Altered sensation varies from total loss (anesthesia) to excess (hyperesthesia). Be sure the patient is not using the term ‘numbness’ to describe limb weakness. Ask the patient to outline any abnormal area of sensation. Another point of possible misinterpretation is to label sensory inattention as sensory loss. In the former patients may require a good deal of verbal encouragement to pay attention during the examination.
In examination of an asymptomatic patient, examine the limb extremities first: if these are normal, detailed proximal examination is not usually necessary. During sensory examination, expose the area of interest, together with the equivalent part of the opposite side of the body.
Observation of the skin provides information on sensory innervation before examining each sensory modality. Insensitive skin is susceptible to damage from unnoticed minor trauma. An extreme example of these trophic changes is in leprosy, where the long term sequelae is loss of digits.