In apraxia, which brain region's disruption most commonly leads to impaired skilled movements, and what is the hallmark symptom?

• A. Left frontal/postcentral-premotor networks; ideomotor apraxia (difficulty performing gestures on command)
• B. Right frontal networks; ideomotor apraxia
• C. Temporal-parietal junction networks; limb-kinetic apraxia
• D. Left parietal/postcentral-premotor networks; ideomotor apraxia (difficulty performing gestures on command)

Answer: (D)

Skilled movements rely on a left-hemisphere network that links sensory information with motor planning, particularly the parietal region near the postcentral gyrus and its connections to premotor areas. When this left parietal/postcentral-premotor system is disrupted, the brain struggles to translate a desired gesture into the correct motor sequence. That deficit characterizes ideomotor apraxia: a person understands the task and can move, but on command has difficulty performing gestures or pantomiming tool use, even though automatic or spontaneous actions may be relatively preserved. This reflects a breakdown in translating intention into purposeful action, rather than a primary motor weakness or a neglect-like deficit.