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Nerves arising from S3

- See: Innervation:

- Discussion:
    - paresthesias in buttocks are an important sign of possible cord dysfunction;
    - since segments S3, S4, S5 are the lowest and most peripheral segments in the spinal cord, an extramedullary lesion
          at any level may first compress these fibers and affect pain and temperature sensation;
    - if saddle area of the buttocks is not examined for pain and temp sensation, an early spinal cord lesion may not be suspected;
    - in contrast, if an intramedullary tumor is present, the buttocks is last to be affected, w/ resultant sacral sparing;
    - in trauma to S1-2 level of the spinal cord there is weakness of hip abductors and ankle plantar flexors and toe flexors;
    - S3-5 level lesions do not leave any motor paralysis, but bowel, urinary bladder, and sexual functions are impaired