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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 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.

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. Cranial and spinal MR images of 27 consecutive patients with classic SIH symptoms, who eventually received epidural autologous blood patches (EBPs), were analyzed. 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). 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.

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.Cranial and spinal MR images of 27 consecutive patients with classic SIH symptoms, who eventually received epidural autologous blood patches (EBPs), were analyzed.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).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.

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.

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 ± 2.4 mm and 12.8 ± 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.

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-β (Aβ) 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, Aβ42 (LD/FD = 0.80, p

OBJECTIVEThe 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.METHODSEighty-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.RESULTSOf 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.CONCLUSIONSPatients 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.

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 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.

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. 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. 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. 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.

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.

Objectives The cerebrospinal fluid tap test for idiopathic normal pressure hydrocephalus (iNPH) is one of the good predictors of the shunt treatment, although this test has a low sensitivity. We aimed to identify key parameters that could be used to improve this sensitivity. Materials & methods During 2010–2011, we recruited and then followed 93 patients with possible iNPH for 12 months after shunt. Among them, 82 patients were finally enrolled in this study. The modified Rankin Scale, iNPH grading scale, and several quantitative measurements were evaluated at entry, after the tap test, before and after shunt. Area under the receiver-operating characteristic curves (AUCs), sensitivities, and specificities of the tap test for predicting shunt effectiveness were calculated for each measurement. They were additionally assessed after stratification by disease duration since the initial presentation of iNPH symptoms. Results The gait disturbance on the iNPH grading scale had the highest accurate scale at the tap test for predicting effectiveness 12 months after shunt: AUC 0.74, sensitivity 56.5%, specificity 91.7%. This AUC increased to 0.76, 0.91 and 0.94 in the subgroup of disease duration

Decision making for either surgery or gamma-knife for the treatment of arteriovenous malformations (AVMs) cannot be uniform. The skill of the neurosurgeon in operating on AVMs is now being compared with that of the gamma-knife. The decision varies from case to case and is to be taken by the neurosurgeon. This report presents three cases in which such decision making was not easy. Case 1 was a non-ruptured cingulate AVM of 2.5 cm diameter in the cingulate cortex. The operative field was anticipated to be very narrow between the parietal bridging veins. Case 2 was a tiny ruptured AVM in the speech-motor area which was buried underneath the cortex. Case 3 was a large ruptured thalamo-stiriate-capsular AVM with feeders from the anterior and posterior choroidal arteries. All cases were operated without serious morbidity. A combination of pre-operative intravascular surgery (cases 1 and 3) or postoperative gamma-knife (case 3) was adopted. In conclusion, there is no unitary rule to decide on surgery or gamma-knife for the treatment of AVMs. It depends on what good or harm the responsible surgeon or the gamma-knife does.

BACKGROUND Jugular bulb diverticulum is a rare condition that has never been reported in association with lower cranial nerve palsy. CASE DESCRIPTION A 54-year-old woman developed acute swallowing disturbance and hoarseness. Neuroradiological examinations demonstrated a jugular bulb diverticulum as well as unruptured internal carotid and basilar tip aneurysms on the same side. Laboratory data for both serum and cerebrospinal fluid were normal. Steroids were given, and the cranial nerve palsy disappeared within 1 month. The aneurysms were successfully clipped. During the follow-up period of more than 1 year, the patient has done well and has no neurological deficit. CONCLUSION This is the first reported case of jugular bulb diverticulum associated with a lower cranial nerve palsy and multiple aneurysms. We recommend close observation of patients with this condition regardless of its clinical presentation.

The migration of lumboperitoneal shunt cathe- ters into the abdominal subcutaneous space is not uncom- mon. To prevent migration we devised a new method for installing the peritoneal tube. After catheter insertion into the lumbar spinal subarachnoid space, the tube on the peritoneal side is pulled into the areolar space between the abdominal fat and the anterior rectus sheath. A 4 cm incision is made in the sheath and the tip of the catheter is obliquely passed through the rectus abdominis muscle using a mosquito clamp. The tube is then inserted into the abdominal cavity through small openings in the posterior sheath and peritoneal membrane, located 3 cm inferior and 3 cm medial to the opening on the anterior rectus sheath. Consequently, the peritoneal tube runs obliquely, upper lateral to lower medial, through the anterior sheath, the rectus abdominis muscle, the posterior sheath, and the peritoneum. To date, we operated on 59 patients using this method. No migration of the abdominal shunt cathe- ter occurred during a follow-up period of 5.51 ± 3.6 months (mean ± standard deviation). Our technique is safe, effec- tive without migration of the peritoneal tube, and can be performed in less well-equipped operating rooms.

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.

BACKGROUND A more simplified and easier technique for the orbitozygomatic approach is sought. We have developed a new modification to fully expose the temporal base before using one-piece craniotomy. METHODS By transposing the temporalis muscle underneath the zygomatic arch before osteotomy, the temporal base and the inferior orbital fissure can be fully exposed. Craniotomy is made in one piece with the frontotemporal and orbitozygomatic bone together by using a high-speed drill. RESULTS AND CONCLUSIONS Osteotomy was easy and the cosmetic result was satisfactory. This technique also allows better access to the subtemporal region without removing the zygomatic arch.

Migration of the lumboperitoneal shunt catheter into the abdominal subcutaneous space is not uncommon. We devised a new simple method (Transrectus Gap method we call) for installment of peritoneal tube aiming to prevent the migration.