Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus (Third Edition): Endorsed by the Japanese Society of Normal Pressure Hydrocephalus

Abstract

Among the various disorders that manifest with gait disturbance, cognitive impairment, and urinary incontinence in the elderly population, idiopathic normal pressure hydrocephalus (iNPH) is becoming of great importance. The first edition of these guidelines for management of iNPH was published in 2004, and the second edition in 2012, to provide a series of timely, evidence-based recommendations related to iNPH. Since the last edition, clinical awareness of iNPH has risen dramatically, and clinical and basic research efforts on iNPH have increased significantly. This third edition of the guidelines was made to share these ideas with the international community and to promote international research on iNPH. The revision of the guidelines was undertaken by a multidisciplinary expert working group of the Japanese Society of Normal Pressure Hydrocephalus in conjunction with the Japanese Ministry of Health, Labour and Welfare research project. This revision proposes a new classification for NPH. The category of iNPH is clearly distinguished from NPH with congenital/developmental and acquired etiologies. Additionally, the essential role of disproportionately enlarged subarachnoid-space hydrocephalus (DESH) in the imaging diagnosis and decision for further management of iNPH is discussed in this edition. We created an algorithm for diagnosis and decision for shunt management. Diagnosis by biomarkers that distinguish prognosis has been also initiated. Therefore, diagnosis and treatment of iNPH have entered a new phase. We hope that this third edition of the guidelines will help patients, their families, and healthcare professionals involved in treating iNPH.

Evans index among adult Ghanaians on normal head computerized tomography scan

“…NPH can be classified as secondary NPH and Idiopathic NPH [4]. Currently, some guidelines propose the use EI for diagnosis of hydrocephalus radiologically [5,6]. Reported in the early 1940s, EI was based on pneumoencephalographic findings for pediatric hydrocephalus, and was calculated as the linear ratio of Maximum Anterior Horn Width (MAHW) of the frontal horns of the lateral ventricles at the level of foramina of Monroe and the Maximum Intracranial Diameter (MICD) of the inner skull.…”

Gait Assessment Using Three-Dimensional Acceleration of the Trunk in Idiopathic Normal Pressure Hydrocephalus

“…All patients or their representatives gave written informed consent, and their private information was anonymized in a linkable manner at each institute. Improvements of gait and cognitive symptoms were assessed by the iNPH grading scale (Ishikawa, 2004;Mori et al, 2012;Nakajima et al, 2021), with quantitative examinations given before, 1 day, and 4 days after the CSF tap test. All patients underwent brain and whole-spine MRI and single-photon emission computed tomography to determine in the differential diagnosis or coexistence of Alzheimer's disease, cerebral infarction, and cervical or lumber canal stenosis, etc.…”

“…Because each pathological gait was related to the others and to the severity of gait disturbance, we created a new parameter that indicates a pathological gait specific to iNPH, which is calculated as (the sum of each evaluation point of eight pathological gait features)/16 × 100 (%). Compared to each assessment of pathological gait specific to iNPH, the probability of iNPHspecific gait was reliable, because it was significantly associated with the gait domain of the Japanese iNPH grading scale which was rated as normal, complaints of instability, walks without supportive devices, walks with supportive devices, and unable to walk (Ishikawa, 2004;Mori et al, 2012;Nakajima et al, 2021). All gait features of 68 healthy elderlies were treated as normal, i.e., the probability of iNPH-specific gait was rated as 0%.…”

“…The pathological gait that is specific to iNPH has been characterized as the freezing of gait, wide-based gait, short-stepped gait, shuffling gait, instability, gait festination, difficulty in changing direction, and balance disorder in standing up (Stolze et al, 2000(Stolze et al, , 2001Marmarou et al, 2005;Ishikawa et al, 2019a). Videorecorded gait performance before and after the spinal tap test and shunt surgery has been recommended for gait assessments of patients with iNPH (Marmarou et al, 2005;Mori et al, 2012;Ishikawa et al, 2019a;Nakajima et al, 2021). However, pathological gait is generally evaluated subjectively and exhibits no standardized rating system.…”

Reversible Reduction of Dopamine Transporter Uptake in a Case of Hydrocephalus

“…Brain MRI at age 66 revealed more enlarged ventricles than before, but both lateral sulci were narrowed, unlike the widening that has been reported in cerebral atrophy or “normal pressure” hydrocephalus (Fig B). 1 Also, the cerebral aqueduct was ballooned because of stenosis at its junction with the fourth ventricle (Fig C). Cerebrospinal fluid dynamics were disturbed on time‐spatial labeling inversion pulse MRI and on radioisotope cisternography.…”