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Proper palmar digital nerve (hand)

The proper palmar digital nerves are terminal sensory branches of the median and ulnar nerves, supplying the volar aspect of the fingers. Each finger typically receives two proper digital nerves (radial and ulnar), which travel along the sides of the phalanges beneath the digital arteries and digital fibrous sheath.

These nerves provide cutaneous sensation to the palmar surface of the fingers and dorsal fingertip sensation, and carry autonomic fibers for sweating and trophic function. Their superficial course makes them vulnerable to laceration, crush injuries, neuromas, and entrapment within scar tissue.

Synonyms

  • Proper digital nerve

  • Volar digital nerve

  • Palmar digital nerve

Origin, Course, and Distribution

Origin:

  • Arise as terminal branches of the common palmar digital nerves from the median or ulnar nerve.

Course:

  • Run distally along the medial and lateral sides of each finger

  • Travel deep to the palmar aponeurosis, then along the fibrous digital sheath

  • Closely accompany the proper palmar digital arteries

Distribution:

  • Volar skin of fingers

  • Lateral nail folds and pulp

  • Dorsal distal phalanx

  • Autonomic innervation of fingertip skin

Relations

  • Medially/Laterally: Digital arteries (neurovascular bundle)

  • Anteriorly: Subcutaneous tissue, skin of finger pulp

  • Posteriorly: Flexor tendon sheath and phalanges

  • Proximally: Common digital nerves

Function

  • Provides fine tactile sensation to palmar surfaces of fingers

  • Supplies pain and temperature sensation

  • Sensory input critical for precision grip and object manipulation

  • Autonomic fibers regulate sweat glands and skin trophic properties

MRI Appearance

T1-weighted images:

  • Nerve appears as a thin, low-to-intermediate signal tubular structure

  • Surrounded by bright subcutaneous fat in the volar finger

  • Neurovascular bundle appears as paired nerve–artery units

T2-weighted images:

  • Proper palmar digital nerve displays intermediate-to-mildly hyperintense signal relative to muscle

  • Digital artery remains low-to-intermediate signal

  • Flexor tendon sheath shows low signal posteriorly

STIR:

  • Normal nerve: intermediate-to-dark signal

  • Fat suppression highlights nerve as a thin dark band within bright suppressed fat

CT Appearance

Non-Contrast CT:

  • Nerve itself not clearly visualized due to soft tissue similarity

MRI image

Proper palmar digital nerve hand MRI axial image-img-00000-00000

MRI image

Proper palmar digital nerve MRI coronal image-img-00000-00000