The sensory examination is used to determine areas of abnormal sensation, the severity and type of sensory impairment and the extent of the involvement. A good knowledge of the somatosensory pathways will help guide your examination. A sensory exam involves evaluating different types of sensation, including light touch, pain, temperature, vibration and position sensation as well as cortical sensation such as stereognosia, graphesthesia and two-point discrimination.

The sensory exam relies completely on the ability or willingness of the patient to report what he is feeling. It can therefore often be the most difficult part of the exam to interpret with certainty. Sensory testing is subjective and therefore it is important to ensure the patient is not too tired and understands exactly what is expected during testing. Sometimes, it is necessary to perform the complete sensory exam after the patient has had a rest if they are tired. Repeating the tests gives more accurate results.

If a patient has delirium or dementia, they can likely only give the crudest picture of his/her perception of sensory stimuli. On the other hand, an alert, stable person may report slight asymmetries that are insignificant. It is important not to lead the patient by suggesting a response. Therefore, you should ask whether the stimulus feels the same or different. Tests should be performed in all extremities, as well as on the face and trunk, with the patient's eyes closed or covered. Sensory changes that are not associated with any other abnormalities such as motor, reflex, cranial or hemispheric dysfunctions must be considered weak evidence of disease unless the loss is in a classical sensory pattern such as a typical pattern of peripheral nerve or nerve root distribution. Therefore, one of the principle goals of the sensory exam is to identify meaningful patterns of sensory loss.