Florence G. Weijnen

Timing of Social Gaze Behavior in Children with a Pervasive Developmental Disorder

The aim of the study was to compare social initiatives and gaze behavior in low-functioning children with a pervasive developmental disorder (PDD), high-functioning children with a PDD, children with a language disorder, and normally developing children. Behavior of the children was observed while they watched television and performed a playful task with a parent. Compared to the high-functioning children, the low-functioning children with a PDD showed fewer social initiatives. The high-functioning children with a PDD did not differ from the non-PDD control children in the number of social initiatives and gazes. However, in children with PDD, timing of social gaze proved to be different in that they had lower levels of visual checking before but not after a declarative pointing gesture. Furthermore, they had lower levels of returning gaze.

Tongue force in patients with myasthenia gravis

Objectives– The aim was to study tongue force in patients with bulbar myasthenia gravis and compare it with that of patients with ocular myasthenia gravis, patients in clinical remission who previously suffered from bulbar myasthenia gravis, and healthy subjects. Material and methods– Tongue force was measured with a tongue force transducer in cranial and lateral directions, which coincide with the directions in which the tongue exerts force during swallowing, speech, and mastication. Results– Tongue force in lateral direction was significantly decreased in patients with bulbar myasthenia gravis. In addition, our findings suggest an incomplete recovery of lateral tongue force in the patients of the remission group. Conclusion– Our tongue force measurements may be useful for longitudinal evaluation of therapy in individual patients and also in studies of therapy efficacy in matched groups of patients if the influence of factors such as age, dental state, and sex is taken into account.

Maximal bite force and surface EMG in patients with myasthenia gravis

Masticatory muscle strength was quantified in patients with bulbar myasthenia gravis and compared with that of patients with ocular myasthenia gravis, patients in clinical remission (whether or not pharmacological) who previously suffered from bulbar myasthenia gravis, and healthy subjects. Maximal bite force and maximal activity of the masseter and temporalis muscles and of the submental muscle complex were measured. Bite force was decreased in the patients with bulbar myasthenia gravis, but was normal in the patients in the clinical remission group and in the ocular group. These findings were consistent with the results of electromyographic data. Although subjective reports of masticatory muscle weakness provide valuable information, quantitative measurements provide more information about the degree of muscle weakness of individual muscles. This is especially important for longitudinal evaluation of therapy in individual patients and for pharmacotherapeutic research.

Masticatory performance in patients with myasthenia gravis

Masticatory muscle electromyograms (EMGs) were recorded while patients with bulbar myasthenia gravis chewed artificial food and compared with those of patients with ocular myasthenia gravis, patients in clinical remission who had previously suffered from bulbar myasthenia gravis and healthy individuals. Masticatory performance and EMGs were significantly smaller in the bulbar group. There were no indications of subclinical masticatory muscle weakness in patients with bulbar myasthenia gravis in remission and in patients with ocular myasthenia gravis. Patients with bulbar myasthenia gravis barely compensated for muscular weakness by chewing at a higher percentage of their maximal EMG. These quantitative findings, when combined with subjective reports of masticatory muscle weakness, show that a need to support the jaw is characteristic of patients with bulbar myasthenia gravis who produce low EMG activity.

Oral Functions of Patients with Myasthenia Gravis

With the use of the methods developed to quantify oral dysfunctions in bulbar MG patients, our results indicate that we can distinguish the patients from their matched controls. These results can add to our knowledge of myasthenia gravis and these methods may improve diagnosis and therapy evaluation in individual patients. In addition, these methods may be used in future pharmacological research.