Ulnar Neuropathy Lecture Notes

Overview

• Ulnar neuropathy, also known as cubital tunnel syndrome, is a mononeuropathy affecting the ulnar nerve.
• It involves numbness and tingling sensations in the pinky (fifth digit), ulnar aspect of the hand, and half of the ring finger closest to the pinky.
• Second most common nerve entrapment condition in the forearm after carpal tunnel syndrome.
• More common in males (3 to 8 males per female) and increasingly prevalent after age 35.

Anatomy & Pathophysiology

• The ulnar nerve originates from the neck, runs down the arm, and ends at the medial aspect of the hand.
• Responsible for sensation in:
  • Medial half of the fourth digit (ring finger, closer to pinky)
  • Entire fifth digit (pinky)
  • Ulnar aspect of the posterior hand
• Common entrapment sites:
  • Elbow (cubital tunnel, epicondylar ulnar groove)
  • Wrist (canal of Guyon)
  • Forearm (between elbow and wrist)

Causes

• Direct Pressure:
  • Sleeping position
  • Sitting/resting on elbow
  • Compression during medical procedures (e.g., anesthesia)
• Anatomical Causes:
  • Rheumatoid arthritis, osteoarthritis, blunt trauma, ganglion cysts, tumors
• Metabolic Causes:
  • Diabetes, malnutrition, hypothyroidism, anemia
• Other Causes:
  • Cigarette smoking, chronic alcoholism, brachial artery occlusion, venipuncture issues, hemophilia-induced hematomas
• Idiopathic causes

Signs and Symptoms

• Paresthesias: numbness and tingling in the medial half of the fourth digit, entire fifth digit, and medial/ulnar aspect of hand
• Shooting pain down the arm, often transient
• Weakened grip, possible muscle wasting/atrophy in rare cases
• More common on the left side

Diagnosis

• Clinical diagnosis based on characteristic symptoms
• Blood tests for underlying causes:
  • TSH, T3, T4 (hypothyroidism), CBC (anemia), Hemoglobin A1c (diabetes)
  • ANA, ESR, renal function tests, Lyme serology, vitamin levels (B12, B6, folate, MMA)
• Radiographic Imaging:
  • Elbow and wrist for anatomical anomalies (valgus deformity, bone spurs, tumors)
• Other diagnostics:
  • Ultrasonography, MRI, electromyography

Treatment

• Non-surgical/Conservative Treatment:
  • Positional changes (e.g., sleep, sitting)
  • NSAIDs for pain relief
  • Tricyclic antidepressants for neuropathic pain
  • Vitamin B6 supplementation
  • Occupational therapy
  • Splints and elbow pads
• Surgical Treatment:
  • Required if conservative treatment is ineffective or severe atrophy/weakness is present
  • Ulnar decompression, anterior transposition, medial epicondylectomy
  • Endoscopic cubital tunnel release (experimental)

Conclusion

• Non-surgical methods are often sufficient.
• Surgical options available for more severe cases.
• For more details on related conditions, such as carpal tunnel syndrome, refer to additional resources.