Distinguishing motor pattern between spastic CP and dyskinetic CP?

• A. Spastic CP shows hypertonia with brisk reflexes; dyskinetic CP shows involuntary choreiform/dystonic movements with fluctuating tone.
• B. Spastic CP shows hypotonia with reduced reflexes.
• C. Spastic CP is characterized by tremors with ataxia only.
• D. Dyskinetic CP is always rigid and non-fluctuating.

Answer: (A)

Spastic CP and dyskinetic CP show different motor patterns because they reflect different types of brain involvement. Spastic CP is driven by upper motor neuron injury, so muscles are in a state of increased tone (hypertonia) and reflexes are brisk or hyperactive. This stiffness and exaggerated reflex response are typical and can lead to certain postures or contractures over time. Dyskinetic CP, on the other hand, is characterized by involuntary movements such as chorea or dystonia, with tone that is not fixed but fluctuates—sometimes higher, sometimes lower—depending on the moment and the movement. So the best description contrasts spastic CP’s hypertonia with brisk reflexes against dyskinetic CP’s involuntary, fluctuating movements and variable tone.

The other options don’t fit as well because spastic CP does not present with hypotonia and reduced reflexes; that pattern points away from spastic CP. Tremor with ataxia is more characteristic of ataxic CP rather than spastic or dyskinetic types. And dyskinetic CP is not limited to rigid, non-fluctuating tone; it typically involves fluctuating tone with involuntary movements.