ABSTRACT
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.
Subject(s)
Masseter Muscle/physiopathology , Mastication/physiology , Myasthenia Gravis/physiopathology , Temporal Muscle/physiopathology , Adult , Analysis of Variance , Bite Force , Case-Control Studies , Electromyography , Female , Food , Humans , Male , Middle Aged , Particle Size , Statistics, NonparametricABSTRACT
Mastication was evaluated in patients with bulbar myasthenia gravis and compared with that of patients with ocular myasthenia gravis, patients in remission who previously suffered from bulbar symptoms, and healthy controls. Bulbar myasthenia gravis may impair mastication due to weakness of the masticatory muscles. The aim of the study was to objectively evaluate the influence of myasthenia gravis on mastication. The subjects chewed a piece of breakfast cake and chewed 1 min on a piece of chewing gum. Surface EMG of the masseter muscle, temporalis muscle and jaw opener muscles was recorded. Statistical analysis revealed that bulbar patients produced significantly less EMG activity in the closing phase of a chewing cycle in both experiments. The EMG of the masseter muscle expressed as percentage of the maximum EMG during maximal clenching showed significantly higher values in the bulbar group than in the other groups. This was not found for the temporalis muscle. It was suggested that bulbar patients use a strategy of limited effort to produce a bolus that can be swallowed. The ocular patients and the patients in remission showed no subclinical impairments in muscle function during chewing.
Subject(s)
Electromyography , Mastication/physiology , Masticatory Muscles/physiopathology , Myasthenia Gravis/physiopathology , Adult , Analysis of Variance , Chewing Gum , Deglutition/physiology , Female , Food , Humans , Linear Models , Male , Mandible/physiopathology , Masseter Muscle/physiopathology , Middle Aged , Movement , Muscle Contraction/physiology , Signal Processing, Computer-Assisted , Statistics as Topic , Temporal Muscle/physiopathologyABSTRACT
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.
Subject(s)
Muscle Weakness/etiology , Muscle, Skeletal/physiopathology , Myasthenia Gravis/physiopathology , Tongue , Adult , Analysis of Variance , Female , Humans , Male , Middle Aged , Muscle Weakness/physiopathology , Myasthenia Gravis/complications , Myasthenia Gravis/diagnosis , Myography/instrumentation , Predictive Value of TestsABSTRACT
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.
Subject(s)
Bite Force , Electromyography , Myasthenia Gravis/diagnosis , Myasthenia Gravis/physiopathology , Adult , Female , Humans , Male , Masseter Muscle/physiopathology , Mastication/physiology , Middle Aged , Temporal Muscle/physiopathology , TransducersABSTRACT
Many patients with myasthenia gravis who experience bulbar symptoms show a vertical smile, which may have a considerable, and often underestimated, impact on social life. Peri-oral muscle function can be quantified by calculating lip-length and snout indices, which indicate the degree to which a person is capable of smiling and of pursing the lips, respectively. In the present study patients with bulbar myasthenia gravis were compared to patients with ocular myasthenia gravis, patients now in remission (but previously suffering from bulbar myasthenia gravis), and healthy subjects. The lip-length and snout indices of patients with bulbar myasthenia gravis were significantly lower than those of the other groups. The facial impairments were no longer detectable in patients with bulbar myasthenia gravis in remission and no subclinical impairments in lip-length and snout indices were found in the ocular myasthenia gravis group. These findings were consistent with the patients' reports of impairment of smiling and other oral functions. The patients suffering from a vertical smile or other oral impairments were well aware of their condition, most probably because of the social consequences of being unable to smile. The indices could be of importance in the longitudinal evaluation of therapy in individual patients and in pharmacotherapeutical research. We found a low correlation between the lip-length and snout indices, which reflects the capricious pattern of involvement of separate muscles in myasthenia gravis. Therefore both indices deserve special attention if they are used for monitoring myasthenic symptoms.
Subject(s)
Facial Muscles/physiopathology , Myasthenia Gravis/physiopathology , Smiling/physiology , Adult , Anthropometry , Brain Stem/physiopathology , Cholinesterase Inhibitors/pharmacology , Cholinesterase Inhibitors/therapeutic use , Female , Humans , Lip/pathology , Male , Middle Aged , Myasthenia Gravis/classification , Myasthenia Gravis/drug therapy , Nose/pathologyABSTRACT
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.
Subject(s)
Deglutition Disorders/physiopathology , Dysarthria/physiopathology , Facial Expression , Mastication , Myasthenia Gravis/physiopathology , Tongue/physiopathology , Deglutition , Deglutition Disorders/etiology , Dysarthria/etiology , Humans , Masticatory Muscles/physiology , Masticatory Muscles/physiopathology , Reference Values , Tongue/physiologyABSTRACT
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.
Subject(s)
Attention , Child Development Disorders, Pervasive/diagnosis , Fixation, Ocular , Reaction Time , Social Behavior , Autistic Disorder/diagnosis , Autistic Disorder/psychology , Child , Child Development Disorders, Pervasive/psychology , Child, Preschool , Female , Gestures , Humans , Intellectual Disability/diagnosis , Intellectual Disability/psychology , Intelligence , Interpersonal Relations , Language Development Disorders/diagnosis , Language Development Disorders/psychology , Male , Parent-Child Relations , Verbal BehaviorABSTRACT
BACKGROUND: It has been suggested that the key variable in reduced plasma immunoreactive beta-endorphin concentrations in autistic subjects may be concomitant self-injurious behaviour. METHOD: We studied morning levels of plasma beta-endorphin in 33 learning disabled people with self-injurious and/or autistic behaviour. RESULTS: The beta-endorphin level of the subjects with severe self-injurious behaviour proved to be significantly lower than of autistic subjects without severe self-injurious behaviour (3.6 (1.4) pmol/l v. 5.8 (4.3) pmol/l; t-test: P = 0.045. Replication: 3.7 (1.1) pmol/l v. 5.7 (3.8) pmol/l; t-test: P = 0.043). Individuals with mild and occasional self-injurious behaviour were found to have beta-endorphin levels comparable to those without self-injurious behaviour. Further, subjects being treated with neuroleptics and lower beta-endorphin levels than untreated subjects. CONCLUSIONS: These results stress that in any study of opioid systems of learning disabled people, it is very important to differentiate between people with and without severe self-injurious behaviour. The results support the idea that severe self-injurious behaviour may be related to functional disturbances in the endogenous opioid system.
Subject(s)
Autistic Disorder/physiopathology , Learning Disabilities/physiopathology , Self-Injurious Behavior/physiopathology , beta-Endorphin/blood , Adult , Autistic Disorder/diagnosis , Autistic Disorder/psychology , Brain/physiopathology , Female , Humans , Intellectual Disability/diagnosis , Intellectual Disability/physiopathology , Intellectual Disability/psychology , Learning Disabilities/diagnosis , Learning Disabilities/psychology , Male , Psychiatric Status Rating Scales , Receptors, Opioid/physiology , Self-Injurious Behavior/diagnosis , Self-Injurious Behavior/psychologyABSTRACT
Chewing requires a low level of muscle activity for jaw movement. Additional muscle activity is required to overcome the resistance of the food. The additional muscle activity consists of two contributions, an anticipating contribution before food contact and a peripherally induced contribution, about 23 ms after food contact. The amounts of both contributions depend on the information about food resistance obtained in preceding chewing cycles. It is not known whether this information is preserved if the resistance is absent during only a limited number of chewing cycles. Our aim was to investigate the extent to which information about food resistance obtained during chewing is used during subsequent cycles to generate anticipating and peripherally induced muscle activity. Subjects made rhythmic open-close movements at their natural chewing frequency, controlled by a metronome. Food resistance was simulated by an external force acting on the jaw in a downward direction during part of the closing movement. Jaw movement and surface EMG of the masseter and suprahyoid muscles were recorded during experiments in which sequences of at least 20 cycles with the force were alternated with a small, random number (from 1 to 10) of cycles without the force. The amount of anticipating muscle activity as well as the peripherally induced muscle activity in the first cycle with the force gradually decreased as a function of the number of preceding forceless cycles. About 30% of the additional muscle activity had an anticipatory origin, whereas the rest of the activity was evoked by the force regardless of the number of preceding forceless cycles.
Subject(s)
Mouth/physiology , Periodicity , Sensation/physiology , Adult , Dental Stress Analysis/instrumentation , Dental Stress Analysis/methods , Electromyography/methods , Female , Humans , Male , Masseter Muscle/physiology , Mastication/physiology , Movement/physiology , Random Allocation , Reference ValuesABSTRACT
In a double-blind, placebo-controlled crossover trial 23 autistic children were treated with a single 40-mg dose of the opiate antagonist naltrexone. Drug effects were monitored by detailed playroom observations, actometers, and parents' checklist ratings (Aberrant Behavior Checklist, social items and target behaviors). Naltrexone treatment failed to produce significant changes in social behavior, but it did reduce irritability and target scores on behavior checklists. The playroom data indicated that naltrexone significantly affected indices of activity and attention.
