Follow-up study of macrocephalic children with enlargement of the subarachnoid space

Fetal wide subarachnoid space and its outcome in cases of macrocephaly without ventriculomegaly

Objective: To examine the occurrence and outcomes of fetuses with wide subarachnoid space (WSS) without ventriculomegaly in pregnant women with fetal macrocephaly as a sole diagnosis.Study design: A retrospective study was performed, analyzing patients with fetal macrocephaly between the years 2008 and 2018. All these patients underwent MRI, in order to detect brain anomalies. In the absence of any other brain abnormality, they were evaluated for WSS and their offspring's database was followed for at least two years after birth.Results: Ten patients were found to be carrying fetuses with macrocephaly, nine of them were diagnosed with WSS without ventriculomegaly prior to delivery. Following at least two years of follow up, all patients did not present significant neurodevelopmental abnormalities, apart from one child that had a genetic mutation of 15q21.2-22.31 deletion with other anomalies that were not diagnosed prenatally.Conclusions: We present herein for the first time in the literature a cohort of patients with a prenatal diagnosis of WSS without ventriculomegaly in fetuses with macrocephaly. Our data show that, in the presence of normal anomaly scan and normal chromosomal study, there is a low chance for significant neurodevelopmental abnormalities in fetuses with WSS without ventriculomegaly.

Benign external hydrocephalus: a review, with emphasis on management

Benign external hydrocephalus in infants, characterized by macrocephaly and typical neuroimaging findings, is considered as a self-limiting condition and is therefore rarely treated. This review concerns all aspects of this condition: etiology, neuroimaging, symptoms and clinical findings, treatment, and outcome, with emphasis on management. The review is based on a systematic search in the Pubmed and Web of Science databases. The search covered various forms of hydrocephalus, extracerebral fluid, and macrocephaly. Studies reporting small children with idiopathic external hydrocephalus were included, mostly focusing on the studies reporting a long-term outcome. A total of 147 studies are included, the majority however with a limited methodological quality. Several theories regarding pathophysiology and various symptoms, signs, and clinical findings underscore the heterogeneity of the condition. Neuroimaging is important in the differentiation between external hydrocephalus and similar conditions. A transient delay of psychomotor development is commonly seen during childhood. A long-term outcome is scarcely reported, and the results are varying. Although most children with external hydrocephalus seem to do well both initially and in the long term, a substantial number of patients show temporary or permanent psychomotor delay. To verify that this truly is a benign condition, we suggest that future research on external hydrocephalus should focus on the long-term effects of surgical treatment as opposed to conservative management.

Idiopathic macrocephaly in the infant: long-term neurological and neuropsychological outcome

RATIONALE

The long-term outcome of idiopathic macrocephaly is presently unknown.

METHODS AND RESULTS

In the current study (n=15), MRI conducted at long-term review showed regression of orbito-frontal extradural collections and normal or slightly enlarged ventricular space compared to infant examination. Head circumference had normalised in all but one participant. Neuropsychological assessments of nine participants showed general intellectual ability within the normal range in the majority of participants; however, specific deficits in attention were evident. Clinical interviews conducted with a smaller sub-group revealed anecdotal histories of behavioural difficulties and reading or arithmetic difficulties in half of the total sample.

CONCLUSIONS

Prospective review studies such as this indicate that abnormal radiological findings in infancy are not necessarily predictive of neurodevelopmental problems and may reflect a normal variant. However, while overall intellectual ability may be within average limits in this diagnostic sample, considerable individual variations remain in specific areas of neuropsychological function.

Magnetic resonance imaging characteristics of benign macrocephaly in children

Benign macrocephaly of infancy is a common problem in the child neurology practice. The radiologic features of this entity are not well defined. In most of the previous studies, macrocephalic patients were evaluated by computed tomography. To define the radiologic characteristics of this entity, 20 children with macrocephaly with normal neurologic examinations were enrolled in the study. All the patients were evaluated by magnetic resonance imaging studies. Sixty-five percent of patients had enlargement of the subarachnoid space and 35% of patients had megalencephaly. None of the patients had subdural collections. The mean age of patients with enlargement of the subarachnoid space was found to be younger than those with megalencephaly. The cases with parental histories of macrocephaly demonstrated both enlargement of the subarachnoid space and megalencephaly. Our results suggest that the radiologic finding of benign macrocephaly can be both enlargement of the subarachnoid space and megalencephaly.

[Idiopathic peri-cerebral enlargement in infants: simple anatomical variant or hemorrhagic risk factor?]

BACKGROUND

Idiopathic subarachnoid space enlargement (ISSE) is usually regarded as a benign lesion.

CASE REPORTS

Two infants, 6 and 8 months old respectively, were hospitalized for neurological disorders revealing subdural hematoma. The first one was drowsy after an apparent life threatening event. The CT scan showed a recent subdural hematoma with ISSE. The outcome was spontaneously uneventful. The second patient presented a febrile hemiconvulsion preceding a status epilepticus. The diagnosis of empyema complicating subdural hematoma with ISSE was done on MRI. Recovery occurred after a 3 week course of parenteral antibiotics and 1 year of antiepileptic treatment. In these two cases, there was no history of head injury and the retrospective study of cranial perimeter growth curves showed acceleration before the acute event.

CONCLUSION

The reputation of benignity is not usurped regarding the ISSE. Nevertheless, it must be recognized as a factor furthering emergence of subdural hematoma, even in absence of injury context.