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Biomedical subjects

V Tugnoli

Publications and source records attributed to V Tugnoli.

At least 55 records · Page 3Linked to original sources
PubMed1995

Sympathetic skin response in patients with Duchenne muscular dystrophy.

To verify an eventual disfunction of the palmar sympathetic skin activity in Duchenne Muscular Dystrophy, we studied the sympathetic skin response (SSR) with endogenous, Deep Breathing (DB-SSR), exogenous Startle (SE-SSR) and Electric type stimuli (EE-SSR) in a group of patients and a control group. At the same time as the SSR, the heart rate (HR) and the basic R-R interval variation (RRIV) as well as the EMG diaphragmatic activity were checked. In this way, significant differences in the latency (p = 0.02) and amplitude (p = 0.009) values of the EE-SSR and in the amplitude values of the SE-SSR (p = 0.001) and of the DB-SSR (p = 0.02) were noted in the DMD group compared to the control group. In the group of patients the rise in latency of the EE-SSR correlates with the age (p = 0.0001) and with the reduction of its amplitude (p = 0.03). This last parameter correlates with the stage of the illness (p = 0.02). In the control group the mean amplitude of the EE-SSR is approximately 30% greater than that of startle and 50% of deep breathing. Although with amplitudes homogeneously reduced, these ratios are also conserved in the DMD group. Moreover the HR is greater (p = 0.0001) whilst the RRIV is reduced (p = 0.02) in the group of the patients. However these parameters do not correlated either to the cardiac involvement or to the stage of the illness. The presence of the SSR for all the modalities of stimulation indicates the substantial integrity of the afferent and the efferent paths of the ANS. The alterations in latency and amplitude of the SSR in the patients could be the consequence of a lack of dystrophin at the level of the sudoriparous myopithelium in analogy to what has been demonstrated in the mdx mouse.

Adolescent↗
PubMed1984

[The effect of fatigue on the biopotential of muscle fiber cells].

Muscular fatigue is a biological situation which is very difficult to quantify. The Authors studied through a computer analysis the power spectrum of electromyogram, recorded from abductor digiti minimi muscle during maximal and minimal contraction effort before and after fatigue and after muscle prolonged relaxation in 8 normal subjects. No significant spectrum differences were found between maximal and minimal effort in each trial, and between the spectra obtained before fatigue and after muscle prolonged relaxation. On the contrary significant differences were found between the spectra obtained after fatigue and the other conditions. The power spectrum analysis appears, also, to be a reliable neurophysiological parameter for the study of biological aspects of muscular fatigue.

Adult↗
PubMed1984

[The origin of the electroretinogram induced by structured stimuli in man].

The Authors studied the checkerboard pattern electroretinogram (PERG) behaviour in normal subjects and in patients suffering from traumatic lesion of optic nerve, demyelinating optic neuritis, axonal optic neuritis, retinal vascular disorders and retinitis pigmentosa in order to verify the PERG origin. According to our data the PERG appears to originate from ganglion cells since the signal diminished or disappeared in axonal lesion of optic nerve, as a result of retrograde ganglion cell degeneration. Furthermore, the demyelinating lesions of optic nerve were not able to modify the PERG wave. In patients suffering from retinal receptor disturbances the flash electroretinogram (FERG), which is probably an expression of receptor activity, was greatly impaired, whereas PERGs were either normal or less impaired than FERGs. These data demonstrate the different origin of PERG and FERG.

Electrophysiology↗
PubMed1984

[The effect of thoracic pressoreceptors on heart rate in man].

Sinus arrhythmia (SA) is a physiological event related to the respiratory activity. The aim of this study was to find a relation between SA and different deep breathings. A transductor monitored the chest respiratory movements and a cardiotachometer calculated and plotted the instantaneous heart rate, synchronously during different breathing efforts. In 10 normal subjects a good linear correlation was found between the breathing depth and SA quantifying the relation between the chest receptor activity and SA also with limited chest expansion.

Adult↗
PubMed1984

[The conduction of optic nerve fibers using different visual patterns].

The Authors have studied the behaviour of checkerboard pattern visual evoked potential (VEP) latencies by using different spatial frequency stimuli and different stimulating visual fields in order to demonstrate whether spatial frequency might constitute a parameter capable of exciting different retinal regions like different stimulus fields. According to the recent literature low spatial frequency stimuli generate VEP with latencies which are significantly shorter than high spatial frequency stimuli, making this method more reliable for the differentiation of macular and peripheral retinal fields.

Adult↗
PubMed1984

Posterior interosseous nerve palsy. Report of three unusual cases.

Three unusual cases of posterior interosseous nerve palsy involving an entrapment mechanism are described. The findings in these three cases seem to support the view that PIN entrapment usually results from interaction of exogenous factors (occupation, pregnancy, compression during sleep, etc.) with anatomical anomalies at the level of the supinator brevis muscle.

Adult↗
PubMed1984

Muscle-nerve ephaptic excitation in some repetitive after-discharges.

We describe high frequency muscular repetitive after-discharges (MRDs), induced by maximal or near maximal electrical nerve stimulation, in 5 patients suffering from different peripheral neuropathies. No MRDs were observed at rest or during voluntary contraction. In all the MRDs the interval between the onset of the M wave and the onset of the MRD did not change in relation to the nerve stimulation point; double supramaximal stimulation with adequate delay, delivered at the same nerve site, could suppress the MRDs. From the electrophysiological features the authors suggest an interpretative model: the muscular electric field of the M wave could reexcite ephaptically an intramuscular axon, with defective repolarizing capacity, producing a muscle-nerve reverberating loop.

Adult↗
PubMed1984

Pattern electroretinogram in multiple sclerosis.

The pattern electroretinogram obtained in patients affected by multiple sclerosis were compared with those in a normal population. The pattern electroretinogram amplitude in multiple sclerosis optic neuritis frequently appeared normal, but pattern electroretinogram amplitude abnormalities were found in patients suffering from recurrent multiple sclerosis optic neuritis. Pattern electroretinogram examination appears a useful method in the differential diagnosis between axonal and demyelinating optic nerve impairment.

Adult↗