Causes and Symptoms of DCD
DCD is heterogeneous in nature (Banhart et al., 2003). Numerous theories about the causes have been discussed in literature, however, a definitive answer about the precise causality is unknown (Missiuna et al., 2006). Firstly, it is proposed that DCD is part of the continuum of cerebral palsy. It is believed to occur after a prenatal, perinatal or neonatal insult or after neuronal damage at the cellular level in the neurotransmitter or receptor systems. It has also been proposed that DCD is caused by immature development in parts of the brain. This leads to incorrect motor neurons development and consequently, a decrease in nerve cell connections. If motor neurons cannot form proper connections, the brain will take longer to process information (Hendrickx, 2009).
Difficulties that children experience can result from one or more impairments in proprioception, motor programming, timing or sequencing of muscle activity (Banhart et al., 2003). Therefore, the brains of young children are underdeveloped, and information is not capable of being fully processed (Boon, 2010). As illustrated, children usually learn by integrating sensory information from a variety of different sources, which connects them to their environment.
DCD children have difficulty processing information from various sources, causing a delay in their ability to learn (Boon, 2010). Ayres (1985) also suggested that difficulties in coordination occur due to sensory integrative dysfunction, where the child is unable to integrate sensory or perceptual motor information. Several hypotheses have been proposed to explain DCD, but a clear mechanism has yet to be defined.
Symptoms
DCD involves a broad range of symptoms. As illustrated, DCD symptoms can be split up into six domains; gross motor skills, fine motor skills, concentration, communication, classroom difficulties and organization. When looking at gross motor skills, deficits include difficulties in large movements such as poor balance and posture, lack of rhythm, and clumsy gait (Hendrickx, 2009). Symptoms that are caused by fine motor skills include difficulties in small movements such as lack of manual dexterity and manipulative skills (Hendrickx, 2009). As illustrated, individuals experience difficulty with concentration, where they are easily distracted and have limited focus. In terms of communication, individuals experience unclear speech or uncontrolled pitch. DCD children also have classroom difficulties, where they are affected by background noise and have difficulties with note- taking. Finally, individuals with DCD typically have poor organizational skills; where they have difficulties planning and rely on visual reminders.