Open-aqueduct LOVA, LIAS, iNPH: a comparative clinical-radiological study exploring the "grey zone" between different forms of chronic adulthood hydrocephalus

Purpose

The definition of chronic adult hydrocephalus encompasses different pathological entities with overlapping characteristics, including long-standing overt ventriculomegaly in adults (LOVA), late-onset idiopathic aqueductal stenosis (LIAS) and idiopathic normal pressure hydrocephalus (iNPH). The aim of our study was to identify preoperative clinical and radiological features peculiar of these diseases providing some pathophysiology inferences on these forms of hydrocephalus.

Methods

Clinical and radiological preoperative records, type of surgical treatment and clinical outcome of patients with chronic adult hydrocephalus who were surgically treated between 2013 and 2019 were retrospectively reviewed. Univariate and multivariate analyses were performed to evaluate the contribution of each variable to the differential diagnosis.

Results

In total, 105 patients were included: 18 with LOVA, 23 with LIAS and 64 with iNPH. On multivariate analysis, an enlarged cisterna magna and a more severe ventriculomegaly were associated with the diagnosis of LOVA, while an older age and DESH with iNPH. LIAS patients tend to have an higher prevalence of raised ICP symptoms. Based on that, a clinical and radiological scoring system was developed to distinguish between iNPH and no iNPH cases. A precise cut-off value with a sensitivity of 95.1% and a specificity of 90.6% was identified.

Conclusions

LOVA, LIAS and iNPH are different forms of chronic adulthood hydrocephalus and present different and peculiar clinical and radiological features, with an impact on the treatment and outcome prediction. The implementation of a clinical-radiological score for differential diagnosis may help the differentiation. Further studies are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-022-05215-9.

Gait characteristics and effects of the cerebrospinal fluid tap test in probable idiopathic normal pressure hydrocephalus

OBJECTIVES

To evaluate gait characteristics and investigate changes pre- and post- cerebrospinal fluid tap test (CSF TT) in gait parameters in patients with probable idiopathic normal pressure hydrocephalus (iNPH).

METHODS

Sixty patients were sequential circuited and diagnosed with possible iNPH according to Japanese second iNPH guidelines at our hospital from December 2016 to March 2021. All patients underwent the CSF TT. Gait parameters, cognitive and urinary function were assessed pre- and post-CSF TT. Patients who were unable to ambulate to take the tests or could not walk independently or walked normally were excluded.

RESULTS

Twenty-six patients were diagnosed with probable iNPH using the CSF TT. After CSF TT, the Boon sum score improved from 20.0 ± 7.7-16.6 ± 8.0 (p < 0.001), the Boon walking score improved from 8.9 ± 3.5-7.8 ± 4.4 (p = 0.008), the Boon step score improved from 6.3 ± 2.3-5.2 ± 2.1 (p < 0.001), the Boon time score improved from 4.9 ± 2.4-3.7 ± 2.3 (p < 0.001), tandem walking disturbance improved from 1.7 ± 0.7-1.4 ± 0.9 (p = 0.043), tendency toward falling improved from 1.7 ± 0.7-1.3 ± 1(p = 0.022), 3-meter timed up and go test (3-mTUG) improved from 21.9 ± 7.1-17.6 ± 5.1( p < 0.001), 10-meter walking (10-MWT) step improved from 31.1 ± 13.1-24.6 ± 7.5 (p < 0.001), velocity improved from 0.7 ± 0.2-0.8 ± 0.3 (p < 0.001) and stride length improved from 0.4 ± 0.1-0.46 ± 0.1(p < 0.001), compared with before the CSF TT.

CONCLUSION

These results suggest that many parameters in the Boon gait test were responsive to the CSF TT, and the Boon gait test may help objectify response to the CSF TT by combining the 10-MWT and 3-mTUG gait assessments.

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

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.