The prevalence and clinical associations of disproportionately enlarged subarachnoid space hydrocephalus (DESH), an imaging feature of idiopathic normal pressure hydrocephalus in community and memory clinic based Singaporean cohorts

Abstract

Introduction: Disproportionately Enlarged Subarachnoid space Hydrocephalus (DESH) is considered as an important imaging feature of idiopathic normal pressure hydrocephalus (iNPH). Method: Subjects aged 60 and over in a memory clinic and a community-based cohort were assessed for the presence of ventriculomegaly, Sylvian dilatation, and high convexity tightness by neuroimaging, and a clinical triad of iNPH symptoms, i.e. cognitive, gait and urinary symptoms. Results: In the memory clinic-based study (548 subjects), the prevalence of DESH was 1.1% and increased with age. The clinical triad was significantly more frequent in subjects with DESH (50%) compared to those with normal images (none), Sylvian dilatation (7%), and ventriculomegaly (12%). Gait disturbance was also significantly more frequent in DESH (83%) compared to those with normal images (2%), Sylvian dilatation (14%), and ventriculomegaly (26%). In the community-based cohort (946 subjects), the prevalence of DESH was 1.0% and increased with age. The clinical triad (11%) was significantly more common in subjects with DESH compared to those with normal images (none), Sylvian dilatation (2%), and ventriculomegaly (7%). Gait disturbance was also significantly more common in DESH (33%) compared to those with normal images (1%), Sylvian dilatation (4%), and ventriculomegaly (10%). Conclusion: The reported prevalence of DESH was approximately 1%, and increased with age. DESH and high convexity tightness were specifically associated with the clinical triad of iNPH. Of the triad, gait disturbance was associated to DESH and high convexity tightness. 1. Introduction With rapidly aging societies globally, the medical care of the elderly has become an important social issue. As aging is the strongest risk factor for dementia, the burden of dementia is increasing worldwide, and has major impact on quality of life as well as the economy [1,2]. Idiopathic normal pressure hydrocephalus (iNPH) is a neurodegenerative disease of the elderly, marked by triad of symptoms:

CSF dynamics as a predictor of cognitive progression

“…Although CSF dynamics disorders have been under-appreciated in clinical and research setting, awareness is beginning to grow. Recent studies have shown the prevalence of DESH imaging features to be approximately 1–7% in community-based populations ( Akiba et al, 2020 ; Graff-Radford et al, 2019 , ; Hiraoka et al, 2008 ; Jaraj et al, 2014 ). Although less common than Alzheimer’s disease or cerebrovascular disease, CSF dynamics disorders warrants consideration in evaluation of cognitive decline.…”

“…DESH has been found to predict clinical improvement in NPH symptomatology following CSF shunting ( Hashimoto et al, 2010 ; Narita et al, 2016 ). DESH has since been more widely recognized in the community and has been found to be associated with worse cognition ( Akiba et al, 2020 ; Graff-Radford et al, 2019 ; Hiraoka et al, 2008 ). Although few studies have shown the presence of DESH imaging features in community or non-NPH study populations, the clinical significance of DESH with regard to cognitive decline outside of NPH is not yet well defined.…”

Magnetic resonance imaging findings of idiopathic normal pressure hydrocephalus and cognitive function before and after ventriculoatrial shunt

“…After the introduction of guidelines, only the patients who fulfilled the radiological diagnostic criteria have been selected for shunt surgery. [ 7 8 13 27 28 29 30 31 32 ] It has been difficult to verify the validity of EI >0.3 as the radiological diagnostic criteria for iNPH. Naruse and Matsuoka reported the symptoms of all the 14 patients improved remarkably by shunt despite EI ≤0.3.…”

Update on the Cognitive Presentations of iNPH for Clinicians

“…A number of recent studies have now investigated the presence of DESH in the wider population, where it is found in 1–7% and associated with poorer cognition ( 49 – 52 ). A study examining over a thousand participants with either no or only mild cognitive impairment found that DESH was a predictor of progressive cognitive decline independent of established features including age, cortical thickness, or APOE status ( 48 ).…”