Cerebral ventriculomegaly in myotonic dystrophy type 1: normal pressure hydrocephalus-like appearances on magnetic resonance imaging

Abstract

Background Cerebral ventriculomegaly is an abnormal feature characteristic of myotonic dystrophy type 1 (DM1). This retrospective study investigated the morphologic changes accompanied by ventriculomegaly in DM1 on brain MRI. Methods One hundred and twelve adult patients with DM1 and 50 sex- and age-matched controls were assessed. The imaging characteristics for evaluations included the z-Evans Index (ventriculomegaly), callosal angle (CA), enlarged perivascular spaces in the centrum semiovale (CS-EPVS), temporo-polar white matter lesion (WML) on 3D fluid-attenuated inversion recovery (FLAIR), disproportionately enlarged subarachnoid-space hydrocephalus (DESH), and pathological brain atrophy. The “z-Evans Index” was defined as the maximum z-axial length of the frontal horns to the maximum cranial z-axial length. To determine the imaging characteristics and genetic information (CTG repeat numbers) that were associated with the z-Evans Index, we used binominal logistic regression analyses. Results The z-Evans Index was significantly larger in the patients than in the controls (0.30 ± 0.05 vs. 0.24 ± 0.02; p < 0.01). The z-Evans Index was independently associated with the callosal angle (p < 0.01) and pathological brain atrophy (p < 0.01) but not with age, gender, CTG repeat numbers, or CS-EPVS. Of the 34 patients older than 49 years, 7 (20.6%) were considered to have DESH. Conclusions Our MRI study revealed a normal pressure hydrocephalus (NPH)-like appearance as a morphologic finding accompanied by ventriculomegaly in DM1 that tends to occur in elderly patients.

Normal-Pressure Hydrocephalus-Like Appearance in Myotonic Dystrophy Type 1

“…In elderly DM1 group, prevalence of DESH was 21% and the z-Evans index [12], an improved version of the Evans index, increased with age [11]. Notably, there was no significant difference in average callosal angle between DM1 and age-matched control (DM1 and control; 123° vs. 123°) [11].…”

“…In the brain imaging of DM1, several findings are reported including whole-brain atrophy, increased ventricular volume, widespread volume reduction of cortical and deep gray matter and reduced cortical thickness (occipital, parietal and temporal lobes) [ 10 ]. Additionally, an MRI study of 112 patients with DM1 revealed that NPH-like appearances including enlarged ventricles and DESH are frequent signs in DM1 over 50 years old [ 11 ]. In elderly DM1 group, prevalence of DESH was 21% and the z-Evans index [ 12 ], an improved version of the Evans index, increased with age [ 11 ].…”

“…Additionally, an MRI study of 112 patients with DM1 revealed that NPH-like appearances including enlarged ventricles and DESH are frequent signs in DM1 over 50 years old [ 11 ]. In elderly DM1 group, prevalence of DESH was 21% and the z-Evans index [ 12 ], an improved version of the Evans index, increased with age [ 11 ]. Notably, there was no significant difference in average callosal angle between DM1 and age-matched control (DM1 and control; 123° vs. 123°) [ 11 ].…”

“…In elderly DM1 group, prevalence of DESH was 21% and the z-Evans index [ 12 ], an improved version of the Evans index, increased with age [ 11 ]. Notably, there was no significant difference in average callosal angle between DM1 and age-matched control (DM1 and control; 123° vs. 123°) [ 11 ]. Additionally, the diagnosis of NPH is generally evaluated by TT, whereas the sensitivity and specificity of TT for NPH vary among previous reports; sensitivity: 72%-100% and specificity: 33%-100% [ 13 - 16 ].…”

In Vivo Parieto-Occipital White Matter Metabolism Is Correlated with Visuospatial Deficits in Adult DM1 Patients

“…Brain involvement in DM1 includes the presence of hyperostosis and whole brain atrophy, mostly evaluated in group analysis using advanced brain MRI techniques [ 5 ], and subcortical atrophy in form of increased ventricular volume that rarely can result in a severe cerebral ventriculomegaly with a normal pressure hydrocephalus-like appearance on MR imaging [ 6 ].…”