Successful re-innervation of proximal limb peripheral nerve injuries is rare. Axons regenerate at ~1 mm/day, reaching hand muscles by 24 months, finding them atrophied and fibrosed. Peripheral nerve injury repair is often delayed waiting for spontaneous recovery. This waiting time should not be longer than 6 months as after 18 months reinnervation will not achieve effective muscular function. When spontaneous recovery is impossible, referral too late or damage too severe, other options like a transfer from a nearby healthy nerve to the injured one must be considered. They are very successful, and the deficit in the donor site is usually minimal. The most common nerve transfers are a branch of the spinal nerve to the trapezius muscle to the suprascapular nerve, a branch of the long head of the triceps to the axillary nerve, a fascicle of the ulnar nerve to the motor branch of the biceps muscle, two branches of the median nerve to the posterior interosseous nerve and the anterior interosseous nerve to the ulnar nerve. There are many more options that can suit particular cases. Introduced in brachial plexus injury repair, they are now also applied to lower limb, to stroke and to some spinal cord injuries.
Part of the book: Peripheral Nerve Regeneration
The immense majority of patients with chronic headaches can be controlled with medical treatments. However, there is a subset of them with poor response, and it is for those patients that new therapeutic strategies are being designed. Neuromodulation has been used for chronic pain management in many areas for the past 50 years. The application of these techniques to the treatment of the most refractory chronic headache disorders has offered hope to these patients. There is a large variety of different techniques, each of them particularly suitable to specific types of chronic headaches. The surgically implanted devices are still in use in some particularly recalcitrant cases. Nevertheless, new percutaneous devices allow new treatment strategies. Percutaneous devices do not always show the same effectivity as surgically implanted stimulating devices, but they are user-friendly and have no serious adverse effects. Thus, they are becoming the treatment of choice once the pharmacological means are no longer effective. In case of failure, the surgical procedures would still be available as a last resort.
Part of the book: Transcranial Magnetic Stimulation in Neuropsychiatry