Advanced magnetic resonance imaging of neuromyelitis optica: a multiparametric approach.

BACKGROUND: Several authors have used advanced magnetic resonance imaging (MRI) techniques to investigate whether patients with neuromyelitis optica (NMO) have occult damage in normal-appearing brain tissue, similarly to multiple sclerosis (MS). To date, the literature contains no data derived from the combined use of several advanced MRI techniques in the same NMO subjects. OBJECTIVE: We set out to determine whether occult damage could be detected in the normal-appearing brain tissue of a small group of patients with NMO using a multiparametric MRI approach. METHODS: Eight female patients affected by NMO (age range 44-58 years) and seven sex- and age-matched healthy controls were included. The techniques used on a 1.5 T MRI imaging scanner were magnetization transfer imaging, diffusion tensor imaging, tract-based spatial statistics, spectroscopy and voxel-based morphometry in order to analyse normal-appearing white matter and normal-appearing grey matter. RESULTS: Structural and metabolic parameters showed no abnormalities in normal-appearing white matter of patients with NMO. Conversely, tract-based spatial statistics demonstrated a selective alteration of the optic pathways and the lateral geniculate nuclei. Diffusion tensor imaging values in the normal-appearing grey matter were found to be significantly different in the patients with NMO versus the healthy controls. Moreover, voxel-based morphometry analysis demonstrated a significant density and volume reduction of the sensorimotor cortex and the visual cortex. CONCLUSIONS: Our data disclosed occult structural damage in the brain of patients with NMO, predominantly involving regions connected with motor and visual systems. This damage seems to be the direct consequence of transsynaptic degeneration triggered by lesions of the optic nerve and spine.

Relationship between the angle of the coronoid process of the mandible and the electromyographic activity of the temporal muscle in skeletal Class I and III individuals.

The aim of the present study was to verify the relationship between the angle of the coronoid process of the mandible in the latero-lateral direction and electromyographic activity of the anterior part of the temporal muscle in skeletal Class I and III individuals. Forty-five volunteers were assessed subdivided into two groups, according to angle ANB, in Class I and III. Two radiographic examinations were performed, one lateral cephalogram to measure angle ANB and one frontal cephalogram to measure the angle of the coronoid process. The electromyographic examination of the volunteers' temporal muscles was performed. Statistical analysis of the data showed that the relationship between the angle of the coronoid process and the skeletal class was negative for both classes analysed. The relationship between electromyographic activity of the temporal muscle and angle of the coronoid process was negative for Class I individuals. In the Class III group, smaller angles of the coronoid process were related to higher values of electromyographic activity of the temporal muscle. There was no statistically significant difference between the electromyographic activity of the temporal muscle in skeletal Class I and III individuals. Based on the results obtained, it was concluded that there was no influence of the skeletal classes analysed on the angle of the coronoid; the angle of the coronoid process may be influenced by the electromyographic activity of the temporal muscle in the Class III group; the electromyographic activity of the temporal muscle is not influenced by the skeletal class in Class III individuals.

Effect of congenital blindness on EMG activity of the facial muscles.

The aim of this work was to analyze electromyographically the facial muscles: orbicularis oris (upper and lower fascicles), orbicularis oculi (right and left lateral portions) and frontal, in blind and clinically normal (control) individuals, in various clinical conditions. Electromyographic averages of all data collected were normalized by maximal voluntary contraction of the studied muscles and statistical analysis was performed by Student's t test, using "Statistical Package for the Social Sciences" software--SPSS 12.0 (Chicago, IL). It was found that electromyographic alterations occur in the facial musculature that influences facial expressions of individuals. Results for the orbicularis oris muscle demonstrated that myoelectric activity among blind and control subjects was greater for the control group at muscular rest, blowing, and in labial projection. Electromyographic analysis of the orbicularis oculi among blind and control subjects in three clinical conditions studied demonstrated that activity was greater for the control group at muscular rest, blinking, and forced blinking. For the frontal muscles were demonstrated that electromyographic activity was greater for blind individuals. These data suggest the influence of congenital blindness on muscular development, including alterations in electromyographic activity of skin musculature in individuals with visual impairment.

Fetal alcohol syndrome and developing craniofacial and dental structures--a review.

OBJECTIVES: Fetal alcohol syndrome (FAS) is a collection of signs and symptoms seen in children exposed to alcohol in the prenatal period. It is characterized mainly by a distinct pattern of craniofacial malformations, physical and mental retardation. However, with the increased incidence of FAS, there is a great variation in the clinical features of FAS. DESIGN: Narrative review. RESULTS: This review describes data from clinical and experimental studies, and in vitro models. Experimental studies have shown that alcohol has a direct toxic effect on the ectodermal and mesodermal cells of the developing embryo, particularly in the cells destined to give rise to dentofacial structures (i.e. cranial neural crest cells). Other effects, such as, abnormal pattern of cranial and mandibular growth and altered odontogenesis are described in detail. The exact mechanism by which alcohol induces its teratogenic effects remains still unknown. The possible mechanisms are outlined here, with an emphasis on the developing face and tooth. Possible future research directions and treatment strategies are also discussed. CONCLUSION: Early identification of children affected by prenatal alcohol exposure leads to interventions, services, and improved outcomes. FAS can be prevented with the elimination of alcohol consumption during pregnancy. We need to provide education, target high-risk groups, and make this issue a high priority in terms of public health.

EMG analysis of the upper and lower fascicles of the orbicularis oris muscle in deaf individuals.

The aim of this study was to analyze electromyographically the upper and lower fascicles of the orbicularis oris muscle in deaf patients comparing them with clinically normal patients. These patients present several disorders in facial muscles, temporomandibular joints disorders and constantly headache in virtue of not the use of the face expression muscles. This was performed in 30 patients from both sexes with a mean age of 18.5 years, divided into 3 groups of 10 patients each: 1. deaf patients with buccal breathing and incompetent lips; 2. in deaf patients with nasal breathing and competent lips; 3. clinically normal patients, in 7 clinical conditions: at rest with and without labial contact, sucking water, blowing, pursing and reciprocal compression of the lips and the emission of the syllabi "PA". It was observed that in the deaf patients group, both fascicles of the orbiculares oris muscles presented hyperactivity in most of the analyzed movements, mainly in buccal breathing with incompetent lips, and the lower fascicle demonstrated the highest electromyographic activity.

Electromyographic study of the masseter muscle in individuals with Class II malocclusion.

The objective of this work was to study the action of the masseter muscle through electromyography and to analyze the difference of action potential generated by several pre-established jaw movements in individuals with Class II malocclusion. It was studied nine young individuals from both sexes, with ages ranging from 17 to 35, with no history of orthodontic treatment and/or having some kind of alteration in the temporomandibular joint (T.M.J.). In order to collect the electromyographic signs we have used a TECA TE-4 Electromygraph and surface electrodes type Beckman. The data were submitted to nonparametric statistical analysis by Friedman test. The response variables left occlusive contact, free protraction, protraction with occlusive contact, incisor mastication, right molar mastication and forced central occlusion movements showed significant outcomes. Thus we have concluded that as the occlusive balance suffers alterations, the malocclusions become predominant and the masseter muscle undergoes functional and structural modifications.

EMG activity of the orbicularis oculi muscle in normal and in individuals indicated to receive eye prosthesis, before and after its placement.

To analyze comparatively through electromyography (EMG) the orbicularis oculi muscle from normal patients and those indicated to receive eye prosthesis (treated patients), it was studied 24 male patients with a mean age of 32.5 years old, who were divided into 2 groups as follows: 12 individuals with absence of the left eyeball and indicated to receive prosthesis (treated); 12 normal individuals (control). The work was performed in 4 different clinical conditions: initial resting; normal opening and closure of the eyelids; forced opening and closure of the eyelids and final resting, before and after placement of eye prosthesis. The exams were made using an Electromyograph K6-I Light Channel and Surface Electrodes. By the results obtained under the work conditions, we can conclude that: the use of eye prosthesis did not interfere in the clinical conditions of opening and closure of the eyelid; the loss of the eyeball increases the EMG activity of the orbicularis oculi muscle; the use of eye prosthesis for a period of 7 days, was not enough to diminish the muscular activity, even its perfect adaptation been evidenced clinically.

EMG activity of the orbicularis oris and mentalis muscles in children with malocclusion, incompetent lips and atypical swallowing--part II.

The EMG activity of the orbicularis oris (upper and lower), and of the mentalis muscles was verified during several movements of the lips, in 18 children ageing from 8 to 12 years, divided into three groups: one with normal occlusion, and two with class II division 1, with atypical swallowing and/or incompetent lips and who had received no orthodontic treatment. In blowing through a straw the muscular activity of the orbicularis oris and the mentalis was significantly greater in the incompetent lips group. The mentalis presented moderate activity in the competent lips group and negligible in normal occlusion. In puffing out of the cheeks, the malocclusion groups developed marked activity of the orbicularis oris and very marked activity of the mentalis, while the normal occlusion presented moderate and negligible activities, respectively. In pursing of the lips, only the incompetent lips group presented a very marked activity of the lower segment. The compression of the lips against the teeth revealed a marked activity of the upper segment of the orbicularis oris in the groups of malocclusion and the mentalis presented greater activity in the competent lips group. The reciprocal compression of the lips presented a hyperactivity of the three muscles.

EMG activity of the orbicularis oris and mentalis muscles in children with malocclusion, incompetent lips and atypical swallowing--part I.

The function and the level of activity of the orbicularis oris (upper and lower), and of the mentalis muscles were verified electromyographically in resting position and in several movements and carried out in 18 children aged 8-12 years, divided into three groups: one with normal occlusion, and two with Class II division 1, with atypical swallowing and/or incompetent lips, who had received no orthodontic treatment. It was observed that, in a resting position with the lips separated, there was no activity in any of the muscles. When there was a contact of the lips, action potentials were recorded in the muscles studied, in those individuals with incompetent lips. In the movements of sucking either through a straw or a pacifier and the thumb, there were no differences among the groups. The incompetent lips group presented very marked muscle activity of the lower orbicularis oris and mentalis in the movement of sucking a lollipop. In deglutition of saliva, the orbicularis oris presented slight activity, and the mentalis, moderate. In deglutition of water, the mentalis presented very marked activity, whereas, the upper and lower orbicularis oris presented moderate and marked activities, respectively.

Participation of the sternocleidomastoid muscle on deep inspiration in man. An electromyographic study.

The sternocleidomastoid muscle (SCM), which is responsible for the mechanical action in the majority of the head movements, is also considered an accessory muscle for respiration. Its action in the inspiratory movements was studied electromyographically in 30 healthy young adults by considering the types of respiration, the different forms of deep inspiration, the breathing effort and the body position of these subjects. A prominent activity was found in those subjects whose respiration was of the costal type when they breathed rapidly and roughly and during the breathing effort. An outstanding difference of the action potentials of the SCM muscle was not observed during variation of the body positions.

Electromyographic study of the sternocleidomastoid muscle in head movements.

The function of the sternocleidomastoid muscle in head movements of 30 young individuals (19-28 years old, both sexes) was studied electromyographically using a TECA TE-4 electromyograph and Beckman surface electrodes. Action potentials were found in the following head movements: free heterolateral rotation; free homolateral inclination; free and counter-resistance protraction; free and counter-resistance flexion and free extension. These movements were performed with the subjects seated and in supine position.

Thyroid function in hemidecorticate rats.

1. Thyroid function was evaluated in hemidecorticate (HD) and control (C) rats by determining serum T3 and T4 levels and the development of incisors and mandibles and through analysis of various histological features of the thyroid such as follicle size, colloid droplet content and [3H]-glycine uptake by follicular cells. 2. HD animals presented normal levels of circulating T3 but significantly lower T4 levels. 3. There was slight atrophy of the gland in HD animals and fewer colloid droplets were present in the cytoplasm of the follicular cells in this group, indicating a reduction in the breakdown of thyroglobulin. [3H]-glycine uptake by HD indicated that the rate of thyroglobulin biosynthesis was not altered in the experimental animals. 4. The growth of mandibles (weight) and incisors (weight and length) was reduced in HD compared to the control animals. 5. These results suggest that hemidecortication causes mild hypothyroidism (trophoprivic type) probably by affecting hypothalamic function.

Thyroid function in hemidecorticate rats

1. Throid function was evaluated in hemidecorticate (HD) and control (C) rats by determining serum T3 and T4 levels and the development of incisors and mandibles and through analysis of various histological features of the thyroid such as follicle size, colloid droplet content and [3H] - glycine uptake by follicular cells. 2. HD animals presented normal levels of circulating T3 but significantly lower T4 levels. 3. There was slight atrophy of the gland in HD animals and fewer colloid droplets were present in the cytoplasm of the follicular cells in this group, indicating a reduction in the breakdown of thyroglobulin. [3H] - glycine uptake by HD indicated that rate of thyroglobulin biosynthesis was not altered in the experimental animals. 4. the growth of mandibles (weight) and incisors (weight and lenght) was reduced in HD compared to the control animals. 5. These results suggest that hemidecortication causes mild hypothyroidism (trophoprivic type) probably by affecting hypothalamic function