Idiopathic Normal Pressure Hydrocephalus and Elderly Acquired Hydrocephalus: Evaluation With Cerebrospinal Fluid Flow and Ventricular Volume Parameters.

Wen-Jie He,Xian-Jian Huang,Qi-Zhong Xu,Guang Yang,Jun Jiang,Xi Zhou,Jia Long,Jun Xia

doi:10.3389/fnagi.2020.584842

Abstract

PurposeTo investigate differences in cerebrospinal fluid (CSF) flow through the aqueduct and to determine whether there is a relationship between CSF flow and ventricular volume parameters in idiopathic normal pressure hydrocephalus (iNPH) patients, elderly acquired hydrocephalus patients and age-matched healthy volunteers by phase-contrast MR (PC-MR).MethodsA total of 40 iNPH patients and 41 elderly acquired hydrocephalus patients and 26 age-matched healthy volunteers in the normal control (NC) group were included between November 2017 and October 2019 in this retrospective study. The following CSF flow parameters were measured with PC-MR: peak velocity, average velocity (AV), aqueductal stroke volume (ASV), net ASV, and net flow. The following ventricular volume parameters were measured: ventricular volume (VV), brain volume, total intracranial volume, and relative VV. Differences between the iNPH and acquired hydrocephalus groups were compared Mann–Whitney U test and correlations between CSF flow and ventricular volume parameters were assessed using the Spearman correlation coefficient.ResultsAqueductal stroke volume was significantly higher in the iNPH and acquired hydrocephalus groups than in the NC group, but did not differ significantly between the iNPH group and acquired hydrocephalus group. The AV, net ASV, and net flow in the iNPH and acquired hydrocephalus groups were significantly higher than those in the NC group (P < 0.0001), and those in the acquired hydrocephalus group were significantly higher than those in the iNPH group (P = 0.01, P = 0.007, P = 0.002, respectively). The direction of the AV and net ASV significantly differed among the three groups. There were no associations between the volume parameters and CSF flow according to PC-MR among the three groups.ConclusionCompared with iNPH, elderly acquired hydrocephalus demonstrated higher CSF hyperdynamic flow. Although increased CSF flow may contribute to further changes in ventricular morphology, there is no linear relationship between them. These findings might help increase our understanding of flow dynamics in iNPH and elderly acquired hydrocephalus.

Highlights

Normal pressure hydrocephalus (NPH), first reported by Adams et al (1965), is a treatable syndrome with a triad of symptoms comprising gait instability, cognitive disturbances, urinary incontinence and the presence of normal cerebrospinal fluid (CSF) pressure on lumbar puncture
On the basis of the idiopathic NPH (iNPH) guidelines and the outcome of the CSF tap test within the department of neurosurgery (Relkin et al, 2005; Mori et al, 2012), patients fulfilled the diagnosis of possible iNPH, patients were diagnosed with acquired hydrocephalus that developed after known etiology, such as history of prior meningitis, trauma, intracranial hemorrhage, prior neurosurgery. 41 acquire hydrocephalus suffered from different types of etiologies: five patients had aneurysmal subarachnoid hemorrhage; 13 patients had intracranial hemorrhage; 19 patients had trauma, of which 16 patients underwent cranioplasty; three patients had prior neurosurgery because of brain tumor; one patient had meningitis
There were no associations between the volume parameters (VV, brain volume, sulcal volume, total intracranial volume, ventricular volume (VV)/ sulcal volume, and relative VV) and CSF flow parameters in the iNPH group, acquired hydrocephalus group or normal control (NC) group (Table 2)

Summary

Introduction

Normal pressure hydrocephalus (NPH), first reported by Adams et al (1965), is a treatable syndrome with a triad of symptoms comprising gait instability, cognitive disturbances, urinary incontinence and the presence of normal cerebrospinal fluid (CSF) pressure on lumbar puncture. Previous studies used PC-MRI to demonstrate that patients with iNPH presented net retrograde aqueductal flow and hyperdynamic flow of CSF (Ringstad et al, 2016; Yin et al, 2017). Several CSF parameters measured with PCMR, including both aqueductal stroke volume (ASV) and net ASV, may play an important role in the pathophysiology of ventriculomegaly in iNPH patients (Bradley et al, 1996; Ringstad et al, 2016; Yin et al, 2017). Ventricular enlargement is a key diagnostic criterion for hydrocephalus, but it remains unclear whether the increase in CSF flow stems from or causes the changes in ventricular morphology that are observed in iNPH and acquired hydrocephalus (Chiang et al, 2009; Yin et al, 2017). CSF flow dynamics parameters measured in the cerebral aqueduct may be partly age and sex dependent (Sartoretti et al, 2019)

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