perception, sensation
6
•Epilepsy common due to brain damage
Incidence of CPStatistical data varies from country to country Incidence: 2-4/1000 live births (Styer-Acevado ,2008)
Contravening expectations, the incidence has remained unchanged even in 1st world countries
Newest study in US showing an increased incidence in cerebral palsy amongst premature infants (Science Daily, February:2010)
Medical advances in neonatal intensive care has resulted in a decrease in neonatal mortality, and smaller and smaller infants are surviving longer
Incidence of CPUNFORTUNATELY , this is creating
a whole new population of children at risk of marked central nervous system dysfunction
So when does the brain insult occur causing CP?85% congenital in nature
“Perinatal causes” in-utero, during or shortly after birth process
15% postnatal due to e.g. TBI, anoxia, near drowning, meningitis
PERINATAL RISK FACTORS FOR CP
Prenatal risk factorsAnoxia – due conditions
placenta or umbilicusRh and ABO
incompatibility – severe anaemia in newborn
Maternal infectionsMetabolic disorders e.g.
DM, hyperthyroidismGenetic factors
Prenatal risk factorsSubstance addiction of mother e.g.
alcohol, cocaine, nicoteneToxin ingestion Certain medicationsMultiple births e.g. twins and tripletsPET in motherCerebral hemorrhaging in foetus
due sepsis, middle cerebral artery infarct in foetus
Risk factors during labour Cord Prolapse - hypoxia Intrapartum hemorrhaging Prolonged or traumatic deliver
due to malpresentation Shoulder dystotia Maternal shock Cerebral bleed due forceps
delivery
ASPHYXIA=hypoxia & ischaemic brain damange
Risk factors at birth
Prematurity (30 -43% become CP’s)ELBW/ VLBW (40% and 18% chance
severe disability respectively)IUGR
Risks during neonatal period
SeizuresSepsisHIEUncontrolled hypoglycaemiaUntreated severe jaundice
(kernicterus)Neonatal stroke
THE CHALLENGE OF DIAGNOSING CEREBRAL PALSY
Is there is something wrong with my child?
Clinicians often feel like they are treading on eggshells!!!!
Parents want definitive answers that are often not easy to provide
CP notoriously difficult to formally diagnose within the first 12 months of life
Unless child is severely affected
Often difficult to address parents fears and concerns in a satisfactory manner
Why is it so difficult to provide clear cut answers
to parents of infants at risk ??????
Immature Brain : A continuously changing system
A substantial part of the brain’s development occurs in utero. This includes neuronal proliferation, migration and differentiation
Differentiation and neuronal pruning are prolific in the first months of life after birth
The first eighteen months of the normal child’s life is the most significant period of significant and rapid development
The human brain is a extremely complex and
dynamic, constantly changing system
Immature Brain : A continuously changing system
Myelinisation is most significant during the 1st year of life, but is only completed around the age of 30 years of age
Shaping of the nervous system by extrinsic and intrinsic factors e.g. stimulation, exposure, opportunity to practice, internal motivation and personality plays an important role
Brain is in a constant process of remodelling and evolution during childhood
Even though neurons themselves do not regenerate, neural plasticity during childhood may have a marked impact on clinical outcome of children with cerebral damage
Concept of neural plasticityAdaptability and plasticity of the infantile brain Neuronal circuitry of brain reorganises itself,
new synapses form to compensate for areas of damage.
Practice and repetition important here.Plasticity and opportunity for change is
greatest in young children
Thus the value of early intervention programmes
HOW DOES ONE THEN OBJECTIVELY GO ABOUT MAKING A DIAGNOSIS
OF CEREBRAL PALSY IN AN INFANT ????????
How does one make a diagnosis of CMD? Neurological evaluation
Neurological assessment often insensitive & unreliable early on
Dubowitz & Dubowitz’sNew Ballard ScoreMilestones charts
Clinical observations : level of alertness, behavioural status [Neonatal Behavioural Assessment Score (NBAS)]
Regularly measuring and monitoring head circumference
Muscle tone, deep tendon
reflexes, persistent
primitive reflexes, sensory & motor
function dysfunction
Challenges of neurological assessment in infants ............ Accurate execution of neurological testing often complicated Predicting outcome in young infants based on a neurological
assessment is often very difficult Primitive reflexes not always integrated yet Children with transient signs often incorrectly diagnosed Tonal changes & presentation of asymmetry often only visible from
approximately 6/12 Children who initially appear asymptomatic and clinical signs only
appear later Developmental delay and “late bloomers” ? Where do they fall
Misdiagnosis or incorrect diagnosis have huge implications on a family!!!!
LOT OF FALSE POSITVE RESULTS SOME FALSE
NEGATIVE RESULTS
Neurological evaluationClinical neurological evaluation still
widely used as a tool in the diagnosis of neurological dysfunction and cannot be discarded
Performing a comprehensive neurological evaluation in a premature infant often not possible due to their fragile state and health challenges.
The predictive value of results from neurological assessment is far poorer in premature vs. term and older infants.
Dubowitz: New Ballard Score for Neuromuscular maturity
Clinical observation –signs for concern
Behavioural state disturbances e.g. low arousal level or a child that cannot self soothe
Persisting primitive reflexes e.g. ATNR, grasp, startle Feeding difficulties e.g. coughing, aspirating, takes long to feed Poor interaction with environment e.g. Child will not cuddle Disturbances in muscle tone Disturbances in movement – asymmetry, failure to develop
righting reactions and delayed development of head control Parents notice child not reaching his milestones as expected, Parents report difficulties with ADL activities e.g. dressing, bathing
Objective diagnosis tools Objective neuro-imaging studies as techniques for studying the neonatal brain
Sensitive enough early on???
MRI CT Cranial Ultrasound EEG
90% children CP will have abnormalities
Neuroimaging studies: Cranial Ultrasound (US)
Serial US is the imaging technique of choice in premature infants and neonate.
Using this imaging method can show the soft tissues of the brain.
Infants with severe abnormalities have been linked to poor neurological outcome over time. Milder abnormalities shown on US have shown to of less accurate prognostic value.
Neuroimaging studies: Computed Tomography (CT scan)
This is used to be able to see a picture of the brain from many different positions.
Is used to detect abnormalities in the brain structure and tissue.
Neuroimaging studies: Magnetic Resonance Imaging (MRI)
The use of magnets and radio waves to allow a more detail image of the brain.
In children with neurological dysfunction one will look out for areas of brain atrophy indicating under development of the brain
Neuroimaging studies: Electroencephalogram (EEG)
Is used to measure electrical activity in the brain and is performed on babies that have had seizures
total dependence of neuroimaging to diagnose early brain dysfunction in ill and premature infants
Other clinical investigations
If neuroimaging studies do not show any atypical findings the following may be considered :
Metabolic studies metabolic causes are however rare (0-4% of all cases).
Genetic studies
Muscle biopsy to rule out conditions e.g. muscular dystrophy, SMA surgical procedure where an incision approximately 3 inches long is made, and a small section of muscle is removed. Usually they remove the muscle from the upper thigh. The biopsy is used to check for degeneration of muscle tissue.
Neurophysiological tests electroencephalogram and somatosensory evoked potentials
Prechtl’s method of qualitative
assessment of spontaneous
movements of the infant
???? The way
forward in the early diagnosis of CP
Prechtl’s method of neuromotor assessment Heinz Prechtl pioneer in field of early neurological
development Realised that self generated motility early in development
played an important role in survival and adaptation These spontaneous general movements (GM) are present
from the foetal period until approximately 58 weeks post- conception (4 months).
Prechtl discovered that the quality of these spontaneous general movements accurately reflected the condition of the nervous system in the foetus and young infant
Change in the type of GM strongly related to gestational age
Also affected by endogenous maturation process of the CNS important
To some limited degree, postnatal experience This method is used in the early detection of brain
dysfunction.
How are the images generated? Serial video imaging of infant over time using a portable
video camera set up on a tripod (direct overhead or lateral view of the infant)
GM are also affected by the behavioural state of the child – best state to view GM is the active, awake state or sleeping state in the prem.
If there is too much crying or fussing the video session should be postponed
Infant positioned in supine with the head end of the crib elevated at 30 o
The child is to be clothed in a diaper or short clothing and the crib must be free of restricting devices that may negatively impact on the infants freedom of movement
Duration of the video recording between 10-20 minutes
Done weekly up until 58 weeks post-conception age (4 months)
How is the video material then Interpreted?
Interpretation of the images is based on the “gestalt perception” of the observer.
Based on pattern recognition when viewing static or moving images of GM
Intuitively guidedInter-observer reliability is extremely high,
from studies done it is reported to be between 89-93%
Normal optimal General Movements (GM)
Neuronal network generates signals to the muscles in the absence of sensory input – central pattern generator(CPG)
Series of gross motor movements of variable amplitude, force, intensity and speed
These complex movements involve all body parts including the limbs, trunk and head
Lasts few seconds to a few minutesObserved during the awake and sleep states
of the infantGM are of the first movements the foetus
developsGM show age specific characteristics
Age- specific characteristics of GM Age specific characteristics:
Preterm GM’s 28 to 36-38 wks gestation Extremely variable Including may pelvic tilts and trunk movements
Writhing GM’s 36-38 to 52 wks post conception age Writhing movement now added Movements seem somewhat slower and less participation of the trunk
and pelvis
Fidgety GM’s 46-52 to 54-58 wks post conception age Continuous flow of small elegant movements, circular movements Superimposed by large and fast movements
Normal optimal General movements (GM)
Complexity and variation of the movements are key
Constant variation of flexion/extension, abduction/adduction and IR/ER limbs
Fluent Gradual beginning & endOver time the infant continuously
produces new movement patterns10- 20% infants
Sub-optimal general Movements (GM)
Sufficient variabilityNot fluentMost infants
Abnormal General Movements (GM)
Loss of the complexity, variability and fluency of GM happens when the CNS is impaired
Stereotypical movements hallmark of early brain dysfunction
The transition periods between the various types of GM are important markers
Abnormal General Movements (GM)
Then described as being:
Poor repertoire –sterotyped, monotonous movements
Cramped synchronous GM- movements appear rigid, lack smooth and fluent character. Limb and trunk muscles contract simultaneously. Strongly associated with later hypertonicity and dyskinetic types of CP
Chaotic movements –appear abrupt, large amplitude
Clinical significance of abnormal GM
PVL, IVH, HIE, IUGR and hyperbilirubinaemia can give rise to abnormal GM’s
Quality of GM’s can be influenced by severe illness and sedation, but these abnormalities may be transient (why series of images over time is important)
GM considered mildly abnormal if periods of atypical movements interspersed with normal GM –long term predictive value less accurately predicted
Neurological evaluation often insensitive in fragile premature infants. GM are of far higher predicative value in these infants.
Better correlation between the neurological evaluation and the assessment of GM improves with increasing age
Clinical significance of abnormal GMPredictive value highest at the stage of transition
to fidgety movements (46-58 wks post-conception)
Infant who do not develop fidgety or show abnormal fidgety movement at an extremely high risk of developing CP
Specificity and sensitivity estimated to be 95% Infants who develop abnormal GM, who do not
develop CMD develop some other developmental disorder.
No studies to date have been done where infants with mildly abnormal GM have been followed up until school going age where perceptual & learning and scholastic difficulties often first present
Mildly abnormal GM associated with ADHD and behavioural problems
Normal evolution of GMAt 15/52 GM start to declineInfant starts to develop other patterns of
spontaneous movementDevelopment then of postural control Followed by typical sensory-motor
development Then observer focus more on the
observation of volitional active movement
??? Employ similar observational methods here
Conclusion............ Highly specific and valid objective
measure for indentifying early neurological dysfunction
Persistently abnormal GM especially relating to repertoire and cramped synchronous movements show a high predictive value of poor neurological outcome over time
Advantages of the qualitative method of assessment of spontaneous movements
Non-invasive Low cost Easy to learn to execute Non time-consuming Ideal for serial observation/assessment over time. The value of
developmental profiles over time is extremely valuable in predicting long term outcome in preterm, term and post-term infants.
More reliable than neurological examination and neuroimaging techniques early on and especially in premature infants
Enables early rehabilitation and intervention and family support allowing the child to reach his full potential
Suggested to be of the greatest clinical value when used in combination with
neurological assessment and neuroimaging techniques in predicting
early neurological dysfunction
Limitations of this assessment method ........ Cannot be used in infants who have severely
depressed neurological status e.g. children with acute severe HIE (often comatose) or children on CNS suppressing medication (sedation)
Cannot completely replace a comprehensive neurological system including assessment of auditory, visual and sensory sub-systems
Method cannot be used in infants that are mechanically ventilated due to restrictive apparatus
Video series may need to be interrupted id the child’s condition deteriorates
Training expensive Local expertise in the execution of the technique
limited, which makes skill transfer in the profession a challenge
So how is this relevant to us as physiotherapists?
As PT’s working in NICU and in early intervention care with this at risk population we needs to be multi-skilled as these infants more often than not have multi-system involved. Unfortunately cannot just focus’ on basic neurodevelopmental care programmes, chest PT or even the odd baby massage.
If working in a NICU one has to be knowledgeable regarding neurodevelopment as we have a critical role to play in initial neurodevelopmental screening , assessment and implementation of early neurodevelopmental therapy intervention programmes to ensure the best possible functional outcome for these children and their families
NEED TO BE COME MORE AWARE OF ADVANCES IN
OUTR FILEDS, AND BECOME MORE OPEN TO TRYING
DIFFERENT EVIDENCE BASED ASSESSMENT AND
INTERVENTION APPROACHES IN THE MANAGEMENT OF OUR
PATIENTS
Training ???Physicians and physiotherapists working in
the NICU and field of infant neurologyEuropeR 10 000 for a 4 day courseCredentialing needed to execute the
technique in an official capacity
References Dubowitz gestational age assessment. 2010. retrieved on 01 March 2010
Available online at : http://neopraxis.org/Dubowitz_gestational_age_assessment.htm
Hadders-Alga, M. 2004. General movements: a window for early identification of children at high risk for developmental disorders
journal of Paediatrics August 2004: S12-S18 Bax, M. Goldstein, M, Rosenbaum, P, Leviton, A & Paneth, N. 2005. Proposed
definition of Cerebral palsy 2005. Developmental Medicine & Child Neurology 2005, 47:571-576
Garcia, J.M., Gherpelli, J.L.D. 7 Leone, C.R. 2004. The role of spontaneous general movements in the neurological outcome of cerbral lesions in preterm infants. Journal de Pediatrica 80(4): 296-304
Cioni, G., Pretchlib, H, Paoliclli F.P.B., Einspielerb, C., Federica, M. & Roversi, C. 1997 . Which better predicts later outcome in fullterm infant: quality of general movements or neurological examination. Early human development 50; 1: 71-75
Nel, M. 2009.Prechtl’s qualitative method of assessment of spontaneous movements . NDT early intervention course (unpublished)
Smith, R. 2010. Aetiology and Classification of CP. Lecture presentation UFS (unpublished)
Styer-Acevado, J. 2008. The infant and child with cerebral palsy in Pediatric Physical Therapy. Lippincott, Williams & Wilkins. Baltimore. Pp179-186
top related