Which finding is most characteristic of spastic cerebral palsy?

Which finding is most characteristic of spastic cerebral palsy?

• A. Tremor with hypotonia
• B. Hypertonicity with increased deep tendon reflexes
• C. Uncoordinated gait
• D. Involuntary writhing

Answer: (B)

Spastic cerebral palsy is driven by upper motor neuron injury, which leads to increased muscle tone and brisk reflexes. The most characteristic finding is hypertonicity—muscles feel stiff and resist passive movement—often accompanied by increased deep tendon reflexes and sometimes a positive Babinski sign. This combination reflects the loss of inhibitory control over the motor pathways, producing a velocity-dependent resistance to stretch and exaggerated reflex responses. Other options point to different patterns: tremor with hypotonia is not typical of spastic CP and suggests other motor issues; uncoordinated gait can occur in CP but isn’t the defining feature; involuntary writhing indicates dyskinetic (athetoid) CP, which involves choreiform movements from basal ganglia dysfunction rather than the corticospinal tract.

Spastic cerebral palsy is driven by upper motor neuron injury, which leads to increased muscle tone and brisk reflexes. The most characteristic finding is hypertonicity—muscles feel stiff and resist passive movement—often accompanied by increased deep tendon reflexes and sometimes a positive Babinski sign. This combination reflects the loss of inhibitory control over the motor pathways, producing a velocity-dependent resistance to stretch and exaggerated reflex responses.

Other options point to different patterns: tremor with hypotonia is not typical of spastic CP and suggests other motor issues; uncoordinated gait can occur in CP but isn’t the defining feature; involuntary writhing indicates dyskinetic (athetoid) CP, which involves choreiform movements from basal ganglia dysfunction rather than the corticospinal tract.