Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 May;78(5):508-11.
doi: 10.1136/jnnp.2006.108761. Epub 2007 Jan 3.

Evidence that congenital hydrocephalus is a precursor to idiopathic normal pressure hydrocephalus in only a subset of patients

Robin K Wilson  1 , Michael A Williams
Affiliations

Evidence that congenital hydrocephalus is a precursor to idiopathic normal pressure hydrocephalus in only a subset of patients

Robin K Wilson et al. J Neurol Neurosurg Psychiatry. 2007 May.

Abstract

Objective: To identify the proportion of patients in a large idiopathic normal pressure hydrocephalus (INPH) cohort with large head circumference (HC) who presumably have congenital hydrocephalus that has not become clinically apparent until late in life.

Methods: HC was measured in 158 patients diagnosed with communicating INPH and assigned to HC centile range adjusted for height and sex. The proportion of patients with INPH and HC above the 97th, 90th or 50th centiles was compared with the proportion expected in a normal population.

Results: The proportion of patients with HC >90th centile was significantly larger than would be expected in a normal distribution (19.6% vs 10%, p = 0.0001), as was the proportion of patients with HC >97th centile (8.9% vs 3%, p = 0.0001). The relative association between INPH and HC >97th centile was nearly tripled (relative association 2.95; CI 1.36 to 6.41), but the relative association between INPH and HC >50th centile was not significantly higher than predicted (relative association 1.13; CI 0.95 to 1.34).

Conclusion: A significantly larger proportion of elderly adults with INPH have a HC greater than the 90th or 97th centile than predicted by population norms, supporting the concept that compensated congenital hydrocephalus that does not become symptomatic until late in life is one aetiology of INPH, but is not responsible for all INPH. The mechanism that leads to the development of INPH in most patients remains elusive.

PubMed Disclaimer

Conflict of interest statement

Competing interests: RKW has no personal or institutional financial interest in drugs, materials or devices described in this report. In the 12 months prior to the submission of this manuscript, MAW has received honoraria from Medtronic for speaking on the topic of adult hydrocephalus. The Johns Hopkins Adult Hydrocephalus Program has received support from Medtronic for research related to adult hydrocephalus, but not related to the topic of this manuscript.

References

    1. McGirt M J, Woodworth G, Coon A L.et al Diagnosis, treatment, and analysis of long‐term outcomes in idiopathic normal‐pressure hydrocephalus. Neurosurgery 200557699–705. - PubMed
    1. Graff‐Radford N R, Godersky J C. Symptomatic congenital hydrocephalus in the elderly simulating normal pressure hydrocephalus. Neurology 1989391596–1600. - PubMed
    1. Krefft T A, Graff‐Radford N R, Lucas J A.et al Normal pressure hydrocephalus and large head size. Alzheimer Dis Assoc Disord 20041835–37. - PubMed
    1. Bradley W G, Safar F G, Furtado C.et al Increased intracranial volume: a clue to the etiology of idiopathic normal‐pressure hydrocephalus? Am J Neuroradiol 2004251479–1484. - PMC - PubMed
    1. Bradley W G, Jr, Bahl G, Alksne J F. Idiopathic normal pressure hydrocephalus may be a “two hit” disease: benign external hydrocephalus in infancy followed by deep white matter ischemia in late adulthood. J Magn Reson Imaging 200624747–755. - PubMed