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F Zappasodi

Publications and source records attributed to F Zappasodi.

18 recordsLinked to original sources
PubMed2006

Sensory-motor interaction in primary hand cortical areas: a magnetoencephalography assessment.

Movement control requires continuous and reciprocal exchange of information between activities of motor areas involved in the task program execution and those elaborating proprioceptive sensory information. Our aim was to investigate the sensorimotor interactions in the region dedicated to hand control in healthy humans, focusing onto primary sensory and motor cortices, by selecting the time window at very early latencies. Through magnetoencephalographic recordings, we obtained a simultaneous assessment of sensory cortex activity modulation due to movement and of motor cortex activity modulation due to sensory stimulation, by eliciting a galvanic stimulation to the nerve (the median nerve) innervating a muscle (the opponens pollicis), at rest or during voluntary contraction. The primary sensory and motor cortices activities were investigated respectively through excitability in response to sensory stimulation and the cortico-muscular coherence. The task was performed bilaterally. A clear reduction of the cortico-muscular coherence was found in the short time window following stimuli (between around 150-450 ms). In the same time period, the motor control of isometric contraction was preserved. This could suggest that cortical component of voluntary movement control was transiently mediated by neuronal firing rate tuning more than by cortico-muscular synchronization. In addition to the known primary sensory cortex inhibition due to movement, a more evident reduction was found for the component known to include a contribution from primary motor areas. Gating effects were lower in the dominant left hemisphere, suggesting that sensorimotor areas dominant for hand control benefit of narrowing down gating effects.

Adult↗
PubMed2006

Long-term effects of stroke on neuronal rest activity in rolandic cortical areas.

To understand the relationship between neuronal function and clinical state in the framework of stroke, the long-term poststroke rolandic spontaneous neuronal activity was studied by means of magnetoencephalography. Fifty-six patients who had suffered a unilateral stroke within the middle cerebral artery were enrolled. Median time since stroke was 2.8 years. In association with lesion features and clinical picture, total and relative band powers and the spectral entropy were analyzed in the affected (AH) and unaffected (UH) hemispheres in comparison with an age-matched control group. An increase of absolute and relative slow band powers and a reduction of relative fast band powers were found in patients' AH with respect to both UH and control values. Absolute delta band was higher than in controls also in UH. New findings were the increase of rolandic rest activity power also in the alpha band and the decrease of spectral entropy in AH with respect to both UH and control values. Moreover, our results in chronic stroke patients indicate frequency-selective alterations related to specific dysfunctions: global clinical status was mostly impaired in patients with larger lesions and increased total and slow band activity powers, whereas hand functionality was mostly disrupted in patients with subcortical involvement and reduction of high-frequency rhythms and spectral entropy. Total power increase and spectral richness decrease are in agreement with a higher synchrony of local neuronal activity, a reduction of the intracortical inhibitory network's efficiency, and an increase of neuronal excitability.

Adolescent↗
PubMed2003

Does cerebrovascular disease affect the coupling between neuronal activity and local haemodynamics?

The relationship between neurophysiological and cerebrovascular-metabolic findings in patients affected by severe cerebrovascular deficits was investigated by comparing magnetoencephalographic (MEG-evoked fields) and blood oxygen level-dependent functional MRI (BOLD fMRI) responses to median nerve electric stimulation. Despite the use of identical stimuli, the two techniques elicited always-detectable responses in the control group (10 subjects), but demonstrated uncorrelated activation properties in our patient sample (10 subjects). All patients showed clear MEG signals in both the affected and unaffected hemispheres, indicating well synchronized, stimulus-locked firing of neurons in the primary sensorimotor cortex, but some patients showed no fMRI activation in either the affected or the unaffected hemisphere. In order to clarify the origin of this uncoupling, we investigated the possible role of lesion site, white matter hyperintensities, current medication, risk factors, anatomy of the neck vessels, and cerebral vasomotor reactivity (VMR) as measured by transcranial Doppler (TCD) during CO2 inhalation. Neither neuronal activation properties nor any of the considered factors were related to the lack of fMRI activation, with the exception of altered vasomotor reactivity, which was, on the contrary, strongly related. Preserved VMR was paired with absent BOLD bilaterally in the only patient affected by microangiopathy. This finding suggests that BOLD contrast could be more sensitive than TCD to chronic microvascular impairments, measuring small- rather than large- vessel reactivity.

Adult↗
PubMed2001

Detection of fetal auditory evoked responses by means of magnetoencephalography.

MagnetoEncephaloGraphy (MEG) is proposed as a non-invasive technique to detect the physiological activity of fetal brain, due to its ability to record brain activity without direct contact with the head and the transparency of magnetic signals in passing through extracerebral fetal layers and the mother's abdomen. Healthy women with uncomplicated pregnancies and fetuses in breech presentation were examined; gestational ages at time of study ranged between 36 and 40 weeks. In order to evaluate fetal well-being, ultrasound and cardiotocographic data were assessed a few days before and after MEG recording sessions. The participating women were placed in a semi-reclining position in a magnetically shielded room; here the presentation of the fetus and precise region of the mother's abdomen corresponding to the fetal head were determined by ultrasound investigation in order to place the MEG detecting system as near as possible to the fetal brain. MEG recordings were performed by means of a 28-channel neuromagnetic system. Every MEG recording session was performed during the acoustic stimulation of fetuses, in order to detect the cerebral events evoked by peripheral stimuli. The auditory stimuli were delivered from a plastic tube placed on mother's abdomen, near the fetal head, and consisted of a 300 ms 103 dB pure tone at 500 and 1000 Hz, presented at a 0.4 c/s repetition rate. In six cases following accurate digital subtraction of maternal and fetal electrocardiographic (EKG) signals we remained with a stimulus-related response peaking at about 250 ms; this was considered to originate from the fetal brain. In favour of this in three cases a clear dipolar distribution was evident at the peak of brain response centered on the fetal head and consistent with a brain generator. Despite several technical problems requiring solution before a possible routine clinical application, MEG has been found to be suitable for the non-invasive exploration of the fetal brain.

Acoustic Stimulation↗
PubMed2000

[Ultrasonography features of the diaphragmatic crura: normal anatomy and its variants].

PURPOSE: To report the various US patterns of the diaphragmatic crura and the changes occurring during the different phases of respirations. The diaphragm has two US patterns: the central membranous part appears highly reflective while the posterior, upper and lateral muscular portions are hypoechoic and thick. The crura can sometimes appear quite bulky, which appearance is easy to misinterpret. MATERIAL AND METHODS: We carried out a three-stage work: first we reviewed the US examinations of 23 subjects with a nodular appearance of the posteromedial bundles and studied the changes in thickness during respiration. Second we studied the diaphragmatic crura in 30 subjects aged 18-71 years, 15 men and 15 women. We used a commercially available unit with sector and convex 3.5 MHz probes at baseline and during breath hold and acquired multiple parasagittal and transverse scans. The crura thickness was measured in all patients. Last, we studied the diaphragmatic regions of 10 patients with right pleural effusion and of 8 patients with associated ascites and pleural effusion using 2.0-5.0 MHz convex phased-array transducers. RESULTS: We found focal thickening of the crura in 11 of 23 patients with US findings of diaphragmatic nodules, but only in deep inspiration. The thickening was 1.5-2.2 cm long and maximum thickness was 10 mm. In the other 12 subjects we found 9 small lobules in the right and 3 in the left crus. In the anatomic study, we observed a 3-band appearance of the diaphragmatic crura, probably referable to muscle bundles, in 30 subjects on sagittal images, in 12 on coronal images and in 28 on anterior transverse images. The diaphragmatic crura were identified in 26 subjects only. The left posterior crus was identified in 29 subjects on left coronal images and in 15 on anterior transverse images; it was demonstrated on anterior sagittal images in close proximity to the aorta in only 4 subjects. Right crus thickness, measured on sagittal scans, ranged 3-10 mm in deep inspiration and 1-4 mm in expiration while the left crus was 3-6 mm in inspiration and 1-2 mm in expiration. The length of the right crus, studied in the preaortic portion, ranged from 7 cm in deep inspiration to 9.7 cm in expiration while the left one was 6.5 to 8.8 cm. The right lateral diaphragmatic bundles were seen in 28 subjects only on repeated subcostal oblique scans and the the left ones in 11 subjects only. Finally the thin anterior bundles were shown on parasagittal images in 13 cases in the right side and in 2 in the left. A 2-band appearance of the diaphragm was seen in 10 patients with pleural effusion and in 8 patients with associated ascites. A single band was found only in the tendinous portion of the diaphragm. DISCUSSION AND CONCLUSIONS: US is presently considered the imaging method of choice in the assessment of changes in thickness and length of the diaphragmatic crura. These structures have different US patterns and can sometimes appear quite bulky and thus be easily mistaken for other anatomic or abnormal structures; orthogonal scans may be required for the differential diagnosis.

Adolescent↗
PubMed1993

[Echo-color Doppler in thyroid disease].

One-hundred and sixty-six patients affected with thyroid diseases were examined, together with 41 healthy volunteers, by means of color-Doppler US. Four main reference patterns were identified: no appreciable glandular flow (I); presence of signal in perinodular location (II); peri- and intranodular flow (III); increased vascularization (IV). In 72 cases, parenchymal and nodular goiters, with no signs of thyroid hyperfunction, were characterized as belonging to pattern III, while pattern II was observed in 57 nodular lesions; only in 7 patients was pattern III detected. Hyperfunctioning autonomous nodules exhibited pattern III in 10/11 cases and the same pattern was followed by the six carcinomas. Pattern IV resulted peculiar to Basedow disease and to glandular hyperplasia related to high values of circulating thyroid hormone (6 cases). When color-Doppler specificity in typifying the major thyreopathies can be confirmed, the possibility is actually in sight of reducing, in the near future, the number of thyroid scintigraphies and of US-guided needle biopsies.

Adolescent↗
PubMed1988

Myelolipoma of the adrenal gland: sonographic and CT features.

The radiologic findings in 13 patients with pathologically proved adrenal myelolipomas were reviewed. All lesions involved the right adrenal gland; they ranged from 2 to 9 cm in diameter. Sonograms showed hyperechoic tumors in 11 cases (five homogeneous, six heterogeneous). Two myelolipomas composed primarily of myeloid tissue were hypoechoic. A propagation speed artifact was seen in seven lesions, all of which were composed primarily of fat and larger than 4 cm. CT identified fat-density tissues in all lesions. Contrast-enhanced CT showed positive attenuation values in the two predominantly myeloid tumors. CT appears to be sensitive for the diagnosis of adrenal myelolipomas. However, precontrast images are required to avoid errors.

Adrenal Gland Neoplasms↗
PubMed1986

Ultrasonography of the normal adrenal glands: a study using linear-array real-time equipment.

The adrenal glands were evaluated in 70 normal volunteers using linear-array real-time ultrasonography. All the scanning approaches described for manual B-scanning were used and, on the left side, longitudinal scans along the axillary lines were also performed. The right adrenal gland was imaged in 68 of the 70 volunteers and the left gland in 63. The dynamic capabilities of real-time equipment were of great help for proper localisation and identification of the glands. Changes in the scanning plane demonstrated variations in the adrenal morphology, because different portions of the gland were encountered by the scanning beam.

Adrenal Glands↗
PubMed1985

[Intrauterine ultrasound diagnosis in a case of urethral agenesis].

A rare case of obstruction of the lower urinary tract due to urethral agenesia, diagnosed echographically in utero, is presented. This case illustrates that ultrasound, in addition to its importance as a diagnostic tool in pregnancy, can also lead to meaningful therapeutic consequences.

Female↗
PubMed1985

Small hyperechoic nodules of the renal parenchyma.

Twenty-four hyperechogenic nodules ranging from 0.5 cm to 2.5 cm in diameter were observed within the renal parenchyma in 22 patients. Eighteen patients did not complain of renal symptoms, one had microhematuria, one renal colic, and two pain in the right flank. Because of the sonographic features suggesting fat-containing masses, these lesions were considered to be small angiomyolipomas. Two of our patients underwent surgery, which confirmed this histopathologic interpretation. Twelve patients had a sonographic follow-up, which lasted from 4 to 30 months. We did not observe any change in size or shape of the lesions.

Adult↗
PubMed1985

Spontaneous rupture of renal angiomyolipoma with perinephric haemorrhage: sonographic findings.

The sonographic findings observed in four patients with spontaneous rupture of a renal angiomyolipoma and perinephric haemorrhage are presented. In all cases, a hyperechoic renal mass surrounded by a large hypoechoic haematoma was identified. Furthermore, the actual site of rupture of the tumour could be seen in one case as a wedge-shaped hypoechoic structure extending from the periphery to the centre of the mass. CT has been suggested as the method of choice in the assessment of both the presence and extent of haemorrhagic complications of angiomyolipomas. However, since such lesions can be demonstrated and identified by ultrasound, which is often used as the first imaging procedure in abdominal complaints, the technique may also prove of value in planning further diagnostic tests and in choosing the appropriate therapeutic approach to these patients.

Adult↗
PubMed1984

[Echographic symptomatology of closed abdominal injuries].

The importance of echography is emphasised in the diagnosis of closed abdominal injuries. The symptomatology of the possible types of alternative revealable by echography--fluid exudates and parenchymal injuries--are discussed in detail. Personal experience of parenchymal injuries to the liver, spleen and kidneys is then described.

Abdominal Injuries↗
PubMed1982

Ultrasonographic patterns in hepatic hemangiomas.

Twenty-one cases of hepatic hemangioma were examined by ultrasound, and three main sonographic patterns were identified. In 14 cases hyperechoic focal areas were observed, in five cases larger hemangiomas exhibited a complex pattern, and in two cases hemangiomas appeared as rounded sonolucent areas with distal enhancement mimicking cysts. Hemangiomas may have significantly variable ultrasonographic features. According to the authors' experience, only in cases of hyperechoic well-defined lesions in asymptomatic patients can a definite diagnosis of hemangioma be made.

Adult↗
PubMed1982

Pancreatic cystadenocarcinoma: diagnostic problems.

Eleven cases of pancreatic cystadenocarcinoma were studied with respect to the differential diagnosis from that of pancreatic pseudocysts, using diagnostic ultrasound as the initial investigative technique. Most of the cases presented an ultrasonic picture that correlated well with the gross pathology, but this correlation was not reliable enough to be considered characteristic in differentiating such masses from pseudocysts. The authors divide the cystadenocarcinomas of the pancreas into four echographic classes. In all but one of the classes, diagnostic ultrasound was insufficient by itself to render an accurate diagnosis. In such cases other techniques, i.e. CT, tissue biopsy, and especially angiography, were required for a reliable diagnosis.

Adult↗
PubMedDate not supplied

[Exposure to traffic noise and effects on attention].

This study was aimed to evaluate if workers exposed to environmental stressors, including the urban traffic noise, might show significant differences compared to a control group in neuro-psychological and emotional profile as well as neurophysiological functions. In particular if these differences could be evidenced by the application of the "oddball paradigm" for event related potential P300 component. The study consisted of the following examinations: (1) exposed workers vs. controls under the odd-ball paradigm and the Stroop test in baseline condition; (2) amplitude and latency ofP300 (in baseline condition and after administration of acute urban traffic noise and Stroop test). The research was carried on a sample of 81 volunteers: 39 workers exposed to environmental stressors and 42 controls. The phonometric measurements showed mean levels of noise due urban traffic like 74 dBAeq. In baseline condition significative differences in exposed workers vs. control were found in Raven's Matrices PM 38 (p = 0.002) and Arithmetic reasoning from WAIS-R (p = 0.0024). Attention capacities as measured by Digit Span Forward and Visual Search, emotional functioning as measured by state- and trait-anxiety test and mood profile were not different in the two groups. Either in baseline condition or after acute stimuli no significant changes were found in two groups concerning the odd-ball paradigm. Exposed workers showed a higher execution time at Stroop test compared to controls (p = 0.047). No differences were found in the number of errors at the Stroop test. Before the acute stimulus, P300 amplitude was significant higher in the exposed workers than in controls (p = 0.002) while the latency was not different between two groups. Both noise (p = 0.001) and Stroop test (p = 0.002) stimulation increased the P300 latency of the whole sample, without significant differences between exposed workers and controls. A significative decrease of P300 amplitude due noise both in the exposed workers (p = 0.001) and in controls (p = 0.012) was found, without significant difference between the two groups. These results are interpreted as follows: (1) there are chronic effects on cognitive functioning in the exposed group vs. controls in baseline condition, like showed by significant differences in Raven PM38 and WAIS-R; (2) the exposed workers have a smaller cognitive flexibility, as shown by the Stroop test results; (3) in baseline condition the greater P300 amplitude in exposed workers reflect a greater division of attentive resources vs. controls, probably linked to the chronic stimulation by environmental stressors, especially noise, to which these workers are exposed; (4) the effects on P300 latency and amplitude can document the physiological response both in the exposed and not exposed to the acute stimulus and that the lack of significative differences in P300 latency and amplitude may be due to adaptative response to acute stimuli in exposed too. Our results allow us to consider that in workers exposed to urban stressor, such as noise, there are effects on cognitive functioning, especially on attention, without auditory damages. The valuation of P300 might represent a valid diagnostic instrument to evaluate the effects on cognitive functions especially on attention, in workers chronically and acutely exposed to urban stressors.

Adult↗