Brain Malformations Do Not Predict Hypopituitarism in Young Children with Optic Nerve Hypoplasia

Pituitary deficiencies related to optic nerve hypoplasia and visual acuity

OBJECTIVE

Optic nerve hypoplasia (ONH), the congenital underdevelopment of the optic nerve, is an increasing cause of visual impairment and is associated with pituitary dysfunction. Past studies have focused on the relationship between ONH, pituitary deficiencies, and brain imaging. However, recent studies have demonstrated the true risk for hypopituitarism lies with the presence or absence of ONH, irrespective of midline brain findings. This study reviewed the relationship between the health of the optic nerve (visual acuity) and pituitary gland (number and age of development of pituitary deficiencies) as a way to stratify risk, regardless of imaging findings.

DESIGN, PATIENTS AND MEASUREMENTS

Retrospective chart review of 197 patients seen at a single center from 2013 to 2022. Visual assessment was defined by distance acuity, and the presence of nystagmus or afferent pupillary defect. Pituitary deficiencies were diagnosed per Endocrine Society guidelines.

RESULTS

In children with bilateral ONH (bONH), profound visual impairment was associated with more pituitary deficiencies between 0 and 15 years of age. The odds of having any pituitary deficiency were 4.9 times higher (95% confidence interval [95% CI]: 2.4-10.1) for patients with bONH versus unilateral ONH (uONH). Central hypothyroidism was the most common first presenting pituitary deficiency followed by growth hormone across all patients.

CONCLUSION

This study shows a significant association between severity of visual impairment and increased probability of pituitary deficiencies in children with bONH versus uONH. Children with ONH require urgent endocrine evaluation due to risk of pituitary deficiencies, but risk stratification may also be based on severity of visual impairment.

Neuroimaging Features in Children with Optic Nerve Hypoplasia and Septo-Optic-Pituitary Dysplasia

BACKGROUND

Optic nerve hypoplasia (ONH) and septo-optic-pituitary dysplasia (SOD) are common causes of congenital visual impairment. Our primary aim was to investigate the prevalence of abnormal neuroimaging features in patients with these disorders in Manitoba, Canada, and compare them with published reports.

METHODS

A retrospective neuroimaging review was performed in patients resident in Manitoba with ONH/SOD.

RESULTS

There were 128 patients (M = 70) with ONH/SOD who had neuroimaging. Their mean age (SD) at the end of the study was 13.2 (7.5) years. Males were significantly more likely to have bilateral ONH and a small optic chiasm size, while females were more likely to have a left ONH and a small left optic chiasm size on neuroimaging (p = 0.049). ONH and small optic chiasm size were seen in most patients on neuroimaging. Absent septum pellucidum was noted in 40%, small pituitary gland size in 28%, neuronal migration disorders (NMD) in 20% (>1 type and bilateral in 13 cases), corpus callosum abnormalities were present in 9%, while olfactory bulbs-tracts and olfactory sulci were absent in 8.6% of cases. Unilateral ONH was not significantly associated with other structural brain abnormalities, while NMD were significantly associated with other midline brain abnormalities including a symmetrically small optic chiasm size.

CONCLUSION

The prevalence of structural neuroimaging abnormalities in our cohort with ONH/SOD was generally in the same range reported in other studies with corpus callosum abnormalities being relatively less common in our study. Bilateral NMD were relatively common among patients with NMD. The association between sex and ONH laterality requires further study.

Association of prepregnancy body mass index and gestational weight gain on severity of optic nerve hypoplasia

BACKGROUND

Optic nerve hypoplasia (ONH) is a birth defect of unknown etiology and a leading cause of visual impairment in developed countries. Recent studies suggest that factors of deprivation and exposures of poor nutritional status, such as lower gestational weight gain (GWG), may be associated with increased risk of ONH. The present study describes the prenatal features of mothers of ONH cases, including prepregnancy BMI and GWG, and the associations with clinical features of disease severity.

METHODS

Retrospective study of prenatal records for cases of ONH enrolled in a research registry. Prepregnancy BMI and GWG were compared to maternal characteristics and clinical findings of ONH severity including bilaterality, hypopituitarism, and neuroradiographic abnormalities.

RESULTS

Compared to population-based normative data of births in the United States, mothers of ONH cases (n = 55) were younger (23.3 vs. 25.8 years; p = 0.03), with higher incidence of inadequate GWG (34.0% vs. 20.4%; p = 0.03) predominantly in the first and second trimesters. The presence of major brain malformations was associated with younger maternal age (21.6 [IQR 19.4, 24.7] vs. 24.9 years [IQR 22.1, 28.5] [p = 0.02]), primiparity (44.1% vs. 13.3%; p = 0.05) and decreased prepregnancy BMI (20.9 kg/m2 [19, 22.5] vs. 25.5 kg/m2 [21.3, 28.2]; p < 0.01).

CONCLUSION

Decreased prepregnancy BMI and inadequate GWG correlated with clinical features of ONH severity, specifically bilateral disease and presence of major brain malformations.

Delineating septo-optic dysplasia

BACKGROUND

Septo-optic dysplasia (SOD), once a variable triad of septum pellucidum defects (SPDs), optic nerve hypoplasia (ONH), and hypopituitarism, has had multiple findings added, with uncertain causes, definitions, and limits.

METHOD

Literature review.

RESULTS

SOD is a complex vascular sequence with confounders.

CONCLUSIONS

Proximal anterior cerebral artery trunk disruptions cause overlapping primary effects, giving ONH alone most often, and isolated SPD less. ONH disruptions can spread to pituitary, SPD disruptions to the cerebral cortex, causing schizencephaly and related anomalies. Pituitary defects are rare without ONH, and cortical findings are rare without SPD. Extensions are unidirectional, so isolated pituitary or cortical defects are separate from SOD. Micro- an- ophthalmia, a suggested ONH variant, is not part of SOD. Disruption by-products can affect development, causing cognitive and endocrine issues, and structural anomalies such as corpus callosum thinning, ventriculomegaly, and hippocampal and olfactory findings. Limbic extensions may also contribute to the same structural defects as by-products. Midline CNS developmental anomalies can act as disruptive foci, most likely through vascular variants, but have separate pathogenesis. Relative frequencies of specific pituitary hormone defects change as SOD rates increase. Increasing relative rates of midline CNS developmental defects and cortical anomalies are consistent with rising levels of exogenous exposures sensitizing to midline predispositions.

Onset of pituitary hormone deficiencies in optic nerve hypoplasia: a temporal trend analysis of 32 children at Mayo Clinic

Background The objective of this study was to evaluate the age at onset and frequency of individual pituitary hormone deficiencies (PHDs) in optic nerve hypoplasia (ONH). Methods We performed a retrospective chart review of patients ≤21 years of age evaluated between 1996 and 2014. Patients were included if they had: (1) ONH diagnosed by an ophthalmologist and/or magnetic resonance imaging (MRI), (2) documentation of pituitary hormone function on at least two separate occasions and (3) at least one PHD documented or a midline abnormality of the brain on MRI. Results Thirty-two patients (18 females, 14 males) were included (median age, 8 years [range, 1.1-21.0 years]). All patients had ONH (bilateral, n = 31; unilateral, n = 1) and at least one midline abnormality of the brain. At least one PHD was present in 75% of patients (n = 24). The remaining 25% of patients (n = 8) did not develop any PHD at least until the last follow-up (<2-8.6 years of follow-up), despite the presence of ONH and a midline abnormality of the brain. The median age (years) at diagnosis of antidiuretic hormone (ADH), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH) and growth hormone (GH) deficiencies was 0.5, 0.6, 0.7 and 1.6, respectively. Twenty-three percent of all PHDs were identified during the neonatal period, 56% by 12 months and 72% by 36 months of age. The latest age at diagnosis of GH, ACTH and TSH deficiencies was 9.6, 9.9 and 12.6 years, respectively. Conclusions The majority of the PHDs in ONH develop within the first 3 years of life. We propose evaluation for endocrinopathies at the time of diagnosis of ONH, with repeat assessment for new deficiencies every 3-4 months until age 3 years and at least semi-annually until growth and puberty are complete.

High prevalence of pituitary hormone deficiency in both unilateral and bilateral optic nerve hypoplasia

AIM

This study examined the prevalence of neurological impairment and pituitary hormone deficiency (PHD) in patients with unilateral and bilateral optic nerve hypoplasia (ONH).

METHODS

A population-based cross-sectional cohort study of 65 patients (51% female) with ONH was conducted in Stockholm. Of these were 35 bilateral and 30 unilateral. The patients were below 20 years of age, living in Stockholm in December 2009 and found through database searching. The median age at the analysis of the results in January 2018 was 16.1 years (range 8.1-27.5 years). Neurological assessments and blood sampling were conducted, neuroradiology was reviewed and growth curves were analysed. Diagnoses of PHDs were based on clinical and biochemical evidence of hormone deficiency.

RESULTS

Neurological impairments were identified in 47% of the patients and impairments in gross and fine motor function were more prevalent in bilateral ONH (p < 0.001). In addition, 9% had cerebral palsy and 14% had epilepsy. The prevalence of PHD was 29 and 19% had multiple PHD.

CONCLUSION

Children with ONH had a high risk of neurological impairment, especially in bilateral disease. Both unilateral and bilateral ONH signified an increased prevalence of PHD and all these children should be endocrinologically followed up until completed puberty.

Diagnostic Value of Two-Dimensional plus Four-Dimensional Ultrasonography in Fetal Craniocerebral Anomalies

BACKGROUND

To assess the clinical value of two-dimensional (2D) plus four-dimensional (4D) ultrasonography in diagnosis of fetal craniocerebral anomalies.

METHODS

Retrospective analysis was performed on the sonographic features of 83 maternity patients admitted to Northwest Women's and Children's Hospital, Xian China from January 2013 to December 2017 diagnosed with suspected fetal anomalies of the brain and skull through 2D and 4D ultrasonography.

RESULTS

Fifty six patients were diagnosed with the anomalies by 2D ultrasonography only, 65 patients by 4D ultrasonography only, and 74 patients by 2D plus 4D ultrasonography.76 patients were confirmed to have fetal craniocerebral anomalies after birth or induced labor. Diagnostic accuracies of 2D ultrasound only, 4D ultra-sound only, and 2D plus 4D ultrasound were 68.67%, 81.93% and 95.18%, respectively (P<0.05). The accuracy of 2D plus 4D ultrasound was greater than those of 2D ultrasound only and 4D ultrasound only, and the accuracy of 4D ultrasound only was higher than that of 2D ultrasound only (P<0.05). The sensitivity of 2D plus 4D ultrasound was greater than those of 2D ultrasound only and 4D ultrasound only (P<0.05). The specificity of 2D plus 4D ultrasound was greater than those of 2D ultrasound only and 4D ultrasound only (P<0.05).

CONCLUSION

Combined ultrasonography can better differentiate fetal craniocerebral anomalies, providing early and more accurate information for clinicians as well as maternity patients to make a decision. This clinical practice would be valuable for improving the quality of the newborn population.

Outcome of Isolated Absent Septum Pellucidum Diagnosed by Fetal Magnetic Resonance Imaging (MRI) Scan

Improved fetal imaging has resulted in increased diagnosis of isolated absent septum pellucidum without other intracranial abnormalities. There is little literature regarding outcomes for these fetuses. This study hypothesized the majority of infants diagnosed by fetal magnetic resonance imaging (MRI) with isolated absent septum pellucidum would retain this diagnosis postnatally. Specifically, in the absence of postnatal endocrine or ophthalmologic abnormalities, postnatal imaging would find no additional related findings, and fetuses would be at low risk for developmental delay. Two of 8 subjects met postnatal criteria for septo-optic dysplasia; remaining subjects had normal postnatal endocrine and ophthalmologic evaluations and no significant related findings on postnatal MRI. One subject without septo-optic dysplasia had delays on developmental screening; all others had normal screening (range of follow-up 8-72 months). Our study questions the necessity of postnatal imaging for prenatally diagnosed isolated absent septum pellucidum. Majority of fetuses with isolated absent septum pellucidum retained this diagnosis postnatally.