Pronator teres syndrome

Background

Pronator teres syndrome is considered to be the least common of the three median nerve entrapment syndromes, the other two of which carpal tunnel syndrome and anterior interosseus nerve syndrome. Compression of the nerve occurs at the level of the elbow or at the immediate proximal portion of forearm.

• Common in the 4th and 5th decades of life
• Women have higher incidence, as well as those with forearm hypertrophy (athletes)

Clinical Features

Symptoms

• Primarily will complain of parasthesias overlying the 1st, 2nd, 3rd and lateral portion of the 4th digit
• Pain to the volar aspect of proximal forearm which may be worse on palpatioon
• Typically does not feature nocturnal exacerbation
• May report decreased grip strength

Physical Examination Findings

• Symptoms worsened with resisted forearm pronation, resisted elbow flexion
• Exacerbating examination techniques may produce parasthesias to volar aspect of proximal forearm, which helps distinguish from other median nerve entrapment syndromes
• May have concomitant medial epicondylitis

Differential Diagnosis

• Medial epicondylitis
• Carpal tunnel syndrome
• Anterior interosseus nerve syndrome
• Thoracic outlet syndrome
• Brachial plexus neuritis

Evaluation

• Ortho appreciates dedicate elbow films at minimum
  • Usually no gross appreciable pathology
• Ultrasound and MRI also useful though not required in ED setting

Management

• Conservative management first indicated and most beneficial in large majority of cases
  • Course of extremity rest and NSAID treatment, 3-6 month management period
• Referral to orthopaedics
  • Surgical management possible if no response or worsening of symptoms over 3 month period

Disposition

Outpatient