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Biomedical subjects

S Calzetti

Publications and source records attributed to S Calzetti.

At least 37 records · Page 2Linked to original sources
PubMed1989

Spontaneous hemiballism and disappearance of parksinsonism following contralateral lenticular lacunar infarct.

Hemiballism was observed in a 77-year-old woman with Parksinson disease after a contralateral lenticular infarct without apparent involvement of the subthalamic nucleus. Parkinsonian signs ipsilateral to the hemiballism remained abolished despite subsequent nearly complete recovery from the hyperkinesias. It is argued that clinical events were due to a single ischemic lesion of the putamen-pallidum complex.

Aged↗
PubMed1988

Double-blind comparison of primidone and phenobarbital in essential tremor.

In a double-blind cross-over trial, primidone was superior to both placebo and phenobarbital in reducing essential tremor in 13 patients. Phenobarbital, at a dosage yielding serum barbiturate levels greater than those seen with primidone, was not better than placebo. Thus, primidone has an effect in essential tremor independent from that of its metabolite phenobarbital.

Clinical Trials as Topic↗
PubMed1987

[Polycythemic chorea. Description of a clinical case].

The authors report a 69-year-old man affected by polycythaemia rubra vera since the age of sixty, who presented persistent left hemichorea of acute onset, occurring ten months before the exacerbation of the haematologic abnormalities. Previously he had been suffering from a transient episode of chorea concomitant with relapsing of polycythaemia. CT scan of the brain showed diffuse cortico-subcortical atrophy, whereas Doppler velocimetry of carotid arteries demonstrated a rise in cerebral blood flow resistance and a stenosis of the right carotid artery in its first tract. Pathogenetic mechanisms of chorea complicating polycythaemia vera are discussed and a multifactorial origin of the syndrome is suggested.

Aged↗
PubMed1987

Frequency/amplitude characteristics of postural tremor of the hands in a population of patients with bilateral essential tremor: implications for the classification and mechanism of essential tremor.

Amplitude/frequency characteristics of postural hand tremor in 59 patients with bilateral essential tremor of various degrees of severity were assessed using accelerometric recordings and spectral analysis. Intra-subject comparisons of tremor characteristics between the more and less affected hands were used to control for variability of tremor due to age factors and intersubject differences in amplitude and frequency. Statistical analysis distinguished three different patient groups. Some patients had low amplitude (less than 0.1-0.015 cm) tremor in the less affected limb (which tended to be 7 Hz or more in frequency in the young) and a larger amplitude tremor in the more affected hand which was 1 Hz or more lower in frequency. Other subjects had either bilaterally small or bilaterally large amplitude tremors of similar frequencies. These findings imply that there is a downwards step in frequency between symptomatic tremors of small and large amplitude. The amplitude and frequency of the small amplitude tremors were unrelated but frequency declined with age. The frequency of the large amplitude tremor was generally determined by amplitude but a wide range of amplitudes were compatible with similar frequencies. The frequency of large amplitude tremor also declined with age. It was concluded that there are two types of essential tremor, the smaller amplitude tremor probably derives from an exaggeration of some or all of the mechanisms of normal physiological tremor whereas the larger amplitude tremor probably arises from a separate "pathological" central nervous mechanism. It is not known if or how one may transform into, or be replaced by, the other during progression of the disease.

Adolescent↗
PubMed1985

Primidone in essential tremor of the hands and head: a double blind controlled clinical study.

Uncontrolled clinical studies have suggested that primidone may be effective in reducing essential tremor thus providing a valuable alternative to beta-adrenoreceptor antagonists which are currently the drugs of first choice. A double blind, placebo controlled trial of primidone in essential tremor of the hands and head was carried out using both clinical and objective methods of assessment. Primidone was significantly superior to placebo in reducing the magnitude of hand tremor, its efficacy being comparable to that of propranolol. In two patients tremor was reduced to non-symptomatic levels, an effect rarely seen with propranolol. No consistent attenuation of head tremor was found. There was no correlation between serum primidone or derived phenobarbitone concentrations and the reduction of hand tremor. An acute toxic reaction to an initial small dose (62.5 mg) of primidone was seen in six of 22 patients.

Adolescent↗
PubMed1984

Fluctuation of arterial blood pressure during end-of-dose akinesia in Parkinson's disease.

The supine and erect arterial blood pressure and pulse rate were measured in 13 patients with Parkinson's disease, chronically treated with levodopa and peripheral decarboxilase inhibitors presenting with or without On-Off phenomenon (end-of-dose akinesia). In the patients with dose-related response fluctuations the mean systo-diastolic blood pressure, both supine and erect, was found significantly higher during the Off phase as compared to the On phase and to that of the control group (patients with stable clinical response). The mean diurnal "excursion" of systo-diastolic supine and erect blood pressure in patients with On-Off phenomenon was significantly larger than in the control group. Although the clinical implications of such findings remain to be established, the results of this study indicate that arterial blood pressure fluctuations are a definite autonomic component of end-of-dose akinesia.

Autonomic Nervous System↗
PubMed1983

[Epidemiological study on tremor in the aged].

203 hospitalized old-aged patients were examined for the presence of tremor. This physical sign was found in 58.6% of cases. By far the largest diagnostic category resulted that of essential tremor: 46.7% of all patients investigated and 77.8% of all cases of tremor. The frequency of this type of tremor was found to increase proportionally to age. The conclusion is drawn that also tremor, as well as other neurological signs frequently demonstrable in "normal" old people (for example, the so-called primitive reflexes), should be inscribed in the group of the phenomena due to the ageing process itself.

Aged↗
PubMed1983

The effect of amantadine on arousal and EEG patterns in Creutzfeldt-Jakob disease.

In recent years, Creutzfeldt-Jakob disease (CJD) has been supposed to be of viral origin, and amantadine hydrochloride has been suggested as therapy because of its proved antiviral action. We studied nine patients with CJD (confirmed at autopsy in seven). Four were treated with amantadine hydrochloride, in dosages ranging from 3.5 to 15 mg/kg/day for an average period of 32 days. The clinical evolution of their disease was compared with that in five patients receiving only supportive maintenance therapy. The length of survival from the onset of clinical care did not differ significantly between the two groups. Nevertheless, a transient improvement in wakefulness and mentation was observed in three patients treated with amantadine, and EEG changes were observed in two, consisting above all of a reduction in the slow-wave activity and the periodic discharges (PDs). Amantadine administered intravenously did not induce any short-term changes in the PDs or the cyclic alternating pattern.

Aged↗
PubMed1983

Effect of a single oral dose of propranolol on essential tremor: a double-blind controlled study.

The effect of a single oral dose of propranolol (120 mg) on essential tremor was investigated in a double-blind, placebo-controlled study in 26 patients. Hand tremor was recorded by means of accelerometers, and its frequency and amplitude calculated by using spectrum analysis. Recordings were made before and 1 1/2 hours after drug or placebo administration. Pretreatment tremor ranged from 4.2 to 9.6 Hz (median, 6.9 Hz) in frequency and from 0.002 to 1.33 cm (median, 0.014 cm) in amplitude. Neither propranolol nor placebo affected the frequency of the underlying tremor. The amplitude of tremor was reduced by 43 +/- 11% (SEM) after propranolol (p less than 0.01) and by 12 +/- 8% after placebo (NS). The reduction observed after propranolol was significantly greater than that observed after placebo. The tremor response after propranolol correlated negatively with baseline frequency and positively with pretreatment amplitude, duration of tremor, and age of the patient. No significant relationships could be found between tremor response, serum propranolol levels, and degree of cardiac beta blockade as assessed by the inhibition of standing tachycardia. There was a clear tendency for patients with small tremor amplitude (less than 0.006 cm hand displacement) to show the least satisfactory response to propranolol. These results indicate that a single oral dose of propranolol is effective in producing a rapid and marked reduction of essential tremor. Measurement of pretreatment amplitude and frequency might be useful in predicting the therapeutic outcome in these patients.

Adult↗
PubMed1983

Immunological abnormalities in a family with progressive external ophthalmoplegia.

The authors report the muscular and humoral immunological abnormalities found in a family with progressive external ophthalmoplegia (PEO) of the "pure" form. Serum circulating immune complexes as determined by the polyethylen glycol (PEG) test and double radial immunodiffusion (DRID) were positive for IgG in both cases studied and for IgM and Clq for the propositus. In the latter circulating auto-antibodies against smooth muscle were also present. Immunohistochemical studies on striated muscle of the propositus showed positive perivascular IgG and IgM staining and IgG in the sarcolemma basement membrane complex. It is suggested that in this family a genetically inherited abnormal immune response to the muscular blood vessel wall has induced vascular injury and ultimately chronic ischemic muscular damage. This is consistent with the view that PEO is a clinical syndrome, i.e. the expression of various defects affecting primarily or secondarily the energy metabolism of the muscular tissue.

Aged↗
PubMed1983

The response of essential tremor to propranolol: evaluation of clinical variables governing its efficacy on prolonged administration.

The factors influencing the response of essential tremor to prolonged administration of propranolol (120 mg daily for two weeks followed by 240 mg daily for a further two weeks) were investigated in a double-blind, cross-over, placebo-controlled study in 16 patients. Hand tremor was assessed by means of accelerometers with off-line computer analysis. Propranolol was found to be superior to placebo only at the higher dosage regimen (240 mg daily). At this dosage, the median reduction in tremor amplitude (as compared to the control value) was by 45%. The response to the drug (expressed as percentage change in tremor amplitude) was correlated positively with the control amplitude (rs = 0.71, p < 0.01) and negatively (but more weakly) with the control peak frequency of tremor (rs = -0.53, p < 0.05). In the patients with hand tremor greater than 6 x 10(-3) cm hand displacement the tremor amplitude was reduced by 65%, as compared to only 17% in patients whose tremor amplitude was below this limit. No statistically significant relationship could be found between percentage change in tremor amplitude and duration of the disorder, age of the patients, degree of cardiac beta-blockade or serum propranolol levels. The results suggest that patients with small tremor amplitude should not be treated with propranolol unless their tremor becomes severely aggravated under conditions of excessive adrenergic discharge.

Adult↗
PubMed1982

Controlled study of metoprolol and propranolol during prolonged administration in patients with essential tremor.

The efficacy of propranolol and metoprolol in the treatment of essential tremor was compared in a double blind crossover placebo-controlled study in 16 patients. Each treatment was given for a period of 4 weeks at two different dosage regimens (150 and 300 mg daily for metoprolol, 120 and 240 mg daily for propranolol). Each dosage regimen lasted for 2 weeks. Tremor assessment was carried out by accelerometry, clinical evaluation, patient's self-rating and a battery of performance tests. At the lower dosage, propranolol was found to be superior to placebo on the basis of performance tests and patient's self-assessment. At the higher dosage, propranolol was superior to placebo on all methods of assessment. By contrast, the tremorolytic effect of metoprolol was not significantly different from that of placebo, irrespective of the dosage or of the method of assessment used. Propranolol (120 mg daily) was better than metoprolol (150 mg daily) on the basis of clinical evaluation and patient's self-assessment. Propranolol (240 mg daily) was superior to metoprolol (300 mg daily) on the basis of patient's self-assessment. Both drugs antagonised standing tachycardia to a similar extent. These results indicate that the effectiveness of metoprolol, previously demonstrated in a single-dose study in the same patients, is not fully maintained during prolonged administration. In the absence of specific contraindications, propranolol represents a better choice in the treatment of patients with essential tremor.

Adult↗
PubMed1982

Polyneuropathy in progressive external ophthalmoplegia.

A case of progressive external ophthalmoplegia (PEO) in association with peripheral neuropathy and other neural and visceral manifestations is reported. Pathological studies of the sural nerve demonstrated loss of large myelinated fibers, segmental demyelination with remyelination, and excess of zebra bodies in the Schwann cells on electron microscopy. Peripheral neuropathy in the course of PEO is regarded as a further although rare aspect of a multisystem disease.

Biopsy↗