C6 pinprick loss finding
This patient has pinprick sensory loss over the thumb in the C6 dermatome.
[Doctor] Okay, is this sharp?
[Patient] Yes.
[Doctor] Is this sharp?
[Patient] No.
[Doctor] Is this sharp?
[Patient] Yes.
[Doctor] Is this sharp?
[Patient] Yes.
[Doctor] Is this sharp?
[Patient] Yes.
About C6 pinprick loss
Patients may have loss of sensation in a focal area of skin within a limb or over the trunk corresponding to a dermatome. This pattern of sensory loss is most easily detected using pinprick stimulation. Knowledge of the distribution of the dermatomes aids in performance and interpretation of the sensory exam. The thumb lies within the C6, or sixth cervical dermatome.
Localization
A dermatome is a segment of skin supplied by a single nerve root. C6 dermatomal pinprick loss is due to dysfunction of the 6th cervical nerve root, also known as a C6 radiculopathy. Nerve root compression by a herniated disc or osteophyte is the most common cause of radiculopathy.