A wide-based stance with inability to stand with feet together regardless of eyes open or closed points to a lesion in which region?

• A. Cerebral cortex
• B. Basal ganglia
• C. Posterior column
• D. Cerebellum

Answer: (D)

Gait ataxia from cerebellar dysfunction produces a wide-based stance because the cerebellum normally coordinates balance and coordinating movements of the legs and trunk. When the cerebellum, especially the midline vermis that controls trunk stability, is impaired, the person loses precise postural control, so they adopt a broad stance to compensate and struggle to stand with feet together. This difficulty persists regardless of whether the eyes are open or closed because the underlying problem is impaired motor coordination, not simply a loss of proprioceptive input. In contrast, a sensory (posterior column) problem would typically worsen when vision is removed (positive Romberg), not remain equally problematic with eyes open. Therefore, this presentation points to a cerebellar lesion.