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Biomedical subjects

A Amantini

Publications and source records attributed to A Amantini.

31 records · Page 2Linked to original sources

Electrophysiological investigations of the brainstem in the vertebrobasilar reversible attacks.

A total of 70 selected patients affected by reversible ischemic attacks in the vertebrobasilar system were studied. 50 patients presented transient ischemic attacks (TIA), while the other 20 patients suffered from 1-2 protracted transient ischemic attacks (PTIA). All patients underwent brainstem acoustic evoked potentials (BAEP) and electrooculography (EOG) 7-20 days from the last reversible ischemic attack, when all signs and symptoms completely disappeared. The combination of BAEP and EOG gave objective evidence of brainstem dysfunction in 61 out of 70 patients. BAEP resulted abnormal in 26 patients (16 TIA, 10 PTIA), EOG in 49 (36 TIA, 13 PTIA). Serial controls at 3, 6, and 12 months were conducted in 27 patients. 5 patients showed a normalization for BAEP and 7 for EOG 12 months after the first examination.

Adult↗

BAEP and autopsy findings in Wallenberg syndrome.

BAEPs were recorded in a 70-year-old man who had developed symptoms indicative of Wallenberg syndrome. He died, of extracerebral causes, shortly after hospitalization and an autopsy study was done on the brainstem lesions. Right ear stimulation disclosed BAEP abnormalities, but gave no indication of the level of the ischemic disorder. Histopathological examination showed a typical right dorsolateral medullary infarct. A detailed study of the acoustic pathways demonstrated their anatomical integrity. These findings confirm the uncertainty that still exists as to the exact location and type of generators of BAEP components. They suggest, moreover, that BAEPs can give objective evidence of functional impairment of brainstem acoustic structures even in the absence of persistent anatomical damage.

Aged↗

Electric and CO2 laser SEPs in a patient with asymptomatic syringomyelia.

We recorded electrically stimulated somatosensory evoked potentials (electric SEPs) and pain-related SEPs following CO2 laser stimulation (CO2 laser SEPs) from a 17-year-old patient affected by myotonic dystrophy whose MRI disclosed a large syrinx extending from spinal level C2 to S3. Careful clinical and electromyographic examinations revealed no motor or sensory disturbances, apart from myotonia. The only abnormality noted in median and ulnar nerve short-latency electric SEPs (recorded with a non-cephalic reference electrode) was the absence of cervical component N13, the other SEP responses (N9, N10, N11, P14, N20) being normal. The cutaneous pain threshold and CO2 laser SEPs (both obtained by a CO2 laser beam applied to the back of the hand) were normal. Thus cervical component N13 appears to be highly sensitive to the effects of central cord lesions, even when these are asymptomatic.

Adolescent↗

Transmission times from cutaneous and mixed nerves of lower limbs.

In each of 10 normal subjects, P28 and N31 far-field components as well as the cortical N37 and P40 waves were identified for both Sural (SN) and Posterior Tibial nerve (PTN) stimulation at the ankle. Peripheral conduction velocity along the popliteal fossa-L3 segment and spinal transmission velocity over the L3-Cv2 segment did not differ significantly for the two nerves. The average latencies of N37 and P40 to stimulation of PTN were 2.55 and 3.65 msec shorter than corresponding latencies from SN. If we consider the P28-N37 and P28-P40 intervals as central transmission times, only the former approaches upper limb CCT values closely enough to support the analogy between median nerve N20 and PTN N37. At the intracranial level, the P28-N37 inter-peak latency was significantly shorter for PTN than SN. The P28 component is generally attributed to lemniscal activity. Thus, the discrepancy in afferent transmission times from the leg's mixed and sensory nerves would appear to take place at a level that is supralemniscal but subcortical.

Adult↗

[CNV and SEP in shoe-industry workers affected by neuropathy due to toxic effects of adhesive solvents (author's transl)].

The sensitivity of the CNV and somatosensory evoked potentials (SEP) was assessed in shoe industry workers suffering from neurotoxic effects of adhesive solvents. We have examined 21 patients with clear electroneuromiographic and clinical signs of polyneuropathy as well as EEG signs of diffuse brain damage. 10 normal volunteers served as a control group. The maximal motor conduction velocity (MMCV) was considerably reduced in all patients. The maximal sensory conduction velocity (MSCV) was in the lower normal range (or borderline) in 12 patients, whereas in 9 or more severe decrement was detected. In comparison with normal subjects, none of the patients showed clear differences in latency or amplitude of SEP components (p always greater than .2). It was very easy to elicit CNVs over all areas explored and all the 10 patients showed normal characteristics. These results, therefore, suggest that CNV and SEP are not helpful for an early diagnosis of toxic effects of the solvents on the function of the central and peripheral nervous system.

Adolescent↗

Selective shunting based on somatosensory evoked potential monitoring during carotid endarterectomy.

Somatosensory Evoked Potentials (SEPs), to median nerve stimulation, were continuously monitored in 58 patients undergoing carotid endarterectomy A first group of patients was shunted routinely; in a second group the shunt was selectively applied when inadequacy of collateral circulation was suspected based on stump pressure values and SEP changes. Both amplitude and latency modifications of SEPs occurred during surgery; however no post-operative neurological deficit was seen unless there was a complete flattening of cortical waves, even a transitory one. Inadequate collateral circulation and embolic ischemia affected SEPs differently. While the latter produced a disappearance of all cortical waves, the former led first to a progressive flattening of later cortical waves and then of N20 as well. For values of stump pressure ranging between 20 and 50 mmHg SEPs were unchanged in some patients and altered in others. These findings may explain the controversies existing about the usefulness of stump pressure for predicting tolerance to carotid clamping.

Aged↗

[Brain-stem auditory evoked potentials (BAEPs) and computerized tomography (CT scans) in patients with reversible ischemic attacks (RIAs) in the vertebro-basilar system (author's transl)].

BAEPs recordings and brain CT Scans have been conducted in 11 patients with RIAs of the vertebral-basilar system. Five patients presented recurrent transient ischemic attacks (TIAs) completely clearing in 24 h, while in the other patients a full recovery took place over a longer period, within 3 week (RINDs). Each patient underwent BAEPs recording, as well CT Scans, EEG and oto-neurological examination, 7-20 days after the last RIA, when all signs and symptoms had disappeared. Both ears were subsequently stimulated and bipolar EEG activity was recorded from Cz and the mastoid electrode ipsilateral to stimulation. At least two sets of 1500 averaged responses from each ear were added. The I-III, III-V, I-V interpeak latencies (IPLs) as well as the IV-V/I amplitude ratio were measured and compared with the values obtained in a control group. Increased IPLs were detected in 4 cases of the TIA group and in 2 of the RIND group. Amplitude ratio was always normal. Any positive information provided by CT Scan showed cerebral atrophy in 4 patients with TIAs and in 1 patient with RIND. BAEPs recording is a relatively simple, non-invasive neurophysiologic test, which can give objective evidence for brainstem dysfunction in vertebro-basilar RIAs.

Adult↗

Familial AL-amyloidosis in three Italian siblings.

BACKGROUND AND METHODS: Familial occurrence of immunoglobulin-related (AL) amyloidosis has occasionally been reported. In this work we describe the concomitance of systemic amyloidosis and monoclonal gammopathy (one case of Waldenström's macroglobulinemia and two cases without multiple myeloma or related diseases) in three Italian siblings, two males and one female. RESULTS AND CONCLUSIONS: All of them showed a common pattern of polyneuropathy to different degrees; two presented a sicca syndrome and one also suffered from nephropathy. Two of them showed the same HLA typing with the same light chain type (k), but had different presenting symptoms. Polyneuropathy and a history of peptic disease in two cases was suggestive of type III familial amyloidotic polyneuropathy (FAP) occurring in the setting of a familial monoclonal component. However, immunohistochemical studies on different tissue specimens using anti-apolipoprotein A1 and anti-transthyretin antibodies were negative. Further screening of DNA samples for transthyretin (TTR) gene mutations was also negative. Clinical and laboratory investigations ruled out reactive or senile amyloidosis and immunohistochemical studies with anti-light chain antibodies on amyloidotic tissue specimens were positive. As a consequence, this family represents a new case of familial AL-amyloidosis.

Aged↗