Clinical and neurobiological advances in promoting regeneration of the ventral root avulsion lesion

Root avulsions due to traction to the brachial plexus causes complete and permanent loss of function. Until fairly recent, such lesions were considered impossible to repair. Here we review clinical repair strategies and current progress in experimental ventral root avulsion lesions. The current gold standard in patients with a root avulsion is nerve transfer, whereas reimplantation of the avulsed root into the spinal cord has been performed in a limited number of cases. These neurosurgical repair strategies have significant benefit for the patient but functional recovery remains incomplete. Developing new ways to improve the functional outcome of neurosurgical repair is therefore essential. In the laboratory, the molecular and cellular changes following ventral root avulsion and the efficacy of intervention strategies have been studied at the level of spinal motoneurons, the ventral spinal root and peripheral nerve, and the skeletal muscle. We present an overview of cell-based pharmacological and neurotrophic factor treatment approaches that have been applied in combination with surgical reimplantation. These interventions all demonstrate neuroprotective effects on avulsed motoneurons, often accompanied with various degrees of axonal regeneration. However, effects on survival are usually transient and robust axon regeneration over long distances has as yet not been achieved. Key future areas of research include finding ways to further extend the post-lesion survival period of motoneurons, the identification of neuron-intrinsic factors which can promote persistent and long-distance axon regeneration, and finally prolonging the pro-regenerative state of Schwann cells in the distal nerve

Impaired Automatic Arm Movements in Obstetric Brachial Plexus Palsy Suggest a Central Disorder

Neurological Motor Disorder

Outcome following Nerve Repair of High Isolated Clean Sharp Injuries of the Ulnar Nerve

<div><h3>Objective</h3><p>The detailed outcome of surgical repair of high isolated clean sharp (HICS) ulnar nerve lesions has become relevant in view of the recent development of distal nerve transfer. Our goal was to determine the outcome of HICS ulnar nerve repair in order to create a basis for the optimal management of these lesions.</p> <h3>Methods</h3><p>High ulnar nerve lesions are defined as localized in the area ranging from the proximal forearm to the axilla just distal to the branching of the medial cord of the brachial plexus. A meta-analysis of the literature concerning high ulnar nerve injuries was performed. Additionally, a retrospective study of the outcome of nerve repair of HICS ulnar nerve injuries at our institution was performed. The Rotterdam Intrinsic Hand Myometer and the Rosén-Lundborg protocol were used.</p> <h3>Results</h3><p>The literature review identified 46 papers. Many articles presented outcomes of mixed lesion groups consisting of combined ulnar and median nerves, or the outcome of high and low level injuries was pooled. In addition, outcome was expressed using different scoring systems. 40 patients with HICS ulnar nerve lesions were found with sufficient data for further analysis. In our institution, 15 patients had nerve repair with a median interval between trauma and reconstruction of 17 days (range 0–516). The mean score of the motor and sensory domain of the Rosen's Scale instrument was 58% and 38% of the unaffected arm, respectively. Two-point discrimination never reached less then 12 mm.</p> <h3>Conclusion</h3><p>From the literature, it was not possible to draw a definitive conclusion on outcome of surgical repair of HICS ulnar nerve lesions. Detailed neurological function assessment of our own patients showed that some ulnar nerve function returned. Intrinsic muscle strength recovery was generally poor. Based on this study, one might cautiously argue that repair strategies of HICS ulnar nerve lesions need to be improved.</p> </div

Classification of the type of HICS ulnar nerve injury according to the level of transection.

<p>Classification of the type of HICS ulnar nerve injury according to the level of transection.</p

Characteristics of Leiden study group.

<p>Characteristics of Leiden study group.</p

Results of review.

*<p>Total Ulnar Nerves in manuscript, # Cut-off point of successful outcome in manuscript hUN High Ulnar nerve, NG Nerve grafting, FS fascicular suture, ES epineural suture, WH Woodhall Method, 2PD Two-point discrimination, PTT pain touch temperature.</p

Details of patients after ulnar nerve repair following HICS as identified in literature review.

<p>Column A  =  Gap (distance in mm), B  =  Age (gender), C  =  Delay (Months), D  =  Follow-up (Months), E  =  Birch Score, F  =  Motor function: (Before) After surgery, G  =  Sensory function: (Before) After surgery AP <i>adductor pollicis</i>, INT1 <i>first interosseus</i>, ADQ <i>Abductor digiti quinti, SwT−, Sweat test negative</i>, <i>PS+ Protective sensation</i>, *identification in manuscript.</p

Ulnar nerve function-assessment with different scoring systems.

<p>Column A  =  Froment's Sign, B  =  Flexor Carpi Ulnaris, C  =  Best of Flexor Digitorum Profundus III or IV, D  =  Abductor Digiti Quinti, E  =  Abduction Index finger – first dorsal interosseus muscle, F  =  Adduction Little finger – third palmar interosseus muscle, G  =  Little finger, H  =  Ulnar half of ring finger, I  =  Birch Score (Good  = 3, Fair  = 2), J  =  Abduction of index finger, K  =  Abduction of little finger, L  =  Adduction of little finger, M  =  Motor domain, N  =  Sensory domain.</p>*<p>Percentage of normal hand.</p