Topographical strategies to control neural outgrowth.

In this work a synergistic approach is used to investigate how directional anisotropic surfaces (i.e., nanogratings) control the alignment of PC12 neurites. Finite Element models were used to assess the distribution of stresses in non-spread growth cones and filopodia. The stress field was assumed to be the main triggering cause fostering the increase and stabilization of filopodia, so the local stress maxima were directly related to the neuritic orientation. Moreover, a computational framework was implemented within an open source Java environment (CX3D), and in silico simulations were carried out to reproduce and predict biological experiments. No significant differences were found between biological experiments and in silico simulations (alignment angle, p = 0.4685; tortuosity, p = 0.9075) with a standard level of confidence (95%).

Activities on PNS neural interfaces for the control of hand prostheses.

The development of interfaces linking the human nervous system with artificial devices is an important area of research. Several groups are working on the development of devices able to restore sensory-motor function in subjects affected by neurological disorders, injuries or amputations. Neural electrodes implanted in peripheral nervous system, and in particular intrafascicular electrodes, seem to be a promising approach for the control of hand prosthesis thanks to the possibility to selectively access motor and sensory fibers for decoding motor commands and delivering sensory feedback. In this paper, activities on the use of PNS interfaces for the control of hand prosthesis are presented. In particular, the design and feasibility study of a self-opening neural interface is presented together with the decoding of ENG signals in one amputee to control a dexterous hand prosthesis.

Experiments on the development and use of a new generation of intra-neural electrodes to control robotic devices.

The development of interfaces linking the human nervous system with artificial devices is an important area of research and several groups are now addressing it. Interfaces represent the key enabling technology for the development of devices usable for the restoration of motor and sensory function in subjects affected by neurological disorders, injuries or amputations. For example, current hand prostheses use electromyographic (EMG) signals to extract volitional commands but this limits the possibility of controlling several degrees of freedom and of delivering sensory feedback. To achieve these goals, implantable neural interfaces are required. Among the candidate interfaces with the peripheral nervous system intra-neural electrodes seem to be an interesting solution due to their bandwidth and ability to access volition and deliver sensory feedback. However, several drawbacks have to be addressed in order to increase their usability. In this paper, experiments to address many of these issues are presented as part of the development of a new generation of intra-neural electrodes. The results showed seem to confirm that these new interfaces seem to have interesting properties and that they can represent a significant improvement of the state of the art. Extensive experiments will be carried out in the future to validate these results.

Analysis of spontaneous and click-evoked otoacoustic emissions in newborns.

This paper addresses the quantitative investigation of the contribution of spontaneous (SOAE) to click-evoked (TEOAE) otoacoustic emissions in newborns. The hypothesis was that a weighted linear combination of the spontaneous peaks is strongly similar to the corresponding click-evoked emissions. After identification of the main spontaneous peaks for each subject, a best fit procedure was applied to find the amplitude and phase of each spontaneous tone in the weighted summation. The comparison of the weighted signal (SpTEOAE) with the actual click-evoked response (TEOAE) from the same subject was performed, obtaining correlation coefficient higher than 50% in more than 100 ears over 132.

A hospital based universal neonatal hearing screening programme using click-evoked otoacoustic emissions.

Since 1997 a hospital-based universal hearing screening programme (Milan Programme) has been carried out at the Neurophysiopathology Unit of the Mangiagalli Clinic in Milan, for the early identification of hearing loss in neonates (5650 well babies, 749 newborns from the Neonatal Pathology Unit (NPU) without risk for hearing loss and 118 newborns at risk for hearing loss). As a result, considering the well baby population, three pathological neonates (one profound bilateral and two unilateral hearing loss) were identified. Three additional cases were found among the NPU newborns, whereas 16 cases with bilateral and 11 with unilateral hearing loss were found among the at-risk babies.

Laboratory evaluation of a new delivery system to improve patient compliance with chelation therapy.

As thalassaemia patients live longer, compliance with chelation therapy becomes more and more of a problem. Teenagers rebel against the continual need for treatment, and young adults with jobs, active social lives and families, find it hard to find the time to prepare and deliver their treatments. In an effort to find a solution to this problem, we evaluated a non-electronic, disposable pump (Infusor 5 ml/h, Baxter Healthcare) to determine its suitability for high dose desferrioxamine (DFO) infusions. We wanted an infusion time of 12 h to support overnight delivery in the patient's home. Because of DFOs viscosity, infusion times vary at different concentrations. We found the optimal prescription for total delivery within 12 h to be a dose of 70 mg/kg x patient's body weight diluted in constant volume of 40 ml of water for injection. Our tests were carried out in vitro and the results show that the 5 ml/h Infusor may be used to deliver high dose DFO chelation therapy within 12 h. The variability of the flow rate, dependent on the concentration of the solution, and the absence of a warning system, are more than compensated for by the simplicity of the pump.

[Comparison among perineometric, radiologic and electromyographic parameters in patients with urinary stress incontinence]. / Confronto tra parametri perineometrici, radiologici ed elettromiografici nelle pazienti affette da incontinenza urinaria da sforzo.

In order to increase our knowledge of the physiopathology of urinary stress incontinence related to pelvic relaxation, the Authors examined 20 women suffering from SUI (Stress Urinary Incontinence) almost always characterized by concomitant slight or moderate urethrocystocele and 20 women without urological problems. They analyzed and compared the measurement of perineal descent with radiological and electromyographic parameters in order to detect if a suffering of some fibers of the pudendal plexus can be related to the pathology of SUI. They pointed out that patients affected by SUI show a perineal position, either at rest and under switch, below the ischial tuberosities plane. Furthermore the anterior angle at rest is always more than 30 degrees and electromyographic records are pathological in 90% of cases.

Evidence of motor neuron involvement in chronic respiratory insufficiency.

Nineteen patients with chronic respiratory insufficiency, mean age 61.4 +/- 12.2, have been investigated with pulmonary function tests, clinical neurological examination and neurophysiological methods including motor and sensory conduction studies and needle electromyography. None of them had conditions known to affect the peripheral nervous system such as diabetes, alcoholism, or uraemia. The motor and sensory conduction studies showed only a reduced mean amplitude of the ulnar nerve SAP and of the compound muscle action potential of the APB and EDB muscles. The EMG was abnormal in 94.7% of the cases and showed an increased percentage of polyphasic potentials and a reduced recruitment pattern of motor units firing at high frequency. The data seem to support the hypothesis of an involvement of motor neurons in this condition although the evidence for a neuropathy is lacking.

Ophthalmoplegia plus. A multisystem disorder of unknown etiopathogenesis.

Six cases of Ophthalmoplegia Plus (OP) have been studied: all the patients had palpebral ptosis, ophthalmoparesis and descending myopathy. Hypoacusis, cardiac conduction impairment, small stature, mental deficit and vestibulo-cerebellar dysfunction were present only in some cases. EMG showed a severe slowing of motor and sensory conduction velocity in one patient. Polyphasic and long duration MU action potentials, which are indicative of a neurogenic myopathy, were found in all cases. Every muscle biopsy showed many "ragged red fibers" which, in EM, appeared to contain abnormal mitochondria. According to the literature and our data, OP appears to be a multisystemic disorder with severe muscle mitochondrial abnormalities, but it is not certain whether it must be considered a syndrome with multiple etiological factors or a single nosological entity with different possibilities of clinical manifestations.