Giorgio Brunelli

Anatomy of the Extensor Pollicis Brevis Muscle

52 hands have been dissected to check the anatomy and function of the extensor pollicis brevis. Various abnormalities were found: absence of the E.P.B. (two), insertion on the distal phalanx (four), absence of bony insertion on the base of the first phalanx and insertion on the extensor hood (36). In ten cases (in addition to the two with absence of E.P.B.), no function was elicited by pulling the tendon which inserted upon the extensor hood.

Une nouvelle intervention pour la dissociation scapho-lunaire. Proposition d'une nouvelle technique chirurgicale pour l'instabilité carpienne avec dissociation scapho-lunaire (11 cas)

A new operation for correcting carpal instability with scapholunate dissociation is presented. Rupture of the volar scaphoid-trapezium-trapezoid ligament (i.e. the fibrous sheath of the F.C.R.) is recognized to play a prominent role in the etiology of this instability. The scar formed in between the scaphoid and lunate bones is removed as well as that formed between scaphoid, trapezium and trapezoid. A slip of F.C.R. is passed throughout a tunnel pierced in the distal pole of the scaphoid. The slip is then sutured to the dorsolunar ridge of the distal radius with correction of both the dissociation and the scaphoid flexion. The operation is easy and quick. Eleven cases are presented with satisfactory results.

Computer added locomotion by implanted electrical stimulation in paraplegic patients (SUAW).

Paraplegia means a live long sentence of sensory loss, paralysis and dependence with approximately 1000 new victims in every European country every year and 11.500 new traumatic SCI cases in the US. respectively. Sixty percent are injured before age 30. More than 90% of SCI victims may survive with nearly normal experience of live. Most patients will recover somewhat from SCI over time but no patient who remained plegic for one year regains voluntary motor function after that time period. Despite remarkable efforts and recent achievements in rehabilitation no treatment can be recommended so far to enhance functional recovery and restoring locomotion in paraplegic humans. FES as a technical compensation has become therefore a challenging treatment to restore muscle function and to prevent atrophy and to improve mobility and quality of life at the same time. In paraplegics FES could be the basis to restore locomotion. One of the advantages of an implanted FES version (neuroprosthesis) is that the FES system, electrodes, and cables remain permanently implanted within the body, so that the patient can stay without cables, the programmer attached to the crutches. The SUAW project, supported under BIOMED II Programme by the European Community was aimed to finalize and to put into practice the results of previous research and development. The novel implant with an ASCI-Chip has 16 channels, 8 on each side, 20 mA for monopolar and 2 mA for bipolar stimulation, only one electrode can be stimulated at a given time. Stimulation of 6 muscle groups of both legs are known to be sufficient for locomotion: M. ileopsoas (erector of the body, hip flexor), M. gluteus maximus (hip extensor), M. gluteus medius (lateral hip stabilisator, knee abductor), Mm. hamstrings (knee flexor) stimulated by epimysial electrodes, Mm. sartorius and rectus femoris (knee extensor) stimulated by neural, bipolar electrodes. Patients selection criteria were: stable spinal cord lesion between T7 and T11, minimum 1 year after the accident without deformity of the spine, the muscle groups for locomotion responding to external FES with the EXOSTIM programmer with the same programme used later for the neuroprosthesis. Two paraplegic male patients, T8, 38 and 31 years old respectively, were operated on by an international group of surgeons according to the protocol in 09/1999, respectively 7/2000. The postop. course was uneventful. Because the threshold of the primary implant was too low regarding scare tissue around the electrodes, this implant was changed in 01/2000 and worked perfectly. Both patients are happy with the success of the novel treatment modalities.

A fourth type of brachial plexus lesion: the intermediate (C7) palsy.

A new type of brachial plexus lesion has been defined to be added to the classical types, i.e. the upper (Duchenne Erb), the lower (Dejerine Klumpke) and the total type. This new type is the intermediate palsy. The lesion is a partial involvement of the plexus, the predominant lesion of which involves C7 with a variable involvement of the upper or lower plexus. By observations during operation, and in cadavers, three different mechanisms are considered responsible for the three different types of lesion. A trauma with downwards traction principally involves the upper plexus. Trauma in abduction first involves the lower plexus while a traumatic force acting from an anterior to a posterior direction involves firstly and predominantly the C7 spinal nerve which is in an anterior position and less oblique than the other roots. Avulsion from the cord or rupture are possible. 33 cases have been observed.

Microvascular fibular grafts in skeleton reconstruction

Extensive bone defects from any cause require large bone grafts. Such large defects usually cannot be repaired by conventional, nonvascularized cancellous grafts. Before the advent of microsurgery, many of these lesions could not be cured, and amputation was often the only solution. The bone may be transferred alone or in combination with skin or muscle or both. Idiopathic femoral head necrosis is 1 of the main indications for free microvascular (fibular) transfer. The authors propose a new classification for idiopathic femoral head necrosis. A technique that has been used for the past 14 years, on providing mechanical support and improved blood supply to the femoral head, is described. The fibula is favored for its mechanical properties and its vascular pedicle, and because it is easier to harvest.

Glutamatergic innervation of rat skeletal muscle by supraspinal neurons: a new paradigm in spinal cord injury repair

Acetylcholine is the specific chemical code of spinal nerve terminal transmission at the mammalian neuromuscular junction (NMJ), whereas nicotinic acetylcholine receptors inserted into the membrane of muscle fibres mediate signalling for the muscle response. Glutamate has a primary role in neuromuscular transmission of organisms that are phylogenetically distant from mammals, the invertebrates, including insect and molluscs. Recent research has shown that diverting descending glutamatergic fibres in the spinal cord to rat skeletal muscle by means of a peripheral nerve graft causes the cholinergic synapse to switch to the glutamatergic type. These data demonstrate that under appropriate surgical manipulation supraspinal neurons can directly target muscle fibres and specify the postsynaptic receptors to achieve a functional glutamatergic NMJ.

Strategy and timing of peripheral nerve surgery

The authors review the latest theories of peripheral nerve regeneration and repair. They present their research on nerve regeneration including the alterations in the mother cell body, and in the distal part of the axon, and the time required to reach the best production of amino acids for cytoskeleton reconstruction. Other research of particular interest which is presented regards the chemotactic arrangement of motor and sensory axons inside a vein. This research has shown that the axons are able to find their way to the appropriate (sensory or motor) distal endoneural tubes.Adoption phenomena are also presented.The discussion of surgery includes the type (suture, glueing, grafts, tubulization) and the time of surgical repair. Timing and repair strategies are related to the site of the lesion (which can require that a greater or smaller amount of cytoskeleton be reconstructed), the type of the injury, the state of surrounding tissues, the age of the patients, injuries to muscles, tendons, bones, vessels and skin. A scheme of strategy is proposed.

Glutamatergic Reinnervation and Assembly of Glutamatergic Synapses in Adult Rat Skeletal Muscle Occurs at Cholinergic Endplates

After denervation of adult rat abdominal muscles, the postsynaptic apparatus of neuromuscular junctions (NMJs) retains its original architecture and clustering of acetylcholine receptors (AChRs). When descending fibers of the spinal cord are surgically diverted to this muscle by a nerve grafting procedure, supraspinal glutamatergic neurons can innervate muscle fibers and restore motor function; the newly formed NMJs switch from a cholinergic to a glutamatergic-type synapse. We show here that regenerating nerve endings contact the fibers in an area occupied by cholinergic endplates. These NMJs are morphologically indistinguishable from those in controls, but they differ in the subunit composition of AChRs. Moreover, by immunofluorescence and immunoelectron microscopy, new NMJs express glutamatergic synapse markers. The &agr;-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit GluR1 partially colocalizes with AChRs, and vesicular glutamate transporter 2 is localized in the presynaptic compartment. Immunoprecipitation analysis of membranes from reinnervated muscle showed that AMPA receptor subunits GluR1 and GluR2 coimmunoprecipitate with rapsyn, the AChR-anchoring protein at the NMJ. Taken together, these results indicate that cholinergic endplates can be targeted by new glutamatergic projections and that the clustering of AMPA receptors occurs there.

Restoration of locomotion in paraplegics with aid of autologous bypass grafts for direct neurotisation of muscles by upper motor neurons — the future: surgery of the spinal cord?

OBJECTIVES Paraplegia means a lifelong sentence of sensory loss, paralysis and dependence. Complete spinal cord lesions cannot heal up to now despite intensive experimental research, remarkable efforts and recent achievements in bio-technology and re-engineering. Traumatic paraplegia due to spinal cord injury (SCI) is a quite frequent condition and related to the socio-economical situation of the population. It is experienced disproportionately by young people. The rise in gunshot wounds is dramatic. SCI has appeared refractory to treatment. PATIENTS AND METHODS Since 1980 G.A.B. had tried surgical repair of the spinal cord (SC) after experimental bisection in rats, and since 1993 research was done on monkeys (macaca fascicularis) to be closer to human physiology. The sciatic nerve was removed and used as an autologous graft from the lateral bundle of the spinal cord (tractus corticospinalis ventro lateralis) to the three muscles of both legs being known to be most important for locomotion: M. gluteus maximus, M. gluteus medius and M. quadriceps femoris. The first fruitful transplantation in a human being was performed in July 2000. RESULTS The results in rats were promising and fulfilled the requirements of the American Task Force of the National Institute of Neurological and Communicative Disorders and Stroke of the US. The results in monkeys confirmed the paradigm so that we performed the first operation in a young lady suffering for four months from complete SC lesion T9 after approval by the ethical committee. First voluntary movements of the connected muscles after 17 months. 27 months after op she was able to walk up to 60 steps with the help of a walker and to climb steps in the water. Improvement is still continuing. DISCUSSION SCI has appeared refractory to any kind of treatment. Compensatory strategies are still experimental in human beings. Autologous nerve grafts from the spinal cord tissue (the lateral spinal bundle) connected to peripheral muscle nerves seem promising in paraplegics. But the physiology is still unclear when the glutamatergic upper motor neuron connected to motor end-plates (cholinergic) does work like in our patient. CONCLUSION Further studies in primates and paraplegic patients are necessary to clarify the bypass grafting of the SC to muscle groups distal to the complete SCI to restore locomotion.

Consensus of clinical neurorestorative progress in patients with complete chronic spinal cord injury.

Currently, there is a lack of effective therapeutic methods to restore neurological function for chronic complete spinal cord injury (SCI) by conventional treatment. Neurorestorative strategies with positive preclinical results have been translated to the clinic, and some patients have gotten benefits and their quality of life has improved. These strategies include cell therapy, neurostimulation or neuromodulation, neuroprosthesis, neurotization or nerve bridging, and neurorehabilitation. The aim of this consensus by 31 experts from 20 countries is to show the objective evidence of clinical neurorestoration for chronic complete SCI by the mentioned neurorestorative strategies. Complete chronic SCI patients are no longer told, “nothing can be done.” The clinical translation of more effective preclinical neurorestorative strategies should be encouraged as fast as possible in order to benefit patients with incurable CNS diseases. This manuscript is published as part of the International Association of Neurorestoratology (IANR) special issue of Cell Transplantation.