[Overview of the Guidelines for Managing Idiopathic Normal Pressure Hydrocephalus].

Japanese guidelines for idiopathic normal pressure hydrocephalus (iNPH) (iNPHGL) are the first and only guidelines in the world that were revised following subsequent developments in iNPH research. We first discuss the virtuous cycle in which the development and revision of the iNPHGL and how the implementation of two consecutive multicenter prospective studies conducted in Japan, SINPHONIs, have worked together to advance iNPH practices. Subsequently, we explained the most characteristic features of the iNPHGL, such as "Positioning of iNPH," "Diagnostic Criteria," and "Algorithms for Diagnosis and Treatment." To classify iNPH, we categorized chronic adult-onset normal pressure hydrocephalus (NPH) as iNPH, secondary NPH, Congenital/Developmental NPH, and Familial NPH. In the diagnostic criteria and algorithm, we classified iNPH into four categories: Suspected iNPH, Possible iNPH, Probable iNPH, and Definite iNPH, depending on the certainty of the diagnosis. In addition, a positioned disproportionately enlarged subarachnoid space hydrocephalus (DESH) on head computed tomography and magnetic resonance imaging is an important finding for the diagnosis of iNPH. Finally, we presented the results of a survey on the treatment status of patients with suspected iNPH, awareness of DESH, and use of this iNPHGL among medical centers for dementia in Japan.

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.

Aqueductal CSF stroke volume measurements may drive management of shunted idiopathic normal pressure hydrocephalus patients.

CSF shunting with adjustable valve is the treatment of idiopathic normal pressure hydrocephalus. The opening pressure valve setting is left to the neurosurgeon's experience. Aqueductal CSF stroke volume by phase-contrast magnetic resonance measures the CSF passing through the Sylvian aqueduct and it changes with intracranial hydrodynamics. We sought to identify a window of stroke volume differences associated with the best clinical outcome and lowest rate of complications. The records of 69 patients were reviewed. At every clinical check, stroke volume, opening pressure valve, clinical outcome, and CSF overdrainage were analyzed. The correlation between stroke volume differences and negative outcome was also analyzed. The median follow-up was 2.3 years (range 0.3-10.4 years). The odds of negative outcome between two consecutive checks significantly increased by 16% (95%CI 4-28%, p = 0.006). Taking the lowest risk group as reference, the odds ratio of negative outcome was 1.16 (95%CI 0.51-2.63, p = 0.726) for SV differences less than - 37.6 µL, while it was 1.96 (95%CI 0.97-3.98, p = 0.062) for stroke volume changes above + 23.1 µL. Maintaining stroke volume values within a definite range might help maximize clinical benefit and avoid the risk of CSF overdrainage.

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.

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

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.

Altered glymphatic system in idiopathic normal pressure hydrocephalus.

OBJECTIVE: To assess the glymphatic activity in patients with idiopathic normal pressure hydrocephalus (NPH) using the "Diffusion Tensor Image-Analysis aLong the Perivascular Space (DTI-ALPS)" method, and determine the feasibility of non-invasive MRI for the evaluation of the glymphatic function. METHODS: Between April 2017 and March 2019, 16 patients diagnosed with NPH and 16 age- and sex-matched controls were included. On 3T DTI-MRI, the diffusivities along x-, y-, and z-axes were measured, and the ALPS-index - a ratio that accentuated water diffusion along the perivascular space - was calculated by two independent readers. The inter-observer agreement was tested using the interclass correlation coefficient. The differences in the diffusivities and the ALPS-index between the NPH and control groups were compared using the Mann-Whitney test. The values were also compared according to the treatment response to the cerebrospinal fluid drainage and correlated with the callosal angle using a correlation coefficient. RESULTS: The inter-observer agreements were excellent for the diffusivities and the ALPS-index. The diffusivity along the x-axis in the projection fibers area and the ALPS-index were significantly lower in patients with NPH (median, 0.556/1.181) than in the controls (0.610/1.540), respectively (P = 0.032/< 0.0001). The ALPS-index was significantly lower in the NPH group who did not show treatment response than those who showed symptomatic relief (0.987/1.329; P < 0.0001). The ALPS-index showed a significant positive correlation with the callosal angle (r = 0.82, P = 0.0001). CONCLUSIONS: The DTI-ALPS method can be a useful imaging tool for identifying glymphatic dysfunction and for individually quantifying glymphatic activity in patients with NPH.

Intracerebral hematoma at the basal ganglia following lumbar puncture.

BACKGROUND: In patients with normal pressure hydrocephalus (NPH), lumbar puncture (LP) is an effective method for assessing both the diagnosis as well as the possible efficacy of ventriculoperitoneal shunting based on symptom improvement. However, it should be considered that there exists a low risk of complications and that these risks may result in morbidity and mortality. We present a patient who developed hematoma in the basal ganglia following LP. CASE DESCRIPTION: A 56-year-old man presented with progressive dementia, ataxia, and urinary incontinence for 8 months. The patient received LP. He had no history of coagulopathy and had NPH findings on cranial magnetic resonance imaging. On the second day after LP, he complained of headache and had left hemiparesis, and intracerebral hematoma was observed at the basal ganglia, posterior to the lentiform nucleus. CONCLUSIONS: Although intracerebral hematoma after LP is one of the rare complications to be more cautious about, particularly in patients with a history of chronic disease or chronic changes in imaging, a history of previous cerebrovascular events and recurrent LPs with probably less cerebrospinal fluid drainage should be planned. Moreover, it should be considered that intracerebral hematoma may develop in patients with clinical deterioration, and good clinical follow-up is required.

Standardized regression-based clinical change score cutoffs for normal pressure hydrocephalus.

BACKGROUND: Presently, for patients presenting with suspected Normal Pressure Hydrocephalus (NPH) who undergo temporary drainage of cerebrospinal fluid (CSF) there is no defined model to differentiate chance improvement form clinical significance change at the individual patient level. To address this lack of information we computed standard regression based clinical change models for the 10 Meter Walk Test, Timed Up & Go, Dual Timed Up & Go, 6-Minute Walk Test, Mini-Balance Evaluation Systems Test, Montreal Cognitive Assessment, and Symbol Digit Modalities using data from patients with suspected NPH that underwent temporary drainage of CSF. These clinically significant change modes can classify clinically significant improvement following temporary drainage of CSF at the individual patient level. This allows for physicians to differentiate a clinically significant improvement in symptoms from chance improvement. METHODS: Data was collected from 323 patients, over the age of 60, with suspected NPH that underwent temporary drainage of CSF with corresponding gait and cognitive testing. McSweeney Standardized Regression Based Clinical Change Models were computed for standard gait and cognitive measures: Timed Up & Go, Dual Timed Up & Go, 10 Meter Walk Test, MiniBESTest, 6-Minute Walk Test, Montreal Cognitive Assessment, and Symbol Digit Modalities Test. To assess the discriminate validity of the measures we used correlations, Chi2, and regression analyses. RESULTS: The clinical change models explained 69-91.8% of the variability in post-drain performance (p <  0.001). As patient scores became more impaired, the percent change required for improvement to be clinically significant increased for all measures. We found that the measures were not discriminate, the Timed Up & Go was highly related to the 10 Meter Walk Test (r = 0.85, R2 = 0.769-0.738, p <  0.001), MiniBESTest (r = - 0.67, R2 = 0.589-0.734, p <  0.001), and 6 Minute Walk Test (r = - 0.77, R2 = 0.71-0.734, p <  0.001). CONCLUSION: Standardized Regression Based Clinically Significant Change Models allow for physicians to use an evidence-based approach to differentiate clinically significant change from chance improvement at the individual patient level. The Timed Up & Go was shown to be predictive of detailed measures of gait velocity, balance, and endurance.

The efficacy and limitation of lumboperitoneal shunt in normal pressure hydrocephalus.

OBJECTIVE: To investigate whether the efficacy of the lumbar-peritoneal (LP) shunt is sustainable, we measured the outcomes of patients with idiopathic NPH (iNPH) preoperatively and postoperatively. PATIENTS AND METHODS: We retrospective reviewed records of 58 patients with iNPH from 2013 to 2015. Exclusion of 7 patients expired, 1 patient shunt infection, and 8 patients was loss of follow-up. In the remaining 42 patients, the mood, talking response, movement, attention, recalling memory, and mini-mental state examination (MMSE), representing patient outcomes, were measured. All of whom were follow-up for 3 years. RESULTS: Mood (1.91 ±â€¯0.30), talking response (1.98 ±â€¯0.15), movement (1.71 ±â€¯0.51), attention (1.95 ±â€¯0.22), and recalling memory (1.86 ±â€¯0.35) were significantly improved after surgery (1 week;p <  0.0001). However, the indicators significantly declined after 3 years (mood: 0.31 ± 0.52, talking response: 0.50 ± 0.59, movement: 0.17 ± 0.38, attention: 0.40 ± 0.59, recalling memory: 0.21 ± 0.42). The MMSE was also significantly improved after 3 months of surgery (17.9 5 ± 2.80 vs. 25.02 ± 3.36; p <  0.0001). However, it declined after 3 years (17.83 ± 3.66; p = 0.83). CONCLUSION: The iNPH is considered potentially reversible. Our data supported that the LP shunt was efficient in the short term. However, the neurological degeneration was still progressive.

Corticospinal excitability in idiopathic normal pressure hydrocephalus: a transcranial magnetic stimulation study.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is a neurodegenerative disease with an unknown etiology. Disturbed corticospinal inhibition of the motor cortex has been reported in iNPH and can be evaluated in a noninvasive and painless manner using navigated transcranial magnetic stimulation (nTMS). This is the first study to characterize the immediate impact of cerebrospinal fluid (CSF) drainage on corticospinal excitability. METHODS: Twenty patients with possible or probable iNPH (16 women and 4 men, mean age 74.4 years, range 67-84 years), presenting the classical symptom triad and radiological findings, were evaluated with motor function tests (10-m walk test, Grooved Pegboard and Box & Block test) and nTMS (silent period, SP, resting motor threshold, RMT and input-output curve, IO-curve). Evaluations were performed at baseline and repeated immediately after CSF drainage via lumbar puncture. RESULTS: At baseline, iNPH patients presented shorter SPs (p < 0.001) and lower RMTs (p < 0.001) as compared to normative values. Positive correlation was detected between SP duration and Box & Block test (rho = 0.64, p = 0.002) in iNPH patients. CSF drainage led to an enhancement in gait velocity (p = 0.002) and a steeper IO-curve slope (p = 0.049). CONCLUSIONS: Shorter SPs and lower RMTs in iNPH suggest impaired corticospinal inhibition and corticospinal hyperexcitability. The steeper IO-slope in patients who improve their gait velocity after CSF drainage may indicate a higher recovery potential. Corticospinal excitability correlated with the motor function of the upper limbs implying that the disturbance in motor performance in iNPH extends beyond the classically reported gait impairment.

Our Efforts in Understanding Normal Pressure Hydrocephalus: Learning from the 100 Most Cited Articles by Bibliometric Analysis.

BACKGROUND: Normal pressure hydrocephalus (NPH) is a syndrome that was characterized several decades ago; however, its optimal diagnosis and management remain unclear. Our objective was to evaluate citation and bibliometric characteristics of the 100 most cited articles about NPH to better understand the state of research efforts in the field and where improvements may arise. METHODS: Elsevier's Scopus database was searched for the 100 most cited articles that focused on NPH. Articles were characterized and various bibliometric parameters were compared. Categorical data were analyzed using Pearson χ2, and continuous data were analyzed using either linear regression or a Student t test. RESULTS: The 100 most cited articles were published between 1965 and 2014, from 16 unique countries in 38 unique journals. The most common outcome types of these articles were clinical (n = 77). Median number of citations and rate of citations were 114 citations and 5.9 citations/year since publication, respectively, with a significant inverse linear relationship between the 2 parameters (P < 0.01). The most common year of publication was 2002 (n = 10), and the most common country of origin was the United States (n = 40). Higher citation rates were associated with more recent articles (P < 0.01) and more authors (P < 0.01). CONCLUSIONS: In the 100 most cited articles about NPH, there has been a distinct shift toward a more globalized effort in recent decades. The lack of more impactful articles in recent decades highlights that particular classic studies still penetrate practice and the possible need to reconsider our contemporary views on NPH to further advance the field.

Normal pressure hydrocephalus-an overview of pathophysiological mechanisms and diagnostic procedures.

Normal pressure hydrocephalus (NPH) is an important differential diagnosis of neurodegenerative diseases. The prevalence of dementia is increasing in line with the worldwide increase in life expectancy. NPH can be divided into idiopathic (iNPH) and secondary (sNPH) which is important in terms of clinical symptoms, future progress, and the outcome of possible treatment. The full clinical triad is not prevalent in all of the cases and the pathophysiology of iNPH remains unclear. Diagnosis is based on the evaluation of clinical symptoms (Hakim's triad) combined with an MRI assessment, evaluation of CSF dynamic parameters by different methods such as a tap test, lumbar infusion test (LIT), and external lumbar drainage (ELD). Despite the development of diagnostic techniques and strategies in management, NPH remains to be a challenge for the specialists despite more than 50 years of research. However, results of this research have brought new opportunities in the diagnosis, therapy, and quality of life as well as survival time of NPH patients with improved symptoms. The aim of this article is to present the pathophysiological hypotheses of NPH and an overview of the diagnostic techniques used for the evaluation of NPH patients.

Quantitative analysis of cerebrospinal fluid dynamics at phase contrast cine-MRI: predictivity of neurosurgical "Shunt" responsiveness in patients with idiopathic normal pressure hydrocephalus.

BACKGROUND: Aqueductal stroke volume (ACSV) measured by phase-contrast cine (PCC)-MRI has been proposed with controversy as a tool for the selection of patients with normal pressure hydrocephalus (NPH) as candidates for shunt-surgery. The aim of this study was to assess if PCC-MRI scan measurements of ACSV could select properly these patients. METHODS: We retrospectively reviewed charts and MRI of 38 shunted patients (72.16±6.16 years). ACSV measurements were performed 7-30 days before shunt and at the first and sixth months after surgery. Normally distributed variables were compared in the two groups (improved/unimproved) by t-test for baseline values and with repeated measures analysis of variance. RESULTS: Twenty-six patients (68,4%) improved after VPS (mean time of symptom onset was 8.15±7.19 months). Mean preoperative ACSV value was 271.85±143.03, which decreased by 21.6% (mean 213±125.14) at the first month and 40.3% sixth months after VPS (mean 162.15±91.5). Twelve patients (31.6%) did not improve (mean time of symptom onset was 29±5.62 months). Mean preoperative ACSV value was 79.83±31.24, decreased to 8.7% (mean 72.83±28.66) at first month after VPS. 21.2% (mean 62.83±31.12) after six months. We found statistical difference between preoperative ACSV of improved and unimproved patients (P<0.01), onset time of symptoms (P<0.01) and the changes in ACSV after one and six months in both groups (P<0.001). CONCLUSIONS: ACSV is useful to stratify patients with NPH after surgery (improved /not improved) suggesting to proceed with serial ACSV measurements before deciding treatment.

Indicación de estimulación cerebral profunda en casos complejos de enfermedad de Parkinson. Experiencia en el Hospital Clínico Universidad de Chile / Indication of deep brain stimulation in complex cases of Parkinson's disease. Experience at the Hospital Clínico Universidad de Chile

Introduction: Deep brain stimulation (DBS) is a standard surgical procedure for the treatment of advanced Parkinson Disease (PD) with motor complications that cannot be adequately managed by medical treatment. Currently available literature can guide physicians on basic aspects of patients' selection and indications for DBS. However, there is a range of real-world clinical settings where the indications of DBS for Parkinson disease are debatable. Objective: to present the experience on PD patients with complex clinical manifestations treated with DBS in our hospital. Method: Report of four PD cases treated with DBS. Case 1: 63-year old woman with advanced PD and severe motor complications; Case 2: 60-year old man with 5 years of disease duration and mild motor complications; Case 3: 67-year old man with severe ventriculomegaly that may have precluded direct electrode passage to the surgical target; Case 4: 67- year-old woman with putative severe axial disability. Results: After one year of follow-up, all patients showed improvement on motor symptoms as well as quality of life. Discussion: We provide a brief rationale for the patient selection in each case to support the decision-making in the management of PD patients with complex clinical cases. (AU)

Are gait changes linked to CSF flow changes in the sagittal sinus?

PURPOSE: To identify if specific findings on magnetic resonance imaging (MRI) cerebrospinal fluid (CSF) flow studies can be utilised to identify which patients with idiopathic normal pressure hydrocephalus (iNPH) will have improved gait following a CSF tap test (TT). METHODS: Prospective study of patients undergoing a CSF TT for iNPH. Functional gait was assessed using the timed up and go (TUG) test before and after the CSF TT. MRI CSF flow studies accompanied the CSF TT. The minimum clinically important difference for the TUG (3.63 s) was used as a cutoff value to categorise patients as responders to the CSF TT. RESULTS: Fifty-three patients underwent CSF TT and MRI CSF flow studies. Significant differences were identified between groups for (non-responder vs responder) superior sagittal sinus flow (47.10% vs 40.41%), sagittal sinus stroke volume (274 vs 176.5 µl), sagittal sinus to arterial stroke volume ratio (0.203 vs 0.164), sagittal sinus area (42.2 mm2 vs 36.2 mm2) and circumference (27.7 mm vs 24.95 mm). No differences were present for aqueduct stroke volume, arterial stroke volume or aqueduct net flow. CONCLUSION: A link between gait improvement resulting from CSF drainage and sagittal sinus measurements indicates that the sagittal sinus may play a role in the manifestation of symptoms in iNPH. This may have implications for the diagnosis of iNPH and potentially inform clinical decision making regarding surgical intervention.

Recent Advances in Rational Diagnosis and Treatment of Normal Pressure Hydrocephalus: A Critical Appraisal on Novel Diagnostic, Therapy Monitoring and Treatment Modalities.

BACKGROUND: Normal pressure hydrocephalus (NPH) is a critical brain disorder in which excess Cerebrospinal Fluid (CSF) is accumulated in the brain's ventricles causing damage or disruption of the brain tissues. Amongst various signs and symptoms, difficulty in walking, slurred speech, impaired decision making and critical thinking, and loss of bladder and bowl control are considered the hallmark features of NPH. OBJECTIVE: The current review was aimed to present a comprehensive overview and critical appraisal of majorly employed neuroimaging techniques for rational diagnosis and effective monitoring of the effectiveness of the employed therapeutic intervention for NPH. Moreover, a critical overview of recent developments and utilization of pharmacological agents for the treatment of hydrocephalus has also been appraised. RESULTS: Considering the complications associated with the shunt-based surgical operations, consistent monitoring of shunting via neuroimaging techniques hold greater clinical significance. Despite having extensive applicability of MRI and CT scan, these conventional neuroimaging techniques are associated with misdiagnosis or several health risks to patients. Recent advances in MRI (i.e., Sagittal-MRI, coronal-MRI, Time-SLIP (time-spatial-labeling-inversion-pulse), PC-MRI and diffusion-tensor-imaging (DTI)) have shown promising applicability in the diagnosis of NPH. Having associated with several adverse effects with surgical interventions, non-invasive approaches (pharmacological agents) have earned greater interest of scientists, medical professional, and healthcare providers. Amongst pharmacological agents, diuretics, isosorbide, osmotic agents, carbonic anhydrase inhibitors, glucocorticoids, NSAIDs, digoxin, and gold-198 have been employed for the management of NPH and prevention of secondary sensory/intellectual complications. CONCLUSION: Employment of rational diagnostic tool and therapeutic modalities avoids misleading diagnosis and sophisticated management of hydrocephalus by efficient reduction of Cerebrospinal Fluid (CSF) production, reduction of fibrotic and inflammatory cascades secondary to meningitis and hemorrhage, and protection of brain from further deterioration.

Idiopathic Normal Pressure Hydrocephalus (Hakim-Adams Syndrome): Clinical Symptoms, Diagnosis and Treatment.

Idiopathic normal pressure hydrocephalus is a chronic steadily progressing disease. Nowadays a vital and acute socially significant problem still has not been solved. The etiology and pathogenesis of this disease remain so far poorly understood. Variable clinical manifestations, as well as difficulties in differential diagnosis with other neurodegenerative diseases - lead to underdiagnosing of the illness that causes a significant decrease in patient's quality of life and even results in disability. The number of patients with idiopathic normal pressure hydrocephalus has been steadily increasing. That is why, the coverage and a full study of this problem is of great interest for a broad circle of medical professionals.

The effect of CSF drainage on ambulatory center of mass movement in idiopathic normal pressure hydrocephalus.

BACKGROUND: Although gait and balance disturbances are core symptoms of idiopathic normal pressure hydrocephalus (iNPH), the ambulatory center of mass (COM) movements in patients with iNPH remain unclear. We aimed to clarify the ambulatory COM movements using an accelerometer on the patients' lower torsos and to investigate the changes in COM movement after cerebrospinal fluid tap tests (TT) and shunt surgeries (SS). METHODS: Twenty-three patients with iNPH and 18 age-matched healthy controls (HCs) were recruited. A triaxial accelerometer was fixed with a belt onto each participant's torso at the L3 vertebra level. We assessed each patient's 10-m gait before TT, 3 days after TT, and 1 week after SS. RESULTS: Compared to the HCs, the patients exhibited decreased gait velocities, increased step numbers, and increased step times. Their movement trajectory amplitudes (i.e., the COM movements) were increased in the medial/lateral direction and decreased in the vertical direction. They also exhibited greater variability (measured as coefficients of variation) in step time and movement trajectory amplitude in both the medial/lateral and vertical directions. The patients' gait parameters were significantly improved after TT and SS. SIGNIFICANCE: Our results suggest that iNPH-associated gait disturbances could cause abnormal ambulatory COM movements and that these disturbances are mitigated by TT and SS.