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Biomedical subjects

S Passero

Publications and source records attributed to S Passero.

At least 37 records · Page 2Linked to original sources

Sensory neural conduction of median nerve from digits and palm stimulation in carpal tunnel syndrome.

The median sensory nerve conduction between ring finger and wrist is a suitable parameter for early detection of carpal tunnel syndrome (CTS), although shorter segments of median nerve have also been proposed for the same goal. In order to assess the relative diagnostic value of the sensory nerve conduction velocity (SNCV) of the third palmar branch versus the SNCV of the second palmar branch, generally performed until now, we studied 62 patients with typical signs and symptoms of CTS. The following parameters were evaluated by surface recording: orthodromic SNCVs in digit-wrist segments for median (index = M2, third = M3 and ring = M4 fingers), ulnar (fourth = U4 finger) and radial (thumb = R1) nerves; SNCVs in palm-wrist segments by surface bipolar stimulation at each metacarpo-phalangeal interspace (second = P2 and third = P3 for the median nerve and fourth = P4 for the ulnar nerve); and distal motor latencies of the median and ulnar nerves. No responses at the wrist were recorded in 22.6% of patients after digital stimulation of M4, whereas the SNCV of P3, the palmar nerve branch arising from digital nerves of the medial side of M3 and the lateral side of M4, was measurable in 93.5% of patients. As significantly expressed (P < 0.001) by the increased ratio of the mean values of P2 and P3 in CTS patients, the SNCV of P3 decreased more frequently and to a greater extent than the SNCV of P2.

Action Potentials↗

Diagnosis of thoracic outlet syndrome. Relative value of electrophysiological studies.

The diagnostic utility of various electrophysiological techniques was evaluated in patients with thoracic outlet compression syndrome (TOCS). Our results suggest that in true neurogenic TOCS, there is no standard electrophysiological picture, but that this evolves with the severity of the syndrome. The first changes observed are electromyographic, followed by changes in F-wave and SEPs, followed finally by changes in nerve conduction parameters. EMG study was certainly more informative, showing neurogenic damage not only in limbs with neurological signs but also in about 1/4 of limbs with only subjective symptoms. The study of F-wave and SEPs does not seem to be particularly helpful, however, in view of the peculiar changes found in these patients, SEPs may be a useful complement to EMG. Nerve conduction studies were of little utility since changes in these parameters are only found in patients with long-standing anomalies and severe atrophy.

Adult↗

An electromyographic evaluation of motor complications in thoracic herpes zoster.

Motor complications in thoracic herpes zoster were evaluated in 52 patients by electromyographic examination of the paraspinal muscles. At the initial EMG examination, abnormal findings were observed in 18 patients (35%). In 8 patients the myomers involved coincided in location with affected dermatomes, while in 10 patients, in addition to the involvement of myomers corresponding to affected dermatomes, there also appeared an involvement of one or more contiguous myomers not corresponding to affected dermatomes. Our study demonstrated that motor involvement in thoracic HZ is much more common than previously suggested and its incidence (35%) appears to be greater than that reported in both cervical and lumbosacral HZ.

Adult↗

Involvement of peripheral sensory fibers in amyotrophic lateral sclerosis: electrophysiological study of 64 cases.

We report electrophysiological findings of conduction along peripheral sensory fibers in 64 patients with amyotrophic lateral sclerosis. Distribution of the values of action potential amplitudes and conduction velocities of peripheral afferent fibers were significantly lower than in normal age-matched controls. Sensory action potential amplitudes (SAPas) were more affected than sensory conduction velocities (SCVs). When single patients were considered, SAPas were slightly but significantly reduced in 22% of the cases (median nerve 17%, ulnar nerve 11%, and sural nerve 22%). A parallel decrease in SCVs and MCVs in 14 patients in whom the study was repeated over a period of time was also found. All these electrophysiological findings are due to progressive neuronopathy of peripheral sensory fibers. A pathogenetic mechanism is proposed.

Action Potentials↗

Electrophysiologic evaluation of local steroid injection in carpal tunnel syndrome.

Extensive sensory and motor nerve conduction studies were performed in a series of patients with electrophysiologically proven, idiopathic carpal tunnel syndrome who were treated by a single steroid injection (40 mg of triamcinolone acetonide). Electrophysiologic studies, which included evaluation of median, ulnar, and radial orthodromic sensory action potentials, median and ulnar motor action potentials, and electromyography of two intrinsic muscles of the hand, were done before and at 45 days and six months after the treatment. By the end of the follow-up period, the symptoms had remitted completely in 11 hands (35%), 18 (58%) benefitted from partial relief, and two did not improve. In addition to the relief of symptoms, abnormalities of motor nerve conduction improved in 65% of cases, and abnormalities of sensory nerve conduction improved in 73% of all the individual digital branches of the median nerve examined. Recovery of function of the median nerve continued for a long period, even after the pharmacologic effect of the steroid agent had presumably ceased.

Action Potentials↗

Arachnoid cysts of the middle cranial fossa: a clinical, radiological and follow-up study.

Twenty-seven patients with CT-scan-diagnosed arachnoid cysts in the middle cranial fossa were studied. Five (18%) presented with progressive symptoms related to raised intracranial pressure which had developed after minor trauma and secondary bleeding, 12 (44%) presented with non-progressive symptoms, and 10 (37%) exhibited neurological syndromes not referable to the cyst. Among those with non-progressive symptoms, epilepsy was the most common presentation (67%). More than 60% of the cysts were small and limited to the anterior temporal region or to the Sylvian fissure, the remaining cysts involved both the anterior temporal region and the Sylvian fissure, and expanded to the adjacent fronto-temporal or fronto-parietal regions. The volume measurements of the brain tissue performed on CT scan revealed that between the volume of the two hemispheres there was no significant difference suggesting any evidence of agenesis or hypoplasia of the affected temporal lobe.

Adolescent↗

Diagnostic specificity of sensory and motor nerve conduction variables in early detection of carpal tunnel syndrome.

In the carpal tunnel syndrome (CTS) sensory nerve conduction is more sensitive than motor conduction. However, 8%-25% of the sensory distal latencies in symptomatic hands may still be normal. A systematic study was made of the median, ulnar and radial orthodromic nerve conduction velocities (SNCV) stimulating each of the fingers separately. Four SNCVs from the median nerve, two SNCVs from the ulnar nerve and one from the radial nerve were obtained, and the ratio of the median to radial SNCV and the ratios of the median and ulnar SNCVs were estimated. The significance of these parameters in the diagnosis of the CTS was studied, and a rapid technique for the screening of nerve entrapment in the initial stages of the disease is proposed. Three hundred and seventy-five symptomatic hands were examined. Seventy-five hands showed normal distal latency, in which cases, however, the SNCV of the ring finger was always outside the normal range, while the SNCVs of the thumb, index and middle fingers were abnormal in 64%, 80% and 92% of cases respectively. The amplitudes of the sensory responses were the least sensitive of the parameters studied. Our results suggest that a study of the median nerve digital branch to the ring finger may be of value in providing an easily performed and rapid technique for screening an early median nerve entrapment at the wrist.

Adolescent↗

Italian multicenter study of reversible cerebral ischemic attacks. Part 5. Risk factors and cerebral atherosclerosis.

As part of a prospective study, the influence of several premorbid and environmental factors on the presence, extent and severity of cerebral vessel atherosclerosis was studied in 462 patients with clinical diagnosis of RIA who underwent cerebral angiography. The extent and severity of atherosclerosis of the cerebral vessels was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesions in 11 extracranial and 21 intracranial arterial segments. Results of univariate and multivariate analyses indicate that the presence of atherosclerotic changes of cerebral vessels, as shown by angiography, was strongly related with age in both sexes. The lesions were more frequent in males, in particular under age 55. Elevated cholesterol was associated with a higher incidence of atherosclerotic lesions. Smoking was associated with a higher incidence of extracranial lesions. Age, smoking and history of hypertension were the best predictors of the extent and severity of cerebral vessel atherosclerosis.

Adult↗

[Effects of reduction of blood viscosity at constant hematocrit on the cerebral blood flow].

It is well established that cerebral blood flow (CBF) is low in patients with high hematocrit and is high in anemic patients. An inverse relationship between CBF and hematocrit has been found. Furthermore, if hematocrit is reduced, CBF increases. There is some debate as to whether these observations are due to viscosity or to oxygen carrying capacity of the blood. In order to further elucidate this problem, CBF, blood viscosity and hematocrit were measured in 4 patients with paraproteinemias before and after paraproteins had been removed by plasmapheresis without changes in hematocrit. After plasmapheresis, blood viscosity significantly decreases and CBF increases by a mean of 24.4 ml/100 g/min. Mean arterial blood pressure and hematocrit were not influenced by plasmapheresis. These results indicate that blood viscosity is an important factor in determining CBF. This does not exclude the role of oxygen transport as an associated factor, but it is evident that oxygen transport and blood viscosity are independent variables in the control of CBF.

Blood Viscosity↗

Toxic polyneuropathy of shoe workers in Italy. A clinical, neurophysiological and follow-up study.

Cases of polyneuropathy due to exposure to industrial solvents have been studied at several shoe factories in the province of Siena. After the screening of 654 employees 98 verified cases were detected. Of these, 16 were rated as moderate to severe, 45 as mild, and 37 were minimally involved but with characteristic electrodiagnostic abnormalities. Follow-up study in 53 patients showed that neurological signs and symptoms as well as electrodiagnostic abnormalities continued for years in several patients. In addition, after a year's observation, some patients showed signs of central nervous system dysfunction such as spasticity of the lower limbs and increased deep tendon reflexes. High percentages of commercial n-hexane were found in all the samples of glues and solvents collected from home-workers and from factories where cases of polyneuropathy occurred.

Adhesives↗

Depression of cerebral glucose utilization during animal hypnosis in the rabbit.

The rates of local cerebral glucose utilization have been measured in normal conscious and hypnotized rabbits by the [14C]deoxyglucose method. In control rabbits the rates vary widely throughout the brain, with the values in gray matter broadly distributed around an average which is about 3 times greater than that of white matter. The higher values area in structures of auditory system (superior olive, inferior colliculus, auditory cortex). Animal hypnosis reduces the rates of glucose utilization in all structures of the rabbit brain, particularly in the caudate nucleus, putamen and sensory and motor cortices.

Animals↗

Effect of pentoxifylline on cerebral blood flow in patients with chronic cerebrovascular disease.

The effect of pentoxifylline on cerebral blood flow (CBF) was studied with the intravenous 133Xe clearance technique in eleven patients with chronic cerebrovascular disease. Pentoxifylline was administered orally at a dose of 1200 mg/day over a period of 30 days (eight patients) or by intravenous infusion of 100 ml saline containing 400 mg of the drug in 1 hour (three patients). CBF was measured before and after pharmacological treatment. CBF was found to be significantly increased by both acute and chronic administration of pentoxifylline.

Aged↗

Pathophysiology of cerebral blood flow in brain ischemia.

On the basis of findings obtained by means of both traditional and modern tomographic techniques, Authors discuss changes of cerebral blood flow (CBF) and metabolism in acute cerebral ischemia and chronic cerebral circulatory insufficiency. Drug effects on cerebral circulation and metabolism are examined and experiences with pentoxifylline, substance provided with haemorheologic action, are reported.

Brain Ischemia↗