Normal pressure hydrocephalus and large head size.

OBJECTIVE

To determine if patients with normal pressure hydrocephalus (NPH) have larger head size than normal controls.

BACKGROUND

In 1989, Graff-Radford and Godersky noted that 3 of 30 patients diagnosed with NPH had large heads. They hypothesized that the cause of NPH in their patients was arrested congenital hydrocephalus becoming symptomatic later in life.

METHODS

Participants included 31 newly diagnosed NPH patients (21 male, 10 female) seen by the same neurologist (N.R.G.-R.) at Mayo Clinic Jacksonville from January 1, 1995 through December 31, 2000, and 459 normal controls (226 male, 233 female) from the Charlotte County Healthy Aging Study.

RESULTS

Head size was statistically larger for NPH males (median, 59.0 cm, range, 57.0-63.0 cm) compared with normal males (median, 57.8 cm, range, 53.3-62.8) (p < 0.01). Head size was also larger for NPH females (median, 6.3 cm, range, 53.5-58.0 cm) compared with normal females (median, 54.6 cm, range, 51.4-59.7 cm) (p < 0.02).

CONCLUSION

Patients with NPH have larger head circumferences as a group than normal controls. This was found in both males and females. Results suggest that a significant proportion of patients with NPH may have congenital hydrocephalus that becomes symptomatic later in life.