Curariform peripheral block of muscular tone selectively increases precentral N30 somatosensory evoked potentials component. A pharmacological study carried out on healthy subjects and parkinsonian syndromes.

In the present study we investigated whether the precentral component (N30) of short somatosensory evoked potentials (SEPs) to median nerve stimulation may be modified by peripheral neuromuscular blocking agent in patients affected by rigidity. We, therefore, recorded SEPs in nine Parkinson's disease (PD) patients and in seven psychotic patients affected by neuroleptic malignant syndrome (NMS), all showing severe rigidity. Each patient group was studied before and after the placebo, and before and after an atracurium besilate bolus of 0.05 mg/kg, in a single recording session. At the time of the test the PD patients had not taken any antiparkinsonian therapy for at least 48 h. The same recordings were also taken on nine neurologically normal subjects undergoing surgical procedures. Atracurium administration produced a remarkable amplitude increase of the major precentral component (N30) of SEPs. An atracurium-induced N30 amplitude increase was observed in both PD patients (from 2.41 to 4.07 microV) and NMS psychotic patients (from 2.03 to 3.97 microV), whereas there was a minor N30 amplitude increase in healthy subjects (from 3.53 to 4. 10 microV). The N30 latency was unaffected. Amplitude and latency of the major parietal SEPs component (N20) was unchanged in the three groups studied. Our results lead to the conclusion that a neuromuscular blocking agent is capable of increasing the N30 amplitude in patients affected by severe rigidity, exclusively reducing their muscular tone without interfering with the central dopaminergic system. Thus, a "peripheral gating" of sensory input to the supplementary motor area due to rigidity may play a relevant role in producing the N30 amplitude decrease described in patients affected by degenerative or pharmacologically induced parkinsonism. The reduction of rigidity could be the mechanism by which dopamine may increase the precentral N30 amplitude in parkinsonian syndromes.

Cerebrospinal fluid estrone in pseudotumor cerebri: a change in cerebral steroid hormone metabolism?

Estrogen and androgen hormones were studied in the plasma and cerebrospinal fluid (CSF) of five patients affected by pseudotumor cerebri (PTC). Six men and six women without cerebral or endocrine diseases were selected as controls. Androstenedione (A), testosterone (T), 17-hydroxyprogesterone (17OH-P), E1 and E2 were measured in plasma and CSF in baseline conditions and following 1 month prednisone therapy (2 mg/die, per os) using RIA following chromatographic separation on celite microcolumns. Men and women affected by PTC show increased CSF E1 levels and marked decreased CSF A levels, with respect to controls. In plasma, on the contrary, normal values of these parameters were observed in PTC. In normal subjects A/E1 ratio shows the same values in plasma and CSF, suggesting for the two hormones analogous feasibility to cross the blood brain barrier. In PTC patients A/E1 ratio is comparable to controls in plasma, but lower in CSF as a result of decreased A and increased E1 contents. The CSF imbalance between A and E1 attenuates but does not disappear after treatment. No correlation is found between pressure levels and steroid pattern both in baseline condition or after one month of treatment. In conclusion, our results demonstrate that PTC is not only associated with increased CSF E1 levels, as previously suggested, but, above all, with decreased CSF A levels and this hormonal impairement seems to be confined to the CSF compartment and not observed in plasma. These data do not lead to any definitive conclusion about the role of altered CSF estrogen and androgen levels in PTC pathogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

[Replacement of the mitral and aortic valves with bioprostheses. Long-term results]. / Sostituzione valvolare mitralica e aortica con bioprotesi. Risultati a distanza.

The purpose of the study was to analyze the medium-term results (late mortality, thromboembolism, valve failure) in patients who underwent bioprosthetic valve replacement at "A. De Gasperis" Cardiovascular Surgery Division. From October 1975 to December 1982, 195 patients were consecutively operated on and discharged (118 with mitral prosthesis, 54 with aortic prosthesis, 22 with mitral and aortic prosthesis, 1 with mitral and tricuspid prosthesis). We reviewed 115 (97.45%) of 118 patients with mitral prosthesis (mean follow-up 46.61 months) and 54 (100%) patients with aortic prosthesis (mean follow-up 38 months). Eleven late deaths (2.4%/pt-yr) and 13 thromboembolic events (2.8%/pt-yr) occurred in patients with mitral prosthesis, 6 late deaths (3.5%/pt-yr) and 5 thromboembolic events (2.9%/pt-yr) occurred in patients with aortic prosthesis. Actuarial survival curves and actuarial incidence of thromboembolic event-free patients at 5 years are, respectively, 91.2% and 87.3% in patients with mitral prosthesis, 82.8% and 86.3% in patients with aortic prosthesis. The risk factors for thromboembolism were analyzed. Reoperation was requested in 14 cases (10 mitral and 4 aortic prostheses) for prosthetic leak (6 patients) or valve failure (8 patients). In linearized terms, the rate of valve failure requiring reoperation is 1.3%/pt-yr for mitral prostheses and 1.1%/pt-yr for aortic prostheses. The medium-term results suggest that the bioprostheses are, at the present time, an effective choice to the mechanical prostheses, nevertheless they are not free from risks of thromboembolic complications.

Effects of distraction on the contingent negative variation in presenile dementia and normal subjects.

The authors recorded contingent negative variation (CNV) in a group of subjects affected by presenile dementia, at the onset of the symptoms, with a slight degree of intellectual deterioration. Recordings were carried out in rest basal conditions and upon administration of an insignificant distracting stimulus. Results were compared with data obtained in a group of normal subjects of the same age under the same experimental conditions. In the patients a marked decrease of the wave was observed upon the administration of a distracting stimulus.

[Ebstein's malformation. Report of 9 cases surgically treated (author's transl)]. / Anomalia di Ebstein. A proposito di 9 casi operati.

Nine patients with Ebstein's malformation have undergone surgical repair since 1971. Their ages ranged from 10 to 49 years. Two patients were in functional class II and six in III. Dysrhythmias were indicators for operation in the remaining patient. All patients underwent prosthetic valve replacement. Other procedures included atrial septal defect closure in eight and plication of the atrialized ventricular segment in four cases. Three patients died during the postoperative period. Three patients died during the postoperative period. Functional classification improved in five of the six operative survivors. The multiple aspects of the clinical features, the different surgical management and the variability of results are explained by the wide range of morphologic and functional aspects of the malformation.