PEDIATRICS Vol. 122 No. 1 July 2008, pp. 219-220 (doi:10.1542/10.1542/peds.2008-0995)
LETTER TO THE EDITOR |
What We Gain by Measuring Head Circumference
Robin K. Wilson, MD, PhDMichael A. Williams, MD
Adult Hydrocephalus Center
LifeBridge Health Brain & Spine Institute
Sinai Hospital
Baltimore, MD 21209
To the Editor.—
We applaud the recently published population-based study by Zahl and Wester,1 which demonstrates the importance of routine measurement of head circumference (HC) in infancy, and we wish to further emphasize the long-term benefit. Of 173 children diagnosed with primary hydrocephalus during their study period, rapidly increasing HC was the symptom that led to the diagnosis in 124 (72%) of the cases; in 99 (57%) cases, increasing HC was the only symptom of hydrocephalus. The article did not indicate how many infants with enlarging HC as the only symptom were treated surgically and how many were managed conservatively by observation.
For readers of Pediatrics who may not follow the literature on adult hydrocephalus, we wish to point out that it is possible for ventriculomegaly associated with enlarged HC to remain asymptomatic until adulthood. We have shown in a large cohort of patients with idiopathic normal-pressure hydrocephalus who were aged 
66 years that 20% had a HC above the 90th percentile as measured by adult norms,2 which is 10% more than predicted and, we have concluded, represents congenital hydrocephalus that remained asymptomatic until late in adult life.3 Many of our patients were born before the 1940s when pediatricians started measuring HC routinely, and many of those with large heads told us that they had difficulty fitting into hats or were teased about their head size during childhood.
We also note that we are frequently asked to evaluate young adults with previously unrecognized and, thus, untreated hydrocephalus who have a HC above the 97th percentile. Some patients are asymptomatic and are followed longitudinally; others have developed subtle symptoms of headache, imbalance, syncope, cognitive slowing, or urinary urgency, known as the syndrome of hydrocephalus in young and middle-aged adults, and improve after shunt surgery.4
Thus, early detection of hydrocephalus by HC measurement during infancy does not necessarily have to lead to early surgical treatment, because periodic, longitudinal monitoring of otherwise asymptomatic patients may be a reasonable alternative. A recent National Institutes of Health workshop has noted that there are no guidelines for surgical treatment of hydrocephalus in infants, children, or young adults.5
REFERENCES
- Zahl SM, Wester K. Routine measurement of head circumference as a tool for detecting intracranial expansion in infants: what is the gain? A nationwide survey. Pediatrics.2008; 121 (3). Available at: www.pediatrics.org/cgi/content/full/121/3/e416
- Bushby KM, Cole T, Matthews JN, Goodship JA. Centiles for adult head circumference. Arch Dis Child.1992; 67 (10):1286 –1287
- Wilson RK, Williams MA. Evidence that congenital hydrocephalus is a precursor to idiopathic normal pressure hydrocephalus in only a subset of patients. J Neurol Neurosurg Psychiatry.2007; 78 (5):508 –511
- Cowan JA, McGirt MJ, Woodworth G, Rigamonti D, Williams MA. The syndrome of hydrocephalus in young and middle-aged adults (SHYMA). Neurol Res.2005; 27 (5):540 –547
- Williams MA, McAllister JP, Walker ML, et al. Priorities for hydrocephalus research: report from an NIH-sponsored workshop. J Neurosurg.2007; 107 (5 suppl):345 –357
PEDIATRICS (ISSN 1098-4275). ©2008 by the American Academy of Pediatrics
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