Severity Scale for Cubital Tunnel Syndrome

To properly evaluate and diagnose cubital tunnel syndrome, a uniform and widely accepted grading scale is required. Three major scales have been proposed, but none are universally accepted.

Dellon Scale

Dellon created a detailed and well-defined scale based on sensory and motor changes as well as other physical findings, such as Tinel’s sign and the elbow flexion test (defined below):

  • Mild
    Sensory, Intermittent paresthesias; vibratory perception increased
    Motor, Subjective weakness, clumsiness, or loss of coordination
    Tests, Elbow flexion test or Tinel’s sign may be positive
  • Moderate
    Sensory, Intermittent paresthesias; vibratory perception normal or decreased
    Motor, Measurable weakness in pinch or grip strength
    Tests, Elbow flexion test or Tinel’s sign is positive; finger crossing may be abnormal
  • Severe
    Sensory, Persistent paresthesias; vibratory perception decreased; abnormal two-point discrimination
    (static >6 mm, moving >4 mm)
    Motor, Measurable weakness in pinch and grip plus muscle atrophy
    Tests, Positive elbow flexion test or positive Tinel’s sign may be present; finger crossing usually abnormal

The medical terms are defined as follows:

  • paresthesias – a sensation of tingling, pricking, or numbness of a person’s skin
  • vibratory perception – the nerve’s ability to sense vibrations
  • elbow flexion test – most diagnostic test for cubital tunnel syndrome; patient flexes the elbow past 90 degrees, rotates the forearm so palm is up, and extends the wrist
  • Tinel’s sign – tapping over the cubital tunnel causes pain, tingling or shock-like sensation down the arm into the fingers
  • two-point discrimination – ability to tell the difference between a single or double prick in fingers

This is an excellent scale for categorizing pre-operative patients. However, doctors have found it to be complex and unwieldy to categorize patients after surgery.

McGowan Scale

McGowan created in 1950 the scale most often used to grade cubital tunnel syndrome:

  • Grade I – Mild lesions with paresthesias in the ulnar nerve distribution and a feeling of clumsiness in the affected hand; no wasting or weakness of the intrinsic muscles
  • Grade II – Intermediate lesions with weak interossei and muscle wasting
  • Grade III – Severe lesions with paralysis of the interossei and a marked weakness of the hand

The medical terms are defined as follows:

Unfortunately, some experts believe these grades are poorly defined and omit important symptoms such as pain and numbness.

Gabel/Amadio Scale

Gabel and Amadio created a scale that grades cubital tunnel syndrome severity by assigning points based on the severity of three factors: motor function, sensation, and pain (see table below). No points are given for the most severe symptoms; an increasing number of points are given for less severe symptoms.

Score (Points) Motor Sensory Pain
3 Normal no numbness no pain
2 Weaker than opposite side 2-point discrimination normal; intermittent paresthesias intermittent pain
1 obvious atrophy 2-point discrimination >6 mm; constant numbness constant pain; intermittent meds
0 intrinsic paralysis with claw deformity 2-point discrimination > 10 mm; anaesthesia needs narcotics regularly

Post-operative outcome can be graded by summing the points as follows:

  • Excellent – score of 9
  • Good – score of 2 or more in each category with an increase in score in each category of 1 or more points, or an increase in total score of 4 or more points
  • Fair – score less than 2 points in any category, but with an increase in total score of 1-3 points
  • Poor – no change or decline in total score

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Related posts:

  1. Questions to Ask Your Doctor About Cubital Tunnel Syndrome
  2. Top 10 Things You Need to Know About Cubital Tunnel Syndrome
  3. Studies on Cubital Tunnel Syndrome
  4. Conclusions from Studies on Cubital Tunnel Syndrome
  5. Tennis Elbow vs. Cubital Tunnel Syndrome

June 3rd, 2008 Cubital Tunnel, Diagnosis, Symptoms

 

One Response to “Severity Scale for Cubital Tunnel Syndrome”

  1. My Experience with Ulnar Decompression Surgery | Cellbow.org says:
    August 3, 2009 at 9:40 am

    [...] I was diagnosed with cubital tunnel syndrome 3 years ago.  My symptoms were considered "moderate": measurable loss of nerve conduction, moderate to severe pain at times, slight numbness, some [...]