Biomedical subjects

Ubaldo Bonuccelli

Publications and source records attributed to Ubaldo Bonuccelli.

25 records · Page 2Linked to original sources

PubMed2002

Impaired attention modulation of the blink reflex R3 component in Parkinson's disease: a non-task warning paradigm study.

PURPOSE: the aim of this experimental study was to evaluate the attention modulating actions on the polysynaptic component of blink reflex responses and especially of the R3 component in patients suffering from Parkinson's Disease (PD). To this end, a non-task warning paradigm was adopted. METHODS: attention processing was evaluated by means of a non-task paradigm in 55 patients suffering from PD. Subjects were presented with a visual 'warning' prestimulus and the blink reflex (BR) analyzed with special regard for any modulation of its polysynaptic components (R2-R3). RESULTS: The mean amplitude of the post-warning R3 component (PW-R3c) of 'de novo' PD patients was 62% of the corresponding component following unannounced stimuli, a figure which differs significantly from both treated PD patients (18.9%) and control subjects (15.4%). De novo patients subsequently started on L-dopa therapy exhibited a more pronounced inhibition of the R3 component after warning stimulus, as the PW-R3c percentage decreased. Inversely, treated patients whose therapy was withheld showed decreased inhibition of this component. Regarding R2, the mean PW-R2c in the de novo patients differed slightly from that of the treated patients (P<0.05), but not from that of the control subjects. Such a finding may be attributable to a specific effects on the excitability of the polysynaptic responses. CONCLUSIONS: Attention disorders in PD have been well documented by means of this kind of non-task warning paradigm, which appears to probe the modulation of the BR R3 component, even if the interpretation of this R3 changes suggesting a specific alteration of attention processing must be put forward extremely carefully, because something similar, but less evident, appears also for R2.

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PubMedDate not supplied

Pergolide in the treatment of patients with early and advanced Parkinson's disease.

Introduced on the market in 1989, pergolide, a D1/D2 dopamine receptor agonist, is still widely prescribed for the treatment of patients with early and advanced Parkinson's disease (PD). Initially, pergolide was introduced as an adjunct therapy to levodopa treatment in patients exhibiting fluctuating motor responses and dyskinesias. Results of recent randomized controlled clinical trials in de novo patients with PD show that pergolide is able to improve parkinsonian symptoms when used as monotherapy. Moreover, preliminary results of a long-term monotherapy study in early PD suggest that pergolide is as effective as levodopa, and that a significant delay in the time of the onset of levodopa-induced motor complications can be obtained. A number of randomized studies have shown that pergolide is more effective than bromocriptine as adjunct therapy to levodopa in patients with advanced PD; the greater benefit found with pergolide could be ascribed to its action on both D1 and D2 dopamine receptors. However, controlled comparative studies with new dopamine agonists, such as ropinirole, cabergoline, and pramipexole, have not been performed yet. Interestingly, few open studies in patients with complicated PD have shown that high doses of pergolide (> 6 mg/d) are able to improve motor fluctuations and dyskinesias through a dramatic reduction of levodopa dosage. The side-effect profile of pergolide is similar to that of other dopamine agonists, and complications such as sleep attack and serosal fibrosis have been rarely reported.

Antiparkinson Agents↗

PubMedDate not supplied

Activity-based diary for Parkinson's disease.

The objective of this study was to develop a Parkinson's disease diary that evaluates a patient's difficulties in performing activities as a substitute for the amount of "on"- and "off"-time and to assess its clinimetric qualities. In this study, 84 patients with Parkinson's disease kept a diary for 2 or 3 periods of 5 days. Daily, five items were recorded across 11 time periods. Patients simultaneously recorded "on-off" in the traditional way. The diary was easily understood, and median recording time was 5-10 minutes a day. Clinimetric analysis showed that the diary could be reduced successfully to 3 days, in which five items (walking, transfers, manual activities, dyskinesias, and sleep) with four response options (no, slight, moderate, and severe difficulty) were assessed seven times daily. Sumscores of the first three items accurately predicted being "on" or "off" in 93% of the cases, making separate scoring of "on" and "off" unnecessary. The diary was internally consistent and showed good reproducibility. Construct validity with external measures was adequate, and comparisons between patients grouped by disease severity and by degree of fluctuations revealed significant differences in the expected directions. Taken together, this Parkinson's disease diary has a sound clinimetric basis, provides information on the extent of perceived disability, and thereby accurately reflects the severity of "off"-periods and the variability of motor fluctuations.

Activities of Daily Living↗

PubMedDate not supplied

Treatment of patients with tardive dystonia with olanzapine.

Tardive dystonia represents a complication of long-term use of neuroleptics and its treatment is often unsatisfactory. Atypical neuroleptics appear to improve tardive dystonia, and cases of tardive dystonia successfully managed with clozapine have been reported. The aim of this open-label video-blinded study was to evaluate the antidystonic efficacy of olanzapine, a new atypical neuroleptic with a low risk of agranulocytosis, in a group of four patients (one man and three women) with tardive cervical dystonia. They developed severe dystonia after several years of neuroleptic treatment. Extensive laboratory evaluations, as well as neurophysiologic and neuroradiologic investigations, were negative. Olanzapine was started at a dose of 5 mg/d and increased up to 7.5 mg/d. All patients were evaluated at baseline and after 2, 4, 8, and 12 weeks of treatment, using the Toronto Western Spasmodic Torticollis Rating Scale, and videotaped. At the end of the trial, the videotapes were reviewed and scored by a blind observer. A self-rating visual analog scale completed the disability evaluation.A moderate to marked improvement in dystonia was observed in all patients, and significant differences were observed in Toronto Western Spasmodic Torticollis Rating Scale scores and videotape ratings after 8 and 12 weeks of treatment compared with the basal values (p < 0.05). The average percentage of improvement in Toronto Western Spasmodic Torticollis Rating Scale score and visual analog scale was 26.4% and 42.6%, respectively. No serious side effects were reported at the maximum dosage reached (7.5 mg/d). This study warrants a larger controlled study to conclusively demonstrate the efficacy of olanzapine in tardive dystonia.

Adult↗

PubMedDate not supplied

Comparison of the Unified Parkinson's Disease Rating Scale and the Short Parkinson's Evaluation Scale in patients with Parkinson's disease after levodopa loading.

The Short Parkinson's Evaluation Scale has been compiled and validated previously (Clinical Neuropharmacology, 1997). In the present study, we have assessed and compared the motor scoring of the Unified Parkinson's Disease Rating Scale and the Short Parkinson's Evaluation Scale in 23 patients (mean age, 61.8 years) with Parkinson's disease. Patients were 12 hours off medication at the beginning of the series. They were then given levodopa, 125 mg and 250 mg, on different days and were evaluated each 30 minutes for 2 hours. In addition, patients' motor skills (finger tapping and walking velocity) were measured at each time. Analysis of variance with repeated measures was applied. The results presented show that both scales have the same ability to measure levodopa-dose effect within time. In addition, Spearman's correlation coefficients showed a negative correlation between finger tapping and upper-limb impairment and a positive correlation between walking velocity and lower-limb impairment in both scales. In summary, the present results suggest that Short Parkinson's Evaluation Scale is a useful tool in assessing the effect of medication, having the advantage of being easier and quicker.

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PubMedDate not supplied

Motor response to apomorphine in patients with Parkinson's disease with long-duration response to levodopa.

The authors studied the motor response to apomorphine before and 1 year after levodopa therapy in 12 patients with Parkinson's disease. At the 1-year evaluation, the basal tapping score, recorded after a 12-hour levodopa withdrawal, was higher compared with the test performed while patients were de novo, indicating the presence of a long-duration response to levodopa. The amplitude (net increase) of the motor response to apomorphine was similar before and during levodopa therapy. However, because of the better baseline, the maximal tapping score was higher during levodopa therapy. The duration and the latency of the motor response to apomorphine did not change. The presence of a short-duration response to apomorphine, in the presence of a long-duration response to levodopa, may imply that either different compartment (i.e., postsynaptic versus presynaptic) or transduction pathways are involved in such responses.

Aged↗

PubMedDate not supplied

Changes in pattern electroretinograms to equiluminant red-green and blue-yellow gratings in patients with early Parkinson's disease.

In Parkinson's disease (PD), the luminance pattern electroretinogram (PERG) is reported to be abnormal, indicating dysfunction of retinal ganglion cells (RGCs). To determine the vulnerability of different subpopulations of RGCs in PD patients, the authors recorded the PERG to stimuli of chromatic (red-green [R-G] and blue-yellow [B-Y]) and achromatic (yellow-black [Y-Bk]) contrast, known to emphasize the contribution of parvocellular, koniocellular, and magnocellular RGCs, respectively. Subjects were early PD patients (n = 12; mean age, 60.1 +/- 8.3 years; range, 46 to 74 years) not undergoing treatment with levodopa and age-sex-matched controls (n = 12). Pattern electroretinograms were recorded monocularly in response to equiluminant R-G, B-Y, and Y-Bk horizontal gratings of 0.3 c/deg and 90% contrast, reversed at 1Hz, and presented at a viewing distance of 24 cm (59.2 x 59 degree field). In PD patients, the PERG amplitude was significantly reduced (by 40 to 50% on average) for both chromatic and luminance stimuli. Pattern electroretinogram latency was significantly delayed (by about 15 ms) for B-Y stimuli only. Data indicate that, in addition to achromatic PERGs, chromatic PERGs are altered in PD before levodopa therapy. Overall, chromatic PERGs to B-Y equiluminant stimuli exhibited the largest changes. Data are consistent with previous findings in PD, showing that visual evoked potentials (VEP) to B-Y chromatic stimuli are more delayed than VEPs to R-G and achromatic stimuli. The results suggest that the koniocellular subpopulation of RGCs may be particularly vulnerable in early stages of Parkinson's disease.

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