Benign Enlargement of Subarachnoid Spaces in Infancy with Developmental Delay

doi:10.21203/rs.3.rs-2740171/v1

Download PDF

Case Report

Benign Enlargement of Subarachnoid Spaces in Infancy with Developmental Delay

https://doi.org/10.21203/rs.3.rs-2740171/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Background

Benign enlargement of subarachnoid spaces (BESS) is a common cause of macro crania in infancy and may present with developmental delay due to enlargement of the brain. The self-limiting nature of this condition allows most children to regain developmental milestones as they grow older. The aetiology of developmental delay in full-term infants with BESS is unclear and prognosis varies since only some children have been reported to have long-term deficit in gross motor and language domains.

Case presentation:

This case report illustrates the clinical profile and findings on brain imaging in a full-term infant who presented with BESS along with delay in attaining age-appropriate gross motor and language milestones. Assessment of developmental milestones at 15 months of age supported the benign nature of this condition although the head circumference remained above the 95th percentile for age.

Conclusions

Despite the self-resolving nature of this condition, regular evaluation of developmental milestones is necessary to ensure timely intervention in appropriate cases. Further research on the aetiology could also aid clinicians in determining which children are at risk for developing long-term developmental delay.

Benign enlargement of subarachnoid spaces

external hydrocephalus

developmental delay

macrocephaly

intracranial pressure

Benign enlargement of subarachnoid spaces in infancy is a self-limiting condition that presents as macrocephaly. It is more common in male infants with an enlarged head circumference in the father¹. Head circumference at birth is usually normal and macrocephaly is evident at about 3–12 months of age². These children lack features of raised intracranial pressure or periventricular lucency although mild ventricular enlargement may be present³. It is also referred to as benign external hydrocephalus or extra-ventricular hydrocephalus².Developmental delay in a child with BESS has been attributed to the stagnant flow of CSF in the subarachnoid space which affects cortical development since CSF helps in transporting growth factors and removing toxic metabolites⁴.While some children show normal development, others develop deficits in gross motor and rarely, language skills. Due to the benign, self-resolving nature of this condition, most children regain age-appropriate developmental milestones at follow-up. Developmental delay in children with BESS needs to be distinguished from other possible causes like TORCH infections, mucopolysaccharidoses, rickets and intracranial haemorrhage.

A 11-month-old boy was brought by his parents to the out-patient department (OPD) with complaints of rapid increase in the size of his head over the past five months. He was born at term via lower segment caesarean section due to prolonged labour and weighed 3.5 kg at birth. Head circumference at birth was normal at 35cm. Maternal and paternal head circumference were 53 cm and 55.5 cm respectively. Family history revealed no similar occurrence of macro crania. Prenatal history was insignificant for toxoplasmosis, rubella, cytomegalovirus, herpes simplex, and HIV (TORCH) infections during pregnancy. Postnatally, the child had no history of significant infection or trauma. Immunisations were up to date. Length and weight on presentation were 70 cm (between the 3rd -95th percentile) and 7.08 kg (< 3rd percentile). Head circumference on examination was 51cm (> 95th percentile for age). Developmental assessment revealed delay in attaining gross motor milestones (developmental quotient (DQ) = 55) and a delay in speech (DQ = 64). On neurological examination, muscle tone, power and reflexes were within normal limits. Magnetic resonance imaging (MRI) and computerised tomography (CT) revealed enlargement of subarachnoid spaces bilaterally in the frontal and temporal regions of the brain (Fig. 1).

Follow-up evaluation at 15 months of age revealed a head circumference of 51 cm (> 95th percentile) and a DQ of 80 and 67 on assessment of gross motor milestones and speech, respectively. Gross motor milestones and speech were regained to age-appropriate levels on evaluation at 18 months of age, however, the child’s head circumference remained slightly above the 95th percentile.

Macrocrania in infancy due to extra- axial fluid collection in the brain is also referred to as external hydrocephalus or benign enlargement of sub-arachnoid spaces. When familial, it presents with a head circumference greater than the 95th percentile in the parent and has a male preponderance⁵. The aetiology behind extracellular fluid collection in the brain in term infants has been attributed to immaturity of the arachnoid villi⁶. This explains the spontaneous resorption of CSF as the child grows older thereby allowing most children to regain developmental milestones. Kuruvilla et al., reported a decrease in size of subarachnoid spaces 14 months following admission of a 4-month-old infant despite an enlarged head circumference⁷.

Our patient was born at term with normal head circumference. Enlargement of head circumference was observed at about 6 months of age. Developmental delay in children with BESS and prior history of trauma could be a consequence of damage to the developing brain. Having ruled out history of trauma, infection during pregnancy or other genetic causes like mucopolysaccharidoses or deficiency of vitamin D, our patient was most likely susceptible to developmental delay due to the stagnant flow of CSF. Pre-term infants with BESS were found to have a higher risk for developing deficits in gross and fine motor function domains as compared to term infants with BESS⁸.

Nickel et al., reported gross motor delay in 7 of 9 children who presented with BESS during their first year of life⁶. These children had age-appropriate gross milestones on follow-up, however, 3 children had persistent speech delay. The inability to regain certain milestones can point towards the development of autism spectrum disorder⁴. Thus, BESS may not always have a transient delay in the development of a child bringing to question the benign nature of this condition⁹. The aetiology behind persistent deficit in gross motor and speech domains on follow-up in selective infants with BESS is unknown and further research on this would help clinicians predict prognosis of these infants and arrange for appropriate interventions to prevent long-term deficits.

Benign enlargement of subarachnoid spaces (BESS), cerebrospinal fluid (CSF), developmental quotient (DQ), magnetic resonance imaging (MRI), computerised tomography (CT), toxoplasmosis, rubella, cytomegalovirus, herpes simplex, and HIV (TORCH), out-patient department (OPD).

Ethics approval and consent to participate: Ethics approval was not applicable for this case report.

Consent for publication: Consent was obtained from the family.

Competing interests: The authors have no relevant financial or non-financial interests to disclose.

Funding: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.

Karimzadeh, Parvaneh, Tonekaboni et al., Benign External Hydrocephalus and Its Relation to Familial Megalencephaly: An Analysis of 20 Cases. J. Pediatr. Neurol. 2009;157–163.
Khosroshahi N, Nikkhah A. Benign Enlargement of Subarachnoid Space in Infancy: "A Review with Emphasis on Diagnostic Work-Up". Iran. J. Child Neurol 2018;12(4),7–15.
Kumar R. External hydrocephalus in small children. Child's Nerv Syst 2006;22(10),1237-1241.
Shen MD, Nordahl CW, Young GS et al., Early brain enlargement and elevated extra-axial fluid in infants who develop autism spectrum disorder. Brain. 2013;136:2825-35.
Day RE, Schutt WH. Normal children with large heads-benign familial megalencephaly. Arch Dis Child 1979;54(7),512–517.
Nickel RE, Gallenstein JS. Developmental prognosis for infants with benign enlargement of the subarachnoid spaces. Dev Med Child Neurol 1987;29(2),181–186.
Kuruvilla LC. Benign enlargement of sub-arachnoid spaces in infancy. J Pediatr Neurosci 2014;9(2), 129–131.
Maruccia F, Gomáriz L, Rosas K et al., Neurodevelopmental profile in children with benign external hydrocephalus syndrome. A pilot cohort study. Child’s Nerv Syst 2021;37(9),2799–2806.
Zahl SM, Egge A, Helseth E et al., Benign external hydrocephalus: a review, with emphasis on management. Neurosurg. Rev. 2011;34(4),417–432.

No competing interests reported.

Download PDF

Version 1

posted

You are reading this latest preprint version

Benign Enlargement of Subarachnoid Spaces in Infancy with Developmental Delay

Status:

Version 1

Abstract

Background

Case presentation:

Conclusions

Figures

Background

Case Presentation

Conclusions

abbreviations

Declarations

References

Additional Declarations

Status:

Version 1