Transient lateral rectus muscle paresis in the newborn infant

Do infants with isolated congenital sixth nerve palsy require comprehensive work-up? A retrospective cohort and review of the literature

PURPOSE

The purpose of this study is to describe a case series of infants with isolated congenital sixth nerve palsy (ICSNP) and suggest a management algorithm based on our experience and a review of the literature.

METHODS

A retrospective cohort design was used. The clinical database of a single tertiary medical center was reviewed to identify all patients diagnosed with ICSNP from January 2020 to November 2022. Data were collected as follows: demographic parameters, age at initial presentation, presenting symptoms and signs, findings on ophthalmic and neurologic examinations, findings on follow-up, and outcome.

RESULTS

Six patients were included. All were born at term. The average gestational weight was 3675.7 ± 262.7 g. Three mothers had gestational diabetes. Five deliveries necessitated labor induction either by oxytocin (n = 4) or by membrane stripping followed by oxytocin (n = 1). One had also gone a forceps assisted delivery. Symptoms were noticed in all newborns by their parents within the first week of life. Ophthalmological and neurological examinations were otherwise unremarkable apart of one patient with a head turn to the side of the involved eye. Four patients underwent brain imaging that were unremarkable. All abduction deficits resolved by 1 to 3 months of age. Follow up examinations were unremarkable (mean follow up 14.3 ± 5.0 months, range 4-23).

CONCLUSIONS

This case series, together with previous reports, support ICSNP's benign nature. We suggest an initial basic work-up that solely includes ophthalmological and neurological examinations which will be elaborated in case of any additional pathologic findings or if ICSNP does not fully resolve by 3 months.

Transient congenital Horner syndrome and multiple peripheral nerve injury: a scarcely reported combination in birth trauma

Objectives

To describe an infrequent association of multiple injuries in relation to perinatal trauma and the challenge of clinical examination for proper diagnosis.

Case presentation

A male newborn was born at 41 weeks gestational age to a multipara diabetic mother, by forceps. Apgar 8/9. Upon admission, he exhibited axial hypotonia, right brachial paresis, a large left parietal cephalohematoma, but no skull fractures or orbital injuries. He also showed ocular misalignment with marked esotropia of the right eye, ptosis and mild anisocoria, suggesting right Horner syndrome, and left facial palsy. During the oculo-cephalic reflex examination he exhibited a normal adduction and impaired abduction of the right eye. The cranial MRI showed an extensive left parietal cephalohematoma, with internal foci of recent bleeding, and supra and infratentorial laminar subdural hematomas. No lesions were evidenced in the cavernous sinuses. The recovery of extra and intraocular motility at one month of life in our patient highlighted the transitory nature of the lesions and was reassuring for the parents.

Conclusions

This case highlights the importance of a detailed clinical examination in the initial evaluation of a newborn at neurological risk after birth trauma. The association of sixth cranial nerve palsy, Horner syndrome, facial palsy, and brachial plexus injury have been scarcely referred in this context and, if not adequately interpreted, might suggest erroneous diagnoses with very different prognoses.

Pediatric third, fourth, and sixth nerve palsies: a population-based study

PURPOSE

To determine the population-based incidence and cause of cranial nerve palsies affecting ocular motility in children in the circumscribed population of Olmsted County, Minnesota.

METHODS

The Rochester Epidemiology Project medical records linkage system captures virtually all medical care provided to Olmsted County residents. By means of this database, all cases of third, fourth, and sixth cranial nerve palsy were identified among county residents less than 18 years of age from 1978 through 1992. Medical records were reviewed to confirm the diagnosis, determine the cause, and document county residency. Incidence rates were adjusted to the age and sex distribution of the 1990 white population in the United States.

RESULTS

Over this 15-year period, 36 incidence cases of cranial nerve palsy were identified in 35 children in this defined population. The age-adjusted and sex-adjusted annual incidence of third, fourth, and sixth nerve palsies combined was 7.6 per 100,000 (95% confidence interval, 5.1 to 10.1). The most commonly affected nerve was the fourth (36%), followed by the sixth (33%), the third (22%), and multiple nerve palsies (9%). The most common cause was congenital for third and fourth nerve palsy, undetermined for sixth, and trauma for multiple nerve palsies. Although three cases were associated with neoplasia, a cranial nerve palsy was not present at the time of diagnosis in any case.

CONCLUSIONS

Unlike many institutionally based referral series, our population-based study provides data on the incidence and cause of third, fourth, and sixth nerve palsies in a geographically defined population. In contrast to previous institutionally based series, nearly half the cases were congenital in origin, and in no case did intracranial neoplasia present as an isolated nerve palsy.

Incidence of neonatal sixth nerve palsy in relation to mode of delivery

During a 10-year period on a level I neonatal service the total incidence (0.4%) and incidence by mode of delivery of neonatal lateral rectus paralysis occurring among 6886 term neonates was determined. The incidence of abducens nerve injury in this population increased progressively from 0% for deliveries by cesarean section to 0.1% for spontaneous vaginal delivery, to 2.4% for forceps delivery, and to 3.2% for vacuum extraction. This suggests that increased complexity of instrumentation during delivery is associated with an increased risk of sixth nerve palsy. A proposed mechanism for the injury to the sixth nerve is described.

Strabismus in infancy

In order to prospectively study the development of strabismus in infancy, the ocular alignment of a large population of normal neonates was studied and follow-up examinations were obtained in a subset of these infants. The characteristic findings of congenital esotropia subsequently developed in three infants who were either orthotropic or exotropic at birth. Pathologic exotropia developed in two infants; both were exotropic at birth, but no more so than most normal neonates. In infants with congenital esotropia or pathologic exotropia, the characteristic deviation appears to develop between 2 and 4 months of age, a period during which normal infants are becoming increasingly orthotropic.

Congenital esotropia

Congenital esotropia represents the most common type of strabismus. Its pathogenesis, however, remains uncertain. It is typically characterized as a large angle, constant esotropia with onset during the first six months of life. Associated clinical findings include normal refractive errors for age, amblyopia, dissociated vertical deviation, inferior oblique muscle overaction and nystagmus. It must be distinguished from Duane's retraction syndrome, Moebius syndrome, nystagmus blockage syndrome, and early onset accommodative esotropia, as well as other causes of esotropia in infancy. The surgical management may involve recession of both medial recti muscles, unilateral recession of a medial rectus muscle and a resection of a lateral rectus muscle or three or four muscle surgery.

Asymmetric crying facies and congenital anomalies

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