The intermuscular 3–7 Hz drive is not affected by distal proprioceptive input in myoclonus-dystonia

In dystonia, both sensory malfunctioning and an abnormal intermuscular low-frequency drive of 3–7 Hz have been found, although cause and effect are unknown. It is hypothesized that sensory processing is primarily disturbed and induces this drive. Accordingly, experimenter-controlled sensory input should be able to influence the frequency of the drive. In six genetically confirmed myoclonus-dystonia (MD) patients and six matched controls, the low-frequency drive was studied with intermuscular coherence analysis. External perturbations were applied mechanically to the wrist joint in small frequency bands (0–4, 4–8 and 8–12 Hz; ‘angle protocol) and at single frequencies (1, 5, 7 and 9 Hz; ‘torque’ protocol). The low-frequency drive was found in the neck muscles of 4 MD patients. In these patients, its frequency did not shift due to the perturbation. In the torque protocol, the externally applied frequencies could be detected in all controls and in the two patients without the common drive. The common low-frequency drive was not be affected by external perturbations in MD patients. Furthermore, the torque protocol did not induce intermuscular coherences at the applied frequencies in these patients, as was the case in healthy controls and in patients without the drive. This suggests that the dystonic 3–7 Hz drive is caused by a sensory-independent motor drive and sensory malfunctioning in MD might rather be a consequence than a cause of dystonia

How women deal with the results of serum screening for Down syndrome in the second trimester of pregnancy

To gain insight into how pregnant women experience serum screening for Down syndrome, we sent questionnaires to two groups of relevant subjects in the north of the Netherlands. The questionnaires addressed the following issues: decision-making process, knowledge and opinions. Questionnaire A was sent to women of 36 years of age and older (n = 99) (group A) who were all 20 to 36 weeks pregnant at that time. In the Netherlands prenatal diagnosis is routinely available to these women. Questionnaire B was sent to women of younger than 36 years (n = 69) (group B) who had received a screen-positive result and had subsequently undergone amniocentesis. About half of these women were still pregnant at that time. For these women, serum screening is only available on the basis of opting-in. The two questionnaires were largely identical. The response rates to questionnaires A and B were 82% and 91%, respectively. Group A (women of 36 years and older) considered that second trimester serum screening made a welcome contribution to the decision-making process about whether to undergo amniocentesis. Moreover, it reduced the amniocentesis rate considerably. The vast majority said they would apply for serum screening in a following pregnancy, but favoured the idea of first trimester screening. In group B (women of younger than 36 years), reassurance was the most commonly mentioned reason for undergoing serum screening. Almost all the women experienced some degree of anxiety when they were informed about the screen-positive result and 13% continued to be anxious, even after the favourable result of the amniocentesis. The majority of the respondents would also apply for serum screening in a following pregnancy and were of the opinion that this screening should be offered to all pregnant women in the Netherlands. Copyright (C) 2000 John Wiley & Sons, Ltd