Introduction to Classification

Home , Diplegia

12/06/2020

INTRODUCTION TO CLASSIFICATION

Dianne Zeller 2020

Objectives

• Introduce and familiarise participants with commonly used and current Classification systems

Classification

• The act or process of dividing things into groups according to their type

• Classifying children with Cerebral Palsy according to their type of CP

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Why do we Classify?

• Common language • To assist in treatment planning • To help predict potential abilities and possible associated problems • For research –for consistency and comparisons across groups of children with CP • Epidemiology • To plan current and future service needs • Evaluation of change over time

Difficulties with classification

• CP is an umbrella term for a heterogeneous groups of disorders

• The clinical picture changes

• The terminology is confusing

• Classification systems have different purposes

Classification systems can be based on:

• Subtype –quality and distribution of tone

• Functional abilities

• Pathology

• THERE IS NO UNIVERSAL CLASSIFICATION SYSTEM

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Current Classification Systems

• Bobath/NDT Classification System

• SCPE: Surveillance of Cerebral Palsy in Europe

• Washington Workshop:

Bobath NDT Classification System

Based on Quality of Tone and Distribution • 4 Main Groups 1. Spastic Hypertonia-Always increased tone in one or more limbs • Quadriplegia, Diplegia, Hemiplegia • Mild, Moderate, Severe 2. Dyskinaesia- Presence of excess or unwanted movement • Dystonic • Chore-Athetosis • Pure Athetosis 3. Ataxia- Generalised hypotonia with cerebellar signs 4. Hypotonia

Continuum of tone Spastic hypertonicity-Always above normal Severe Hypertonia Moderate

Mild Pure Choreo Normal

Mild

Moderate Dystonia with Hypotonia Severe Dystonic spasticity

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SCPE: Surveillance of Cerebral Palsy in Europe

• Established in Europe in 1998- in 8 European countries

• Establish a data base

• Monitor specific trends

• Provide information for service planning

• Collaborative research

SCPE Definition of CP (2000)

• Cerebral Palsy (CP) is a group of disorders involving movement and posture and of motor function; it is permanent, but not unchanging; it is due to a non- progressive interference, lesion, or abnormality of the developing/immature brain. (SCPE, Dev Med Child Neurol 42 (2000) 816-824)

Classification tree of Cerebral Palsy Sub types

SCPE classification(Cans C., (2000) DMCN, 42: 816-824)

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SCPE Classification(Cans C., (2000) DMCN, 42: 816- 824)

• Bilateral Spastic • Unilateral

• Dystonic-hypokinesia, hypertonia Dyskinetic • Choreoathetotic-hyperkinesia, hypotonia

Ataxic

Classification: Clinical subtype

Quality of Tone • Hypertonia: • Hypotonia • Fluctuating, varies through a wide range

Anatomical distribution • Bilateral- Previously known as Quadruplegia/Diplegia • Hemiplegia-Unilateral

• *

Spastic Hypertonia Is there persisting increased muscle tone in one or more limbs

Are both sides of the body involved

Y N

Spastic Bilateral Spastic Unilateral

Spastic CP is characterized by at least two of the following : Abnormal pattern of posture and/or movement Increased tone (not necessarily constant) Pathological reflexes (increased reflexes; hyperreflexia and / or pyramidal signs eg. Babinski response)

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Hypertonia-

• Tone is defined as “resistance to passive stretch while the patient is attempting to maintain a relaxed state of muscle activity”. It reflects the state of active muscle contraction

• Hypertonia is defined as “abnormally increased resistance to externally imposed movement about a joint”. Sanger et al., (2003) Pediatrics 111: 89) • It is measured at rest or during involuntary movement but not on voluntary muscle contraction

Hypertonia vs spasticity

• Are they the same thing?

• Hypertonia has 2 components: • Neural component: Spasticity • Non neural component: Muscle properties, Joint capsule restrictions

• The presence of spasticity suggests the presence of hypertonia(Sanger, (2003))

Hypertonia, Upper Motor Neurone Syndrome and Spasticity: Clinical Management and Neurophysiology , Johnson et al 2001

Neural related, eg spasticity

Upper motor neuron Increased resistance to syndrome passive movement

Non neural related e.g changes in muscle, mechanical properties

Figure 1. Neural and non neural mechanisms contributing to increased resistance to passive motion in an upper motor neuron syndrome

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Hypertonia

• May be caused by spasticity, dystonia, rigidity, or a combination of features

Spastic Dystonic Hypertonia Hypertonia Rigid Hypertonia

Classification and Definition of Disorders Causing Hypertonia in Childhood Terence D. Sanger, et al Pediatrics, 2003;111;e89, DOI: 10.1542/peds.111.1.e89

Spastic Hypertonia. Predominant Lesion in the Brain: Cortex and Corticospinal tracts

Theory of Spasticity The exaggeration of the stretch reflex in patients with spasticity could be produced by two factors.

1. An increased excitability of muscle spindles. In this case, passive muscle stretch in a patient with spasticity would induce a greater activation of spindle afferents with respect to that induced in a normal subject, of course considering a similar velocity and amplitude of passive displacements.

2. The second factor is an abnormal processing of sensory inputs from muscle spindles in the spinal cord, leading to an excessive reflex activation of 훼-motoneurons.

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Definition of Spasticity The pathophysiology of spasticity, G. Sheean, European Journal of Neurology 2002, 9 (Suppl. 1): 3–9 Spasticity ……….is a form of hypertonia due to a velocity-dependent increase in tonic stretch reflexes, which results from abnormal spinal processing of proprioceptive input.

Velocity dependent: Resistance increases as speed of lengthening increases

• Tested using Ashworth , Tardieu • R1: Range at which a catch is felt when moving the limb quickly • R2 Range at which a catch is felt when moving a limb slowly

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Dyskinetic CP

Is there persisting increased muscle tone in one or more limbs? N Is the tone varying?

Y N

Dyskinetic CP Unclassifiable

Reduced activity-Tone Increased activity –Tone tends to be increased tends to be decreased

Dystonic CP Choreo-athetotic CP 25

Dyskinetic CP is dominated by both : Abnormal pattern of posture and/or movement Involuntary, uncontrolled, recurring, occasionally stereotyped movements

Predominant lesion in the Brain- Basal Ganglia

Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas.

The basal ganglia are associated with a variety of functions, including control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition, and emotion.

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Dystonia

• A movement disorder in which involuntary sustained or intermittent muscle contractions cause twisting and repetitive movements, abnormal postures, or both (Sanger et al., 2009)

• .

Sanger article…….

• Dystonia could potentially cause hyperkinetic movements by inserting dystonic postures that result in movement of a part of the body away from the intended position.

• If sustained dystonic postures are inserted in voluntary movements, this could result in the prevention of movement, substitution of an unwanted posture for an intended posture, or slow movement in an attempt to overcome the inserted dystonic posture.

• Thus in our definitions, dystonia is characterized by one or more repeated postures. Chorea is characterized by multiple repeated but not rhythmic movements. Athetosis is characterized by nonrhythmic movements without intervening postures.

Dystonic CP

Reduced activity (Hypokinesia), tone tends to be increased( Hypertonia)

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Choreo-Athetotic CP

• Chorea is distinguished from dystonia due to the apparently random, unpredictable, and continuously ongoing nature of the movements, compared with the more predictable and stereotyped movements or postures of dystonia. • Athetosis involves continuous smooth movements that appear random and are not composed of recognizable sub-movements or movement fragments. The term “athetosis” derives from the Greek meaning “without position or place,” reflecting the inability to maintain a stable posture

• Chorea is characterized by multiple repeated but not rhythmic movements. Athetosis is characterized by non-rhythmic movements without intervening postures.

Choreo-athetotic CP

Increased activity (Hyperkinesia); tone tends to be decreased (Hypotonia)

Ataxia

• Is there persisting increased muscle tone in one or more limbs N

Is the tone varying?

Is there generalised hypotonia with signs of ataxia?

Y N

Ataxia Unclassifiable

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Ataxia • The term “Ataxia” is derived from Greek word meaning ‘lack of order’

• “Ataxia” is defined as an inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints (Sanger et al, 2003)

• Mismatch between intention and action Ataxic CP is characterized by both : Abnormal pattern of posture and / or movement Loss of orderly muscular coordination so that movements are performed with abnormal force, rhythm and accuracy

Main body of cerebellum- 3 functional areas Functional area Function Indication of dysfunction Vestibulocerebellum Equilibrium Cannot control eye movements Postural control/movement during head rotation and when Reciprocal innervation standing and walking. (agonist/antagonist) Wide base of support (Low Anticipatory correction COG) Eye movements Inefficient balance reactions

Spinocerebellum Feedback system Dysmetria (esp grading and (proprioception) direction) Hypotonia/decreased stability Tremors Cerebrocerebellum Motor learning (a complex Disrupt timing of movement feedback loop) Delay in movement initiation Impairment of complex spatial and temporal tasks Dysarthria 35

Ataxia -definition

• The term “Ataxia” is derived from Greek word meaning ‘lack of order’

• Mismatch between intention and action

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Generalised Hypotonia

Signs of ataxia: Poor coordination and difficulties with . balance

Washington Workshop

• An International Workshop on Definition and Classification of Cerebral Palsy was held in Bethesda, Maryland (USA), on July 11-13 2004, co-sponsored by United Cerebral Palsy Research and Educational Foundation in the USA and the Castang Foundation in the United Kingdom

• The task was to revisit and update the definition and classification of cerebral palsy in light of emerging understanding of developmental neurobiology and changing concepts about impairments, functional status and personal ‘participation’.

Washington Workshop, 2004 Rosenbaum et al, DMCN 47(8); 2006

• “Cerebral palsy (CP) describes a group of disorders of the development of movement and posture, causing activity limitation that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication and behaviour, by epilepsy, and by secondary musculoskeletal problems.”

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Washington Workshop

• Gives us more information. Not just about the Quality and Distribution of atypical tone

• Child with Bilateral Spastic Hypertonia GMFCS 1 has a very different presentation to a child that has Bilateral Spastic Hypertonia GMFCS level 4 with associated epilepsy and cognitive impairment.

•

Components of classification: suggested new classification system(Paneth et al, 2005)

Motor Abnormalities- Sub type and Function

Associated impairments

Anatomic and Radiological Findings

Causation and Timing

Motor Abnormalities- Subtypes

Quality of Tone • Hypertonia: severe or moderate degrees • Hypotonia • Fluctuating -through what range does the tone fluctuate

Anatomical distribution • tetraplegia / quadruplegia- Bilateral • Diplegia- Bilateral • Hemiplegia-Unilateral

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Classification: Motor function GMFCS

MACS

CFCS

EDACS

www.canchild.ca

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MACS

CFCS

EDACS

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Functional Mobility Scale (FMS)(Kerr Graham, 2004)

International Classification of Functioning, Disability and Health (WHO: 2001,2002)Another way of classifying according to function

ICF Checklist

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Motor Abnormalities- Sub type and Function

Associated impairments

Anatomic and Radiological Findings

Causation and Timing

The value of including associated impairments within a classification system • The various associated impairments are not equally distributed across the population of children with CP

• Particular clinical subtypes (viz spastic quadruplegia, dyskinetic, ataxic hypotonic) and GMFCS Levels IV and V are associated with > 1 co-morbidity

• Suggests a burden beyond that captured by clinical subtype or functional classification on its own

• Associated impairments are important determinants of health, participation and quality of life

Classification: Associated impairments / co-morbidities

• CVI –diagnosed by opthalmologist • Severe auditory impairment –70dB or greater hearing loss bilaterally • Nonverbal –absence of specific words or recognizable vocabulary • Gavage feeding –temporary or permanent feeding tube • Seizures –occurance of afebrile seizures in the preceding 12 months Shevell et al (2009) Neurology (72); 2090

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Associated impairments

• Non-verbal status and co-existing seizures more likely in children with spastic quadriplegia

• Non-verbal skills and auditory impairment more likely in dyskinetic children

• 35% of Level IV children and 82% of Level V children were non-verbal

Motor Abnormalities- Sub type and Function

Associated impairments

Anatomic and Radiological Findings

Causation and Timing

Classification : Radiologic evidence

• MRI or CT scan to determine underlying pathology

• 80-90% predictive of Cerebral palsy- Novak guidelines for early diagnosis

• Knowing where the lesion is assists with assessment and intervention as well as assisting in understanding the timing of the lesion. Certain areas of the brain are vulnerable at certain times. Intraventricular haemorrhage is common. Periventricular regions more vulnerable at 28 to 32 week gestational age. Cortex and Deep grey matter such as Basal Ganglia more vulnerable at term

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Alec Hoon: Neuroimaging Advances in Cerebral Palsy - PEDIATRIC NEWS • October 2007

Motor Abnormalities- Sub type and Function

Associated impairments

Anatomic and Radiological Findings

Causation and Timing

Causal Pathways of Cerebral Palsy (Stanley, Blair, Alberman, 2000)

• Brain development goes through several phases and the variety of cerebral palsy “syndromes” are associated with different phases of neuronal maturation • Recent study by Lasry et al (2010) revealed that term and pre-term children with concomitant PVL and CP differed in terms of clinical subtype, motor function and associated comorbidities

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Causation and Timing

Difficult to classify on the basis of this and is only used if clearly evident e.g. - Neuronal migration disorder e.g. lissencephaly - Prenatal stroke - Post natal infection eg. meningitis - Hypoxic Ischaemic Encephalopathy (HIE) – often perinatal - Extremely low birth weight (ELBW) prematurity

Including causation and timing in classification can assist in understanding the clinical presentation.

What is the relevance of classification to therapists?

• Understanding the quality of the tone remains the framework for analysing and interpreting functional motor performance (ie what is interfering with what the child wants to do; why can’t the child hold a pen; drink from a cup; roll over; sit up)

• Influencing the tone and changing the patterns of muscle activation is what we aim to do with our hands and / or equipment

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BUT • We also recognise that the quality of the tone might not be the primary problem for the child

Systems • Neuro motor: Quality and distribution • Sensory: • Tactile • Proprioception • Vestibular • Visual • Auditory • Taste • Musculo-skeletal • Cognition and Perception • Attention • Motivation • Cardiovascular/Respiratory