Idiopathic normal pressure hydrocephalus: Validation of the DESH score as a prognostic tool for shunt surgery response.

OBJECTIVE: Several radiological markers have been linked to clinical improvement after shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). However, iNPH has no pathognomonic feature, and patients are still diagnosed as probable, possible, or unlikely cases based on clinical symptoms, imaging findings, and invasive supplementary tests. The predictive value of the disproportionately enlarged subarachnoid space hydrocephalus (DESH) score is not yet conclusively determined, but it might offer a more accurate diagnostic method. The aim of the present retrospective cohort study was to validate the predictive power of the DESH score for clinical improvement after shunt surgery in iNPH patients. METHODS: We retrospectively obtained presurgical MRI and/or CT scans from 71 patients with iNPH who underwent ventriculoperitoneal shunt surgery. Radiological images were evaluated for Evans index (EI), corpus callosal angle (CA), tight high convexity (THC), Sylvian fissure dilation, and focal sulci dilation. These markers were aggregated to determine the DESH score. Patient journal entries were used to subjectively determine the extent of improvement in gait function, urinary incontinence, and/or cognition as a measure of shunt surgery response. RESULTS: Multiple logistic regression analysis, controlling for age and sex (α = 0.05), showed that DESH score was significantly correlated (OR 1.77) with subjective shunt-surgery response at a minimum of 1-month follow-up. Patients with higher DESH scores were more likely to have a favorable response to shunt surgery. CONCLUSION: Aggregating radiological markers into the DESH score is useful for predicting shunt responders among iNPH patients and can aid the selection of patients for surgery. These findings provide further support for the DESH score as a diagnostic tool for iNPH.

A case-based review on the neuroendoscopic management of intraventricular and subarachnoid basal neurocysticercosis.

OBJECTIVE: Extraparenchymal localization of neurocysticercosis (NCC) is rare in non-endemic areas. A case of mixed (intraventricular, IV, and subarachnoid basal, SAB) NCC was surgically treated using the neuroendoscope and a systematic review of the literature was performed with the aim to analyze the use of this instrument in the management of the extraparenchymal forms of the parasitic disease. MATERIALS AND METHODS: Medline and Embase databases were searched for studies where the neuroendoscope was used for the management of IV/SAB NCC cysts, either for the cerebrospinal fluid diversion or cyst removal. Cyst location, complete removal, cyst breakage during removal, intraoperative and postoperative complications, administration of antihelmintic therapy, outcome and follow-up period were extracted from the articles. RESULTS: 281 patients were treated by means of the neuroendoscope. 254 patients who were described in retrospective cohort studies, came all from endemic areas, with no significant difference between sexes. Mean age at surgery was 30.7 years. Of all cysts reported in retrospective studies, 37.9% were located in the fourth ventricle. An attempt of cyst removal was described in the 84.6% of cases and an endoscopic third ventriculostomy was performed in another 76.4%. A small number of complications were reported intraoperatively (9.1%) obtaining, but a good recovery was achieved at follow-up. Only 17 ventriculoperitoneal shunts were placed after the first procedure, defining a low risk of postoperative hydrocephalus even in case of partial cyst removal. CONCLUSION: Neuroendoscopic removal of an extraparenchymal NCC cyst is a safe procedure that should be preferred for lateral and third ventricle localization and, in a specialized centre, even for a localization in the fourth ventricle if feasible. It is also efficient because of the possibility of performing an internal CSF diversion concomitantly to cyst removal, avoiding the complication registered with VPS. The need for cysticidal treatment after surgery should be addressed in a prospective study.

Spinal extradural arachnoid cysts: a rare entity and review of the literature.

OBJECTIVE: Spinal extradural arachnoid cysts (SEDC) are rare primary spinal lesions, accounting for less than 1% of all spinal epidural lesions. The literature contains only case reports of this pathology, and treatment remains controversial due to its rarity. Major reported SEDC cases are caused by leaking out of cerebrospinal fluid through a dural defect in the thecal sac forming an extradural cyst. Other reports describe non-communicating SEDC cases where the dural defect was not identified. We report a literature review on SEDC and the case of a 53 year­old female who presented with type IA extradural cyst with subarachnoid space communication. METHODS: Literature review, preoperative imaging and surgical technique. RESULTS: The extradural cyst was excised completely and the dural defect was repaired. After surgical decompression, neurological symptoms gradually recovered. CONCLUSIONS: The extradural arachnoid cyst is an uncommon entity. Preoperative imaging is one of the determining elements in orienting the therapeutic management of the SEDCs. The choice of the surgical technique must be the least invasive in order to avoid postoperative complications. Subtotal or complete excision of the cyst, followed by obliteration of the communication stalk and repair of the dural defect is the gold standard treatment.

Neurenteric cyst of the craniovertebral junction treated to reduce recurrence using different strategies: Two case reports and a literature review.

RATIONALE: Neurenteric cysts are rare benign lesions that are usually located in the lower cervical and upper thoracic spine and extremely rare in the craniovertebral junction. It is generally challenging to completely remove the neurenteric cysts of the craniovertebral junction. We report the cases of 2 patients with neurenteric cyst in the ventral craniovertebral junction managed using different treatment strategies. PATIENT CONCERNS: The first patient was a 64-year-old man. He man was admitted with headache, posterior neck pain, and a tingling sensation in both the forearms. The second patient was a 53-year-old woman. She was admitted with tingling sensations and numbness in both the hands and feet. DIAGNOSES: Cervical spine magnetic resonance imaging showed 2 intradural extramedullary cystic lesions in case 1 and a C2 to C3 intradural extramedullary cystic mass in case 2. INTERVENTIONS AND OUTCOMES: The patient of the case 1 underwent a left C1 to C2 hemi-laminectomy and the cysts were completely removed. Eleven years after the surgery, there was no recurrence. In case 2, we performed a left C2 to C3 hemi-laminectomy and removed only a part of the outer membrane to enable sufficient communication with the surrounding normal subarachnoid space. After removing the cyst wall, the patient underwent C1 to 2 trans articular screw fixation to prevent cervical instability. Ten years after surgery, there was no recurrence of the cyst or new lesions. LESSONS: Clinicians should consider neurenteric cyst in the differential diagnosis of arachnoid cyst or epidermoid cyst. If performing a complete surgical removal is difficult, partial surgical removal, using a cysto-subarachnoid shunt and stabilization, such as screw fixation, could be an alternative treatment option to reduce the risk of mortality and morbidity.

Fourth ventricle to spinal subarachnoid space stenting in pediatric patients with refractory syringomyelia: case series and systematic review.

A series of 5 patients treated with the fourth ventricle to spinal subarachnoid space stent (FVSSS) is presented. Indication for surgery, surgical technique, pre-operative and post-operative images, and outcome are analyzed. A systematic review of the pertinent literature has also been performed. This is a retrospective cohort review of a series of 5 consecutive patients with refractory syringomyelia who underwent a fourth ventricle to spinal subarachnoid space shunt surgery. The surgical indication was based on the presence of refractory syringomyelia in patients already treated for Chiari malformation or in patients who developed scarring at the level of the outlets of the fourth ventricle following posterior fossa tumor surgery. The mean age at FVSSS was 11.30 ± 5.88 years. Cerebral MRI revealed crowded posterior fossa, with a membrane at the level of the foramen of Magendie. Spinal MRI showed syringomyelia in all patients. Before surgery, the averages of the craniocaudal and the anteroposterior diameter were 22.66 and 1.01 cm, respectively, whereas the volume was 28.16 cm3. The post-operative period was uneventful in 4 out of 5 patients; one child died on the 1st post-operative day due to complications unrelated to surgery. In remaining cases, syrinx marked improvement. The post-operative volume was 1.47 cm3 with an overall reduction of 97.61%. With regard to literature, 7 articles with a total of 43 patients were analyzed. After FVSSS, syringomyelia reduction was observed in 86.04% of cases. Three patients underwent reoperation due to syrinx recurrence. Four patients presented a catheter displacement, one a wound infection and meningitis and one CSF leak requiring placement of a lumbar drain. FVSSS is highly effective in restoring CSF dynamics, with dramatic improvement of syringomyelia. In all our cases, the volume of the syrinx was reduced by at least 90%, with improvement/resolution of accompanying symptomatology. This procedure should be reserved to patients in which other causes of gradient pressure between the fourth ventricle and subarachnoid space are excluded, for example, tetraventricular hydrocephalus. Surgical procedure is not simple, because it requires meticulous microdissection of cerebello-medullary fissure and upper cervical spine, in already operated patients. To avoid migration of the stent, it should be carefully sutured to the dura mater or thick arachnoid membrane.

Idiopathic Intracranial Hypertension with Disproportionately Enlarged Subarachnoid Space Hydrocephalus on Imaging.

The pathophysiology of idiopathic intracranial hypertension (IIH) and idiopathic normal-pressure hydrocephalus (iNPH) differs in terms of cerebrospinal fluid (CSF) pressure and imaging-related characteristics. A 51-year-old man presented with optic nerve papillary edema, visual disturbance, bilateral abducens nerve palsy, and a wide-based gait. Imaging showed characteristic findings of IIH and disproportionately enlarged subarachnoid space hydrocephalus (DESH) - characteristic of iNPH. A CSF examination revealed marked CSF hypertension. IIH with iNPH-like imaging features (DESH) was diagnosed, and ventriculoperitoneal shunt surgery was performed. Postoperatively, the visual acuity and visual field improved. This report also describes the distinct and overlapping pathophysiological mechanisms of IIH and iNPH.

Development of normal pressure hydrocephalus following post-traumatic external hydrocephalus in an adult patient.

We report the case of 74-year-old patient suspected of post-traumatic external hydrocephalus (EH) following a mild traumatic brain injury with a progressive neurological decline and a concomitant enlargement of subarachnoid spaces without ventriculomegaly on CT scan. A lumbar puncture revealed raised ICP and a careful CSF withdrawal was performed, resulting in an immediate neurological improvement, confirming the diagnosis of EH. During the 20-month follow-up, the patient presented progressive signs of normal pressure hydrocephalus (NPH): gait and cognitive decline, ventriculomegaly and the lumbar infusion study confirmed disturbed CSF dynamics. The patient underwent a ventriculoperitoneal shunt surgery, resulting in a long-lasting improvement.

Change in Morphological Features of Enlarged Subarachnoid Spaces Following Treatment in Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND: Focally enlarged sulci (FES) are areas of proposed extraventricular fluid entrapment that may occur within idiopathic normal pressure hydrocephalus (iNPH) with radiographic evidence of disproportionately enlarged subarachnoid-space hydrocephalus (DESH), and should be differentiated from atrophy. PURPOSE: To evaluate for change in FES size and pituitary height after shunt placement in iNPH. STUDY TYPE: Retrospective. SUBJECTS: A total of 125 iNPH patients who underwent shunt surgery and 40 age-matched controls. FIELD STRENGTH/SEQUENCE: 1.5 T and 3 T. Axial T2w FLAIR, 3D T1w MPRAGE, 2D sagittal T1w. ASSESSMENT: FES were measured in three dimensions and volume was estimated by assuming an ellipsoid shape. Pituitary gland height was measured in the mid third of the gland in iNPH patients and controls. STATISTICAL TESTS: Wilcoxon signed-rank test for comparisons between MRI measurements; Wilcoxon rank sum test for comparison of cases/controls. Significance level was P < 0.05. RESULTS: Fifty percent of the patients had FES. FES volume significantly decreased between the pre and first postshunt MRI by a median of 303 mm3 or 30.0%. Pituitary gland size significantly increased by 0.48 mm or 14.4%. FES decreased significantly by 190 mm3 or 23.1% and pituitary gland size increased significantly by 0.25 mm or 6% between the first and last postshunt MRI. DATA CONCLUSION: Decrease in size of FES after shunt placement provides further evidence that these regions are due to disordered cerebrospinal fluid (CSF) dynamics and should not be misinterpreted as atrophy. A relatively smaller pituitary gland in iNPH patients that normalizes after shunt is a less-well recognized feature of altered CSF dynamics. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Resolution of Primary or Recalcitrant Chiari-Associated Syringomyelia Requires Adequate Cerebrospinal Fluid Egress from the Fourth Ventricle.

Syringomyelia is often resistant to various treatment modalities.1 Chiari I malformations are associated with syringomyelia in approximately 69% of operative cases.2 Failure to resolve syringomyelia after Chiari decompression is common.3 The pathophysiology of Chiari-associated syringomyelia has been well studied, with Oldfield emphasizing the water-hammer mechanism, with treatment limited to bony decompression and duraplasty.4 On the other hand, capacious fourth ventricular drainage is thought to be essential for syrinx resolution. Persistence or progression of the syrinx after decompression is an indication for reoperation. Direct shunting of the syrinx is associated with high failure rates.1,5-7 The technique of shunting the fourth ventricle has been applied successfully in the pediatric population.3,8-10 We emphasize the need to ensure outflow from the fourth ventricle in Chiari decompressions associated with syringomyelia. In revisions to treat progressive syringomyelia after failed decompression, we undertake the following steps: 1) adequate lateral bony decompression,11-13 2) lysis of scar/adhesions around the cisterna magna, 3) opening the fourth ventricle outlet by releasing any web/adhesions, 4) insertion of a shunt from the fourth ventricle to the cervical subarachnoid space, and 5) bipolar coagulation of the lateral tonsillar pia to maintain patency of cerebrospinal fluid pathways.8 We favor autologous fascia or pericranium for expansile duraplasty, as the use of nonautologous materials may cause excessive scarring.14-16 In this video, we demonstrate these tenets in 3 cases of Chiari-associated syringomyelia, 2 revisions and 1 primary case, with excellent resolution of the syrinx (Video 1). The patients consented to surgery and publication of images.

[Diagnosis for Idiopathic Normal Pressure Hydrocephalus].

In aging societies, idiopathic normal-pressure hydrocephalus(iNPH)has emerged as an important disease that can negatively affect the activities of daily living among the elderly. Evidence supporting diagnosis and treatment has accumulated and, in Japan, the third edition of the iNPH treatment guideline was published in 2020. Through the promotion of multi-facility research efforts in Japan, diagnosis of iNPH has been based on characteristic phenomena including gait disturbance, overactive bladder, cognitive impairment, and disproportionately enlarged subarachnoid space hydrocephalus(DESH). In supplementary examinations, brain transformations associated with iNPH have been evaluated using modified magnetic resonance imaging methods. Moreover, studies aimed at elucidating the disease state in combination with biological information obtained from cerebrospinal fluid findings are in progress. However, the outcome prediction of shunt treatment for atypical iNPH(i.e., non-DESH iNPH)and coexisting nervous system abnormalities is also important. In these cases, determining indications for surgery is a particular challenge.

Cervical Subarachnoid Drain for the Treatment of Cerebrospinal Fluid Leak: 2-Dimensional Operative Video.

Cerebrospinal fluid (CSF) leak is a common phenomenon encountered by the neurosurgeon. It is most commonly come across after a neurosurgical procedure, but it can be seen idiopathically. Treatment usually ranges from conservative management through cerebrospinal fluid diversion to direct surgical repair. Continuous CSF drainage provides a path for diversion and allowing the site of the dural injury to heal effectively.1 Cervical subarachnoid drain is a safe and effective alternative when lumbar access is contraindicated or not achievable.2 Here we present a case of a 22-yr-old female with progressive symptomatic positional headaches due to a CSF leak from a prior deformity surgery treated with a cervical subarachnoid drain after a failed attempt at a direct repair. This 2-dimensional video illustrates the technique used for the placement of a cervical subarachnoid drain for the treatment of symptomatic CSF leak. Patient consented to the procedure and for the publication of their image.

Comparison of ventriculoperitoneal shunt to lumboperitoneal shunt in the treatment of idiopathic: A monocentric, assessor-blinded, randomized controlled trial.

BACKGROUND: Ventriculoperitoneal shunt (VPS) and lumboperitoneal shunt (LPS) remain the mainstay of idiopathic normal pressure hydrocephalus (INPH). There are no randomized controlled trials completed to compare the efficacy of these 2 shunt techniques. METHODS/DESIGN: We will conduct a monocentric, assessor-blinded, and randomized controlled trial titled "Comparison of Ventriculoperitoneal Shunt to Lumboperitoneal Shunt for the treatment of Idiopathic Normal Pressure Hydrocephalus: Phase I (COVLINPH-1)" trial and recruit patients at West China Hospital of Sichuan University since June 2021. And this trial is expected to end in December 2030. Eligible participants will be randomly assigned into LPS group and VPS group at ratio of 1:1 followed by evaluation before surgery, 1 month, 12 months, and 5 years after surgery. The primary outcome is the rate of shunt failure within 5 years. The secondary outcomes include modified Rankin Scale (mRS), INPH grading scale (INPHGS), mini-mental state examination (MMSE), and Evans index. We will calculate the rate of favorable outcome, which is defined as shunt success and an improvement of more than 1 point in the mRS at evaluation point. We will also analyze the complications throughout the study within 5 years after shunt insertion. DISCUSSION: The results of this trial will provide state-of-the-art evidence on the treatment option for patients with INPH, and will also generate the discussion regarding this subject. TRIAL REGISTRATION NUMBER: ChiCTR2000031555; Pre-results.

A Simple Method to Avoid Brain Shift during Neuronavigation: Technical Note

Introduction The precise identification of anatomical structures and lesions in the brain is the main objective of neuronavigation systems. Brain shift, displacement of the brain after opening the cisterns and draining cerebrospinal fluid, is one of the limitations of such systems. Objective To describe a simple method to avoid brain shift in craniotomies for subcortical lesions. Method We used the surgical technique hereby described in five patients with subcortical neoplasms. We performed the neuronavigation-guided craniotomies with the conventional technique. After opening the dura and exposing the cortical surface, we placed two or three arachnoid anchoring sutures to the dura mater, close to the edges of the exposed cortical surface. We placed these anchoring sutures under microscopy, using a 6­0 mononylon wire. With this technique, the cortex surface was kept close to the dura mater, minimizing its displacement during the approach to the subcortical lesion. In these five cases we operated, the cortical surface remained close to the dura, anchored by the arachnoid sutures. All the lesions were located with a good correlation between the handpiece tip inserted in the desired brain area and the display on the navigation system. Conclusion Arachnoid anchoring sutures to the duramater on the edges of the cortex area exposed by craniotomy constitute a simple method to minimize brain displacement (brain-shift) in craniotomies for subcortical injuries, optimizing the use of the neuronavigation system.

[Hydrocephalus].

Hydrocephalus is caused by excessive accumulation of cerebrospinal fluid(CSF)in the ventricles or the skull. Unlike acute hydrocephalus presenting with elevated intracranial pressure, chronic hydrocephalus is called normal-pressure hydrocephalus(NPH). Because the CSF volume increases slowly, the brain compressively deforms without increasing intracranial pressure. NPH should be diagnosed and treated according to the following three categories: idiopathic NPH(iNPH), secondary NPH(sNPH), and congenital NPH(cNPH). The intracranial CSF distribution in iNPH differed from that in sNPH or cNPH. In iNPH, the Sylvian fissure and basal cistern were conspicuously enlarged, whereas the convexity subarachnoid space was severely decreased. CSF distribution in the subarachnoid space specific to iNPH is known as "disproportionately enlarged subarachnoid space hydrocephalus(DESH)," which might be due to direct CSF communication between the lateral ventricles and the basal cistern at the inferior choroidal point of the choroidal fissure. After shunt surgery in a patient with NPH, the lateral ventricles and Sylvian fissure shrank from top to bottom, while the convexity subarachnoid space expanded. In NPH, except for obstructive hydrocephalus, the flow void sign on spin-echo T2-weighted images is usually observed around the aqueduct, which reflects the increased CSF movement.

Surgical management of a thoracic extradural arachnoid cyst with communication to subarachnoid space through nerve root: a case report.

Spinal extradural cysts are uncommon and may cause cord and nerve root compression. The cysts usually appear in thoracic spine. We report a 29-year-old man with an extradural arachnoid cyst from T4 to T6. The cyst was communicated to the subarachnoid space through a fistula at the left T6 nerve root. To access the fistula, we had to unroof the foramen of left T6 nerve root which could lead to spinal instability. We decided to save the bony and soft tissue elements of the foramen at the mentioned thoracic spine level. Therefore, the cyst walls were excised and then the ostia of the cyst at the cystic side of the fistula was tightly closed.

Experience with Management of Intracranial Arachnoid Cysts.

OBJECTIVES: The aim of this study was to analyze the demographics, clinical presentation, and surgical outcome of intracranial arachnoid cysts and to review the surgical options. METHODS: This is a retrospective observational study of 56 cases of symptomatic arachnoid cysts among all age groups treated between 2004 and 2020 at the Bombay Hospital, Mumbai. Endoscopic fenestration, microsurgical cyst excision, and shunt insertion were the interventions performed. Clinical presentation, cyst reduction post-intervention, and complications were studied. The follow-up period varied from 1 month to 16 years. Statistical analysis was done for 43 patients with a minimum of 3 years' follow-up. RESULTS: In all, 75% of patients were <18 years of age. Of these, the majority were between the age of 1 and 10 years. There were 14 cases of temporal, 13 cases of retrocerebellar, 10 cases of quadrigeminal cistern, and 7 cases each of interhemispheric and suprasellar arachnoid cysts. The most common clinical presentation was headache and vomiting. Concomitant hydrocephalus was seen on imaging in 24 cases. Endoscopic fenestration of cyst was the most routinely performed procedure (35 cases). Four patients of endoscopic fenestration underwent a redo endoscopic procedure on follow-up. Post-operative reduction in cyst size was found to be significantly better after endoscopic fenestration (p < 0.05). CONCLUSION: Though the best available treatment for arachnoid cysts remains controversial, surgery has been found to be beneficial in symptomatic cases. Endoscopic fenestration is considered the first-line surgical option and it may be followed by shunt, if necessary. Shunts may be preferred in very young children where there is associated hydrocephalus/macrocephaly.

Subarachnoid Osteoma of the Right Frontal Lobe.

BACKGROUND: Intracranial osteoma arising from nonosseous tissue and surrounded by brain parenchyma is extremely rare. We report an intracranial osteoma surgical case with no heterotopic ossification. CASE DESCRIPTION: A 32-year-old woman presented with headache, vertigo, and weakness. Preoperative neuroimaging revealed a spherelike, calcified intracranial lesion in the right frontal region. The bone-hard mass was completely removed by right frontal craniotomy; adhesion and invasion of the skull inner plate and dura were not found. The subarachnoid lesion was surrounded by right middle frontal gyrus, and the blood supply was from branches of pia mater. Postoperative histologic examination suggested an extensive intracranial ossification. At 6-month follow-up, the patient demonstrated a good recovery without any neurological deficits and no recurrence. CONCLUSIONS: In this rare surgical case of subarachnoid osteoma, comprehensive preoperative neuroradiologic examinations, accurate surgical management of adjacent brain tissue, and vessel protection were the cornerstones of successful resection.

Endodermal Cyst with a Non-enhancing Nodule in the Quadrigeminal Cistern Developed in an Octogenarian.

BACKGROUND: Intracranial endodermal cysts are congenital lesions that generally develop in the cerebellopontine angle and ventral brainstem of the posterior fossa, whereas endodermal cysts in the quadrigeminal cistern are very rare. We report a rare case of an endodermal cyst in the quadrigeminal cistern with a non-enhancing nodule that developed in patient over 80 years of age. CASE DESCRIPTION: An 85-year-old man presented to our hospital with progressing gait disturbance and urinary incontinence. Preoperative images showed a cystic mass lesion with a nodule in the quadrigeminal cistern and hydrocephalus. There was no enhanced portion in the lesion, and the intensity of the cyst on magnetic resonance imaging revealed a high protein concentration. Subtotal resection was performed due to the adhesion of the cyst to the brainstem. It was diagnosed as an endodermal cyst. The postoperative course was uneventful, and hydrocephalus improved. CONCLUSIONS: This is a rare case of an intracranial endodermal cyst in terms of location and age of onset compared with previous reports. This case demonstrates that endodermal cysts should be considered as a differential diagnosis for lesions in the quadrigeminal cistern with high protein concentration in the cyst and nodule representing chronic inflammation, regardless of enhancing effects.

High prevalence of cervical myelopathy in patients with idiopathic normal pressure hydrocephalus.

BACKGROUND: Both idiopathic normal pressure hydrocephalus (iNPH) and cervical myelopathy may result in progressive gait impairment. Some patients who do not respond to shunting despite a positive tap test may have gait dysfunction from cervical myelopathy. The objective of this study was to determine the prevalence of cervical myelopathy in patients with iNPH. METHODS: A consecutive series of patients undergoing shunt placement for iNPH were screened for cervical stenosis. Clinical manifestations of iNPH and cervical myelopathy, grade of cervical stenosis, cervical spine surgical intervention, timing of intervention, and outcomes were recorded. RESULTS: Fifty-two patients shunted for treatment of iNPH were included for analysis. 58 % were male with a mean age of 75.2 years (SD 7.3 years). All patients presented with gait disturbances. 39/52 (75 %) had cervical stenosis, and 9/52 (17.3 %) had significant (grade 2-3) cervical stenosis with myelopathy and were subsequently treated with surgical decompression. There was an association between increasing grade of stenosis and disproportionately enlarged subarachnoid space hydrocephalus (DESH). All patients with grade 2-3 cervical stenosis and symptoms of cervical myelopathy in addition to iNPH underwent cervical decompression surgery. CONCLUSIONS: Clinically significant cervical myelopathy was prevalent in patients with iNPH and was associated with increased rate of DESH, a finding that requires validation in a larger cohort. Based on these results, cervical imaging could be considered preoperatively in patients with iNPH, particularly when upper motor neuron findings are identified. Additionally, concomitant cervical stenosis should be ruled out in patients whose gait does not improve after shunt placement.

Endoscopic Endonasal Approach for Clival Chordoma with Subarachnoid Invasion: A Two-Dimensional Step-by-Step Operative Video.

Chordomas are slow-growing, low-grade, locally invasive, and locally aggressive tumors. They peak at 40-60 years of age, with a male preponderance (2:1). Belonging to the sarcoma family and thought to develop from the notochord remnant, they are most commonly found in the midline, with half located at the sacrum and about one third at the skull base.1 Their treatment mainly consists of surgical excision, followed by radiation therapy.2 The endoscopic endonasal approach provides direct access to the clival chordomas with no need for brain retraction or manipulation of neurovascular structures.3-5 Herein we present a step-by-step resection technique of a clival chordoma invading the subarachnoid space and touching the brainstem and vertebrobasilar vessels in a 46-year-old man with headaches, with a prior failed attempt of resection at an outside institution, resulting in a biopsy only in the palate. An endoscopic endonasal transclival approach was performed and gross total removal was achieved (Video 1). The patient had an uneventful recovery with no deficits, and he was then sent to proton beam therapy.