Enlarged subarachnoid spaces and intracranial hemorrhage in children with accidental head trauma

Subdural hematoma prevalence and long-term developmental outcomes in patients with benign expansion of the subarachnoid spaces

OBJECTIVE

Benign expansion of the subarachnoid spaces (BESS) is a condition seen in macrocephalic infants. BESS is associated with mild developmental delays which tend to resolve within a few years. It is accepted that patients with BESS are at increased risk of spontaneous subdural hematomas (SDHs), although the exact pathophysiology is not well understood. The prevalence of spontaneous SDH in BESS patients is poorly defined, with only a few large single-center series published. In this study the authors aimed to better define BESS prevalence and developmental outcomes through the longitudinal review of a large cohort of BESS patients.

METHODS

A large retrospective review was performed at a single institution from 1995 to 2020 for patients 2 years of age or younger with a diagnosis of BESS by neurology or neurosurgery and head circumference > 85th percentile. Demographic data, head circumference, presence of developmental delay, occurrence of SDH, and need for surgery were extracted from patient charts. The subarachnoid space (SAS) size was measured from the available MR images, and the sizes of those who did and did not develop SDH were compared.

RESULTS

Free text search revealed BESS mentioned within the medical records of 1410 of 2.6 million patients. After exclusion criteria, 480 patients remained eligible for the study. Thirty-two percent (n = 154) of patients were diagnosed with developmental delay, most commonly gross motor delay (53%). Gross motor delay resolved in 86% of patients at a mean age of 22.2 months. The prevalence of spontaneous SDH in this BESS population over a period of 25 years was 8.1%. There was no significant association between SAS size and SDH formation.

CONCLUSIONS

This study represents results for one of the largest cohorts of patients with BESS at a single institution. Gross motor delay was the most common developmental delay diagnosed, and a majority of patients had resolution of their delay. These data support that children with BESS have a higher prevalence of SDH than the general pediatric population, although SAS size was not significantly associated with SDH development.

Pathogenic variant in NFIA associated with subdural hematomas mimicking nonaccidental trauma

Subdural hematoma (SDH) in infants raises the concern for nonaccidental trauma (NAT), especially when presenting with associated injuries. However, isolated SDH could be caused by multiple etiologies. NFIA (MIM# 600727) encodes nuclear factor I A protein (NFI-A), a transcription factor which plays important roles in gliogenesis. Loss-of-function variants in NFIA are associated with autosomal dominant brain malformations with or without urinary tract defects (MIM# 613735). Intracranial hemorrhage of various types besides SDH has been reported in patients with this condition. Here, we report a patient with a heterozygous novel NFIA pathogenic variant affecting splicing who initially presented with SDH concerning for NAT. We also review previous NFIA-related disorder cases with intracranial hemorrhage. This report emphasizes the importance of genetic evaluation in infants presenting with isolated SDH.

Computed Tomography Measurement and Evaluation of the Subarachnoid Space Over Cerebral Convexities in Infants Aged 1-24 Months

A widened subarachnoid space might be pathologic, potentially pathologic, or simply a normal developmental variant. However, the definition of a normal subarachnoid space width in infants remains unclear, especially on computed tomography (CT) images. To determine the physiological subarachnoid space width among infants aged 1-24 months, its upper limit, and changes with age, we measured the cerebrospinal fluid width on 538 CT images. Measurements were obtained at fixed planes and fixed positions to prevent variance and increase comparability between patients. We observed an asymmetry in the cerebrospinal fluid width of the temporal region. The width increased in all positions until 4-6 months of age, after which it began to decrease, reaching a relatively stable range in infants aged 13-24 months. We suggest considering the 95th percentile of the cerebrospinal fluid width as the upper limit. The correlation between age and the subarachnoid space width should be considered during clinical diagnosing.

External Hydrocephalus After Traumatic Brain Injury: Retrospective Study of 102 Patients

INTRODUCTION

External hydrocephalus (EH) refers to impairment of extra-axial cerebrospinal fluid flow with enlargement of the subarachnoid space (SAS) and concomitant raised intracranial pressure (ICP). It is often confused with a subdural hygroma and overlooked, particularly when there is no ventricular enlargement. In this study, we aimed to describe the epidemiology of EH in a large population of adults with traumatic brain injury (TBI).

METHODS

This observational, retrospective cohort study was conducted in adult patients who were admitted with TBI to the Department of Clinical Neuroscience at Addenbrooke's Hospital (Cambridge, UK) over a period of 3 years (2014-2017). Patients were included in the study if they had ICP monitoring and at least three CT scans within the first 21 days to assess SAS evolution. Patients who underwent a decompressive craniectomy were excluded. SAS was assessed individually on each CT scan by two independent investigators. ICP data were analysed with ICM+ software (Cambridge Enterprise Ltd., Cambridge, UK). Short-term and 6-month outcomes were examined. The groups of patients with and without EH were compared.

RESULTS

Of the 102 patients included in the study, 30.4% developed EH after a delay of 2.98 ± 2.4 days. The initial Glasgow Coma Scale (GCS) scores did not differ between patients with and without EH. Subarachnoid haemorrhage was found to be the main risk factor for EH. Patients with EH required a significantly longer period of mechanical ventilation (+6.9 days), were more likely to have a tracheostomy (55% versus 33%), and had a longer stay in the intensive care unit (+8.5 days). ICP was higher during the 48 h after diagnosis of EH than during the previous 48 h. EH survivors had a lower mean Glasgow Outcome Scale Extended (GOS-E) score (4.6 versus 5.9, P = 0.031) and were more likely to receive a permanent shunt for secondary hydrocephalus (17.4% versus 1.8%, odds ratio 7.1).

CONCLUSION

In adults with TBI, EH remains insufficiently understood and probably underdiagnosed. This study showed that it is a frequent complication of TBI, with significant clinical consequences.