Sensory Nerve Conduction Study with Inching Test in Palmar Digital Neuropathy

Area of Science:

• Neurology
• Neurophysiology

Background:

• Mild palmar digital neuropathy is often underestimated due to the diagnostic challenges of selective nerve conduction studies (NCS) on palmar digital nerves.
• Accurate diagnosis is crucial for effective management and treatment of peripheral nerve disorders affecting the hands.

Purpose of the Study:

• To present two cases of palmar digital neuropathy.
• To demonstrate the utility of standard NCS and sensory nerve inching tests in localizing nerve lesions in the fingers.
• To recommend an improved diagnostic approach for finger sensory impairment.

Main Methods:

• Performed standard sensory nerve conduction studies (NCS) in each finger.
• Utilized the sensory nerve inching test to precisely identify the site of nerve lesion.
• Recorded sensory nerve action potential (SNAP) amplitude at the wrist for each finger.

Main Results:

• Both cases exhibited a reduced SNAP amplitude in the affected finger.
• The sensory nerve inching test successfully pinpointed the specific lesion location within the finger.
• Demonstrated the feasibility and effectiveness of the combined NCS and inching test methodology.

Conclusions:

• Standard NCS and sensory nerve inching testing are valuable tools for diagnosing palmar digital neuropathy.
• Recording SNAP in each finger and employing the inching test is recommended for patients with finger sensory impairment.
• This approach can improve the diagnostic accuracy for subtle cases of palmar digital nerve dysfunction.