Cubital Tunnel Syndrome

Article Author:
Munish Chauhan
Article Editor:
Joe M Das
Updated:
4/1/2019 4:38:44 PM
PubMed Link:
Cubital Tunnel Syndrome

Introduction

Cubital Tunnel Syndrome: A neuropathy of the ulnar nerve causing symptoms of numbness and shooting pain in the medial aspect of the forearm, also including the medial half of the fourth digit and the fifth digit, usually caused due compression or irritation of the nerve.

Ulnar Nerve anatomy: C8 and T1 nerve roots join and give rise to the medial cord in the brachial plexus. Ulnar nerve originates as a branch of medial cord. The ulnar nerve then travels down the arm along with the brachial artery towards the elbow joint, at which point it enters the posterior compartment of the forearm via the cubital tunnel. Cubital tunnel is the region where the ulnar nerve is most likely to be damaged due to its location and anatomy. At this point, the ulnar nerve travels between the olecranon and the medial epicondyle.

Etiology

Multiple causes can result in ulnar nerve compression and damage at the cubital tunnel and cause symptoms such as tingling in the medial aspect of the forearm along with the little finger and medial aspect of the ring finger.

  • Pressure on the ulnar nerve is a common cause of symptoms. The ulnar nerve is superficial at the point of the medial epicondyle; this is why people may experience the feeling of shooting pain and electric shock in the forearm if they accidentally hit their elbow on a hard surface.
  • Stretching the ulnar nerve can also result in similar symptoms. The ulnar nerve lies behind the medial epicondyle. During flexion of the elbow joint, the ulnar nerve gets stretched because of this anatomical position. Repetitive elbow flexion and extension can cause further damage and irritation to the ulnar nerve. Some individuals sleep with elbows bent which can stretch the ulnar nerve for an extended period during sleep, which is an identified cause of damage to the ulnar nerve.
  • Injuries to the elbow joint (fractures, dislocations, swelling, effusions) can cause permanent anatomical damage which will cause symptoms because of compression/irritation of the ulnar nerve.

A study of 117 patients identified that direct pressure on the nerve because of habits while sitting, or secondary to occupational activities is a significant cause of the nerve damage as the nerve passes posterior to the medial epicondyle.[1]

Epidemiology

Ulnar nerve neuropathy is the second most common neuropathy of the arm. A study of 91 patients identified that close to 60% of these patients had anatomical changes in the cubital tunnel that caused the ulnar nerve neuropathy, of which nearly 20% of patients had a subluxation of the ulnar nerve. Other causes identified in this study were osteophytes in almost 7% of patients and luxation of the ulnar nerve in nearly 10% of patients. Post-traumatic lesions also can cause symptoms in about 3.3% of patients.[2]

History and Physical

The presenting patient complaint is typically one of "pins and needles" in forearm/hand. On further questioning of the precise nature of the patient's complaint, the tingling sensation usually presents in the little finger and a half of the ring finger. These symptoms may be present transiently initially then gradually get worse.

There may be a weakness of the interosseous muscles on examination. The extent of muscle damage and sensory changes will depend on the damage caused to the nerve. In advanced disease, there may be a weakness of the handgrip. 

Also on examination, findings may include a complete loss or reduced sensations on the palmar and dorsal sides of the little finger and the medial part of the ring finger.[3][4]

Evaluation

Diagnosis can be made clinically, and nerve conduction studies are often used to confirm the diagnosis. In some patients, however, nerve conductions may be normal in the early stages of symptoms; therefore, interpretation of nerve conduction studies should always be in a clinical context.

X-ray of the elbow joint can be done to exclude bony pathologies such as osteophytes and minor fractures which may cause compression of the nerve.[5]

Both ultrasonic scanning (USS) and magnetic resonance imaging (MRI) have sensitivity and specificity over 80% in diagnosis. MRI and USS are also helpful to identify other causes of compression, which may not be picked up on plain radiograph films such as soft tissue swelling and lesions such as neuroma, ganglions, aneurysms, etc.[6]

Treatment / Management

Pathological findings should undergo careful evaluation when deciding on treatment options. Patients can often benefit from non-surgical interventions; therefore clinician should evaluate and determine an end goal with the patient for treatment before deciding on the route of treatment.

Non-surgical treatment:

  • If the symptoms are purely the result of mechanical factors such as leaning over the desk at work with weight on the elbows or sleeping with bent elbows, then correcting these postures can be the mainstay of treatment.
  • In an Italian study, Padua et al. followed up 24 patients who had willingly declined surgery after the initial diagnosis. About half of these patients reported improvement in their symptoms during their follow-up appointments. Their further nerve conduction studies also showed improvement, which further supports the evidence that patient with mild symptoms can be managed without surgical interventions.[7]
  • Splinting at night time to keep the elbows straight, has been suggested in published papers as an initial management option in a patient with mild symptoms.[4]
  • Simple analgesia such as NSAIDs will also help with the pain.

Surgical treatment: Patient's with severe symptoms might not improve with conservative management. After trying the non-surgical management, some patients may not recover and will require surgical intervention to improve their symptoms. Surgical management involves decompression of the nerve in the cubital tunnel. Some surgeons release the pressure in the cubital tunnel region while others prefer free mobilization of the ulnar nerve. 

Various methods of surgical treatment have been discussed and performed. Some studies have suggested medial epicondylectomy as a method to decompress and release pressure from the ulnar nerve.[4]

Differential Diagnosis

  • Lesions in the Guyon's (ulnar) canal
  • Cervical spondylosis
  • Brachial plexus injuries
  • Thoracic outlet syndrome
  • Syringomyelia
  • Pancoast tumors
  • Motor neuron disease
  • Carpal tunnel syndrome
  • Polyneuropathy

Prognosis

About half the patients achieve an improvement in their symptoms with conservative management.[3]

Complications

  • One  in eight patients may find that their symptoms recur after surgical decompression[8]
  • Recovery may be slow and incomplete
  • Symptoms may worsen before they improve

Deterrence and Patient Education

Patient education about their symptoms and causes is of great importance, which is vital if the aim is to manage the patient with conservative means as a slow improvement of symptoms can put people off from conservative management. 

If using non-steroidal anti-inflammatory medications, then education about the use of NSAIDs and gastric protection is a necessary discussion to have with patients. Gastric protection is obtainable by using proton pump inhibitors (PPIs). It is also suggested to take NSAIDs with or after food.[9]

Enhancing Healthcare Team Outcomes

A multi-disciplinary team including a nurse, physical therapist, and clinician input can enhance recovery. Physiotherapy can provide significant help if muscle weakness is present. Discussion with the pharmacist can help patients to understand the use and side-effects of analgesic medications. The surgeon should discuss the surgical approach and the potential risks/benefits of the procedure. The nurse should assist in follow up care and monitoring for complications.



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References

[1] Omejec G,Podnar S, What causes ulnar neuropathy at the elbow? Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. 2016 Jan     [PubMed PMID: 26093933]
[2] Filippou G,Mondelli M,Greco G,Bertoldi I,Frediani B,Galeazzi M,Giannini F, Ulnar neuropathy at the elbow: how frequent is the idiopathic form? An ultrasonographic study in a cohort of patients. Clinical and experimental rheumatology. 2010 Jan-Feb     [PubMed PMID: 20346240]
[3] Wojewnik B,Bindra R, Cubital tunnel syndrome - Review of current literature on causes, diagnosis and treatment. Journal of hand and microsurgery. 2009 Dec;     [PubMed PMID: 23129938]
[4] Assmus H,Antoniadis G,Bischoff C, Carpal and cubital tunnel and other, rarer nerve compression syndromes. Deutsches Arzteblatt international. 2015 Jan 5;     [PubMed PMID: 25613452]
[5] Cutts S, Cubital tunnel syndrome. Postgraduate medical journal. 2007 Jan;     [PubMed PMID: 17267675]
[6] Ayromlou H,Tarzamni MK,Daghighi MH,Pezeshki MZ,Yazdchi M,Sadeghi-Hokmabadi E,Sharifipour E,Ghabili K, Diagnostic value of ultrasonography and magnetic resonance imaging in ulnar neuropathy at the elbow. ISRN neurology. 2012;     [PubMed PMID: 22888452]
[7] Padua L,Aprile I,Caliandro P,Foschini M,Mazza S,Tonali P, Natural history of ulnar entrapment at elbow. Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. 2002 Dec;     [PubMed PMID: 12464337]
[8] Beekman R,Wokke JH,Schoemaker MC,Lee ML,Visser LH, Ulnar neuropathy at the elbow: follow-up and prognostic factors determining outcome. Neurology. 2004 Nov 9;     [PubMed PMID: 15534254]
[9] Mansuripur PK,Deren ME,Kamal R, Nerve compression syndromes of the upper extremity: diagnosis, treatment, and rehabilitation. Rhode Island medical journal (2013). 2013 May 1;     [PubMed PMID: 23641462]