OBSTETRIC BRACHIAL PALSY. ROLE OF BOTULINUM TOXIN TYPE-A IN EARLY TREATMENT

Objectives: Up to 30% of obstetric brachial palsies (OBP) leave permanent sequelae despite an adequate physical rehabilitation, usually (upper OBP, C5-C6) with fixed deformities in internal rotation, limited abduction and elevation of arm, and hiperpronation. The causes are early imbalance of agonist/antagonist muscles due to axonotmesis, partial or abnormal axon regeneration and a dystonic movement learning. Early infiltrations of Botulinum toxin type A (BoTx-A) to stronger muscles of axonal-damaged OBP help to strengthen the weaker, reaching better function of arm. Results are presented.

Methods: Selection criteria: upper OBP, significant axonotmesis (EMG), clinical involvement (limited abduction, elevation or external rotation or the arm; flexion or extension or supination of forearm), already receiving physiotherapy. Exclusion criteria: initial surgical indication, age below 4 months. 21 patients of 4–24 months of age were treated with BoTx-A infiltrations in pronator teres, teres major, subescapular, biceps brachialis, triceps brachialis, according to their clinical involvement. Doses, by muscle, were 1–1.5 UI/bw Botox or 3–5 UI/bw Dysport. Infiltrations were repeated every 4–9 months when necessary. Number of doses: 1–4. Average follow-up was 2y2m (range 2m-4y). Evaluations: at infiltration, 2 months later, and every 3 months afterwards, with direct and video-recorded clinical observation (range of joint movement, active and passive, contractures), and with surface agonists/antagonists simultaneous EMG- recordings.

Results: Excelent in 5/21, good in 11/21, moderate 3/21, mild in 1 and no improvement 1.

Conclusion: BoTx-A has an important role in early management of OBP. It prevents or reduce the development of contractures improving the balance and function of the arm. Late treatment gives lower results. Videorecording is a crucial tool for evaluation.