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S Spieker

Publications and source records attributed to S Spieker.

31 records · Page 2Linked to original sources

Reliability, specificity and sensitivity of long-term tremor recordings.

We have developed a method of long-term EMG recording that has proven suitable for the quantification of pathological tremor. In the present paper we show that the principal parameters of the method (tremor occurrence, tremor intensity, tremor frequency) are highly reproducible and that the method is specific and sensitive for detection of pathological tremor. Twelve patients with essential tremor (ET) and 13 patients with Parkinson's disease (PD) were recorded repeatedly on 3 successive days. For each patient group and for each parameter the intersubject variability was much larger than the intersubject variability. The intraclass correlation coefficient "R" was in the order of 0.9 for each parameter and the mean of Pearson's correlation coefficient between successive days was also approximately 0.9. Recordings from normal controls demonstrated that the method's specificity for pathological tremor is 94.1% and its sensitivity is 96%.

Adult↗

Memory and skill acquisition in Parkinson's disease and frontal lobe dysfunction.

Animal experiments and human neuropsychological studies have provided evidence for the hypothesis that skill acquisition may be regulated by the basal ganglia. In the present studies, perceptual and cognitive skill acquisition as well as a number of explicit verbal memory functions were investigated in patients in early and more advanced stages of Parkinson's disease (PD) and in patients with frontal lobe lesions. Patients in more advanced stages of PD were impaired at cognitive skill acquisition as well as during recall conditions that involved active semantic organisation of the stimulus material. Similar explicit memory deficits were present in frontally lesioned patients. PD patients with unilateral symptoms showed a selective impairment in acquiring a cognitive skill. Perceptual skill acquisition was preserved in all groups. The overall pattern of memory impairment in PD is largely consistent with dysfunction of fronto-striatal circuitry.

Corpus Striatum↗

Tremorlytic activity of budipine: a quantitative study with long-term tremor recordings.

The tremorlytic activity of the novel antiparkinson agent budipine was quantified in an open trial. Eleven patients with Parkinson's disease (PD) were treated with individual doses of budipine added to stable conventional antiparkinsonian medication. Tremor activity was measured using long-term electromyogram (EMG) recordings. Tremor intensity was reduced by 25%, tremor occurrence by 34%, and conventional "Unified Parkinson's Disease Rating Scale" (UPDRS) scores improved by 20% with this medication. There were two dropouts because of side effects. One dropout appeared not to be related to budipine. Apart from those, the drug was well tolerated by all patients. We conclude that budipine is an effective and well-tolerated tremorlytic drug and that the method of long-term EMG recording is suitable for tremor quantification in clinical studies.

Adult↗

Long-term tremor recordings in parkinsonian and essential tremor.

We have recently developed a method of long-term EMG recording (Bacher et al., 1989), which has proven suitable for the quantification of pathological tremor. In the present paper we show that (1) the principal parameters of the method (tremor occurrence, tremor intensity, tremor frequency) are highly reproducible with intraclass correlation coefficients in the order of 0.9, (2) that the method has both a high specificity (87.5%) and sensitivity (96%) for detection of pathological tremor, and (3) that it can be useful for examining agonist-antagonist muscle activation under everyday conditions.

Adult↗

Multiple system atrophy: natural history, MRI morphology, and dopamine receptor imaging with 123IBZM-SPECT.

Sixteen patients with a clinical diagnosis of probable multiple system atrophy (MSA) were examined clinically by MRI and by 123I-iodobenzamide single photon emission computed tomography (IBZM-SPECT). The clinical records of another 16 patients were also analysed retrospectively. On the basis of their clinical presentation, patients were subdivided into those with prominent parkinsonism (MSA-P, n = 11) and those with prominent cerebellar ataxia (MSA-C, n = 21). Autonomic symptoms were present in all patients and preceded the onset of motor symptoms in 63% of patients. Calculated median lifetime and the median time to become wheelchair bound after onset of disease were significantly shorter for MSA-P than for MSA-C (lifetime: 4.0 v 9.1 years; wheelchair: 3.1 vs 5.0 years) suggesting a better prognosis for cerebellar patients. A significant loss of striatal dopamine receptors (below 2 SD threshold) was detected by IBZM-SPECT in 63% of the patients (56% below 2.5 SD threshold). There was no difference between patients with MSA-C and those with MSA-P in the proportion with significant receptor loss and the extent of dopamine receptor loss. Planimetric MRI evaluation showed cerebellar and brainstem atrophy in both groups. Atrophy was more pronounced in patients with MSA-C than in those with MSA-P. Pontocerebellar hyperintensities and putaminal hypointensities on T2 weighted MRI were found in both groups. Pontocerebellar signal abnormalities were more pronounced in MSA-C than in MSA-P, whereas the rating scores for area but not for intensity of putaminal abnormalities were higher in MSA-P. MRI and IBZM-SPECT provide in vivo evidence for combined basal ganglia and pontocerebellar involvement in almost all patients in this series.

Adult↗

Frontal lobe activity and affective behavior of infants of mothers with depressive symptoms.

Studies of adults and infants indicate that the left frontal brain region is specialized for approach emotions, such as joy, whereas the right frontal region is specialized for withdrawal emotions, such as distress. Furthermore, depressed adults have been found to show reduced brain activity in the left frontal region. In this study, frontal and parietal electroencephalographic (EEG) activity was recorded from 27 infants aged 11-17 months (13 of whose mothers reported elevated depressive symptoms) during baseline and emotion-eliciting conditions. Compared with infants of nonsymptomatic mothers, infants of symptomatic mothers exhibited reduced left frontal brain activity during playful interactions with their mothers and failed to exhibit the typical pattern of greater right frontal activity during a condition designed to elicit distress (maternal separation). Infants of symptomatic mothers also showed less distress during maternal separation; however, no group differences in behavior were found during the playful condition. Group differences were evident in the frontal region, but not in parietal brain activity.

Affect↗

Prevention of parenting alterations for women with low social support.

Parenting is a demanding role. Traditionally societies provide mechanisms for supporting major caregivers. For most parents the partner relationship is a source of refueling energy. In addition, often the extended family members provide support for the parent(s). In a prior research study dealing with early intervention where the family demonstrated double vulnerability, defined by pregnancy complications and social problems, we found the mothers most resistant to help were women who both had a lot of situational problems and few if any friends or family supporting them (Barnard et al. 1985). This finding prompted us to think about parents who did not have the supportive mechanisms cultures generally provide.

Affective Symptoms↗

Infant intermodal speech perception is a left-hemisphere function.

Prelinguistic infants recognized structural correspondences in acoustic and optic properties of synchronized, naturally spoken disyllables, but did so only when they were looking to their right sides. This result suggests that intermodal speech perception is facilitated by rightward orientation of attention and subserved by the left hemisphere.

Attention↗

Tremorlytic activity of budipine in Parkinson's disease.

To objectively quantify the tremorlytic activity of budipine in Parkinson's disease (PD), we performed long-term tremor recordings in addition to the Columbia University Rating Scale (CURS) in a subset of patients (n = 14) who enrolled in a multicenter, double-blind, placebo-controlled study. Tremor occurrence improved in the budipine group (n = 7) from 24.7 +/- 15.5% to 14.8 +/- 14.5% (p < 0.05). Tremor intensity decreased from 9.1 +/- 2.5 (signal-to-noise ratio) to 7.2 +/- 1.6. The CURS sum score improved from 5.7 to 3.0 in the budipine group, whereas there was only a small improvement in the placebo group (from 7.1 to 5.5). These data suggest that budipine is an effective tremorlytic agent in PD and that it may be used as an alternative to anticholinergics.

Aged↗