Enrico Alfonsi - Academia.edu (original) (raw)
Papers by Enrico Alfonsi
Functional neurology
By stimulating the sural nerve at the retromalleolar level and recording EMG response from biceps... more By stimulating the sural nerve at the retromalleolar level and recording EMG response from biceps femoris muscle two components can be evoked: RII (shorter latency, lower threshold, non-nociceptive) and RIII (longer latency, higher threshold, nociceptive). RIII reflex represents a useful tool for pain research in humans since a close correlation exists between the reflex threshold and that of pain. In our study, latency, amplitude, duration and threshold of RII and RIII reflexes were investigated in school-age children (aged 7-14 years) and young adults. RIII threshold was significantly lowered in children, while the other parameters were similar in both groups. Our data suggest the existence of a reduced inhibitory descending control in nociceptive spinal neurones in children.
Giornale italiano di medicina del lavoro
The Authors report their experience in a patient with Multiple Sclerosis. The planning and the fo... more The Authors report their experience in a patient with Multiple Sclerosis. The planning and the follow up of rehabilitative treatment were based on clinical, functional, electrophysiological and posturographic evaluation. The impairment degree was evaluated by Kurtzke's Expanded Disability Status Scale. The electrophysiological evaluation showed an abnormal recruitment flexor pattern at exteroceptive stimulus and posturography confirmed postural control disorder. The treatment was based on PNF techniques and postural feedback on standing balance platform. After rehabilitative treatment the clinical and functional improvement has been confirmed by normal exteroceptive flexion reflex and better stabilometric parameters.
Electromyography and clinical neurophysiology
In the present study a surface-EMG investigation of the rectus femoris muscle was performed in pa... more In the present study a surface-EMG investigation of the rectus femoris muscle was performed in patients with spastic hemiparesis before and after rehabilitation treatment. The EMG activity was detected during 50% of the maximum voluntary contraction by means of FFT automatic analysis; the mean power frequency (MPF) and the time-course of the frequencies of the surface-EMG signals showed significant changes after physiokinesitherapy. In hemiparetic patients a particular distribution of the frequencies of the surface-EMG signals towards the lowest values were observed. These findings could be related to the preferential atrophy of type II fibers which has been demonstrated in morphological studies. Furthermore the surface-EMG analysis after a period of rehabilitation treatment showed some significant modifications of MPF and time-course of the EMG signals. These changes corresponded to an improvement of the spasticity as evaluated by clinical rating-scale. This neurophysiological investigation seem to be a simple and reliable method for better evaluating some effects of the rehabilitation therapy.
Giornale italiano di medicina del lavoro
Electromyography and clinical neurophysiology
Aim of the present study was to evaluate the modifications of neurophysiological and neuropsychol... more Aim of the present study was to evaluate the modifications of neurophysiological and neuropsychological variables during extreme environmental and driving conditions. Eight subjects (four drivers and four passengers) were evaluated while driving a four wheels drive across the Big West Algerian Erg. The following procedures were carried out in basal conditions and at the end of the 1st, 3rd, and 5th day of driving: surface EMG of masseter and cervical para-spinal muscles during maximum isometric contraction lasting 12 sec; test of simple visual and acoustic reaction times, Cancellation test, Trial Making test. As from the second day, the drivers used appropriate dental plates. In the drivers, EMG spectrum analysis revealed a significant decrease in mean frequency values at the end of the 1st day. This finding was more relevant in masseter muscles. No significant fatigue phenomena were detected on the subsequent controls. On the contrary, the passengers showed a decrease in mean EMG frequency values. No significant modifications in the cognitive variables were detected at the end of the 1st day (initial response to stress), whereas a progressive worsening was observed in the subsequent evaluations. EMG fatigue of masseter muscles seems to be more related to psychic stress. The beneficial effects of the dental plates were also confirmed.
Functional neurology
We investigated digastric reflex excitability in normals and in patients with extrapyramidal diso... more We investigated digastric reflex excitability in normals and in patients with extrapyramidal disorders such as primary cranial dystonias and Parkinson's disease. Relationships between exteroceptive suppression of masseter muscle and digastric reflex were also investigated in some cases. Digastric reflex hyperexcitability was observed in dystonic patients when compared to normals and parkinsonian patients. Furthermore, some patients with cranial dystonia presented absence of exteroceptive suppression reflex in masseter muscle with enlarged digastric response. These results indicate hyperexcitability of the digastric reflex and abnormal agonist-antagonist muscle co-contraction in chewing reflexes of patients with cranial dystonias. This shows that digastric reflex is an important electrophysiological investigation to explore the physiopathological mechanisms of primary cranial dystonias.
Functional neurology
In this study relationships between local venous lactate concentrations and power spectrum change... more In this study relationships between local venous lactate concentrations and power spectrum changes in surface EMG due to fatiguing isometric contractions were investigated. Two different isometric efforts of the opponents pollicis muscle, 25% and 50% of maximum voluntary contraction, were examined. In 25% of maximum voluntary contraction no changes in local venous lactate were observed, whereas mean power frequency values of surface EMG shifted significantly towards lower frequencies. On the contrary, in 50% of maximum voluntary contraction lactate significantly increased and was related to the mean power frequency shifts of the surface EMG. These data suggest that lactate plays a role in muscle fatigue only in a limited intensity range of isometric muscle contractions.
Dysphagia, 2015
Electrophysiological assessment provides valuable information on physiological and pathophysiolog... more Electrophysiological assessment provides valuable information on physiological and pathophysiological characteristics of human swallowing. Here, new electrophysiological measures for the evaluation of oropharyngeal swallowing were assessed: (1) the activation pattern of the submental/suprahyoid EMG activity (SHEMG); (2) the reproducibility of the oral and pharyngeal phases of swallowing, by calculating the similarity index (SI) of the SHEMG (SI-SHEMG) and of the laryngeal-pharyngeal mechanogram (SI-LPM) during repeated swallows; and (3) kinesiological measures related to the LPM. An electrophysiological-mechanical method for measuring the activation pattern of the SHEMG, the SI-SHEMG, and the SI-LPM, and maximal LPM velocity and acceleration during swallowing was applied in 65 healthy subjects divided into three age groups (18-39, 40-59, 60 years or over). All the measures were assessed during three trials of eight consecutive swallows of different liquid bolus volumes (3, 12, and 20 ml). A high overall reproducibility of oropharyngeal swallowing in healthy humans was recorded. However, while values of SI-SHEMG were similar in all the age groups, the SI-LPM was found to fall significantly in the older age group. Both the SI-SHEMG and the SI-LPM were found to fall with increasing bolus volumes. The activation pattern of the SHEMG and the LPM kinesiological measures were differently modified by bolus volume and age in the older subjects with respect to the others. We describe a new approach to the electrophysiological study of swallowing based on computed semi-automatic analyses. Our findings provide insight into some previously uninvestigated aspects of oropharyngeal swallowing physiology, considered in relation to bolus volume and age. The new electrophysiological measures here described could prove useful in the clinical setting, as it is likely that they could be differently affected in patients with different kinds of dysphagia.
The Journal of sports medicine and physical fitness, 1999
To assess how muscle ischaemia and isometric fatiguing contraction influence oxygen content in st... more To assess how muscle ischaemia and isometric fatiguing contraction influence oxygen content in striated muscle. We simultaneously measured changes in hemoglobin near-infrared (NIR) spectroscopy and in surface EMG before, during, and after muscle ischaemia and ischaemia plus muscle isometric fatiguing contraction. Seventeen healthy male subjects (age range: 19-40 yrs) were examined in our Clinical Neurophysiology Unit. Test I (9 subjects): hemoglobin NIR spectroscopy and stimulated surface EMG were measured for 2 minutes at rest, for 4 minutes during complete ischaemia of tibialis anterior muscle, and for twelve minutes during recovery. Test II (all subjects): hemoglobin NIR spectroscopy and surface EMG were measured for 2 minutes with the subjects performing brief non-fatiguing contractions, for 4 minutes with the subject performing maximal isometric contraction in complete ischaemia, and for twelve minutes during recovery. EMG parameters measured: median density frequency (MDF); mu...
Electroencephalography and Clinical Neurophysiology, 1996
Electroencephalography and Clinical Neurophysiology, 1983
Twenty New-Zealand 90-100 days old rabbits, weighing between 2.4 and 2.7 kg were used for the stu... more Twenty New-Zealand 90-100 days old rabbits, weighing between 2.4 and 2.7 kg were used for the study. In general anesthesia the sciatic nerve was constricted by means of a strip of aponeurotic bandage, 65 mm long approx., slightly lifting the nerve from its space. Electrophysiological alterations (fibrillation activity and/or reduction of MAPs amplitude and/or slowing of Max SCV) were measured after 15-30 days from the surgical operation (just when the first lesions from scratching appeared on the back of the leg). Semithin and thin sections of the proximal and distal nerve segments fixed in Karnovsky fluid and embedded in Epon revealed distal Wallerian degeneration, with loss of large myelinated fibres and degenerative changes of the paranodal myelin of some of them (10 animals). An external neurolysis was performed in the remaining I0 animals. After 60 days from the decompression no fibrillation activity and a partial recovery of MAPs amplitude and Max SCV were observed. Regenerative patterns as axonal sprouts with outgrowth of fibroblasts and Schwann Cells were observed in the distal nerve segment. The authors discuss the experimental method and the various morphological functional correlations. F218 CORTICAL CORRELATES OF HEMIFACIAL SPASM MONTAGNA PM, Zucconi-lnstitute of Neurology, University of Bologna, Italy
Bilateral sympathetic skin response (SSR) was evaluated in 25 normal subjects aged (29 +/- 5 year... more Bilateral sympathetic skin response (SSR) was evaluated in 25 normal subjects aged (29 +/- 5 years). The stimulation (an electrical pulse train randomly applied to the sural nerve) was equal to 0.5-1.0-1.5 times the nociceptive flexion reflex (RIII) thresholds. This method allowed us to quantify the pain threshold, since a close relationship between the RIII threshold and subjective pain threshold has been described. Decrease in latency, increase in amplitude and duration were observed when increasing intensity of stimulation was used. The right-side stimulation produced significantly shorter latencies and higher amplitudes than the left one. The asymmetry index showed a trend of larger responses on the left hand and shorter latencies on the right hand in males. Females displayed less left-right asymmetry than males. A positive correlation was recognized between RIII threshold and amplitude and duration of SSR. Test-retest evaluation in 12 individuals revealed good reproducibility of SSR in terms of latency and duration, while amplitudes showed large variability. The accuracy of SSR response concerning latency and duration was better (range 0.88-0.92) when 1.5 RIII threshold was used, showing that painful stimulation should be used to obtain reliable SSR in clinical practice.
Electroencephalography and clinical neurophysiology, 1986
Pattern visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded in 20 patient... more Pattern visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded in 20 patients with myotonic dystrophy. Thirteen out of 20 cases presented both VEP and ERG abnormalities, 3 only ERG alterations, 2 only abnormal VEPs. A significant inverse correlation between P100 latencies and b1 wave amplitude was observed, while N1-P100 and b1 wave amplitude exhibited a parallel change. These data suggest that retinal abnormalities may have a role in inducing subclinical visual pathway alterations in myotonic dystrophy.
Electroencephalography and Clinical Neurophysiology, 1996
Paraplegia, 1991
Morphometric and electrophoretic properties of soleus and medialis gastrocnemius fibres from para... more Morphometric and electrophoretic properties of soleus and medialis gastrocnemius fibres from paraplegic patients were studied 1 to 10 months following complete traumatic cord transection (spinal cord level C5-Tl).
Electroencephalography and Clinical Neurophysiology, 1996
Muscle & Nerve, 2010
... Piccolo, G., Cortese, A., Tavazzi, E., Piccolo, L., Sassone, J., Ciammola, A., Alfonsi, E., C... more ... Piccolo, G., Cortese, A., Tavazzi, E., Piccolo, L., Sassone, J., Ciammola, A., Alfonsi, E., Colombo, I. and Moggio, M ... Dipartimento di Scienze Neurologiche, IRCCS Fondazione Ospedale Maggiore Mangiagalli e Regina Elena, Centro Dino Ferrari, Università di Milano, Milano, Italy. ...
Electroencephalography and Clinical Neurophysiology, 1996
Electroencephalography and Clinical Neurophysiology, 1996
Functional neurology
By stimulating the sural nerve at the retromalleolar level and recording EMG response from biceps... more By stimulating the sural nerve at the retromalleolar level and recording EMG response from biceps femoris muscle two components can be evoked: RII (shorter latency, lower threshold, non-nociceptive) and RIII (longer latency, higher threshold, nociceptive). RIII reflex represents a useful tool for pain research in humans since a close correlation exists between the reflex threshold and that of pain. In our study, latency, amplitude, duration and threshold of RII and RIII reflexes were investigated in school-age children (aged 7-14 years) and young adults. RIII threshold was significantly lowered in children, while the other parameters were similar in both groups. Our data suggest the existence of a reduced inhibitory descending control in nociceptive spinal neurones in children.
Giornale italiano di medicina del lavoro
The Authors report their experience in a patient with Multiple Sclerosis. The planning and the fo... more The Authors report their experience in a patient with Multiple Sclerosis. The planning and the follow up of rehabilitative treatment were based on clinical, functional, electrophysiological and posturographic evaluation. The impairment degree was evaluated by Kurtzke's Expanded Disability Status Scale. The electrophysiological evaluation showed an abnormal recruitment flexor pattern at exteroceptive stimulus and posturography confirmed postural control disorder. The treatment was based on PNF techniques and postural feedback on standing balance platform. After rehabilitative treatment the clinical and functional improvement has been confirmed by normal exteroceptive flexion reflex and better stabilometric parameters.
Electromyography and clinical neurophysiology
In the present study a surface-EMG investigation of the rectus femoris muscle was performed in pa... more In the present study a surface-EMG investigation of the rectus femoris muscle was performed in patients with spastic hemiparesis before and after rehabilitation treatment. The EMG activity was detected during 50% of the maximum voluntary contraction by means of FFT automatic analysis; the mean power frequency (MPF) and the time-course of the frequencies of the surface-EMG signals showed significant changes after physiokinesitherapy. In hemiparetic patients a particular distribution of the frequencies of the surface-EMG signals towards the lowest values were observed. These findings could be related to the preferential atrophy of type II fibers which has been demonstrated in morphological studies. Furthermore the surface-EMG analysis after a period of rehabilitation treatment showed some significant modifications of MPF and time-course of the EMG signals. These changes corresponded to an improvement of the spasticity as evaluated by clinical rating-scale. This neurophysiological investigation seem to be a simple and reliable method for better evaluating some effects of the rehabilitation therapy.
Giornale italiano di medicina del lavoro
Electromyography and clinical neurophysiology
Aim of the present study was to evaluate the modifications of neurophysiological and neuropsychol... more Aim of the present study was to evaluate the modifications of neurophysiological and neuropsychological variables during extreme environmental and driving conditions. Eight subjects (four drivers and four passengers) were evaluated while driving a four wheels drive across the Big West Algerian Erg. The following procedures were carried out in basal conditions and at the end of the 1st, 3rd, and 5th day of driving: surface EMG of masseter and cervical para-spinal muscles during maximum isometric contraction lasting 12 sec; test of simple visual and acoustic reaction times, Cancellation test, Trial Making test. As from the second day, the drivers used appropriate dental plates. In the drivers, EMG spectrum analysis revealed a significant decrease in mean frequency values at the end of the 1st day. This finding was more relevant in masseter muscles. No significant fatigue phenomena were detected on the subsequent controls. On the contrary, the passengers showed a decrease in mean EMG frequency values. No significant modifications in the cognitive variables were detected at the end of the 1st day (initial response to stress), whereas a progressive worsening was observed in the subsequent evaluations. EMG fatigue of masseter muscles seems to be more related to psychic stress. The beneficial effects of the dental plates were also confirmed.
Functional neurology
We investigated digastric reflex excitability in normals and in patients with extrapyramidal diso... more We investigated digastric reflex excitability in normals and in patients with extrapyramidal disorders such as primary cranial dystonias and Parkinson's disease. Relationships between exteroceptive suppression of masseter muscle and digastric reflex were also investigated in some cases. Digastric reflex hyperexcitability was observed in dystonic patients when compared to normals and parkinsonian patients. Furthermore, some patients with cranial dystonia presented absence of exteroceptive suppression reflex in masseter muscle with enlarged digastric response. These results indicate hyperexcitability of the digastric reflex and abnormal agonist-antagonist muscle co-contraction in chewing reflexes of patients with cranial dystonias. This shows that digastric reflex is an important electrophysiological investigation to explore the physiopathological mechanisms of primary cranial dystonias.
Functional neurology
In this study relationships between local venous lactate concentrations and power spectrum change... more In this study relationships between local venous lactate concentrations and power spectrum changes in surface EMG due to fatiguing isometric contractions were investigated. Two different isometric efforts of the opponents pollicis muscle, 25% and 50% of maximum voluntary contraction, were examined. In 25% of maximum voluntary contraction no changes in local venous lactate were observed, whereas mean power frequency values of surface EMG shifted significantly towards lower frequencies. On the contrary, in 50% of maximum voluntary contraction lactate significantly increased and was related to the mean power frequency shifts of the surface EMG. These data suggest that lactate plays a role in muscle fatigue only in a limited intensity range of isometric muscle contractions.
Dysphagia, 2015
Electrophysiological assessment provides valuable information on physiological and pathophysiolog... more Electrophysiological assessment provides valuable information on physiological and pathophysiological characteristics of human swallowing. Here, new electrophysiological measures for the evaluation of oropharyngeal swallowing were assessed: (1) the activation pattern of the submental/suprahyoid EMG activity (SHEMG); (2) the reproducibility of the oral and pharyngeal phases of swallowing, by calculating the similarity index (SI) of the SHEMG (SI-SHEMG) and of the laryngeal-pharyngeal mechanogram (SI-LPM) during repeated swallows; and (3) kinesiological measures related to the LPM. An electrophysiological-mechanical method for measuring the activation pattern of the SHEMG, the SI-SHEMG, and the SI-LPM, and maximal LPM velocity and acceleration during swallowing was applied in 65 healthy subjects divided into three age groups (18-39, 40-59, 60 years or over). All the measures were assessed during three trials of eight consecutive swallows of different liquid bolus volumes (3, 12, and 20 ml). A high overall reproducibility of oropharyngeal swallowing in healthy humans was recorded. However, while values of SI-SHEMG were similar in all the age groups, the SI-LPM was found to fall significantly in the older age group. Both the SI-SHEMG and the SI-LPM were found to fall with increasing bolus volumes. The activation pattern of the SHEMG and the LPM kinesiological measures were differently modified by bolus volume and age in the older subjects with respect to the others. We describe a new approach to the electrophysiological study of swallowing based on computed semi-automatic analyses. Our findings provide insight into some previously uninvestigated aspects of oropharyngeal swallowing physiology, considered in relation to bolus volume and age. The new electrophysiological measures here described could prove useful in the clinical setting, as it is likely that they could be differently affected in patients with different kinds of dysphagia.
The Journal of sports medicine and physical fitness, 1999
To assess how muscle ischaemia and isometric fatiguing contraction influence oxygen content in st... more To assess how muscle ischaemia and isometric fatiguing contraction influence oxygen content in striated muscle. We simultaneously measured changes in hemoglobin near-infrared (NIR) spectroscopy and in surface EMG before, during, and after muscle ischaemia and ischaemia plus muscle isometric fatiguing contraction. Seventeen healthy male subjects (age range: 19-40 yrs) were examined in our Clinical Neurophysiology Unit. Test I (9 subjects): hemoglobin NIR spectroscopy and stimulated surface EMG were measured for 2 minutes at rest, for 4 minutes during complete ischaemia of tibialis anterior muscle, and for twelve minutes during recovery. Test II (all subjects): hemoglobin NIR spectroscopy and surface EMG were measured for 2 minutes with the subjects performing brief non-fatiguing contractions, for 4 minutes with the subject performing maximal isometric contraction in complete ischaemia, and for twelve minutes during recovery. EMG parameters measured: median density frequency (MDF); mu...
Electroencephalography and Clinical Neurophysiology, 1996
Electroencephalography and Clinical Neurophysiology, 1983
Twenty New-Zealand 90-100 days old rabbits, weighing between 2.4 and 2.7 kg were used for the stu... more Twenty New-Zealand 90-100 days old rabbits, weighing between 2.4 and 2.7 kg were used for the study. In general anesthesia the sciatic nerve was constricted by means of a strip of aponeurotic bandage, 65 mm long approx., slightly lifting the nerve from its space. Electrophysiological alterations (fibrillation activity and/or reduction of MAPs amplitude and/or slowing of Max SCV) were measured after 15-30 days from the surgical operation (just when the first lesions from scratching appeared on the back of the leg). Semithin and thin sections of the proximal and distal nerve segments fixed in Karnovsky fluid and embedded in Epon revealed distal Wallerian degeneration, with loss of large myelinated fibres and degenerative changes of the paranodal myelin of some of them (10 animals). An external neurolysis was performed in the remaining I0 animals. After 60 days from the decompression no fibrillation activity and a partial recovery of MAPs amplitude and Max SCV were observed. Regenerative patterns as axonal sprouts with outgrowth of fibroblasts and Schwann Cells were observed in the distal nerve segment. The authors discuss the experimental method and the various morphological functional correlations. F218 CORTICAL CORRELATES OF HEMIFACIAL SPASM MONTAGNA PM, Zucconi-lnstitute of Neurology, University of Bologna, Italy
Bilateral sympathetic skin response (SSR) was evaluated in 25 normal subjects aged (29 +/- 5 year... more Bilateral sympathetic skin response (SSR) was evaluated in 25 normal subjects aged (29 +/- 5 years). The stimulation (an electrical pulse train randomly applied to the sural nerve) was equal to 0.5-1.0-1.5 times the nociceptive flexion reflex (RIII) thresholds. This method allowed us to quantify the pain threshold, since a close relationship between the RIII threshold and subjective pain threshold has been described. Decrease in latency, increase in amplitude and duration were observed when increasing intensity of stimulation was used. The right-side stimulation produced significantly shorter latencies and higher amplitudes than the left one. The asymmetry index showed a trend of larger responses on the left hand and shorter latencies on the right hand in males. Females displayed less left-right asymmetry than males. A positive correlation was recognized between RIII threshold and amplitude and duration of SSR. Test-retest evaluation in 12 individuals revealed good reproducibility of SSR in terms of latency and duration, while amplitudes showed large variability. The accuracy of SSR response concerning latency and duration was better (range 0.88-0.92) when 1.5 RIII threshold was used, showing that painful stimulation should be used to obtain reliable SSR in clinical practice.
Electroencephalography and clinical neurophysiology, 1986
Pattern visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded in 20 patient... more Pattern visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded in 20 patients with myotonic dystrophy. Thirteen out of 20 cases presented both VEP and ERG abnormalities, 3 only ERG alterations, 2 only abnormal VEPs. A significant inverse correlation between P100 latencies and b1 wave amplitude was observed, while N1-P100 and b1 wave amplitude exhibited a parallel change. These data suggest that retinal abnormalities may have a role in inducing subclinical visual pathway alterations in myotonic dystrophy.
Electroencephalography and Clinical Neurophysiology, 1996
Paraplegia, 1991
Morphometric and electrophoretic properties of soleus and medialis gastrocnemius fibres from para... more Morphometric and electrophoretic properties of soleus and medialis gastrocnemius fibres from paraplegic patients were studied 1 to 10 months following complete traumatic cord transection (spinal cord level C5-Tl).
Electroencephalography and Clinical Neurophysiology, 1996
Muscle & Nerve, 2010
... Piccolo, G., Cortese, A., Tavazzi, E., Piccolo, L., Sassone, J., Ciammola, A., Alfonsi, E., C... more ... Piccolo, G., Cortese, A., Tavazzi, E., Piccolo, L., Sassone, J., Ciammola, A., Alfonsi, E., Colombo, I. and Moggio, M ... Dipartimento di Scienze Neurologiche, IRCCS Fondazione Ospedale Maggiore Mangiagalli e Regina Elena, Centro Dino Ferrari, Università di Milano, Milano, Italy. ...
Electroencephalography and Clinical Neurophysiology, 1996
Electroencephalography and Clinical Neurophysiology, 1996