Epidemiology, pathogenesis, and etiology of iNPH (familial NPH as a novel subgroup of NPH, and a risk gene for iNPH)

Yoshimi Takahashi^1,2), Takeo Kato^1,3)

¹⁾Division of Neurology and Clinical Neuroscience, Department of Internal Medicine III, Yamagata University Faculty of Medicine
²⁾Zion Medical Corporation Association Haneda Clinic
³⁾Inspector-General of Healthcare, Yamagata City Hall

Idiopathic normal pressure hydrocephalus (iNPH) is a late-onset, progressive disease with gait disturbance, cognitive impairment and/or urinary incontinence.　Brain imaging shows ventriculomegaly (Evans index > 0.3), tight high convex, and widening of Sylvian fissure, the combination of which are called “Disproportionately Enlarged Subarachnoid-space Hydrocephalus:DESH”.　Four population-based studies showed the prevalence of possible iNPH withMRI support (DESH) to be 1.6% among the community-dwelling, Japanese elderlies.　The cause of iNPH remains unknown;however, the presence of familial NPH indistinguishable clinically and on MRI with iNPH and the familial aggregation of iNPH strongly suggest a genetic predisposition of iNPH.　We found a copy number loss within intron 2 of the SFMBT1 gene as a genetic risk for shunt-responsive definite iNPH.

Address correspondence to Dr. Yoshimi Takahashi, Division of Neurology and Clinical Neuroscience, Department of Internal Medicine III, Yamagata University Faculty of Medicine (2-2-2 Iidanishi, Yamagata-city, Yamagata prefecture 990-2331, Japan)