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Biomedical subjects

B Mamoli

Publications and source records attributed to B Mamoli.

At least 91 records · Page 5Linked to original sources
PubMed1985

[Effect of body size, arm length, sex and temperature on somatosensory evoked potential latency].

Beside the technical factors different biological factors contribute to the variability of the somatosensoric evoked potentials. In 30 volunteers the dependence of the latency of the spinal components N9, N13 (recorded at C7), of the cortical component N20 and of the interpeak interval N13-N20 from the body size and length of the arm was investigated. A significant dependence at the 1% level (p less than 0.001) was found for the latencies of N9, N13 and N20, whereas the interpeak interval N13-N20 was significant at the 5% level (p less than 0.05). Similarly in 20 further volunteers a significant dependence of the components N1, P1, N2, P2 and N3 from the body size at the 1% (p less than 0.001) after distal stimulation of the tibial nerve was observed. Using a covariance analysis it could be shown, that even after a body size correction, in females shorter latencies occur than in males. Furtheron we studied the effect of the temperature on the SSEP-latencies, by heating the upper and lower extremity stepwise from 31 degrees C to 37 degrees C using an infrared (DISA-Regler-System) lamp. As no significant dependence could be observed, we believe that the effect of temperature on latencies is so small, that in usual conditions no correction is needed. On the contrary a correction with body size or arm length is necessary, to avoid wrong positive or negative results.

Adult↗
PubMed1985

[Incidence of identification and configuration variants of the NSEP signal in relation to the recording site and measuring moment].

The component evaluation of the spinal and cortical recorded SEP-signals of thirty healthy volunteers after stimulation of the median nerve at the wrist gave information about variation of waveforms and frequency of peak identification with respect to the position of the active electrode and the repetition of the SEP recording. Basically one can distinguish three main groups of NSEP waveforms (Fig. 1). Firstly the "classical form" (i.e. N11 in the ascending part, N13 at the highest peak of the NSEP main component and N14 in the descending part of the curve). Secondly the "plateau-form" and thirdly the "polypeak form" (i.e. many peaks of the same amplitude). The latter two configurations were seen in more than a third of the evaluated NSEP maincomponents. Neither the position of the active electrode (C2 and C7) nor repetition of the SEP recording were found to have significant influence on the waveform. The position of the active electrode influenced the number of identificable peaks: the early components (N9 and N11) were more often recognisable when the recording was made over the lower neckregion (C7), N14 when the recording was made over the upper neckregion (C2). N13 was always identificable in both electrode positions. The repetition of the SEP recordings immediately after the first run is helpful if there was difficulty in identifying the peaks. The normal values of the SEP latency of the spinal and cortical recorded signals were evaluated taking above mentioned criteria into account.

Adult↗
PubMed1984

[Cardiovascular reflexes, vibration thresholds and electroneurography parameters of the peroneal and sural nerves in type I diabetics].

In 26 type I diabetics ranging in age from 18 to 65 years with a duration of illness of between 1 and 34 years the following investigations were performed: 1. case history and questionnaire; 2. neurological examination; 3. determination of the vibration threshold; 4. electroneurography of the peroneal nerve and the sural nerve; 5. determination of the cardiovascular reflexes; 6. medical examination and additional findings; 7. ophthalmological investigation. 21 patients showed evidence of sensorimotor polyneuropathy (SM-PNP), the average age of this group (41 years) being 10 years higher than in the group without SM-PNP (31 years). The values of HbA1c were pathological in 17 of 21 cases with SM-PNP, and 2 of 5 cases without SM-PNP. Retinopathy was found rarely in both groups. 13 patients showed evidence of autonomic neuropathy (ANP). The mean duration of illness (15.4 years) and the average age of patients (36.5 years) in this group was distinctly higher than in the group without ANP (mean duration of illness: 8.9 years, mean age: 31.9 years). 12 patients with ANP and 7 patients without ANP had abnormally high HbA1c levels. Diabetic SM-PNP was most frequently (in 19 of 21 cases) diagnosed by electroneurographical investigation of the peroneal nerve. In the diagnosis of diabetic ANP the anamnesis (8 positive findings) and the determination of the heart rate variation during deep breathing (7 positive findings) are complementary. Among the 13 patients with ANP, 12 also had SM-PNP, whereas among the 21 patients with SM-PNP only 12 showed evidence of concomitant ANP.

Adolescent↗
PubMed1984

The syndrome of continuous muscle fibre activity following gold therapy.

A 72-year-old man suffering from arthritis received a total dose of 500 mg sodium aurothiomalate during a period of 5 months. His clinical state then deteriorated and he had to be hospitalized. Upon admission he was bedridden, his level of consciousness was slightly impaired, he was confused and respiration was laboured. Continuous muscle activity was noted on all extremities and at first, erroneously, fasciculations were diagnosed. The EMG exhibited continuous muscle fibre activity consisting of duplets, triplets and multiplets. The discharges occurred in an irregular pattern; when various muscles were examined at the same time no synchronicity could be observed between muscle discharges. In the left m. deltoideus an increased percentage of polyphasic potentials was found, whereas mean duration of motor unit potentials was normal. Spontaneous activity remained unchanged during sleep and administration of intravenous diazepam or phenytoin. Blocking of ulnar nerve at either elbow or wrist level did not stop spontaneous activity in m. abductor digiti quinti. Ischaemia increased the amount of discharges after 7 min. Within 4 months after termination of gold therapy the patient's condition improved and he was discharged from hospital. Regular EMG follow-up after 8 months showed complete cessation of abnormal spontaneous activities. Nerve conduction velocities were normal except for markedly reduced compound action potential in peroneal nerves. Continuous muscle fibre activity as a side-effect of gold therapy is described.

Aged↗
PubMed1984

Electrophysiological studies in primary biliary cirrhosis.

In 11 female patients with primary biliary cirrhosis, clinical and or electrophysiological signs of a polyneuropathy were found in 9 cases. 8 patients had clinical and 7 patients electrophysiological signs of a polyneuropathy. We derive from the significant correlations between neurographic and metabolic parameters that a hepatic disorder, a disorder of lipid and protein metabolism strongly contribute to the development of polyneuropathy in primary biliary cirrhosis.

Adult↗
PubMed1984

[Electrophysiologic studies in neuropathies].

The value of the electrophysiological investigations can be summarized as follows: Differentiation of different types of polyneuropathies. Detection of subclinical neuropathies. Approach to etiopathogenical aspects. Verification of therapeutic results. Prognosis. The single questions are discussed.

Axons↗
PubMed1983

[Somatosensory evoked potentials: normal values and methodological problems in various recording technics].

In order to optimize the method of examination, somatosensory evoked potentials (SSEP) were studied in 27 healthy subjects, as recorded during stimulation of the median nerve at the wrist. The study shows that recordings with surface electrodes produced better results than with needle electrodes, owing to lesser disturbance from muscle artifacts. The SSEPs of each subject were recorded taking a fixed position of the active electrode placed over the contralateral sensory "hand field", and a reference electrode positioned for the first recording mid-frontally and for the second recording at the contralateral ear or vice versa. The first 3 positive and the first 3 negative peaks were studied. Exact identification of each peak was more often possible when recordings were made with the reference electrode placed mid-frontally than placed at the contralateral er. Normal values were evaluated for the latency P15, P25, P45, N30, N35 and N55, for the amplitudes P15-N20, N20-P25, P25-N35, N35-P45 and P45-N55 and for the latency intervals P15-N20, N20-N35, N35-N55, P15-P25 and P25-P45, with the reference electrode in different positions. In addition, the side difference for each subject was determined. Statistical analysis (T-test for independent variables) revealed a significant difference, depending on the position of the reference electrode: with the reference electrode placed at the contralateral ear, the latency P15 was shorter, the amplitude P15-N20 was increased and the amplitude N20-P25 was decreased as compared with a reference electrode placed mid-frontally.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Plasmapheresis in the treatment of myasthenia gravis.

Between 1978 and 1980, 10 patients with myasthenia gravis underwent treatment by plasmapheresis. Of these, 7 responded to plasma exchange. Pre- and post-exchange anti-acetylcholine receptor antibody concentrations were found to be a useful parameter for intraindividual comparisons, but failed to correlate with the stage of the disease. Anti-acetylcholine receptor antibody assays cannot be replaced by determinations of IgG and globulin concentrations. In view of the potential risks and of the high cost factor, plasmapheresis should be reserved for particularly severe cases for obtaining transient clinical improvement in life threatening situations.

Adult↗
PubMed1983

The value of the edrophonium tonography in the diagnosis of myasthenia gravis.

Tonography of the eye was performed after administration of 10 mg edrophonium chloride (Tensilon) in 13 patients with clinically diagnosed myasthenia gravis. In ten of these patients repetitive nerve stimulation was used to examine the function of the motor end-plate. A significant pressure rise (more than 2 mm Hg) within the 1st min after edrophonium administration was observed in three patients (four eyes), whereas eight of the ten patients who underwent nerve stimulation showed positive results. The edrophonium tonogram test does not seem to be significant enough to define the diagnosis in early myasthenia gravis. Beyond this, these tests might have lost some of their value due to the introduction of antibody analysis against acetylcholine receptors, which serve as a very sensitive diagnostic tool now.

Adolescent↗
PubMed1983

Effect of dantrolene sodium in myotonic dystrophy.

The effect of dantrolene sodium, using a dosage of 120 mg/day, was investigated in 3 patients suffering from myotonic dystrophy. These patients showed a marked reversible deterioration of the clinical symptoms, caused by a reduction of the isometric strength. Dantrolene sodium showed no influence on myotonic discharges and on the latency of the electrical and mechanical muscle response of the adductor pollicis muscle after electrical stimulation of the ulnar nerve. On the other hand a shortening of the relaxation time (in 2 patients) could be observed. The effect of dantrolene sodium on the contractile mechanism without having any influence on the electrical activity is confirmed. Although the relaxation time is shortened, a clinical deterioration is observed, caused by a reduction of the strength. This phenomenon can be explained by a reduction of the calcium release from the sarcoplasmic reticulum after drug application.

Adult↗
PubMed1983

[Determination of average fiber density (single fiber lead), quantitative electromyography and serum CK in the detection of Duchenne carriers].

The fibre density of the extensor digitorum communis muscle was examined with a monopolar single fiber electrode in 2 definite, one probable and 15 possible Duchenne-carriers. In addition serum-CK was evaluated three times in intervals of a least one week. The fibre density was increased in one definite, one probable and 4 possible carriers (greater than 1.6). The highest value was 2.0. Excepting one case the increase of fibre density was accompanied by an increase of serum-CK (greater than 60 mg%). The highest value of CK was 1626 mg%. The conventional EMG was pathological in 2 cases. In no case with an increase of CK or with pathological EMG the fibre density was normal. The fibre density is an unspecific but rather sensible indicator of Duchenne-carriers but as we could observe in a definite carrier, negative results do not exclude carriers.

Adolescent↗
PubMed1983

[Temperature dependence and intraindividual variability of electrophysiologic parameters of the sural nerve].

In 10 healthy volunteers we investigated the temperature dependence of electrophysiological parameters of the sural nerve. The mean values in the range between 28,5 degrees and 35 degrees C with increasing temperatures were: +1.1 m/s/degree C +/- 0,94 for the sensory orthodromic conduction velocity; -0.39 microV/degree C +/- 0.51 for the orthodromic sensory amplitude (NAP-amplitude) and -0.01 ms/degree C +/- 0.04 for the duration of the NAP (NAP-duration). The number of phases did not change. Investigating twice the dependence of the electrophysiological parameters of the sural nerve on the temperature in 9 controls, it was shown that this dependence remains relatively constant in the single subject. In 20 healthy volunteers we determined normal values of the intraindividual variability of the electrophysiological parameters of the sural nerves. The values were: 5.70% +/- 3.81 for the NCV; 23.60% +/- 14.66 for the NAP-amplitude and 10.05% +/- 7.35 for the NAP-duration. The number of phases did not change.

Adult↗
PubMed1983

[Long-term EEG recording in comparison with sleep deprivation and other provocation methods in epilepsy patients].

37 epileptics with routine records without paroxysms were subject to 24 hours mobile long-term EEG registration and independently 24 hours sleep deprivation EEG including hyperventilation and photic stimulation. The anticonvulsive treatment was not changed. In 14 cases we could prove epileptiform discharges (= positive finding) by using both methods, in 13 after sleep derivation (10 at rest, 3 only during hyperventilation) in 7 in the long-term record and in 6 of them both after sleep deprivation and in long-term record. As epileptiform discharges we rated spikes, spikes ans slow waves, epileptic K-complexes, spike and waves and poly spike wave-paroxysms. We refer the small number of positive findings in the mobile long-term EEG mainly to the fact that only 3 EEG canals are disponible until now. Therefore on the one hand it is not definitely possible to distinguish sharp waves from sharp transients physiologically appearing in sleep, on the other hand focal EEG-changes often escape from being recorded.

Adolescent↗
PubMed1982

[Differential diagnostic problems and polygraphic studies in a case of Pickwickian syndrome].

The case report of a male patient with the Pickwickian syndrome is presented. The results of the relevant neurophysiological examinations (polygraphic registration of EEG, electrocardiogram, respiration, thorax excursions, submental and intercostal electromyogram, electrooculogram) give an insight into the pathomechanisms and enable the differential diagnosis to be made between this condition and narcolepsy and also the Kleine-Levin syndrome; respiratory investigations (spirometry, hypercapnic ventilatory response: mouth occlusion pressure) make it possible to differentiate between the Pickwickian and Ondine's curse syndrome. The therapeutic management is discussed.

Adult↗
PubMed1982

Serum and cerebrospinal fluid immune complexes containing hepatitis B surface antigen in Guillain-Barré syndrome.

A 76-yr-old male presented with Guillain-Barré syndrome after acute hepatitis B virus infection. Main immunologic features were: (a) high levels of circulating hepatitis B surface antigen-containing immune complexes in serum and cerebrospinal fluid during the acute neurologic syndrome, and (b) clearance of immune-complex material with recovery. Our data indicate that these immune complexes in cerebrospinal fluid reflect leakage from the systemic circulation via a deranged blood-brain barrier and are not generated in the cerebrospinal compartment. Possibly deposition of such immune complexes along nerve structures is important in the immunopathogenesis of some cases of Guillain-Barré syndrome.

Aged↗
PubMed1981

A combination of spastic paraparesis, polyneuropathy and adrenocortical insufficiency-a childhood form of adrenomyeloneuropathy.

This report describes a combination of spastic paraparesis and symmetrical sensory motor polyneuropathy with a pathological response to the ACTH test in the case of a 16 year-old boy and a borderline response to the ACTH test in the case of his 8-year-old sister. Another sister, aged 14, showed only a pathological response to ACTH testing, the neurological status being unremarkable. The EEG was normal in all three children examined. Visually evoked potentials were borderline in the case of the boy and normal in the case of the clinically involved sister. Although on examination by light microscopy the sural nerve proved to be normal, the clinical diagnosis of adrenomyeloneuropathy (AMN) in its juvenile form may be assumed, in view of the clinical symptoms and the evidence of adrenocortical insufficiency revealed by the ACTH test.

Adolescent↗
PubMed1981

Peripheral nerve lesions in haemophilia.

Among 234 haemophiliacs (A and B) treated between 1948 and 1975 at the First Medical Clinic of the University of Vienna, 25 (10.8%) with 36 peripheral nerve lesions have been observed. This amounts to 15.3% or 2.4 lesions within 100 observation years. The average age of the patients at the time of development of lesion was 26.4 years. Correlations between severity of haemophilia and frequency of occurrence of lesions were found. Patients with mild haemophilia did not show peripheral nerve disturbances. The numbers of times individual nerves were affected are as follows: maxillary (1), radial (2), medial (6), ulnar (4), obturator (1), lateral cutaneous nerve of thigh (1), femoral (12), including lesions of the 2nd and 3rd lumbar roots, sciatic (6), including lesions of te 5th lumbar and the 1st sacral roots, peroneal (3), and tibial (1). In 1978, 11 patients who previously had sustained 16 peripheral lesions were reexamined. Of these, 10 had fully recovered, 4 showed some persisting sensory disturbances, and 2 were unchanged. Motor nerve conduction velocity, distal latency and compound nerve action potentials were systematically examined in 11 cases on both sides of the body. In contrast to our expectations, no signs of subclinical peripheral nerve lesions were found. The comparability of the presence and previous results is discussed.

Adolescent↗