Which test involves tracing a large number on the palm to identify it?

• A. Graphesthesia
• B. Stereognosis
• C. Two-point discrimination
• D. Tinel sign

Answer: (A)

Graphesthesia is a cortical sensory test that assesses the brain’s ability to interpret tactile information. By tracing a large number on the palm, the patient must integrate touch with memory and spatial representation in the somatosensory cortex to identify the symbol without looking. A correct identification indicates intact cortical processing of sensory input. If this ability is impaired, it points to a cortical or thalamocortical sensory pathway issue, typically in the contralateral parietal lobe or sensory cortex, rather than a simple peripheral nerve problem.

Stereognosis, by contrast, involves recognizing objects by touch alone, using memory and haptic cues; two-point discrimination measures tactile acuity and peripheral sensory function; and Tinel sign checks for nerve irritation along a peripheral nerve pathway, such as the median nerve at the wrist.