Paradigm-shift: radiological changes in the asymptomatic iNPH-patient to be: an observational study

Abstract

BackgroundMany radiological signs are known for the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). However, there is little information about these signs in the pre-symptomatic phase. For pathophysiological investigative purposes we conducted a descriptive image analysis study on pre-symptomatic patients.MethodsPatients that had contact with either the neurological or neurosurgical department of the university hospital Tuebingen from 2010 through 2016 with magnetic resonance images > 3 years before onset of symptoms, were included. The date of onset and severity of symptoms, date of first imaging and birth date were recorded. Evan’s index (EI), width of the third ventricle (3VW), tight high convexity (THC), Sylvian fissure, extent of white matter hyperintensities and aqueductal flow were assessed in images before and around symptom onset.ResultsTen patients were included. In all ten patients the first symptom was gait disturbance. Nine of ten pre-symptomatic images showed classic signs for iNPH. EI showed a significant increase between the pre-symptomatic and symptomatic phase. 3VW showed a trend for increase without significance. THC changed back and forth over time within some patients.ConclusionsIn accordance with the scarce literature available, radiological changes are present at least 3 years before onset of iNPH-symptoms. EI seems to be a robust measure for pre-symptomatic radiological changes. Extrapolating the data, the development of iNPH typical changes might be an insidious process and the development of THC might be a variable and non-linear process. Further studies with larger sample sizes are necessary to put these findings into the pathophysiological perspective for the development of iNPH.

Diffusion Tensor Imaging of the Superior Thalamic Radiation and Cerebrospinal Fluid Distribution in Idiopathic Normal Pressure Hydrocephalus

“…Follow‐up quantitative sulcal CSF distribution studies on a larger scale might prove this technique to be promising in quantifying and detecting subtle changes in early stages of iNPH, particularly with the rising evidence of MRI changes years before the onset of iNPH symptoms . While the total sCSFV of iNPH was comparable and not significantly different from the sCSFV in Alzheimer's and age‐matched HE across lifespan.…”

“…Diffusion‐weighted data using a single‐shot, spin‐echo diffusion sensitized echo‐planar imaging (EPI) sequence with the balanced Icosa21‐encoding scheme, a diffusion sensitization of b = 1,000 s/mm 2 , and repetition times (TRs) and echo times (TEs) of 7,900 ms and 70 ms, respectively. EPI distortion artifacts and scan time were reduced by using a SENSE acceleration factor ( R ) or k ‐space under sampling equals to 2 (ie, R = 2) . The slice thickness was 3 mm with 48 axial slices covering the entire brain, foramen magnum to vertex, a square field of view (FOV) = 256 × 256 mm 2 , and an image matrix of 256 × 256.…”

“…EPI distortion artifacts and scan time were reduced by using a SENSE acceleration factor (R) or k-space under sampling equals to 2 (ie, R = 2). [19][20][21] The slice thickness was 3 mm with 48 axial slices covering the entire brain, foramen magnum to vertex, a square field of view (FOV) = 256 × 256 mm 2 , and an image matrix of 256 × 256. The average number of nondiffusion-weighted or b ß 0 magnitude image was 8.…”

MRT bei neurodegenerativen Erkrankungen

“…Ein weiterer wichtiger Aspekt in Bezug auf die Bildgebung ist die Erkenntnis, dass das NPH-Bild ( = NPH-Aspekt) bereits länger als 3 Jahre vor Beginn der klinischen Symptomatik vorliegen kann [12]. Leukenzephalopathien werden als ausreichend für die Entwicklung einer Demenz angesehen, wenn sie mindestens ein Viertel der weißen Substanz einnehmen oder mit anderen vaskulären Läsionen gemeinsam auftreten [26].…”

MRT bei neurodegenerativen Erkrankungen

“…Ein weiterer wichtiger Aspekt in Bezug auf die Bildgebung ist die Erkenntnis, dass das NPH-Bild (= NPH-Aspekt) bereits länger als 3 Jahre vor Beginn der klinischen Symptomatik vorliegen kann [12].…”