Predictive Ability of Frontal Assessment Battery for Cognitive Improvement After Shunt Surgery in Individuals With Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND: The predictive ability of the Frontal Assessment Battery (FAB) for postoperative cognitive improvement in idiopathic normal pressure hydrocephalus (iNPH) is unstudied. OBJECTIVE: To compare the predictive ability of the FAB and the Mini-Mental State Examination (MMSE) for postoperative cognitive improvement in individuals with iNPH after shunt surgery. METHOD: We retrospectively reviewed the medical records of individuals with iNPH who had shunt surgery between January 2016 and October 2018. Individuals had completed the tap test and clinical evaluations (FAB, MMSE, Timed Up and Go [TUG]) both before and 24-48 hours after CSF tapping and after surgery. We excluded individuals without complete clinical evaluations and those with shunt surgery performed >6 months after CSF tapping. Factors associated with postoperative FAB and MMSE improvement as per the 2011 iNPH guidelines were extracted using univariate and multivariate logistic regression analyses. Independent variables were baseline FAB and MMSE scores, FAB and MMSE score changes and TUG amelioration rate after CSF tapping, Evans index, age, and days from CSF tapping to surgery and from surgery to postoperative assessment. RESULTS: The mean number of days from CSF tapping to surgery and from surgery to postoperative assessment were 77.5 (SD = 36.0) and 42.0 (SD = 14.5), respectively. Logistic regression analyses showed significant associations in the univariate analyses of postoperative FAB improvement with baseline FAB scores ( P = 0.043) and with FAB score changes after CSF tapping ( P = 0.047). CONCLUSION: The FAB may help predict postoperative cognitive improvement after shunt surgery better than the MMSE.

Paravertebral Cerebrospinal Fluid Exudation in Young Women with Postdural Puncture Headache: A Hypothetical Interpretation based on Anatomical Study on Intervertebral Foramen.

Background Postdural puncture headache (PDPH) is defined as a prolonged orthostatic headache secondary to a lumbar puncture. The mechanism underlying this unpleasant complication and the reasons explaining its higher incidence in the young are not well understood. Here, we speculate on the mechanisms underlying PDPH based on spinal magnetic resonance imaging (MRI) in patients with PDPH and an anatomical study on the size of the intervertebral foramen. Methods Brain and spinal MRI findings were examined in two young women with PDPH. The relationship between age and size of the intervertebral foramen on computed tomography was assessed in 25 female volunteers (22-89 years old) without spinal disease. Results The causative interventions leading to PDPH were epidural anesthesia for painless delivery in a 28-year-old woman and lumbar puncture for examination of the cerebrospinal fluid (CSF) in a 17-year-old woman. These two patients developed severe orthostatic hypotension following the procedure. Brain MRI showed signs of intracranial hypotension, including subdural effusion, in one patient, but no abnormality in the other. Spinal MRI revealed an anterior shift of the spinal cord at the thoracic level and CSF exudation into the paravertebral space at the lumbar level. Treatment involving an epidural blood patch in one patient and strict bed rest with sufficient hydration in the second led to improvement of symptoms and reduction of paravertebral CSF exudation. The size of the intervertebral foramen at the L2-3 level in the 25 volunteers showed a decrease in an age-dependent manner (Spearman's rho -0.8751, p < 0.001). Conclusion We suggest that CSF exudation from the epidural space of the vertebral canal to the paravertebral space through the intervertebral foramen, which is generally larger in the younger population, is the causative mechanism of PDPH.

Dural sac shrinkage signs on spinal magnetic resonance imaging indicate overdrainage after lumboperitoneal shunt for idiopathic normal pressure hydrocephalus.

Background: We previously found the usefulness of dural sac shrinkage signs (DSSSs), which are the anterior shift of the spinal cord and dura mater behind the cord, detected by magnetic resonance imaging (MRI) at the thoracic level for the diagnosis of spontaneous intracranial hypotension (IH). This is a retrospective survey on the usefulness of DSSSs for the early detection of iatrogenic IH caused by overdrainage through a lumboperitoneal shunt (LPS) for patients with idiopathic normal pressure hydrocephalus (INPH). Methods: Forty-five INPH patients had an LPS using a pressure programmable valve equipped with an anti-siphon device. Results: Nine patients complained of orthostatic headache after the LPS, indicating IH due to overdrainage, which persisted for more than a week in three patients and 2-7days in six patients. The headache was transient/ nonorthostatic in ten patients and absent in 26 patients. The DSSSs and accompanying enlargement of the venous plexus were observed in all three patients with prolonged orthostatic headaches. Only the anterior shift of the dura mater was observed in 1 (4%) among 25 patients who had short-term orthostatic headache, transient/ nonorthostatic headache, or absent headache, and underwent spinal MRI. A patient with prolonged severe orthostatic headache with both DSSSs eventually developed intracranial subdural effusion and underwent tandem valve surgery, which provided a quick improvement of symptoms. The DSSSs on thoracic MRI also disappeared promptly. Conclusion: DSSSs may serve as objective signs for the diagnosis of IH due to overdrainage through an LPS for INPH.

Dural sac shrinkage signs on magnetic resonance imaging at the thoracic level in spontaneous intracranial hypotension-its clinical significance.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is secondary to a cerebrospinal fluid leak at the spinal level without obvious causative events. Several signs on brain and cervical spine magnetic resonance (MR) imaging (MRI) have been associated with SIH but can be equivocal or negative. This retrospective study sought to identify characteristic SIH signs on thoracic spinal MRI. METHODS: Cranial and spinal MR images of 27 consecutive patients with classic SIH symptoms, who eventually received epidural autologous blood patches (EBPs), were analyzed. RESULTS: The most prevalent findings on T2-weighted MRI at the thoracic level were anterior shift of the spinal cord (96.3%) and dorsal dura mater (81.5%), probably caused by dural sac shrinkage. These dural sac shrinkage signs (DSSS) were frequently accompanied by cerebrospinal fluid collection in the posterior epidural space (77.8%) and a prominent epidural venous plexus (77.8%). These findings disappeared in all six patients who underwent post-EBP spinal MRI. Dural enhancement and brain sagging were minimum or absent on the cranial MR images of seven patients, although DSSS were obvious in these seven patients. For 23 patients with SIH and 28 healthy volunteers, a diagnostic test using thoracic MRI was performed by 13 experts to validate the usefulness of DSSS. The median sensitivity, specificity, positive-predictive value, negative-predictive value, and accuracy of the DSSS were high (range, 0.913-0.931). CONCLUSIONS: Detection of DSSS on thoracic MRI facilitates an SIH diagnosis without the use of invasive imaging modalities. The DSSS were positive even in patients in whom classic cranial MRI signs for SIH were equivocal or minimal.

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.

Intraoperative use of cone-beam computed tomography for the safe epidural blood patch: Technical case report.

BACKGROUND: Epidural blood patch (EBP) is a common method utilized to treat intracranial hypotension, and secondarily, to treat unintentional dural puncture. The authors propose an effective technique for correct epidural needle positioning during EBP using cone-beam computed tomography (CB-CT) images. CASE DESCRIPTION: A 31-year-old female underwent an EBP. Following confirmation of the spinal level of the cerebrospinal fluid leakage, the ideal trajectory for the proposed EBP was assessed from the entry point on the skin to the spinolaminar line under CB-CT imaging. The epidural needle was then gently advanced along the appropriate trajectory. At the 10 mm mark, behind the spinolaminar line, the inner needle was removed. This allowed for slow advancement of the outer needle until its tip reached the epidural space, and its location was confirmed by the "loss of resistance to the saline technique." Using biplane epidurography, the spread of dye within the epidural space for appropriate localization was confirmed. In this case study, the patient's postural headache immediately improved. CONCLUSION: Using the CB-CT technique described, a patient successfully underwent EBP without complications.

Two-Point Dynamic Observation of Alzheimer's Disease Cerebrospinal Fluid Biomarkers in Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND: Extensive research into cerebrospinal fluid (CSF) biomarkers was performed in patients with idiopathic normal pressure hydrocephalus (iNPH). Most prior research into CSF biomarkers has been one-point observation. OBJECTIVE: To investigate dynamic changes in CSF biomarkers during routine tap test in iNPH patients. METHODS: We analyzed CSF concentrations of tau, amyloid-ß (Aß) 42 and 40, and leucine rich α-2-glycoprotein (LRG) in 88 consecutive potential iNPH patients who received a tap test. We collected two-point lumbar CSF separately at the first 1 ml (First Drip (FD)) and at the last 1 ml (Last Drip (LD)) during the tap test and 9 patients who went on to receive ventriculo-peritoneal shunt surgery each provided 1 ml of ventricular CSF (VCSF). RESULTS: Tau concentrations were significantly elevated in LD and VCSF compared to FD (LD/FD = 1.22, p = 0.003, VCSF/FD = 2.76, p = 0.02). Conversely, Aß42 (LD/FD = 0.80, p < 0.001, VCSF/FD = 0.38, p = 0.03) and LRG (LD/FD = 0.74, p < 0.001, VCSF/FD = 0.09, p = 0.002) concentrations were significantly reduced in LD and VCSF compared to FD. Gait responses to the tap test and changes in cognitive function in response to shunt were closely associated with LD concentrations of tau (p = 0.02) and LRG (p = 0.04), respectively. CONCLUSIONS: Dynamic changes were different among the measured CSF biomarkers, suggesting that LD of CSF as sampled during the tap test reflects an aspect of VCSF contributing to the pathophysiology of iNPH and could be used to predict shunt effectiveness.

Is the atlas size associated with the pathophysiology of symptomatic spinal canal stenosis at the C1 level?

Narrow cervical spinal canal is an important risk factor for the development of cervical myelopathy. Patients with this disease often present with congenital narrowness of the cervical spinal canal. While there are studies on patients with subaxial spinal canal stenosis (SAS), few examined the coexistence of congenital narrow spinal canal in patients with cervical myelopathy at the C1 level. We investigated the characteristics of patients with C1 stenosis (C1S) with special reference to the size of the atlas. Thirteen patients (8 men, 5 women, mean age 76 years) with C1S were retrospectively analyzed and their clinical characteristics and radiological findings were compared with 27 SAS patients and with 26 age-, sex-, and body habitus-matched asymptomatic individuals. Of the 13 C1S patients, 6 presented with a retro-odontoid pseudotumor, 5 with atlantoaxial subluxation, and 2 with ossification or calcification of the transverse ligament; they were significantly older and shorter, and their body weight was significantly lower than in SAS patients (p < 0.001). Their average C1 anteroposterior- and spinal canal diameter was 26.9 ±â€¯2.4 mm and 12.8 ±â€¯4.1 mm, respectively and significantly smaller than in patients with subaxial stenosis (p = 0.004). These measurements were also statistically smaller than in the controls, even after matching for age, gender, height, and body weight (p < 0.05). In patients with C1S, the atlas size was significantly smaller than in SAS patients and asymptomatic controls, indicating an association between a small atlas size and symptomatic spinal canal stenosis at the C1 level.

Timed up and go test at tap test and shunt surgery in idiopathic normal pressure hydrocephalus.

BACKGROUND: The 3-meter Timed Up and Go test (TUG) is a reliable quantitative test for assessment of gait and balance. We aimed to establish an optimal threshold of TUG at the tap test for predicting outcomes 12 months after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS: The TUG was measured in a total of 151 patients with possible iNPH before and after a tap test and 12 months after shunt surgery. Among them, 81 patients underwent ventriculoperitoneal shunt implantation (SINPHONI) and 70 underwent lumboperitoneal shunt implantation (SINPHONI-2). The areas under the curve (AUCs), sensitivities, and specificities for predicting shunt effectiveness were assessed. RESULTS: The simple differences of time on TUG at the tap test were significantly more accurate for predicting shunt effectiveness than percent improvement of time. The highest AUC for the synchronized moving cutoff point of TUG time was 0.81 (sensitivity 81.0%; specificity 81.6%) at the threshold of 5 seconds in the SINPHONI-2. For predicting improvements of ≥10 seconds 12 months after lumboperitoneal shunt implantation, the AUC was 0.90, and the sensitivity and specificity at the threshold of 5.6 seconds were 83.3% and 81.0%. Only for patients with a <5-second improvement at the tap test, ventriculoperitoneal shunt implantation conveyed significantly better improvements in TUG time 12 months after surgery than lumboperitoneal shunt implantation. CONCLUSIONS: An improvement of 5 seconds was a useful threshold of TUG time at the tap test for predicting a ≥10-second improvement 12 months after shunt surgery, rather than the percent improvement of TUG time.

Cost-effectiveness analysis of shunt surgery for idiopathic normal pressure hydrocephalus based on the SINPHONI and SINPHONI-2 trials.

BACKGROUND: We showed that ventriculoperitoneal (VP) shunt and lumboperitoneal (LP) shunt surgeries are beneficial for patients with idiopathic normal pressure hydrocephalus (iNPH) in the Study of Idiopathic Normal Pressure Hydrocephalus on Neurological Improvement (SINPHONI; a multicenter prospective cohort study) and in SINPHONI-2 (a multicenter randomized trial). Although therapeutic efficacy is important, cost-effectiveness analysis is equally valuable. METHODS: Using both a set of assumptions and using the data from SINPHONI and SINPHONI-2, we estimated the total cost of treatment for iNPH, which consists of medical expenses (e.g., operation fees) and costs to the long-term care insurance system (LCIS) in Japan. Regarding the natural course of iNPH patients, 10% or 20% of patients on each modified Rankin Scale (mRS) show aggravation (aggravation rate: 10% or 20%) every 3 months if the patients do not undergo shunt surgery, as described in a previous report. We performed cost-effectiveness analyses for the various scenarios, calculating the quality-adjusted life year (QALY) and the incremental cost-effective ratio (ICER). Then, based on the definition provided by a previous report, we assessed the cost-effectiveness of shunt surgery for iNPH. RESULTS: In the first year after shunt surgery, the ICER of VP shunt varies from 29,934 to 40,742 USD (aggravation rate 10% and 20%, respectively) and the ICER of LP shunt varies from 58,346 to 80,392 USD (aggravation rate 10% and 20%, respectively), which indicates that the shunt surgery for iNPH is a cost-effective treatment. In the 2nd postoperative year, the cost to the LCIS will continue to decrease because of the lasting improvement of the symptoms due to the surgery. The total cost for iNPH patients will show a positive return on investment in as soon as 18 months (VP) and 21 months (LP), indicating that shunt surgery for iNPH is a cost-effective treatment. CONCLUSIONS: Because the total cost for iNPH patients will show a positive return on investment within 2 years, shunt surgery for iNPH is a cost-effective treatment and therefore recommended. The SINPHONI-2 study was registered with the University Hospital Medical Information Network Clinical Trials registry: UMIN000002730) SINPHONI was registered with ClinicalTrials.gov, no. NCT00221091.

Disability risk or unimproved symptoms following shunt surgery in patients with idiopathic normal-pressure hydrocephalus: post hoc analysis of SINPHONI-2.

OBJECTIVE The study aim was to assess the influence of presurgical clinical symptom severity and disease duration on outcomes of shunt surgery in patients with idiopathic normal-pressure hydrocephalus (iNPH). The authors also evaluated the cerebrospinal fluid tap test as a predictor of improvements following shunt surgery. METHODS Eighty-three patients (45 men and 38 women, mean age 76.4 years) underwent lumboperitoneal shunt surgery, and outcomes were evaluated until 12 months following surgery. Risks for poor quality of life (Score 3 or 4 on the modified Rankin Scale [mRS]) and severe gait disturbance were evaluated at 3 and 12 months following shunt surgery, and the tap test was also conducted. Age-adjusted and multivariate relative risks were calculated using Cox proportional-hazards regression. RESULTS Of 83 patients with iNPH, 45 (54%) improved by 1 point on the mRS and 6 patients (7%) improved by ≥ 2 points at 3 months following surgery. At 12 months after surgery, 39 patients (47%) improved by 1 point on the mRS and 13 patients (16%) improved by ≥ 2 points. On the gait domain of the iNPH grading scale (iNPHGS), 36 patients (43%) improved by 1 point and 13 patients (16%) improved by ≥ 2 points at 3 months following surgery. Additionally, 32 patients (38%) improved by 1 point and 14 patients (17%) by ≥ 2 points at 12 months following surgery. In contrast, 3 patients (4%) and 2 patients (2%) had worse symptoms according to the mRS or the gait domain of the iNPHGS, respectively, at 3 months following surgery, and 5 patients (6%) and 3 patients (4%) had worse mRS scores and gait domain scores, respectively, at 12 months after surgery. Patients with severe preoperative mRS scores had a 4.7 times higher multivariate relative risk (RR) for severe mRS scores at 12 months following surgery. Moreover, patients with severe gait disturbance prior to shunt surgery had a 46.5 times greater multivariate RR for severe gait disturbance at the 12-month follow-up. Patients without improved gait following the tap test had multivariate RRs for unimproved gait disturbance of 7.54 and 11.2 at 3 and 12 months following surgery, respectively. Disease duration from onset to shunt surgery was not significantly associated with postoperative symptom severity or unimproved symptoms. CONCLUSIONS Patients with iNPH should receive treatment before their symptoms become severe in order to achieve an improved quality of life. However, the progression of symptoms varies between patients so specific timeframes are not meaningful. The authors also found that tap test scores accurately predicted shunt efficacy. Therefore, indications for shunt surgery should be carefully assessed in each patient with iNPH, considering the relative risks and benefits for that person, including healthy life expectancy.

Use of the guidewire for repositioning displaced spinal catheter during lumboperitoneal shunt placement.

BACKGROUND: During lumboperitoneal shunt operation, we may inadvertently pull and displace the spinal catheter after the catheter placement into the spinal canal. The authors introduce an easy and efficient technique for repositioning a prolapsed catheter into correct place. METHODS: After the confirmation of cerebrospinal fluid outflow from the end of the catheter, a guidewire for angiogram was gently inserted into the catheter until its tip reached the end of the catheter. The guidewire-inserted catheter was able to be pushed back manually and adequately placed in the spinal canal under the fluoroscope guidance. RESULTS: Three patients underwent repositioning using this "rescue wire technique" without complications. CONCLUSION: This "rescue wire technique" is useful for repositioning of the displaced catheter into the spinal canal.

Use of blunt scalp hooks for abdominal procedure in lumboperitoneal shunt placement: technical note.

In obese patients, we often find difficulty in laparotomy for placing a lumboperitoneal shunt catheter. The authors introduced an easy technique to get a sufficiently wide and shallow operative field through small abdominal incision in obese people. Four blunt scalp hooks and rubber bands, commonly used in craniotomy, were prepared. The fat layer and the rectus abdominis muscle layer were retracted and pulled up using these hooks. Blunt scalp hooks were useful for safe and effective retraction of abdominal wall, which made a sufficient and shallow operative field.