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Biomedical subjects

G A Brunelli

Publications and source records attributed to G A Brunelli.

At least 19 recordsLinked to original sources
PubMed2005

Brachial plexus surgery (honorary lecture).

Brachial plexus injuries (B.p.i.) are lesions occurring more and more frequently due to high velocity road and sport traumas. They are severe lesions with disabling sequelae. Surgical procedures and results could greatly be improved in the last 2 decades. Although the anatomy of brachial plexus is well known, less known are the functional maps of the various brachial plexus elements. In this paper treatment modalities for obstetrical, traumatic (adult) and actinic B.p.i. are being described too.

Brachial Plexus↗
PubMed2004

Coupling between "hand" primary sensorimotor cortex and lower limb muscles after ulnar nerve surgical transfer in paraplegia.

Previous neuroimaging evidence revealed an "invasion" of "hand" over "lower limb" primary sensorimotor cortex in paraplegic subjects, with the exception of a rare patient who received a surgical motor reinnervation of hip-thigh muscles by the ulnar nerve. Here, the authors show that a functional reorganization of cortico-muscular and cortico-cortical oscillatory coupling was related to the recovery of the rare patient, as a paradigmatic case of long-term plasticity in human sensorimotor cortex after motor reinnervation of paraplegic muscles. This conclusion was based on electroencephalographic and electromyographic data collected while the patient and normal control subjects performed isometric muscle contraction of the left hand or lower limb. Cortico-muscular and cortico-cortical coupling was estimated by electroencephalographic-electromyographic coherence and directed transfer function of a multivariate autoregressive model.

Adult↗
PubMed2003

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.

Adult↗
PubMed2001

Remodelling of sensorimotor maps in paraplegia: a functional magnetic resonance imaging study after a surgical nerve transfer.

The adult mammalian brain has the capacity of reorganising its neural connections in response to lesions/modifications of the peripheral and central nervous system. We show in vivo, using functional magnetic resonance imaging (fMRI), that in paraplegics the lower-limb sensorimotor cortex is invaded by the arm representation. This functional reshaping appears to be reversible. Indeed, surgical transfer of the ulnar nerve to the ipsilateral quadriceps and hip muscles allowed their contraction in a paraplegic patient. During fMRI, these voluntary movements activated the hip and thigh representation in sensorimotor cortex. We suggest that the functional recovery of the lower-limb functional maps might have been driven by the restored somatosensory inputs from the reactivated periphery. The voluntary movements of the lower-limbs are regained through the 're-awakening' of the corresponding sensorimotor cortex.

Adult↗
PubMed2001

Direct neurotization of muscles by presynaptic motoneurons.

The spinal cord cannot heal after severance because the central nervous system is "non-permissive" to the advancement of axons that regrow from presynaptic motoneurons. With the aim of overcoming paraplegia, the author has carried out extensive experimental research since 1980, first in rats and subsequently in monkeys, severing the cord and connecting its cephalad stump with the muscular nerve branches by means of peripheral-nerve grafts, and using various surgical protocols. Functional connections were established, ascertained by physical, electrophysiologic, and histologic examinations. In this reported study, it is demonstrated that presynaptic motoneurons are also able to reconstruct the cytoskeleton of peripheral neurons, as well as motor end-plates. The possibility of elongation of the axons of presynaptic motoneurons into the peripheral nerve up to the muscle had not previously even been hypotheized. This possibility, which has now been validated, can open the door to new surgical techniques for spinal-cord lesions. In addition, the author presents preliminary results from a single human case, utilizing the surgical procedures of the preceding animal experiments.

Animals↗
PubMed1999

Restoration of walking in paraplegia by transferring the ulnar nerve to the hip: A report on the first patient.

There is no known way to make paraplegics walk when their spinal cord is completely transected. Many researchers worldwide have been developing different methods to solve this problem. We believe that transferring a sound nerve from the upper limb to the main muscles of the hip could help paraplegics to walk, although light orthotic devices would still be needed. We chose to transfer the ulnar nerve because it is the longest in the upper limb and can reach the glutei without grafts. In addition, palsy of the ulnar nerve can be repaired by classical reconstructive surgery. After many years of research in animals and after obtaining permission from the Ethical Committee of the National Health Surgery, we operated on three human beings bilaterally. The first patient is walking. Two are still recovering.

Adult↗
PubMed1997

[Replacement operations in areas innervated by the median nerve in brachial plexus paralysis].

Brachial plexus lesions generate complex paralysis and deficient sensitivity in the concerned upper extremity. The clinical features are represented in numberless variations, and in any case several nerves will be involved. Isolated median nerve palsies can only be produced by a lesion of its single terminal branch. For this reason, any secondary surgery aiming at restoring muscle function in the median nerve area should consider the entire upper extremity as a functional unit. Using special "charts" will give a better overview and simplify the choice for the most convenient muscles to transfer.

Arm↗
PubMed1997

Experimental spinal cord repair (by means of direct connection of the above-the-lesion CNS with PNS).

There are no medical or surgical treatments able to repair traumatic paraplegia. Experiments done by connecting the above-the-lesion with the below-the-lesion cord by means of PNS grafts have always failed. The grafts are reinhabited by regrowing axons of the first motoneurons which however are not able to progress into the distal spinal cord. At the present state of knowledge no surgical treatment can cure paraplegia. Thousands of researchers are working all over the world in many different types of research ranging from molecular biology to embriology, and from biochemistry to pharmacology and surgery. None of these experiments have proved to be practically effective.

Journal Article↗
PubMed1996

Experimental surgery in spinal cord lesions by connecting upper motoneurons directly to peripheral targets.

This research was aimed at assessing the possibility to connect central motoneurons with skeletal muscles through PNS segments bypassing a lesion of the spinal cord. The investigation was performed in 20 non-human primates (Macaca fascicularis). The surgical paradigm consisted of anastomosing the lateral bundle of the spinal cord directly with the sciatic nerve of the right hindlimb, using the peroneal nerve as a graft. The animals were followed-up clinically for 18 months; at the end of this observation period, they underwent electrophysiological examinations before being killed. Specimens were taken from the spinal cord, graft, sciatic nerve and potentially reinnervated muscles, and processed for routine light microscopy and immunohistochemistry. Postoperative mortality was fairly high (six monkeys), yet the overall outcome was regarded as very good because the animals were neither restrained nor intensively cared for. Five of the surviving monkeys showed clinical, electrophysiological and histological evidence of successful reinnervation. This research demonstrated that upper CNS motoneurons are potentially capable of elongating neuritic processes into the endoneural tubes of a connecting graft, up to reaching a peripheral nerve (sciatic), and restoring functional connections with the relevant skeletal muscles.

Animals↗
PubMed1996

A new surgical technique for carpal instability with scapholunate dissociation.

The most common carpal instability is the scapholunate dissociation (carpal instability dissociative: C.I.D.) with dorsal intercalated segment instability (D.I.S.I.), with the most significant element being the flexion of the scaphoid bone (rotary subluxation). Rupture of the scapholunate ligament was formerly believed to be the prerequisite for the dissociation.':' However, three findings contradict this theory"':

Journal Article↗
PubMed1996

Thumb reconstruction.

Experience in 161 thumb reconstructions are reported. The results of pollicizations are evaluated according to function, cosmesis, and two-point discrimination. Of 49 pollicization, 32 were considered excellent, 10 very good, 5 good, and 2 fairly good. In the 16 wrap-around procedures, all showed a very good (less than 6 mm) or good (6 to 12 mm) two point discrimination. Similar results were seen after toe-to-hand transfers when careful nerve repair had been performed.

Amputation, Traumatic↗
PubMed1995

Preoperative assessment of the adult plexus patient.

Methods of assessing brachial plexus lesions are presented in relation ot the type of lesion, the severity, the prognosis, and the timing of nerve repair and reconstructive surgery. A careful physical examination of both muscles and sensory function, the sweating concordance, and the Tinel sign are considered the most important aspects of assessment which is completed by electromyography (evoked potentials), radiographs, magnetic resonance imaging, and contrast computerised axial tomography (CT scanning). Contrast-CT is considered the most reliable investigation to reveal root avulsion from the cord. An assessment chart able to show the extent and location of the lesion at a glance is included.

Adult↗
PubMed1995

Modified Steindler procedure for elbow flexion restoration.

The results of modified Steindler procedures for elbow flexion performed during the past 20 years were reviewed retrospectively. The modifications were designed to avoid the phenomenon of the patient having to make a fist in order to obtain elbow flexion (Steindler's effect). The flexor carpi ulnaris, the flexor carpi radialis, and the palmaris longus, along with a bone fragment, are transferred to the anterior aspect of the humerus. The muscles are carefully separated from the flexor digitorum superficialis, which is left in place. This avoids both flexion of the fingers and pronation. Indications are discussed, especially in brachial plexus reconstructive surgery. Steindler's procedure is indicated in upper plexus lesions (C5-C6); other transfers are more appropriate for lower plexus palsies. Results were assessed according to elbow flexion against resistance. Flexion over 120 degrees when lifting 3 kg was rated very good. Of 32 modified Steindler procedures reviewed, 18 were rated very good, 8 good, 4 fair, and 2 poor.

Bone Transplantation↗
PubMed1995

[A new surgical technique for carpal instability with scapho-lunar dislocation. (Eleven cases)].

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.

Follow-Up Studies↗
PubMed1995

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.

Adult↗
PubMed1995

Microsurgical reconstruction of sensory skin.

Loss of sensory function is a severe impairment for the hand which loses a lot of its dexterity, becomes "blind" if not guided by sight and is susceptible to burns, wounds and infections. Nerve repair by sutures or grafts is the preeminent operation if the condition of the skin is good. When skin is damaged, various sensory flaps (both free microvascular and local pedicle) may be used. Island flaps from the pulp of another digit give inconsistent results. Sensory flaps from the back of the index finger to the thumb give a fair two-point discrimination. Free microvascular flaps from the pulp or the web of the hallux or from two or even three toes are safe and good operations which restore both perfect skin coverage and excellent sensory function with good two-point discrimination. The damage at the donor site is well tolerated. When previous operations have covered the digit or the hand by means of non-sensory skin, direct neurotization of this skin is possible. Research has been done in animals showing the formation of free endings inside the neurotized skin. Rehabilitation of the previously existing sensory corpuscles is even possible. Our series includes 12 island flaps from the pulp, 19 pedicle flaps from the dorsum, 17 homodigital reverse flow flaps, 38 different types of free neurovascular flaps from the foot and 3 direct sensory neurotization.

Amputation, Traumatic↗