Paresthesia

Definition

Paresthesia is the perception of somatic sensation that occurs either in the absence of, or is not typical for, a particular physical stimulus. These frequently are described as burning, prickling (“pins and needles”), numbing, or tingling sensations, such as when one’s foot or hand “falls asleep.” They can be perceived as very painful or distressing at times, in which case the term “dysesthesia” can be applied. The Dejerine-Roussy syndrome occasionally associated with thalamic lesions would be an example of the latter. These sensations can be transient or chronic. Paresthesias can arise from problems anywhere along the somatosensory pathways from the peripheral nerves, through the dorsal columns or spinothalamic tracts of the spinal cord, to the thalamus or postcentral gyrus of the parietal lobe. Any condition that affects the nerves or other somatosensory structures can result in symptoms. The one experienced by most individuals at some point in time results from...