**2. Overview of clinical classification of CP**

Some factors that influence the clinical classification of CP are the age of a child, reliability of the medical history, and extent of diagnostic investigations [1]. This means that the same child may be classified differently at different times (due to changes in peripheral manifestations with age), by different people (due to variable historical data from maternal recall or case notes), and in different regions (due to differences in availability and affordability of neuroimaging and metabolic studies). Therefore, Bax et al. [1] in 2005 proposed that all classification results should indicate these factors at the time of classification.

Children with CP differ clinically in the following characteristics: type/nature of motor disorder, distribution of motor impairment, etiology, presence/number of accompanying impairments, structural brain abnormalities on neuroimaging, degree of severity of impairments, and individual therapeutic needs. These clinical variables form the basis of the traditional classifications of CP. In 1956, Minear [7] and the Nomenclature and Classification Committee of the American Academy for cerebral palsy classification put forward an early classification system that presented seven classification axes based on the aforementioned features.

Subsequent classification systems originated from the Minear classifications and are either a combination or an expansion of the categories. Such classification systems based on multiple variables include the Swedish classification system [8], Edinburgh classification [9] and classification by the Surveillance for Cerebral Palsy in Europe (SCPE) [10].

The current emphasis on the functional consequences of different health states increased interest and research on the functional classification of CP [1, 3, 4]. The result is an evolution of newer measures (functional scales) that objectively and reliably measure and quantify functional abilities. A number of these functional scales have been validated by multiple studies [11–16]. They include Gross Motor Function Classification System (GMFCS) [11] (functional mobility/ambulatory function), Manual Ability Classification System (MACS) [14] (hand and arm function/manual dexterity), Communication Function Classification System (CFCS) [16] (speech/communication function) and Eating and Drinking Ability Classification System (EDAC) [17] (eating and drinking/oropharyngeal function). They are mainly used for predicting current and future management needs of children with CP, and their use agrees with current thinking in management of CP.

Advances in management of CP including the biopsychosocial method of service delivery that recommends liberal use of assistive devices require additional characteristics or variables to be added to traditional classifications in order to assist management and satisfy other important purposes like clinical description and research [1, 4, 5]. Such a classification would be called holistic, comprehensive or standardized. A consensus on what characteristics/components such holistic classification should incorporate is yet to be reached by experts in the field of CP.
