PURPOSE: Benign external hydrocephalus (BEH) is characterized by excess 
cerebrospinal fluid in the frontal subarachnoid spaces in infants evaluated for 
macrocephaly. We sought to describe the natural history of this disorder, 
specifically its clinical presentation, disease course and long-term health 
status impact using the validated, disease-specific Hydrocephalus Outcome 
Questionnaire (HOQ).
METHODS: An inception cohort of children >5 and <18 years old, with a history of 
BEH was assembled by ICD-9 and a key word search of medical and radiology 
records. Review confirmed the diagnosis of BEH, excluded major medical 
comorbidities and assessed presentation, radiographic features and head 
size/growth velocity. The HOQ was administered by mail.
RESULTS: We identified 99 patients, 5-12 years old (55% males). Twenty were born 
prematurely, 12 with <33 weeks gestation. Children presented at an average age 
of 9 ± 4.8 months (mean ± SD). The presenting complaint was macrocephaly in 65 
cases. Other presenting findings were positional head shape deformity and 
torticollis; 10% had a family history of macrocephaly. Developmental delay was 
present in 21% of patients (4% verbal, 20% gross motor, 4% fine motor delay). 
Four patients had small subdural hematomas, none with suspicion of a 
non-accidental trauma. During clinical reassessment over a mean follow-up of 13 
months, the average head percentile was stable and none of the patients 
developed new subdural hematomas. Gross motor delay resolved in 15/20 and fine 
motor delay in 4/4 patients. Verbal delay resolved in 2/4 patients, but 
interestingly, was newly detected in 6 other children. None of the patients 
required cerebrospinal fluid shunting. The response rate to the HOQ was 25% 
(median age 7 years, 74% females). The average overall HOQ score was 0.75 ± 0.24 
versus 0.68 ± 0.19 for a previously published cohort of shunted hydrocephalic 
children.
CONCLUSIONS: BEH patients in this series generally saw resolution of presenting 
motor developmental delays; however, new verbal delays were detected in a 
non-trivial number of patients. Quality of life measurements suggest some 
reduction in health status, but less so than is seen with shunted hydrocephalus.