Components of CP classification
1. Motor abnormalities
A. NATURE AND TYPOLOGY OF THE MOTOR DISORDER: The observed tonal abnormalities assessed on examination (e.g. hypertonia, hypotonia) as well as the diagnosed movement isorders present, such as spasticity, ataxia, dystonia, athetosis.
Surveillance of Cerebral Palsy in Europe (SCPE),i which divides CP into three groupings based on the predominant neuromotor abnormality – spastic, dyskinetic or ataxic, with dyskinesia further differentiated into dystonia and choreoathetosis.
It is recommended that cases continue to be classified by the dominant type of tone or movement abnormality, categorized as spasticity, dystonia, choreoathetosis, or ataxia, but that any additional tone or movement abnormalities present should be listed as secondary types. The term ‘mixed’ should not be used without elaboration of the component motor disorders.
B. FUNCTIONAL MOTOR ABILITIES: The extent to which the individual is limited in his or her motor function, including oromotor and speech function.
The functional consequences of involvement of the upper and lower extremities should therefore be separately classified using objective functional scales. For the key function of ambulation, the Gross Motor Function Classification System (GMFCS) has been widely employed internationally to group individuals with CP into one of five levels based on functional mobility or activity limitation.vi A parallel classification scale, the Bimanual Fine Motor Function Scale, or BFMF, has been developed for assessing upper extremity function in cerebral palsy, but has not been as extensively studied as the GMFCS.vii A newer instrument for assessing hand and arm function – the Manual Ability Classification System or MACS – has been shown to have good inter-rater reliability
2. Accompanying impairments The presence or absence of later-developing musculoskeletal problems and/or accompanying non-motor neurodevelopmental or sensory problems, such as seizures, hearing or vision
impairments, or attentional, behavioral, communicative and/or cognitive deficits, and the extent to which impairments interact in individuals with cerebral palsy.
3. Anatomical and neuro-imaging findings
A. ANATOMIC DISTRIBUTION: The parts of the body (limbs, trunk, bulbar region, etc.) affected by motor impairments or limitations.
All body regions – trunk, each limb, and oropharyx – need to be described individually in terms of any impairments of movement or posture. A scale for describing truncal posture in cerebral palsy has recently been developed.ix Separate objective classification schemes have also been developed for the upper and lower extremities
B. NEURO-IMAGING FINDINGS: The neuroanatomic findings on CT or MRI imaging, such as ventricular enlargement, white matter loss or brain anomaly.
4. Causation and timing
Whether there is a clearly identified cause, as is usually the case with post-natal CP (e.g. meningitis, head injury) or when brain malformations are present, and the presumed time frame during which the injury occurred, if known.
For the present, timing of insult should only be noted when reasonably firm evidence indicates that the
causative agent, or a major component of the cause, was operative in a specific time-window, as for example, with
post-natal meningitis in a previously well infant. While recording adverse events in the prenatal, perinatal and postnatal life of a child with CP is necessary, clinicians should avoid making the assumption that the presence of such events is sufficient to permit an etiologic classification that implies a causal role for these events in the genesis of CP in the affected individual.
Superintendent, ICH.