Phenobarbital and propranolol in essential tremor: a double-blind controlled clinical trial.

In a double-blind study with Latin square design, phenobarbital (about 1.3 mg per kilogram), propranolol (about 1.7 mg per kilogram), and placebo were given orally for 1 month to 12 patients with essential tremor. By clinical evaluation, only propranolol appeared to be significantly more effective than placebo. As judged by tests of manual skill, none of the treatments significantly improved tremor. Patients' subjective evaluation and tremor amplitude measurement (by accelerometer) showed a significantly better effect of both propranolol and phenobarbital than placebo. These data suggest that phenobarbital may be a valuable alternative to propranolol in essential tremor.

A study of the interhemispheric correlation during sleep in elderly subjects.

The interhemispheric relationship during sleep in elderly subjects was studied throughout the night by a minute-by-minute computation of two linear correlation coefficients between right and left EEG activities. One of these coefficients (X delta) related to the 1-4-Hz band activity, and the other (X sigma) to the 12.5-14.5-Hz band activity. For five of the six subjects examined, it was found that the rapid-eye-movement (REM) mean values of both coefficients were significantly different from the nonrapid-eye-movement (NREM) values. A comparison between this elderly group and a control group of young subjects, examined previously, did not reveal any significant shift, either for the REM or for the NREM mean values of the coefficients.

Total body water estimation using bioelectrical impedance: a meta-analysis of the data available in the literature.

Bioelectric impedance analysis (BIA) is commonly used in clinical settings and field studies for estimating total, extracellular, and intracellular water compartments. The objective of the present study was to carry out a meta-analysis of published reports in which total body water (TBW) was estimated using BIA techniques and comparisons were made with reference values. We identified 16 reports conducted among healthy and obese adults and individuals with chronic renal failure. Based on the weighted mean difference, we found that those studies using only multi-frequency BIA did not significantly overestimate the TBW compared with the reference values. Thus, among BIA techniques, multi-frequency BIA seems to be a more accurate method for estimating the TBW compartment for healthy and obese adults and for those with chronic renal failure.

Topographic variations in EEG asymmetry during sleep.

EEG signals were recorded in 11 normal subjects from F4-C4, F3-C3, P4-O2 and P3-O1 during both stage 2 and the REM stage of each NREM/REM cycle. The logarithm of the right/left ratio for the power in the range of the various frequency bands showed a prevalent right-side asymmetry only with the fronto-central derivations. This trend, observed for all frequency bands, remained stable over the various NREM/REM cycles with the exception of the last one. These data indirectly support the hypothesis that the right hemisphere is more heavily involved in dreaming than the left, and suggest a prevalent involvement of the anterior regions.

[Anorexia nervosa and hyperactivity in adolescence: psychiatric and internal medicine features]. / Anoressia nervosa e iperattività in adolescenza: correlati psichiatrici e internistici.

AIM: The aim of the present study was to verify the influence of hyperactivity on internistic and psychiatric parameters in early onset anorexia nervosa restricting type (ANR). METHODS: Seventy-three adolescent females (mean age 13.5 years, SD: 2.27) with a diagnosis of ANR (DSM-IV-TR) were consecutively enrolled in the Child and Adolescent Eating Disorders Unit of the IRCCS-Stella Maris and assessed by an extensive clinical protocol. All patients completed: psychiatric evaluation for description of the DCA and comorbidities; pediatric assessment including complete auxological data, blood pressure, heart rate and other electro/echo cardiographic and biohumoral parameters. The hyperactivity was estimated by the application of the "Structured Interview for Anorexic and Bulimic Disorder-Expert Form" (Item 40) in the context of clinical observation. Subjects were identified according to their level of hyperactive (ANR+H) and non-hyperactive (ANR-H) activity. RESULTS: In the ANR+H group heart rate, leptin, sodium, potassium and gamma plasma proteins significantly differ compared to the group ANR-H. Patients with hyperactivity also have a complete form of ANR in 94% of cases compared with 66.7% of non-hyperactive; significant differences were found also in thought and attention CBCL and YSR subscales, combined with major internalizing problems. CONCLUSION: This study provides preliminary data which can orient research towards the development of specific treatments for the hyperactivity, in order to improve the prognosis and thus avoid the chronicity of the disorder and the development of complications in adult life.

[Recent progress in energy sources and in technology of electronic circuits (author's transl)]. / Vecchie e nuove fonti di energia e progressi nella costruzione dei circuiti elettronici degli stimolatori.

Since 1957, when the first implantable pacemaker was developed, the performances of cardiac pacemakers have enormously improved. The paper describes the recent progress in the field of energy sources, technology and circuit solutions. The improvements achieved up to now have extended the mean life-time of an implantable pacemaker from about 30 months up to more than 6 years, while some pacemakers with programming capabilities are available and pacemakers with self-adapting capabilities to the individual hemodynamic needs are in the stage of advanced development.

Measuring the stimulating energy threshold in living tissues.

The paper summarizes the various methods of measuring the stimulation threshold in living tissues and emphasizes the usefulness of energy measures. An analog instrument for the direct measurement of the energy threshold is proposed and some experimental results obtained by its clinical application are reported.

Responses of Purkinje cells of cerebellar vermis to sinusoidal rotation of neck.

1. The response of Purkinje (P) cells located in the vermal cortex of the cerebellar anterior lobe to sinusoidal rotation of the neck was investigated in precollicular decerebrate cats. The head of the animal was fixed in a sterotaxic frame while the spinous process of the second cervical vertebra was held by a clamp rigidly fixed to the tilting table. It was then possible to elicit a selective neck input by rotating the neck and the body simultaneously along the longitudinal axis of the animal while maintaining the head in horizontal position. 2. Among the 95 P-cells tested for neck stimulation, 35 units showed a mossy fiber (MF) or a climbing fiber (CF) response to sinusoidal rotation of the axis vertebra at the frequency of 0.026 Hz and at the peak amplitude of displacement of 5--10 degrees. The response consisted in a periodic modulation of the discharge frequency during sinusoidal rotation of the neck. Most of these units were excited during side-down rotation of the neck, but were inhibited during side-up rotation. 3. The threshold amplitude of neck rotation responsible for the MF-induced responses varied in different units from 1 to 3 degrees at the frequency of 0.026 Hz. The sensitivity of the units, expressed in percentage change of the average firing rate per degree of displacement, either did not change or very slightly decreased as a result of increasing amplitude of stimulation from 1--3 degrees to 10--15 degrees at the frequency of 0.026 Hz or by increasing frequency of neck rotation from 0.015 to 0.15 Hz at the amplitude of neck displacement of 5--10 degrees. 4. Changes in amplitude or frequency of stimulation at the parameters reported above did not greatly modify the phase of the unit responses relative to the side-down position of the neck. These findings indicate that the MF and CF responses of P-cells to sinusoidal rotation of the neck depended on changes in neck position and not on changes in velocity of neck rotation. 5. The observation that the majority of responding P-cells located in the vermal cortex of the cerebellar anterior lobe increased their firing rate during side-down rotation of the neck is discussed in relation to the results of stimulation and lesion experiments, indicating that postural changes can be elicited either during asymmetric stimulation of neck receptors or by unilateral interruption of the neck afferents.

Responses of Purkinje cells of the cerebellar vermis to neck and macular vestibular inputs.

1. The dynamic analysis of the control exerted by neck and macular vestibular receptors on the cerebellar cortex has been investigated in precollicular decerebrate cats submitted to sinusoidal rotation along the longitudinal axis of the animal at the frequency of 0.026 Hz and at peak amplitudes up to 10 degrees for the neck input and 15 degrees for the macular input. 2. Purkinje (P) cells located in the vermal cortex of the cerebellar anterior lobe, particularly in the longitudinal parasagittal zone which projects to the ipsilateral lateral vestibular nucleus (LVN), showed a sinusoidal modulation of the firing rate in response to sinusoidal stimulation of the neck receptors or the vestibular receptors, the phase of the responses being in most units related to the extreme neck or head position. Mossy fiber (MF) and/or climbing fiber (CF) responses of the same or different P-cells to the two inputs were observed. 3. The sensitivity of the MF-response of the P-cells to the neck input, elicited by sinusoidal rotation of the neck and expressed in per cent of the average firing rate per degree of neck rotation, corresponded on the average to 2.71 +/- 1.67, S.D. This value was significantly higher than that of the MF-response of the P-cells to the macular input elicited by sinusoidal tilt along the longitudinal axis of the whole animal, which correspond to 1.71 +/- 1.01, S.D. 4. Most of the MF-responses of the P-cells to the neck input were characterized by an excitation during side-down rotation of the neck and by an inhibition during side-up rotation, whereas most of the MF-responses of the P-cells to the macular input showed just the opposite behavior, being inhibited by side-down tilt of the animal and excited by side-up tilt. 5. Units which received a convergent input from both neck and macular receptors and showed an antagonistic pattern of response to the two inputs were tested during rotation of the head alone, in order to excite simultaneously the two kinds of receptors. Due to the higher sensitivity of the neck over the macular response, the magnitude of the combined response tended to be similar to the difference between the individual ones. Moreover, the phase of the resulting response was always modified with respect to that of the response to the neck input alone, and became in some instances related to velocity of neck rotation rather than to neck position. 6. These findings indicate that opposite responses to neck and macular inputs occur at corticocerebellar level. However, a final integration of the two inputs, leading to suppression of the conflicting responses, may occur either at medullary (LVN) or at spinal cord level.

Changes in the interhemispheric correlation during sleep in normal subjects.

The correlation coefficients between left and right activity in the various frequency bands of the EEG signal were computed during sleep for 11 normal adults. The values of the correlation during REM sleep were compared with those for NREM sleep. This comparison was performed 'locally,' i.e., during each period of the REM-NREM cycle, as well as over the whole night. For 9 out of the 11 examined subjects, both a visual comparison with the hypnogram and a statistical analysis showed the existence of cyclic variations during the night in the delta and/or sigma correlation coefficient. These variations lasted for the whole night and were synchronized with the REM-NREM cycle. A possible connection between these results and data on the interhemispheric relationship given by amplitude analysis is briefly discussed.

Differences between surface EMG in male and female subjects evidenced by automatic analysis.

40 healthy volunteers (20 males and 20 females) have been studied by an automatic analysis of their surface EMG. The power density spectrum (PDS) of the electromyographic signal, derived from the tibialis anterior muscle, was used to evaluate the RMS values of the EMG developed during maximal voluntary (Vc) and evoked (Vm) contractions. The ratios between Vc, calculated over each of 5 frequency bands (5-15, 20-40, 45-70, 75-110, 115-160 Hz), and the total Vc have also been calculated. No significant differences emerge in the Vm values for males and females, whereas the Vc values for female subjects are found to be significantly reduced (P less than 0.001) with respect to the corresponding values for males. Significant differences have also been found concerning the percentage distribution of power in the above mentioned frequency bands for men and women (P less than 0.001). It can thus, be hypothesized that there are two different modalities of motor unit recruitment and that different sociological and cultural traditions may be more important in producing these differences than sexually determined physiological differences.

Automatic analysis of surface EMG (preliminary findings in healthy subjects and in patients with neurogenic motor diseases).

Supramaximal electrical stimulation of a motor nerve produces a full contraction of a muscle and the corresponding compound action potential can be recorded. Recent studies appear to support the view that all the motor units are activated during voluntary maximal contraction, at least in the tibialis anterior muscle. The compound action potential and the EMG interference pattern in the tibialis anterior are regarded as two different manifestations of the activation of all the motor units. A method has been developed which compares these EMG activities, by automatic analysis, in order to obtain useful parameters for clinical applications.

[Studies of the expectancy wave (CNV) in patients with interruption of the thalamo-prefrontal interconnnection pathways caused by psychosurgical prefrontal lobotomy operations]. / Rilievi sull'onda d'aspettativa (CNV) in pazienti con interruzione delle vie di interconnessione talamo-prefrontali da interventi psicochirurgici di lobotomia prefrontale.

Frontal and vertex CNVs were studied in 8 selected nonschizophrenic patients subjected to unilateral or bilateral extensive prefrontal lobotomy. The dorsomedial thalamo-frontal pathways had been severed and their regeneration must be considered impossible. Standard CNV task (S1-S2-R) was followed in order to elicit CNVs from the frontal areas anterior to the line of sections and at Cz. In 7 out of 8 patients it was quite easy to evoke CNV with almost normal features and equal latencies in each case from all the cortical areas explored. These results show that CNV formation is not grossly altered in the prefrontal areas which have been irreversibly deprived of normal bi-directional mediothalamic-frontocortical connnections. This suggests that the role of the dorsomedial thalamo-frontal pathways are not essential in the genesis of the frontal CNV in humans. These findings would suggest that the CNV is a diffuse electrical event essentially related to a unitary cerebral process mediated fundamentally by nonspecific ascending meso-diencephalic reticular systems. The differences in morphology and polarity of the CNVs detectable in various brain structures are presumably related to their intrinsic anatomo-functional characteristics and to the method commonly utilized in recording the CNV.