Idiopathic normal pressure hydrocephalus: correlating magnetic resonance imaging biomarkers with clinical response.
Idiopathic Normal Pressure Hydrocephalus (NPH) is a debilitating condition of the elderly. The patient is typically "wet, wobbly and wonky", to different degrees of the triad. The diagnosis is supported by the radiologic finding of dilated ventricles, determined by an elevated Evan's Index (EI) without a demonstrable cause. Patients with newly diagnosed NPH typically respond to ventriculo-peritoneal shunting (VPS). NPH-related dementia is possibly the only surgically reversible dementia. An elevated cerebrospinal fluid (CSF) fl ow rate (FR) is associated with a positive response to shunting. However, post-shunting EI and FRs are unpredictable. Of late, intracranial apparent diffusion coefficient (ADC) quantification via Diffusion Weighted Imaging (DWI) has been emerging as a possible marker in NPH diagnosis. A local study, conducted on a national level, to study the relationship of EI, FR and ADC to pre- and post-shunt clinical measurements has just ended. This review seeks to reconcile the current thinking of NPH, magnetic resonance imaging (MRI) quantification and clinical evaluation, and in the process shed some light on major pathophysiological determinants of the disease.
Ng
Samuel E S
SE
Department of Radiology, Mount Elizabeth Hospital, Singapore. samnes@gmail.com
Low
Angela M S
AM
Tang
Kok Kee
KK
Lim
Winston E H
WE
Kwok
Robert K
RK
D015415:Biomarkers / Q000134:cerebrospinal fluid; D002555:Cerebrospinal Fluid / Q000378:metabolism / Q000502:physiology; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis* / Q000503:physiopathology
D015415:Biomarkers