Symptoms of Sensory Nerve Damage

Sensory Nerve Damage

Sensory Nerves (shown in yellow) send information

to the spinal cord and then finally to the brain

where the sensory information is processed.

As mentioned in the previous blog post (Body Sensations in The Brain),  the somatosensory cortex strip includes sensory pathways that process body information from head to toes, which is transported to the brain via sensory nerves.  

Sensory nerves transport all of the sensory information from our body to the brain, such as: pain, touch, and temperature.  However, when a sensory nerve is damaged after an injury to either the brain, spinal cord, or the actual body part, certain symptoms arise.  These symptoms include pain, numbness, weakness, and other sensations.  Other sensations can include hallucinations which are also known as phantom sensations, because they do not exist.  The type of hallucination depends on the site of injury in the brain and can include visual, tactile, or olfactory.  Visual hallucinations involves seeing things that are not there, tactile hallucinations involves feeling objects that are not there, and olfactory hallucinations involve smelling things that are not there.  

Interestingly, sensory hallucinations seem to be produced by the brain as the result of a compensation mechanism, in order compensate for information input that has been lost after injury. 

Citations:

(2013, 10 21). Brain and Nerves [Web Graphic]. Retrieved from http://www.nlm.nih.gov/medlineplus/brainandnerves.html

Nerve pain and nerve damage. WebMD, Retrieved from http://www.webmd.com/brain/nerve-pain-and-nerve-damage-symptoms-and-causes

Purves, D. and Augustine, G . Neuroscience. 4. Sunderland, MA: Sinauer Associates Inc., 2008. 857. Print.