The Outcomes Of Serial Cerebrospinal Fluid Removal In Elderly Patients With Idiopathic Normal Pressure Hydrocephalus

Safety and Complications of Ventriculoatrial Shunting in Elderly Patients: A Single-Center Retrospective Study

OBJECTIVE

The incidence of cerebrospinal fluid shunting among older adults is increasing. Ventriculoatrial (VA) shunting is a common shunting method, but research on VA shunting for elderly patients is limited. This retrospective study aimed to investigate the complication rate of VA shunting in older patients.

METHODS

Patients aged ≥65 years who underwent VA shunting at Tsukazaki Hospital between January 2019 and September 2023 were included. Follow-up duration, type of valve system, opening pressure, and postoperative complications (including overdrainage, symptomatic intracerebral hemorrhage, perioperative seizure, shunt system revision, infection, cardiopulmonary complications, cranial nerve injury, and other complications) were assessed.

RESULTS

Among 115 included patients (55% female and 71% primary hydrocephalus), the mean age and follow-up duration were 78 years and 464 days, respectively. Overdrainage, infection, symptomatic intracranial hemorrhage, and revision occurred in 22%, 2.6%, 1.7%, and 0.9% of patients, respectively. No other complications were observed. Among overdrainage cases, 84% were asymptomatic, and all cases were cured by resetting the opening pressure. Overdrainage was significantly higher among males (odds ratio [OR]: 3.34; 95% confidence interval [CI]: 1.30-8.56; P = 0.0097) and those aged <70 years (OR: 5.38; 95% CI: 1.32-21.84; P = 0.0226), while higher initial opening pressure (≥18 cmH2O) significantly reduced overdrainage (OR: 0.29; 95% CI: 0.11-0.79; P = 0.0123). All infections were treated using antibiotics, and 1 revision was due to failure of distal catheter implantation.

CONCLUSIONS

The observed complication rate of VA shunting in elderly patients was no higher compared with that of other age groups or other cerebrospinal fluid shunting techniques, reported in previous studies.

Idiopathic normal pressure hydrocephalus: a systematic review and a streamlined six-step algorithm endorsed by the Italian Society of Neurosurgery (SINCH)

INTRODUCTION

Idiopathic normal pressure hydrocephalus (iNPH) is a treatable neurodegenerative disorder characterized by a triad of gait disturbance, cognitive impairment, and urinary incontinence. Early diagnosis and timely intervention are crucial for optimal outcomes. However, the diagnosis of iNPH remains challenging due to its variable presentation and overlap with other neurological conditions.

EVIDENCE ACQUISITION

A comprehensive review of the literature was conducted to identify current diagnostic criteria and treatment strategies for iNPH. Based on this review, a novel, six-step algorithm was developed to streamline the diagnostic process and improve patient outcomes.

EVIDENCE SYNTHESIS

The proposed algorithm includes the following six steps: 1) suspect diagnosis of iNPH: Identification of core clinical features (gait disturbance, cognitive impairment, and urinary incontinence) and radiological evidence of ventricular enlargement; 2) investigate probable iNPH: detailed neuropsychological assessment, gait analysis, and urodynamic studies to confirm the diagnosis; 3) high-volume lumbar puncture: evaluation of the clinical response to CSF drainage, including improvements in gait, cognition, and urinary function; 4) evaluation after HVLP: assessment of the duration and magnitude of symptom improvement after lumbar puncture; 5) shunt surgery: indication for shunt surgery in patients with a positive response to CSF drainage; 6) infusion test and intracranial pressure measurement: alternative diagnostic tools for cases where the diagnosis remains uncertain.

CONCLUSIONS

The proposed algorithm provides a structured approach to the diagnosis and management of iNPH. By combining clinical, radiological, and neurophysiological assessments, clinicians can improve diagnostic accuracy and optimize patient outcomes. Further research is needed to validate this algorithm in larger patient populations and to develop more sensitive and specific biomarkers for iNPH.

Standardizing the large-volume "tap test" for evaluating idiopathic normal pressure hydrocephalus: a systematic review

INTRODUCTION

Idiopathic normal pressure hydrocephalus (iNPH) is characterized by the clinical triad of gait, cognitive, and urinary dysfunction associated with ventriculomegaly on neuroimaging. Clinical evaluation before and after CSF removal via large volume lumbar puncture (the "tap test") is used to determine a patient's potential to benefit from shunt placement. Although clinical guidelines for iNPH exist, a standardized protocol detailing the procedural methodology of the tap test is lacking.

EVIDENCE ACQUISITION

Using PRISMA guidelines, a systematic review of PubMed and Embase identifying studies of the tap test in iNPH was performed, centered on four clinical questions (volume of CSF to remove, type of needle for lumbar puncture, which clinical assessments to utilize, and timing of assessments). A modified Delphi approach was then applied to develop a consensus standardized tap test protocol for the evaluation of idiopathic normal pressure hydrocephalus.

EVIDENCE SYNTHESIS

Two hundred twenty-two full-text articles encompassing a total of 80,322 participants with iNPH met eligibility and were reviewed. Variations in the tap test protocol resulted in minimal concordance among studies. A standardized protocol of the tap test was iteratively developed over a two-year period by members of the International Parkinson and Movement Disorders Society Normal Pressure Hydrocephalus Study Group until expert consensus was reached.

CONCLUSIONS

The literature shows significant variability in the procedural methodology of the tap test. The proposed protocol was subsequently developed to standardize clinical management, improve patient outcomes, and better align future research in idiopathic normal pressure hydrocephalus.

Osteoporosis in older patients with idiopathic normal pressure hydrocephalus

Both osteoporosis and idiopathic normal pressure hydrocephalus may increase the risk of falls and fractures. This study showed that osteoporosis is more common in older patients with iNPH. It is important to raise awareness of osteoporosis in older patients with iNPH to prevent adverse health consequences.

PURPOSE

Idiopathic normal pressure hydrocephalus (iNPH), a potentially reversible condition with timely intervention, may cause cognitive impairment, balance and gait disturbance, and urinary incontinence in advanced age. Osteoporosis is a progressive metabolic bone disease that increases bone fragility in older adults. Both conditions may lead to falls and fractures. Therefore, this study aims to investigate osteoporosis in older adults with iNPH.

METHODS

A total of 64 patients diagnosed with iNPH and 458 participants in the control group were included in the study. Demographic and clinical characteristics, including age, sex, comorbidities, laboratory findings, and comprehensive geriatric assessment parameters, were recorded. Osteoporosis was defined according to the WHO classification. The relationship between osteoporosis and iNPH was assessed with regression analysis.

RESULTS

The mean age was higher in the iNPH group than in the control group (79.91 ± 6.36 vs 75.86 ± 6.51 years, p < 0.001). The frequency of female patients was higher in the control group than in the iNPH group (81% vs 70.3%, p = 0.046). The osteoporosis frequency was higher in the iNPH group than in the controls (51.6% vs 32.1%, p = 0.002). Adjusted for age and gender, iNPH was associated with osteoporosis (odds ratio (OR), 1.750; confidence interval (CI) 95%, 1.002-3.054; p = 0.049).

CONCLUSIONS

This study showed that osteoporosis is more common in older patients with iNPH. Therefore, screening and treatment of osteoporosis in these individuals is crucial to avoid adverse health outcomes such as fractures.

Gait characteristics in idiopathic normal pressure hydrocephalus: a review on the effects of CSF tap test and shunt surgery

BACKGROUND

Idiopathic normal pressure hydrocephalus (iNPH) is a progressive disease characterized by disproportionate ventricular enlargement at brain imaging with gait disturbance and an increased risk of falling. Gait assessment is a key feature in the diagnosis of iNPH and characterization of post-surgical outcomes.

RESEARCH QUESTION

How do gait parameters change 24 h after CSF tap test (CSFTT) and after ventriculoperitoneal shunt surgery?

METHODS

The PRISMA guidelines were used to perform the systematic review. We conducted a search of the following electronic databases: PubMed, Medline, Web of Science and EBSCO. We included studies focusing on gait changes occurring 24 h after a CSFTT or after ventriculoperitoneal shunt surgery in patients with iNPH. All articles were assessed for methodological quality using an adapted version of The Standard Quality Assessment Criteria for Evaluating Primary Research Papers checklist.

RESULTS

Twenty-seven studies were included in the systematic review. Studies were highly heterogeneous due to lack of standardization of CSFTT or shunt surgery methodology, with varying amounts of CSF removed during the tap test (20-50 ml) and varying time of outcome assessment after shunt surgery. Dynamic equilibrium measurements are generally used to assess preoperative levels of cardinal symptoms and postoperative outcomes in iNPH. The most sensitive spatio-temporal parameter assessed 24 h after CSFTT was self-selected walking speed followed by stride length, which increased significantly. Cadence is hence not suitable to consider in the evaluation of effect of CSFTT and shunt surgery. Changes in balance-related gait parameters after CSFTT and shunt surgery are still a controversial area of research.

CONCLUSION

Gait assessment is a key feature in the diagnosis of iNPH and characterization of post-surgical outcomes. Dynamic equilibrium measurements are generally used to assess preoperative levels of cardinal symptoms and postoperative outcomes in iNPH, but quantitative and standardized gait analysis procedures are missing. Changes in balance-related gait parameters after CSFTT might be useful in deciding whether to perform shunt surgery in iNPH patients who hope for improvement in gait ability. The dual-task paradigm after CSFTT could improve the clinical evaluation of higher level frontal gait disturbances in patients with suspected iNPH before shunting.

Sarcopenia in older patients with idiopathic normal pressure hydrocephalus: an observational study from a single geriatric clinic in Turkey

OBJECTIVE

Idiopathic normal pressure hydrocephalus (iNPH), a classical triad of gait abnormality, cognitive disturbance, and urinary incontinence, increases in prevalence with aging. Sarcopenia is also characterized by low muscle strength and mass, contributing to gait difficulty. Gait abnormality and lower physical activity also lead to the development of sarcopenia. Therefore, this study aims to investigate the relationship between sarcopenia and iNPH.

METHODS

A total of 327 participants were included in this retrospective cross-sectional study. Demographic and clinical characteristics, including age, sex, comorbidity index, number of medications, recurrent falls in the last year, laboratory findings and comprehensive geriatric assessment (CGA) parameters were recorded. Sarcopenia was defined according to the EGWSOP2 criteria. The relationship between sarcopenia and iNPH was assessed with regression analysis.

RESULTS

There were 51 participants with iNPH, 49% female, mean age 78 years (SD 5.7) and 276 control participants, 74% female, mean age 72 years (SD 6.1). The sarcopenia rates in patients with iNPH and controls were 19.6% and 2.5%, respectively (p < 0.01). The odds of probable sarcopenia were 3.89 times, and the slow gait speed was 8.47 times higher in iNPH patients than in controls after adjusting for age, sex, and the other confounders. The Mini-Mental State Examination score (p = 0.042, OR = 0.869 with 95% CI:0.759-0.995) was associated with probable sarcopenia among patients with iNPH.

CONCLUSION

This study demonstrated that sarcopenia was common in older patients with iNPH, which seems to be closely associated with decreased muscle strength and slowed gait speed. Thus, considering the potential untoward effects of both diseases, it is important for physicians to evaluate sarcopenia routinely in the follow-up and treatment of older patients with iNPH.

X-linked hydrocephalus genes: Their proximity to telomeres and high A + T content compared to Parkinson's disease

Proximity to telomeres (i) and high adenine and thymine (A + T) content (ii) are two factors associated with high mutation rates in human chromosomes. We have previously shown that >100 human genes when mutated to cause congenital hydrocephalus (CH) meet either factor (i) or (ii) at 91% matching, while two factors are poorly satisfied in human genes associated with familial Parkinson's disease (fPD) at 59%. Using the sets of mouse, rat, and human chromosomes, we found that 7 genes associated with CH were located on the X chromosome of mice, rats, and humans. However, genes associated with fPD were in different autosomes depending on species. While the contribution of proximity to telomeres in the autosome was comparable in CH and fPD, high A + T content played a pivotal contribution in X-linked CH (43% in all three species) than in fPD (6% in rodents or 13% in humans). Low A + T content found in fPD cases suggests that PARK family genes harbor roughly 3 times higher chances of methylations in CpG sites or epigenetic changes than X-linked genes.

Evaluation of Patients With Cognitive Impairment Due to Suspected Idiopathic Normal-Pressure Hydrocephalus at Medical Centers for Dementia: A Nationwide Hospital-Based Survey in Japan

Objective

Treatment of idiopathic normal-pressure hydrocephalus (iNPH) requires collaboration between dementia specialists and neurosurgeons. The role of dementia specialists is to differentiate patients with iNPH from patients with other dementia diseases and to determine if other dementia diseases are comorbid with iNPH. We conducted a nationwide hospital-based questionnaire survey on iNPH in medical centers for dementia (MCDs).

Methods

We developed a questionnaire to assess how physicians in MCDs evaluate and treat patients with cognitive impairment due to suspected iNPH and the difficulties these physicians experience in the evaluation and treatment of patients. The questionnaire was sent to all 456 MCDs in Japan.

Results

Questionnaires from 279 MCDs were returned to us (response rate: 61.2%). Patients underwent cognitive tests, evaluation of the triad symptoms of iNPH, and morphological neuroimaging examinations in 96.8, 77.8, and 98.2% of the MCDs, respectively. Patients with suspected iNPH were referred to other hospitals (e.g., hospitals with neurosurgery departments) from 78.9% of MCDs, and cerebrospinal fluid (CSF) tap test was performed in 44 MCDs (15.8%). iNPH guidelines (iNPHGLs) and disproportionately enlarged subarachnoid space hydrocephalus (DESH), a specific morphological finding, were used and known in 39.4% and 38% of MCDs, respectively. Logistic regression analysis with “Refer the patient to other hospitals (e.g., hospitals with neurosurgery departments) when iNPH is suspected.” as the response variable and (a) using the iNPHGLs, (b) knowledge of DESH, (c) confidence regarding DESH, (d) difficulty with performing brain magnetic resonance imaging, (e) knowledge of the methods of CSF tap test, (f) absence of physician who can perform lumbar puncture, and (g) experience of being told by neurosurgeons that referred patients are not indicated for shunt surgery as explanatory variables revealed that the last two factors were significant predictors of patient referral from MCDs to other hospitals.

Conclusion

Sufficient differential or comorbid diagnosis using CSF tap test was performed in a few MCDs. Medical care for patients with iNPH in MCDs may be improved by having dementia specialists perform CSF tap tests and share the eligibility criteria for shunt surgery with neurosurgeons.

Pathophysiological Mechanisms Underlying Idiopathic Normal Pressure Hydrocephalus: A Review of Recent Insights

The pathophysiologic mechanisms underpinning idiopathic normal pressure hydrocephalus (iNPH), a clinically diagnosed dementia-causing disorder, continue to be explored. An increasing body of evidence implicates multiple systems in the pathogenesis of this condition, though a unifying causative etiology remains elusive. Increased knowledge of the aberrations involved has shed light on the iNPH phenotype and has helped to guide prognostication for treatment with cerebrospinal fluid diversion. In this review, we highlight the central role of the cerebrovasculature in pathogenesis, from hydrocephalus formation to cerebral blood flow derangements, blood-brain barrier breakdown, and glymphatic pathway dysfunction. We offer potential avenues for increasing our understanding of how this disease occurs.

A Comparison of Cerebrospinal Fluid Beta-Amyloid and Tau in Idiopathic Normal Pressure Hydrocephalus and Neurodegenerative Dementias

PURPOSE

Idiopathic normal pressure hydrocephalus (iNPH) is the leading reversible cause of cognitive impairment and gait disturbance that has similar clinical manifestations and accompanies to major neurodegenerative disorders in older adults. We aimed to investigate whether cerebrospinal fluid (CSF) biomarker for Alzheimer's disease (AD) may be useful in the differential diagnosis of iNPH.

PATIENTS AND METHODS

Amyloid-beta (Aß) 42 and 40, total tau (t-tau), phosphorylated tau (p-tau) were measured via ELISA in 192 consecutive CSF samples of patients with iNPH (n=80), AD (n=48), frontotemporal dementia (FTD) (n=34), Lewy body diseases (LBDs) (n=30) consisting of Parkinson's disease dementia and dementia with Lewy bodies.

RESULTS

The mean age of the study population was 75.6±7.7 years, and 54.2% were female. CSF Aβ42 levels were significantly higher, and p-tau and t-tau levels were lower in iNPH patients than in those with AD and LBDs patients. Additionally, iNPH patients had significantly higher levels of t-tau than those with FTD. Age and sex-adjusted multi-nominal regression analysis revealed that the odds of having AD relative to iNPH decreased by 37% when the Aβ42 level increased by one standard deviation (SD), and the odds of having LBDs relative to iNPH decreased by 47%. The odds of having LBDs relative to iNPH increased 76% when the p-tau level increased 1SD. It is 2.5 times more likely for a patient to have LBD relative to NPH and 2.1 times more likely to have AD relative to iNPH when the t-tau value increased 1SD.

CONCLUSION

Our results suggest that levels of CSF Aβ42, p-tau, and t-tau, in particularly decreased t-tau, are of potential value in differentiating iNPH from LBDs and also confirm previous studies reporting t-tau level is lower and Aβ42 level is higher in iNPH than in AD.

Plantar pressure-based temporal analysis of gait disturbance in idiopathic normal pressure hydrocephalus: Indications from a pilot longitudinal study

BACKGROUND AND OBJECTIVE

Idiopathic normal pressure hydrocephalus (iNPH) is a common yet potentially reversible neurodegenerative disease, and gait disturbance is a major symptom. Lots of methodological and clinical work has been conducted on gait disturbance analysis for differential diagnosis, presurgical test, and postsurgery assessment of iNPH. Nevertheless, the verification analysis was mostly lacking for surgery response, and the temporal characteristics of ground reaction force has been rarely investigated.

METHODS

In this work, we propose that plantar pressure features fundamentally signifies iNPH gait disturbance and improvement after cerebrospinal fluid (CSF) drainage by lumbar puncture tap test as well as surgical shunt implantation. The plantar pressure signals of six iNPH patients and eight healthy controls were collected, and an online database of sixteen healthy controls were used. For patients, data were collected in five periods, which are the baseline before the tap test, 8, 24, and 72 hours after the tap test, and one month after the shunt implantation surgery, respectively. Fast dynamic time warping (DTW) with an improved DTW barycenter averaging (DBA) method was proposed for temporal analysis with the measured and online plantar pressure data. An plantar-pressure variation index (PPVI) was formulated to characterize the temporal dynamic stability of walking.

RESULTS

The PPVI based on temporal analysis of plantar pressure well discriminated the impaired gait (baseline, 24 and 72 hours after tap test) with the improved gait (8 hours after tap test and follow up after surgery) of the patients. Further, the PPVI was close for the improved gait of the patients and the healthy gait measured in our study as well as in the online database.

CONCLUSIONS

Plantar pressure-based temporal features are promisingly effective for clinical examination and treatment of iNPH.

Serial Tap Test of patients with idiopathic normal pressure hydrocephalus: impact on cognitive function and its meaning

Background

Idiopathic normal pressure hydrocephalus (INPH) is characterized by gait disturbance, urinary incontinence and cognitive decline. Symptoms are potentially reversible and treatment is based on cerebrospinal fluid shunting. The tap test (TT) is used to identify patients that will benefit from surgery. This procedure consists of the withdrawal of 20 to 50 mL of cerebrospinal fluid (CSF) through a lumbar puncture (LP) after which the symptoms of the triad are tested. Improvement in the quality and speed of gait are already recognized but cognitive improvement depends on several factors such as tests used, the time elapsed after LP for re-testing, and the number of punctures. Serial punctures may trigger similar conditions as external lumbar drainage (ELD) to the organism.

Objective

This study aimed to identify how serial punctures affect cognition to increase the sensitivity of the test and consequently the accuracy of surgical indication.

Methods

Sixty-one patients with INPH underwent baseline memory and executive tests repeatedly following the 2-Step Tap Test protocol (2-STT – two procedures of 30 mL lumbar CSF drainage separated by a 24-h interval). The baseline scores of INPH patients were compared with those of 55 healthy controls, and with intragroup post-puncture scores of the 2-STT.

Results

The group with INPH had lower performance than the control group in all cognitive tests (RAVLT, Stroop, CFT, FAR-COWA, FAB, MMSE, orientation, mental control), except for the forward digit span test (p = 0.707). After conducting LP procedures, the Stroop test (words, colors and errors), RAVLT (stage A1, A6 and B1), and CFT (immediate and delayed R) scores were equal to those of the control group (p > 0.05). The INPH group presented significant improvement after the first puncture in MMSE (p = 0.031) and in the Stroop Test (points) (p < 0.001). After the second puncture, subjects improved in orientation, MMSE, RAVLT (B1), Stroop (points, words, errors) and CFT (IR).

Conclusion

Progressive cognitive improvement occurred over the 2-STT and changes were more significant after the second LP in all cognitive domains except for RAVLT (A7). Encephalic alert system ‘arousal’ seems to participate in early improvements observed during 2-STT. The second LP increased the sensitivity of the drainage test to detect changes in cognitive variables, and consequently improved the quality of the method.

Screening for idiopathic normal pressure hydrocephalus in the elderly after falls

OBJECTIVE

Many patients with idiopathic normal pressure hydrocephalus (iNPH) have reportedly fallen prior to diagnosis. However, there are no previous reports on the iNPH prevalence among the elderly with history of falls. This study investigated the effectiveness of screening for iNPH in elderly patients presenting after a fall.

METHODS

We retrospectively assessed the Evans' index (EI) of 235 consecutive patients aged 60-89 who presented after falls between May and October 2020. We also assessed the presence of the iNPH triad (gait disturbance, cognitive impairment, and urinary incontinence). Patients with EI > 0.3 and with all 3 triad were defined as having possible iNPH; those with clinical improvement after a cerebrospinal fluid (CSF) tap test as having probable iNPH; and those with clinical improvement after a shunt surgery as having definite iNPH. We also examined the 235 patients' EI, and performed a case-control study of EI using sex- and age-matched control patients.

RESULTS

Among the included 235 cases presenting after falls, 44 (18.7%) were diagnosed with possible iNPH, 29 (12.3%) with probable iNPH, and 25 (10.6%) with definite iNPH. The mean EI of these 235 patients was significantly larger than that of controls (0.30 ± 0.04 vs 0.26 ± 0.02, p < 0.0001). The proportion of possible iNPH in the cases was 44 out of 235 (18.7%), significantly higher than that of the controls (0%, p < 0.0001).

CONCLUSION

Screening for iNPH in the elderly presenting after falls can possibly identify iNPH patients in the earlier stage who may benefit more from surgical treatments.

Anterior callosal angle correlates with gait impairment and fall risk in iNPH patients

BACKGROUND

In idiopathic normal pressure hydrocephalus (iNPH), gait and balance impairment is the most frequent symptom, and it is often associated with a higher fall risk. In a prior study, the anterior callosal angle (ACA) was validated as a reliable marker to discriminate iNPH from Alzheimer's disease and healthy controls. However, the potential correlation between the ACA with clinical symptoms and functional outcomes has not been assessed. The objective of this study is to determine the utility of the ACA in predicting gait improvement after ventriculoperitoneal (VP) shunting.

METHODS

Patients with probable iNPH who underwent shunt placement at a single institution were prospectively enrolled from May 2015 to May 2019. Patients were assessed preoperatively and at 6 months postoperatively following a standard clinical and MRI protocol. Callosal angle (CA) and ACA were calculated from 3 T MRI preoperatively and at 6 months postoperatively. CA and ACA were tested for correlation with clinical scores.

RESULTS

Forty-seven patients with probable INPH who completed 6-month postoperative follow-up were enrolled in the study. Baseline ACA was significantly correlated with preoperative fall risk, gait, and balance impairment assessed with Tinetti POMA scale. Additionally, baseline ACA differentiated patients who experienced improvement at Tinetti POMA scale after surgery.

CONCLUSIONS

The baseline ACA is a useful neuroradiological marker to differentiate patients by fall risk and has significant correlation with the improvement in gait and balance impairment following surgery. This study demonstrated that the ACA may be a complementary tool to the CA in predicting shunt responsiveness in iNPH.

The Pathogenesis Based on the Glymphatic System, Diagnosis, and Treatment of Idiopathic Normal Pressure Hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is a rare neurological disorder with no clear prevalence factors and is a significant danger to the elderly. The intracranial glymphatic system is the internal environment that maintains brain survival and metabolism, and thus fluid exchange changes in the glymphatic system under various pathological conditions can provide important insights into the pathogenesis and differential diagnosis of many neurodegenerative diseases such as iNPH. iNPH can be diagnosed using a combination of clinical symptoms, imaging findings and history, and cerebrospinal fluid biomarkers due to the glymphatic system disorder. However, only few researchers have linked the two. Shunt surgery can improve the glymphatic system disorders in iNPH patients, and the surgical approach is determined using a combination of clinical diagnosis and trials. Therefore, we have composed this review to provide a future opportunity for elucidating the pathogenesis of iNPH based on the glymphatic system, and link the glymphatic system to the diagnosis and treatment of iNPH. The review will provide new insights into the medical research of iNPH.

The applause sign in elderly patients with idiopathic normal pressure hydrocephalus

Applause sign (AS) was shown to be an indicator of frontal subcortical dysfunction in many neurodegenerative diseases. Idiopathic normal pressure hydrocephalus (INPH) is one of those in which frontosubcortical disconnection can be displayed. We aimed to examine the presence of AS in the elderly patients with INPH and its possible diagnostic role in the frontal dysfunction commonly seen in the disease. Sixty-six patients diagnosed with probable INPH, 32 with behavioral variant of frontotemporal dementia (bvFTD) and 325 healthy elderly subjects were included in this cross-sectional and retrospective study. AS was evaluated with the clapping test. Patients with INPH were further assessed with frontal assessment battery (FAB), Stroop test, verbal fluency test and clock drawing test (CDT). The concentration of total amyloid-β 42 (Aβ42), Aβ40, total (t) tau and phosphorylated (p)-tau proteins were also measured in the cerebrospinal fluid (CSF). AS was observed in all groups (40% in bvFTD, 28.8% in INPH, 1.2% in controls, respectively). It was significantly more frequent in patients with bvFTD and INPH as compared to the controls (p < 0.001, for each). The frequency was similar in the patients with bvFTD and INPH (p = 0.802). Significant differences were found between the AS(+) and (-) INPH patients with regards to FAB, Stroop test-errors and verbal fluency test, except for the CSF proteins. AS can be used as a simple, useful and rapid clinical test that investigates executive dysfunction in elderly patients with INPH in both inpatient and outpatient settings.

The importance of brain banking for dementia practice: the first experience of Turkey

This study reports the results of the first brain tissue banking experience of Turkey in the Unit for Aging Brain and Dementia at Dokuz Eylul University, Department of Geriatric Medicine, Izmir. Here, we have briefly described our efforts on brain banking in our country, which consist of six brains from autopsies that had at least two years of clinical follow-up in the 2015-2017 period. The evaluation led to the diagnosis of two Alzheimer's disease (AD) with cerebral amyloid angiopathy, one AD with dementia with Lewy bodies, one corticobasal degeneration, one multiple system atrophy, one vascular dementia. We believe that the study is of a special importance because of its potential of becoming a brain banking center in the region and because of its contributing to the international knowledge of the neuropathological features of dementia, while characterizing the epidemiology of these diseases in the region.