T-1 Sensory Dermatome Surface Anatomy

Location

The T1 nerve root can be evaluated by testing sensation on the medial aspect of the arm.

Significance

Loss of sensation should be correlated to the motor exam and associated reflex; in this case finger abduction and triceps reflex.

http://www.orthopaedia.com/display/Main/T-1+Motor–First+Dorsal+Interossei
http://www.orthopaedia.com/display/Main/Triceps+Reflex+%28C7%29

Sensory loss involving a more diffuse area, overlapping several dermatomes suggests a peripheral nerve injury.

The most sensitive way of assessing sensory loss is using two-point discrimination.