Abnormal Head Posture Research Articles

Results after Surgery for Null Point Nystagmus with Abnormal Head Position

Results after Surgery for Null Point Nystagmus with Abnormal Head Position

Vestibulo-ocular abnormalities in spasmodic torticollis before and after botulinum toxin injections.

In order to establish whether vestibular abnormalities often found in spasmodic torticollis are secondary to the abnormal head posture, the vestibulo-ocular reflex (VOR) was studied in eight patients before and after correction of head posture with botulinum toxin. Eye movements were recorded in the dark during sinusoidal and velocity step rotation. Four patients showed a significantly asymmetric response, with the slow phase of the VOR more active ipsilateral to the torticollis (chin). Despite significant improvement of the head posture in all patients for up to 10 weeks following treatment, no correction of the vestibular asymmetry occurred. This suggests that the VOR abnormalities are not caused by the head posture itself. We interpret the findings as evidence of primary involvement of the vestibular system in torticollis and we postulate a widespread derangement of the sensory-motor mechanisms controlling head posture in this disease.

A photographic method to measure abnormal head posture.

There are a wide variety of clinical syndromes which can leave the patient with an abnormal head posture. A simple photographic method has been developed to enable measurement to be made of the abnormality. This is achieved by marking the patient's head with a head band and then photographing him/her against a set of mirrors which gives a series of mean points. Control tests have shown the techniques to be highly accurate.

Streptomycin in the chick embryo: post-hatching vestibular behavior and morphology.

Developing chick embryos were exposed to streptomycin injected on days 5 through 13 of the 21 day developmental period. Histological and behavioral abnormalities were found almost exclusively in chicks exposed after day 7. The nature of the behavioral deficits included abnormal head posture, head tremor, and inability to compensate for applied vestibular stimuli. Head movement measurements showed that the head tremor had frequencies of oscillations from 10-35 Hz. The amplitude of the tremor was a large as 10 degrees. Histology showed damage to the secretory dark cells of the membranous labyrinth in those chicks that showed behavior changes. Even with increased dosages chicks exposed prior to day 7 rarely showed abnormal vestibular behavior but instead experienced increased mortality. Further tests examining tissue levels of streptomycin showed little or no streptomycin in embryos until day 10. These results are discussed in terms of their utility as an alternative model to surgical manipulation of the vestibular system in developing embryos. Behavioral consequences are compared to other work with drugs and to the effects of weightlessness and unusual environments on vestibular orientation and behavior.

Surgical management of congenital nystagmus.

Forty-three patients with congenital nystagmus who underwent surgery in the Ocular Motility Clinic at The Royal Victorian Eye and Ear Hospital, Melbourne, are analysed to assess the effect of different surgical approaches on the abnormal head posture and binocular visual performance. There were 38 patients with a horizontal head turn, and five with a vertical abnormal head posture. In those undergoing horizontal nystagmus surgery the different surgical procedures have been classified as: Anderson procedure, which involves large bilateral augmented recessions only; Kestenbaum and augmented Kestenbaum bilateral recess/resect surgery in which the recess:resect ratio is less than 1; and a modified Anderson-Kestenbaum procedure with the emphasis on large recessions, so that the bilateral recess/resect ratio is greater than 1. In this series the augmented recessions of the Anderson and Anderson-Kestenbaum procedures appeared to produce a more favourable result of improved binocular vision. The five patients with vertical abnormal head posture with nystagmus had various surgical procedures with very encouraging results, both in terms of reduction of the abnormal head posture and an even greater improvement of binocular vision than with the horizontal cases. The surgical techniques in these cases are presented and discussed.

SURGICAL MANAGEMENT OF CONGENITAL NYSTAGMUS

AbstractForty‐three patients with congenital nystagmus who underwent surgery in the Ocular Motility Clinic at The Royal Victorian Eye and Ear Hospitar Melbourne, are analysed to assess the effect of different surgical approaches on the abnormal head posture and binocular visual performance. There were 38 patients with a horizontal head turn, and five with a vertical abnormal head posture.In those undergoing horizontal nystagmus surgery the different surgical procedures have been classified as(4 Anderson procedure, which involves large bilateral augmented recessions only; (ii) Kestenbaum and augmented Kestenbaum bilateral recess/resect surgery in which the recess:resect ratio is less than 1; and (iii) a modified Anderson‐Kestenbaum procedure with the emphasis on large recessions. so that the bilateral recess/resect ratio is greater than 1. In this series the augmented recessions of the Anderson and Anderson‐Kestenbaum procedures appeared to produce a more favourable result of improved binocular vision.The five patients with vertical abnormal head posture with nystagmus had various surgical procedures with very encouraging results, both in terms of reduction of the abnormal head posture and an even greater improvement of binocular vision than with the horizontal cases. The surgical techniques in these cases are presented and discussed.

NEUROVISUAL ADAPTATIONS TO SUBNORMAL VISION IN CHILDREN

AbstractNeurovisual adaptations to subnormal vision in children are of practical importance and need to be remembered in the management of children with low vision The physiological adaptations discussed include shortening the focal distance, abnormal head positions, compensatory head movements, and ocular motor search strategies In addition the concept of neural plasticity, particularly in respect to the ability of the extrageniculate striaete system to assume primary visual function in cortically damaged children is discussed.

Neurovisual adaptations to subnormal vision in children.

Neurovisual adaptations to subnormal vision in children are of practical importance and need to be remembered in the management of children with low vision. The physiological adaptations discussed include shortening the focal distance, abnormal head positions, compensatory head movements, and ocular motor search strategies. In addition the concept of neural plasticity, particularly in respect to the ability of the extrageniculate striaete system to assume primary visual function in cortically damaged children is discussed.

Surgical Treatment of Duane's Syndrome

Nineteen patients undergoing treatment for Duane's syndrome are reported. The patients were treated with appropriate horizontal muscle recession in order to relieve abnormal head position or a significant tropia in primary position. Success rate in eliminating the abnormal head position was 79% while 100% were significantly improved. No overcorrections occurred despite large recessions. Retraction in adduction was reduced in each case. Motility of the eye was not increased following recession and in no case was fusion ability or stereopsis affected. The elimination of abnormal head position appears to be stable for periods up to 8.75 years. Postoperatively, patients obtained approximately 30° of binocular visual field including primary position. Other surgical techniques in treating Duane's syndrome are discussed

Surgical management for abnormal head position in nystagmus: the augmented modified Kestenbaum procedure.

Patients with nystagmus and an eccentric null point in lateral gaze may assume an abnormal head position to maximise visual acuity. Surgical procedures for this condition can result in significant undercorrection of the head turn. A follow-up of 15 patients for an average of 33 months revealed a sustained improvement in head position with the use of the augmented modified Kestenbaum procedure.

Thirty-degree prone positioning board for children with gastroesophageal reflux. Suggestion from the field.

Gastroesophageal reflux (GER) or chalasia in infants can be defined simply as the regurgitation of gastric contents from the abdominal stomach into the thoracic esophagus.1 Chief among its clinical manifestations is recurrent emesis during and after feedings.1,2 This symptom is present in up to 95 percent of reported cases.2 In addition, any or all of the following disorders may be present: anemia, failure to thrive, nocturnal wheeze or cough, recurrent pneumonia because of aspiration, recurrent bronchitis, near-miss sudden infant death syndrome, and abnormal head positioning (Sandifer syndrome).1,2 An important aspect of the treatment regimen for these patients is positioning during and after feeding. Numerous reports in the literature suggest an upright posture in an infant seat at 45 to 60 degrees after feeding will decrease the incidence of GER.3 Other references suggest a prone posture at 30 degrees after feeding will also decrease the incidence of GER in infants.2,4,5

Abnormal head posture associated with induction of cleft palate by methylmercury in C57BL/6J mice.

Maternal treatment with methylmercury (MeHg) has been shown to induce a high frequency of cleft palate and produce growth retardation in rat and mouse fetuses, but the relation between these effects is unknown. The objective of this study was to determine if mandibular growth retardation was a factor that contributed to induction of cleft palate in C57BL/6J mice. Two doses of MeHg (10 mg/kg maternal body weight) were given subcutaneously on days 10 and 11 of gestation, and the fetuses were morphometrically studied on days 14, 15, and 18. Full clefts of the secondary palate were present in approximately half of the treated day 15 and 18 fetuses; therefore, the cleft palate (CP) and noncleft palate (NCP) groups were analyzed separately to facilitate identification of morphologic changes associated with the clefting. The results showed that, compared with controls, the day 14 MeHg-treated fetuses had significantly smaller placental weights, but only half of the fetuses had delayed palatal shelf elevation, reduced body weight, and delayed morphological development. However on day 15, the CP and the NCP groups had similar reductions in body weight and placental weight. A striking downward and forward positioning of the head was present in the MeHg-treated fetuses with the CP group more severely affected than the NCP group. Significant differences between the three groups (control, NCP, and CP) were present with mean head-to-body angles of 67 degrees, 60 degrees and 51 degrees, respectively. The absence of normal head lifting resulted in a relative mandibular retrognathia that when combined with a decrease in mandibular length produced alterations in spatial relations that were most severe in the CP fetuses. The results suggest that after exposure to MeHg, palatal closure is affected by altered tongue posture associated with the abnormal head positioning and shortening of the mandible that develop following placental and embryonic growth retardation.

Chin up and Chin down Head Positions

This section of the symposium on abnormal head position reviews the ocular causes of the chin up and chin down head positions. The conditions discussed are Double Elevator Palsy, Thyroid Myopathy, ...

Abnormal Head Postures

Abnormal Head Postures

Ocular Causes of Abnormal Head Postures

A prospective study was undertaken to analyze the different causes of abnormal head postures on ocular bases. Eight basic mechanisms were found in a series of 188 patients. Incomitance accounted for 62.7% of the head postures and nystagmus for 20.2%. Important diagnostic criteria for evaluating patients with head postures are discussed.

Brain stem and cerebellar lesions in female rats. I. Tests of posture and movement

Lesions were placed in a number of brain stem and cerebellar structures to determine their importance to the control of posture and movement in rats. Lesions of the lateral vestibular nucleus, superior vestibular nucleus, or inferior olive produced severe disturbances of posture and movement. Rats with such lesions had pronounced tremor, abnormal head posture and asymmetrical trunk posture, and failed in a balance beam test. Lesions of the medial medullary reticular formation and medial vestibular nucleus had less overall effect on posture and movement, while animals with lesions of the deep cerebellar nuclei were relatively unimpaired. All lesion groups showed some recovery of function during the course of postoperative testing.

Paroxysmal torticollis in infancy.

To the Editor .—The interesting report Paroxysmal Torticollis in Infancy by C. Harrison Snyder, MD ( Amer J Dis Child 117 :458-460, 1969) does not indicate whether his patients received ophthalmologic evaluation. Although usually not paroxysmal in nature, torticollis is a fairly characteristic accompaniment of certain types of ocular misalignment, especially isolated palsy of the superior oblique muscle. While it is true that, unlike the situation in some of Dr. Snyder's cases, the abnormal head position would relieve rather than exacerbate the child's visual disturbance, such manifestations as agitation and dizziness or even something akin to vertigo might be subjective equivalents for the rather annoying diplopia that could occur with such a condition. Intermittency of the misalignment would not be a usual feature of a cyclovertical muscle paresis in most instances, but the occurrence of symptoms could well be. Another form of incomitant strabismus, the superior oblique tendon sheath of Brown,