ATAXIA: involves muscles continually contracting, resulting in stiff limbs, exaggerated reflexes,

Non-Spastic CP: involves involuntary muscle tone, broken into two group

Spastic (also called Pyramidal) Non-Spastic (also called Extrapyramidal)

Functional Anatomy

Upper Motor Neurons and the Corticospinal Tract

Upper motor neurons originate in cortical layer 5 in the primary motor cortex. These cells are responsible for initiating the voluntary movements of the individual. The axons of these cells become the corticospinal tracts and synapse directly with lower motor neurons in the ventral horn. Spastic CP is caused by damage to the upper motor neurons either at the cortical level or within the pyramidal (corticospinal) tract. This is the most common form of CP.

Cerebellum

The Cerebellum is a multi-faceted processing network of cells taking in information from the brain, spinal cord, and sensory receptors from the rest of the body to output information about smooth, coordinated, timely movements. Ataxic CP is caused by damage to the cerebellum

Basal Ganglia

The Basal Ganglia are a group of structures that regulate voluntary movement through a series of excitation and inhibition through their various connections. Ultimately their goal is to inhibit unwanted movements and facilitate the wanted, necessary movements. Both Athetoid and Dystonic CP are caused by damage to the basal ganglia.