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At least 451 records · Page 25Linked to original sources

Value of computed tomography findings in differentiating between intraosseous malignant tumors and osteomyelitis of the mandible affecting the masticator space.

OBJECTIVES: We sought to evaluate the diagnostic efficacy of computed tomography (CT) images in the differentiation between intraosseous malignant tumors and osteomyelitis spreading into the masticator space. STUDY DESIGN: A retrospective evaluation was carried out by using CT images from 12 patients with intraosseous malignant tumors and 9 patients with osteomyelitis involving the masticator space and accompanying mandibular bone destruction. The following CT observations are discussed: (1) bone destruction pattern subdivided into spotty, gross, or permeative; (2) cortical bone expansion; (3) diffuse osteosclerotic changes; (4) periosteal reaction; (5) masticator muscle involvement; (6) enlargement of the facial muscle; and (7) attenuation in the subcutaneous adipose tissue. RESULTS: The pattern of permeative bone destruction, cortical bone expansion, and the enlargement of both the masseter and medial pterygoid muscles were all observed in patients with malignant tumors. In contrast, diffuse sclerotic change and a periosteal reaction were significant observations in patients with osteomyelitis. CONCLUSION: The efficacy of CT in establishing a differential diagnosis of malignant tumors or osteomyelitis is supported by this study.

Adipose Tissue↗

Geniospasm: hereditary chin trembling.

Geniospasm is a hereditary disorder characterized by episodic, usually stress-induced involuntary trembling of the chin. Nineteen families from Europe and the U.S.A. suffering from this disorder have been described since 1894. We present three cases from two newly detected families. There was no evidence of any other nervous system abnormality, although abnormal EEG, sleep disorders, and involvement of other facial muscles have been described in rare cases. Geniospasm is transmitted as an autosomal-dominant trait with high penetrance. It must be differentiated from facial myokymia, palatal tremor, and essential tremor affecting facial muscles. Neurophysiological and molecular mechanisms of this peculiar disorder are unknown.

Adolescent↗

[Cornea protection in ptosis induced by botulinum injection].

Two patients, men aged 82 and 53 years, with weakness of the facial muscles after surgery in the posterior fossa had keratitis caused by the inability to blink and to close the eye. Botulinum toxin type A was injected into the levator palpebrae superioris muscle under electromyographic control. A selective, reversible paralysis of this muscle was induced without weakness of the anatomically related rectus superior muscle. This botulinum toxin-induced protective ptosis appeared to be effective and safe in the treatment and prevention of keratitis in patients with a temporary weakness of the facial muscles.

Aged↗

Motor and sensory facial nerve grafts. An experimental comparative study.

Two groups of four rabbits each were used. In the first group, the greater auricular nerve was grafted into the ipsilateral facial nerve. In the second group, the facial nerve was grafted into the contralateral facial nerve. Electromyographic studies were performed on both groups 21 to 24 weeks afterward, together with an axonal count of the grafted nerves and histologic studies of the facial muscles. No differences between the groups were found in rest periods, periods of voluntary activity, and magnitude of the action potentials. In the auriculo-facial grafts, the number and density of axons was greater. The conclusion of this study is that the facial nerve can function adequately with a smaller number of axons than it normally has with sensitive nerves of a lesser width proving to be useful grafts.

Action Potentials↗

Juvenile progressive bulbar palsy. Clinical and electrodiagnostic findings.

Differentiation of juvenile progressive bulbar palsy from bulbar myasthenia gravis is difficult. Characteristics of both may include ocular involvement, fluctuant course, abnormal fatigability, and normal acetylcholine receptor (AChR) antibody titers. Electrodiagnostic evaluation may demonstrate moment-to-moment variability in motor unit action potential amplitude, fibrillation potentials, and decremental motor evoked responses. Increased jitter with blocking may be the most prominent electrodiagnostic abnormality in either disorder, even in asymptomatic extremity muscles. Complete paralysis of facial muscles with electrical silence on needle electromyography, low-amplitude facial evoked responses without a decrement to repetitive stimulation, increased jitter and fiber density in asymptomatic extremity muscles, and normal AChR antibody levels suggested juvenile progressive bulbar palsy in two patients initially thought to have bulbar myasthenia. Early differentiation of these disorders is important because of therapeutic, genetic, and prognostic implications.

Adolescent↗

Extension of the clinical range of facioscapulohumeral dystrophy: report of six cases.

Consensual diagnostic criteria for facioscapulohumeral dystrophy (FSHD) include onset of the disease in facial or shoulder girdle muscles, facial weakness in more than 50% of affected family members, autosomal dominant inheritance in familial cases, and evidence of myopathic disease in at least one affected member without biopsy features specific to alternative diagnoses. Six patients did not meet most of these criteria but were diagnosed as FSHD by DNA testing, which showed small EcoRI fragments on chromosome 4q. Their clinical signs and symptoms and results of auxiliary investigations are reported. The patients presented with foot extensor, thigh, or calf muscle weakness. None of them had apparent facial weakness, only one complained of weakness in the shoulders, none had a positive family history. Expert physical examination, however, showed a typical facial expression, an abnormal shoulder configuration on lifting the arms, or scapular winging. This raised the suspicion of FSHD, whereupon DNA analysis was done. In conclusion, the clinical expression of FSHD is much broader than indicated by the nomenclature. The possibility to perform DNA tests is likely to greatly expand the clinical range of FSHD.

Adult↗

Acetylcholine receptor concentration in the mimic musculature of the rat following denervation and reinnervation.

The facial musculature of the rat was denervated by cutting the facial nerve. Over a period of 41 days no facial movements were observed. Acetylcholine receptor concentrations, determined by [125I]-alpha-bungarotoxin binding, increased sharply in the early stage of denervation (at day 10) and were still significantly higher than in the controls after 41 days. When cutting of the facial nerve was followed by immediate nerve repair (primary suture), facial movements returned on about day 16. The receptor concentrations reflected changes monitored by clinical observations. At day 10, when denervation of the facial muscles was still complete, receptor concentrations corresponded to those found in the permanently denervated muscles. At day 16 the reinnervated muscles of half the animals displayed muscle activity and had receptor concentrations identical to those found for normal (control) tissue. The other half of the animals, with no muscular activity detectable, had receptor concentrations as high as in permanently denervated tissue. After 23 days the receptor concentrations had essentially decreased to control levels and all rats had regained complete facial function.

Animals↗

Hypoglosso-facial nerve anastomosis.

The hypoglosso-facial nerve anastomosis (HFA) is a valuable surgical procedure for the treatment of certain types of facial paralysis. HFA was performed 1 to 22 months after resection of an acoustic neurinoma in 32 patients where the operation was complicated by unilateral facial palsy. 56% of these patients obtained excellent facial function, and a total of 66% were satisfied and would have repeated the operation even with their present knowledge about the disadvantages. The recovery of facial function after any nerve anastomosis or plastic procedure is never perfect but HFA usually results in symmetry of the face in response and animation of the face during conversation. HFA is most effective when used as soon as possible after facial palsy has developed, provided a sufficient time has passed for any possible spontaneous recovery. This waiting period should not exceed six months. If the operation is done promptly the results improve, probably because only slight atrophy has occurred in the facial muscles. The disadvantages of HFA are hemiatrophy of the tongue, mass movement of the face and, in some instances, hypertonia of the face. The advantages are improved facial tone with ameliorated cosmetic result, protection of the eye, intentional facial movements controlled by the tongue, and movements associated with physiological function of the tongue.

Adult↗

Facial action recognition for facial expression analysis from static face images.

Automatic recognition of facial gestures (i.e., facial muscle activity) is rapidly becoming an area of intense interest in the research field of machine vision. In this paper, we present an automated system that we developed to recognize facial gestures in static, frontal- and/or profile-view color face images. A multidetector approach to facial feature localization is utilized to spatially sample the profile contour and the contours of the facial components such as the eyes and the mouth. From the extracted contours of the facial features, we extract ten profile-contour fiducial points and 19 fiducial points of the contours of the facial components. Based on these, 32 individual facial muscle actions (AUs) occurring alone or in combination are recognized using rule-based reasoning. With each scored AU, the utilized algorithm associates a factor denoting the certainty with which the pertinent AU has been scored. A recognition rate of 86% is achieved.

Algorithms↗

Blink reflex recovery in facial weakness: an electrophysiologic study of adaptive changes.

OBJECTIVE: To study the electrophysiologic effects of unilateral facial weakness on the excitability of the neuronal circuitry underlying blink reflex, and to localize the site of changes in blink reflex excitability that occur after facial weakness. BACKGROUND: Eyelid kinematic studies suggest that adaptive modification of the blink reflex occurs after facial weakness. Such adaptations generally optimize eye closure. A report of blepharospasm following Bell's palsy suggests that dysfunctional adaptive changes can also occur. METHODS: Blink reflex recovery was evaluated with paired stimulation of the supraorbital nerve at different interstimulus intervals. Comparisons were made between normal control subjects and patients with Bell's palsy who either recovered facial strength or who had persistent weakness. RESULTS: Blink reflex recovery was enhanced in patients with residual weakness but not in patients who recovered facial strength. Facial muscles on weak and unaffected sides showed enhancement. In patients with residual weakness, earlier blink reflex recovery occurred when stimulating the supraorbital nerve on the weak side. Sensory thresholds were symmetric. CONCLUSION: Enhancement of blink reflex recovery is dependent on ongoing facial weakness. Faster recovery when stimulating the supraorbital nerve on the paretic side suggests that sensitization may be lateralized, and suggests a role for abnormal afferent input in maintaining sensitization. Interneurons in the blink reflex pathway are the best candidates for the locus of this plasticity.

Adaptation, Physiological↗

Hemiregional facial asymmetry in expression of emotion: a concept needs to be verified.

In most of the neuropsychological studies the left-right hemifacial asymmetry during expression of emotion has been reported, although the present author proposed a concept of hemiregional asymmetry and reported that greater left hemifacial involvement was specific to the lower region of the face and greater right hemifacial was specific to the upper region of the face. It is speculated that this differential hemifacial involvement is a function of the right hemisphere, and it is explained in terms of neural innervation to facial muscles. This speculation needs to be verified further to arrive at a general conclusion.

Dominance, Cerebral↗

Intrafascicular multi-unit recordings from the human infra-orbital nerve.

Intrafascicular micro-electrode recordings were made from the human infra-orbital nerve close to the infra-orbital foramen. The fascicular organization was studied and multi-unit activity from low-threshold mechanoreceptive afferents was recorded during tactile stimuli, vibration and facial movements. Attempts were also made to record C-fibre activity. Innervation zones corresponding to 66 fascicles were mapped with tactile stimuli on facial hairy skin and the red zone of the lip. Most of these fields were located on the upper lip, where they overlapped, indicating a high innervation density. The fields had a median size of 3.8 cm2. Skin indentation evoked dynamic on- and off-responses and a much less pronounced static discharge. The afferent double-peaked responses to an oscillating probe applied to the peri-oral region induced similar grouping of the EMG activity during sustained lip protrusion. Contraction of facial muscles and stretching of the skin evoked on- and off-responses, whereas the static discharge was less pronounced, especially during sustained stretching. The dynamic sensitivity to minor variations in contraction and stretching was high, and during normal facial movements, as in speech, there was a barrage of impulses originating from mechanoreceptors within large facial areas. Functional implications of these sensorimotor interactions are discussed. Sympathetic C-fibre activity, frequently seen in recordings from the supra-orbital nerve, was never encountered in the infra-orbital nerve recordings, indicating a lack of such fibres. Failure to detect afferent C-fibre activity could be explained by methodological difficulties.

Adult↗

Inadequacy of transcranial magnetic stimulation in the neurophysiologic assessment of Bell's palsy.

Transcranial magnetic stimulation is a non-invasive procedure which to stimulate the brain cortex and the peripheral nerve pathways. A new technique was recently introduced to record the muscle action potential of facial muscles by means of transcranial magnetic stimulation of the facial nerve. The experimental data that was obtained indicate that this technique allows to stimulate the facial nerve above the stylomastoid foramen: a greater tract of the nerve can therefore be explored than what was possible with the traditional electrical stimulation at the mastoid. Until now no comparison data was available on the clinical usefulness of the two methods. We decided to study 14 normal controls and 26 patients suffering from unilateral idiopathic facial palsy (Bell's palsy) and to submit these two groups to magnetic transcranial stimulation and electrical stimulation of the facial nerve in the mastoid region, to the purpose of observing where the nerve is stimulated by the magnetic impulse and which of the two techniques can be of accurate prognostic value in the study of the evolution of the clinical lesion. The electromyographic responses were elicited by the electrical stimulation at the mastoid and by transcranial stimulation after positioning the coil on the parieto-occipital scalp. A recording was taken from the ipsilateral orhicularis oculi muscle utilising two cupped electrodes. The latency and the amplitude of the compound muscle action potential were measured bilaterally in order to compare the results obtained on both the affected and the healthy sides. The patients were scheduled to two neurophysiological and clinical evaluations at about 30 days interval one from the other: the first test was not carried out before 20 days from the onset of the deficit; further clinical examination was carried out only 6 months later. The analysis of the results obtained in the normal controls submitted to transcranial magnetic stimulation indicate that the nerve is activated at the point where it originates from the brainstem. The study carried out showed that transcranial magnetic stimulation of the facial nerve, does not provide data which can be correlated to the clinical situation observed at the time of the study; furthermore, transcranial magnetic stimulation does not supply any prognostic data on the clinical evolution of the lesion.

Action Potentials↗

Histochemical analysis of cleft palate muscle.

Research has clarified the abnormal insertions and orientations of the involved musculature in cleft palate. However, little is known about the physiologic aspects of these muscles, specifically from a histochemical perspective. In this study, 30 muscle specimens were removed from the palatal cleft margin in patients undergoing primary palatoplasty. Nine patients had combined cleft lip and palate deformity, and seven had an isolated cleft palate. Biopsies were taken from the area of the musculus uvulus in all specimens and examined by histochemical techniques. The percentage of type 1 and type 2 fibers was different in isolated cleft palate as compared with cleft lip and palate specimens, being, respectively, 56.7 percent type 1 and 43.3 percent type 2 and 62.0 percent type 1 and 38.0 percent type 2 fibers. This is the opposite ratio from other facial muscles but is in line with the literature regarding normal palatal muscle. Isolated cleft palate muscle fibers also were minimally decreased in diameter as compared with normal facial muscle. Fiber diameters of the combined cleft lip and palate muscles were severely decreased in size compared with those muscles found in the cleft lip. Abnormal mitochondrial accumulations also were found in cleft lip and palate muscle specimens but not in isolated cleft palate muscle specimens. We consider the decrease in muscle diameter found in isolated cleft palate to be secondary to functional atrophy, while that in the cleft lip and palate specimens is secondary to a primary hypoplasia together with a functional atrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗

Young onset hemifacial spasm.

INTRODUCTION: Hemifacial spasm (HFS) frequently affects middle aged individuals and the clinical features and etiology have been well reported. However, there is limited data on the exact pathogenesis in young-onset HFS. If age is a major determinant of the etiology or influences the presentation of HFS, there may be clinical differences between the young and elderly HFS patients. OBJECTIVES: We determined the prevalence, clinical and imaging features of young-onset HFS (age of onset or=65 years) HFS patients. METHODS: We examined consecutive patients clinically diagnosed with HFS in a tertiary referral center. The clinical (demographics, clinical presentation, severity of HFS, associated medical conditions and other variables) and imaging findings of young onset patients and old onset patients were tabulated and compared. RESULTS: Amongst 230 consecutive HFS patients, 15 (6.5%) were young-onset HFS and 50 (21.7%) were old-onset HFS. In the young-onset HFS, the mean age of onset of symptoms was 26.5+/-6.5 (6-30) years, with 80% women and 75.0% of young onset HFS having neurovascular compression (NVC) of the root exit zone (REZ) of the facial nerve on the ipsilateral side; 86.7% had initial onset of twitching in the upper eyelids that later progressed to the lower facial muscles. While the prevalence of hypertension, diabetes mellitus and other associated vascular disorders in late onset HFS was higher than in young onset groups, the clinical features and frequency of NVC of the facial REZ between the two groups were similar. CONCLUSIONS: We demonstrated a 6.5% frequency of young-onset HFS in our cohort of HFS and their clinical presentation was similar to the old onset patients. Genetic, anatomic or other unidentified factors may contribute to NVC in young-onset HFS.

Adult↗

Triazolam improves sleep but fails to alter pain in TMD patients.

Patients with chronic orofacial pain often report disturbances in sleep, leading to the hypothesis that nocturnal motor hyperactivity of the muscles of mastication may contribute to the nociceptive process. This hypothesis was tested in a controlled study to evaluate the relationship between sleep stages, patient self-report of pain in the orofacial region, and nocturnal masticatory muscle activity. Twenty subjects participating in a two-period, within-subject, crossover study received triazolam or placebo for 4 nights. Sleep, pain, and mandibular range of motion were assessed at baseline, following the first period, and again following the second period; a 3-day washout period separated the two treatments. Subjective report of sleep quality was significantly improved following triazolam in comparison to placebo as measured by category scales for sleep quality, restfulness, and sleep compared to usual. The amount of time spent in stage-2 sleep was also significantly increased by triazolam. No improvement was seen in pain as measured by palpation with an algometer, in scales for sensory intensity and the affective component of pain, or in daily pain diaries. Mean facial muscle electromyographic activity for 30-second epochs averaged over the entire period of sleep did not reveal any differences in muscle activity across the three conditions. These data indicate that improvements in sleep quality and alterations in sleep architecture do not affect nocturnal facial muscle activity or subsequent pain report in temporomandibular patients, thereby failing to support the hypothesized relationship between sleep disturbances and chronic orofacial pain.

Adult↗

The seventh cranial nerve of the rat. Visualization of efferent and afferent pathways by cobalt precipitation.

The cobalt sulphide precipitation technique, in conjunction with Timm's intensification procedure, was used to delineate the afferent and efferent intramedullary pathways of the seventh cranial nerve complex in the rat. The branchial motor nucleus with the accompanying first part, genu, and second part of the root are described. The motor branches to the superficial facial musculature do not contain fibres of geniculate ganglion origin or fibres which terminate in the spinal trigeminal nucleus. The motor branches to the deep facial muscles arise from the dorsal part of the branchial motor nucleus and traverse to the midline medial to the genu, then project under the genu into the lateral reticular formation before exiting with the facial nerve. The salivatory and lacrimal nuclei and their intramedullary pathways are described. Sensory fibres from the cutaneous auricular branch enter the spinal trigeminal tract and most of the chorda tympani gustatory fibres enter the fasciculus solitarius. A smaller number of gustatory fibres extend medially to the region of the salivatory nucleus. Fibres of greater superficial petrosal origin also enter the fasciculus solitarius as well as the medial reticular formation. These findings are discussed in relation to previous anatomical, physiological and clinical reports.

Animals↗