Differential Diagnosis for Numbness of Thumb, Index, Middle Finger

• Single most likely diagnosis
  • Carpal Tunnel Syndrome: This condition is the most likely cause of numbness in the thumb, index, and middle fingers due to compression of the median nerve at the wrist.
• Other Likely diagnoses
  • Radial Neuropathy: Although less common, radial neuropathy can cause numbness in the back of the hand and the thumb side of the hand, but it typically spares the palmar surface.
  • Cervical Radiculopathy (C6 or C7): Nerve root compression in the cervical spine can cause numbness in the thumb, index, and middle fingers, depending on the specific nerve root involved.
  • Thoracic Outlet Syndrome: Compression of the nerves and/or blood vessels that pass into the thoracic outlet can cause numbness and tingling in the fingers, including the thumb, index, and middle fingers.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Acute Stroke or Transient Ischemic Attack (TIA): Although less likely, sudden onset of numbness in one hand could be a sign of a stroke or TIA, which requires immediate medical attention.
  • Spinal Cord Injury or Compression: Trauma or other conditions causing spinal cord injury or compression can lead to numbness and other neurological deficits, including those affecting the hand.
• Rare diagnoses
  • Peripheral Neuropathy: Certain types of peripheral neuropathy, such as those associated with diabetes or vitamin deficiencies, can cause numbness in the hands, but the pattern is often more widespread and not limited to the thumb, index, and middle fingers.
  • Tumors (e.g., Schwannoma, Neurofibroma): Rarely, tumors affecting the nerves of the hand or arm can cause localized numbness.
  • Sarcoidosis or other systemic diseases: In rare cases, systemic diseases like sarcoidosis can cause neuropathy leading to numbness in specific areas, including the hands.