CSF Flow Studies Research Articles

The postulated role of brain pulsations and arachnoid membranes in cerebrospinal fluid circulation, ventriculomegaly and related CSF disorders

Hydrocephalus can be obstructive or communicating. In cases of communicating hydrocephalus, patients will typically have enlarged brain ventricles. It has long been thought that the reason for this is obstruction to the outflow of cerebrospinal fluid from the subarachnoid space, which also results in raised intracranial pressure (ICP). However, there are several clinical and anatomic observations that are not well explained by this idea. These are for example, the conditions of Normal pressure hydrocephalus (NPH) which has normal ICP but ventriculomegaly, and idiopathic intracranial hypertension (IIH) which has raised ICP but normal sized ventricles. This hypothesis states that the mechanism for raised ICP and large ventricles seen in communicating hydrocephalus (ventriculomegaly) are different and seeks to explain the cause of ventriculomegaly using illustrative examples. It also suggests explanations for why ventriculomegaly occurs in NPH, infectious or carcinomatous meningitis, but is absent in IIH, or dural venous sinus thrombosis. Based on operative neurosurgical observations it states that the arachnoid membranes in the basal cisterns serve as part of a directional CSF flow mechanism consisting of fluid diodes, or “Tesla valves” of arachnoid membrane, containing CSF that is propelled by brain pulsations from the point of exit from the 4th ventricle to its points of absorption. This hypothesis suggests explanations for the physiologic appearance of a near uniform subarachnoid space, as well as the occurrence of the syndrome of the trephined and external hydrocephalus seen following a decompressive craniectomy. Also suggested are avenues of further research testing with MRI phase contrast CSF flow studies, classification of anatomic and peri-operative observations and rationale for creation of novel experiments to test the hypothesis, and aid diagnosis and treatment of a number of cranial CSF disorders.

Cerebrospinal fluid (CSF) and idiopatic intracranial hypertension (IIH): a critical review

Pseudotumor cerebri is a syndrome that results from increased intracranial pressure. The main symptoms are headache, vision disturbances, and pulsatile tinnitus. Definitive diagnosis requires the presence of clinical and/or radiological signs of intracranial hypertension, high opening pressure on lumbar puncture (LP), and normal CSF constitution. Several studies have evaluated new contributions of CSF in the clinical evaluation and the in understanding of the pathophysiology of pseudotumor cerebri. Such studies have included the analysis of inflammatory biomarkers, adipokines, proteomic analysis, and CSF flow studies. In this review, we present the main results obtained so far and critically discuss the present status and the potential role of research involving the CSF in this condition. Based on current knowledge, it is possible to conclude that CSF research with new biomarkers has not yet provided information that can be employed in clinical practice at this moment. However, a better understanding of the constitution and dynamics of CSF circulation in patients with pseudotumor cerebri has brought some information about this condition and can potentially improve our knowledge about this condition in the future.

Accuracy of MRI CSF Flowmetry in the Diagnosis of Normal Pressure Hydrocephalus

BACKGROUND: Normal pressure hydrocephalus (NPH) is one of the few treatable causes of dementia. NPH is diagnosed using the clinical triad of: Gait disturbance, progressive mental deterioration, urinary urgency, or incontinence in association with radiological findings suggestive of NPH, for example, ventriculomegaly, disproportionately enlarged subarachnoid space hydrocephalus, and narrow callosal angles. AIM: The purpose of the present study was to assess the accuracy of MRI cine phase flow studies as a non-invasive modality in the diagnosis, and also for the prediction of improvement of symptoms suggestive of NPH without the need for CSF tapping. METHODS: Twenty-six patients suffering clinically from the triad of NPH, or at least two of them; attending our neurology, psychiatry, and neurosurgery clinics in Cairo University Hospitals, with ages ranging between 50 and 85 years, randomly chosen regarding sex or other comorbidities. All patients underwent a regular MRI in addition to CSF flowmetry studies to correlate the MRI findings that reveal NPH with their known clinical features. Careful clinical assessment was performed to detect severity of symptoms, and patients were classified accordingly, and a disability score was provided. After CSF tapping, patients were reassessed clinically after 6–8 h to detect improvement of symptoms, and the degree of improvement was compared to the result of CSF flow study. RESULTS: CSF flow studies, particularly stroke volume across the aqueduct of Sylvius, provide the highest significance in diagnosing hyperdynamic circulation evident by many radiological studies in cases of NPH. This was also found to be a good prognostic factor which correlates well with the improvement of symptoms following CSF tapping. However, its use to exclude suspicious cases of NPH seems unreliable, that is, not a good negative predictor. Findings of MRI CSF flow studies also show significance in detecting brain atrophic changes, especially peak systolic velocity, which usually accompany or mimic the clinical picture of NPH. CONCLUSION: MRI CSF flow studies are an excellent aid as an adjuvant non-invasive technique in selection of suspicious cases as it shows significance in detecting hyperdynamic circulation, especially high stroke volume results in cases of NPH. Both CSF tapping and CSF flowmetry findings “low stroke volume values” were not found to be a good negative predictor for clinical improvement after shunting.

Quantifying intraventricular drug delivery utilizing programmable ventriculoperitoneal shunts as the intraventricular access device.

Programmable ventriculoperitoneal shunts (pVP shunts) are increasingly utilized for intraventricular chemotherapy, radioimmunotherapy, and/or cellular therapy. Shunt adjustments allow optimization of drug concentrations in the thecal space with minimization in the peritoneum. This report assesses the success of the pVP shunt as an access device for intraventricular therapies. Quantifying intrathecal drug delivery using scintigraphy by pVP shunt model has not been previously reported. We performed a single-institution, retrospective analysis on patients with CNS tumors and pVP shunts from 2003 to 2020, noting shunt model. pVP flow was evaluated for consideration of compartmental radioimmunotherapy (cRIT) using In-111-DTPA scintigraphy. Scintigraphy studies at 2-4h and at 24h quantified ventricular-thecal and peritoneal drug activity. Twenty-two CSF flow studies were administered to 15 patients (N = 15) with diagnoses including medulloblastoma, metastatic neuroblastoma, pineoblastoma, and choroid plexus carcinoma. Six different types of pVP models were noted. 100% of the studies demonstrated ventriculo-thecal drug activity. 27% (6 of 22) of the studies had no peritoneal uptake visible by imaging. 73% (16 of 22) of the studies had minimal relative peritoneal uptake (< 12%). 27% (6 of 22) of the studies demonstrated moderate relative peritoneal uptake (12-37%). No studies demonstrated peritoneal uptake above 37%. All patients had successful drug delivery of In-111-DTPA to the ventriculo-thecal space. 73% of the patients had minimal relative (< 12%) peritoneal drug uptake. Though efficacy varies by shunt model, low numbers preclude conclusions regarding model superiority. CSF flow scintigraphy studies assesses drug distribution of In-111-DTPA, informing CSF flow for delivery of intraventricular therapies.

Tetraventricular noncommunicating hydrocephalus: Case report and literature review.

Background: Tetraventricular hydrocephalus is a common presentation of communicating hydrocephalus. Conversely, cases with noncommunicating etiology impose a diagnostic challenge and are often neglected and underdiagnosed. Herein, we present a review of literature for clinical, diagnostic, and surgical aspects regarding noncommunicating tetrahydrocephalus caused by primary fourth ventricle outlet obstruction (FVOO), illustrating with a case from our service.Methods: We performed a research on PubMed database crossing the terms “FVOO,” “tetraventriculomegaly,” and “hydrocephalus” in English. Fifteen articles (a total of 34 cases of primary FVOO) matched our criteria and were, therefore, included in this study besides our own case.Results: Most cases presented in adulthood (47%), equally divided between male and female. Clinical presentation was unspecific, commonly including headache, nausea, and dizziness as symptoms (35.29%, 21.57%, and 9.80%, respectively), with ataxic gait (65%) and papilledema (40%) being the most frequent signs. MRI and CT were the imaging modalities of choice (11 patients each), often associated with CSF flow studies, such as cine MRI and CT ventriculogram. Endoscopic third ventriculostomy (ETV) was both the most popular and effective surgical approach (50.85% of cases, with 18.91% of recurrence) followed by ventricle-peritoneal shunt (16.95% of patients, 23.0% of recurrence).Conclusion: FVOO stands for a poorly understood etiology of noncommunicating tetrahydrocephalus. With the use of ETV, these cases, once hopeless, had its morbimortality and recurrence reduced greatly. Therefore, its suspicion and differentiation from other forms of tetrahydrocephalus can improve its natural course, reinforcing the importance of its acknowledgment.

LMD-01. Quantifying intrathecal drug delivery utilizing programmable ventriculoperitoneal shunts

BackgroundProgrammable ventriculoperitoneal shunts (pVP shunts) are increasingly utilized for intraventricular chemotherapy, radioimmunotherapy, and/or cellular therapy. Shunt adjustments allow optimization of thecal space drug concentrations with minimization in the peritoneum. Drug delivery quantification using several types of pVP shunts has not been reported.MethodsWe performed a retrospective analysis on patients with CNS tumors and pVP shunts at Memorial Sloan Kettering Cancer Center from 2003–2020, noting shunt model. CSF flow through the pVP shunt was evaluated using In-111-DTPA scintigraphy at approximately 4 and 24 hours after injection. pVP shunts were calibrated pre-injection to minimize peritoneal flow and re-calibrated to baseline setting 4–5 hours following injection. Scintigraphy studies quantified ventricular-thecal and peritoneal drug activity at these 2 time points.ResultsTwenty-one CSF flow studies were administered to 15 patients, ages 1–27 years. Diagnoses included medulloblastoma (N=10), metastatic neuroblastoma (N=3), pineoblastoma (N=1), and choroid plexus carcinoma (N=1). Models of pVP shunts included Aesculap Miethke proGAV (N=3), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 5), and Sophysa Polaris (N= 1). All 21 studies (100%) demonstrated ventriculo-thecal drug activity. 29% (6 of 21) of the studies had no peritoneal uptake visible by imaging. 73% (16 of 21) of the studies had minimal peritoneal uptake (<12%), and 24% (5 of 21) demonstrated moderate peritoneal uptake (12–37%). Models of pVP shunts measuring minimal to no peritoneal uptake included: Aesculap Miethke proGAV (N=2), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 3), and Sophysa Polaris (N= 1).ConclusionspVP shunts successfully deliver drugs to the ventriculo-thecal space with 80% of studies having minimal (<12%) peritoneal drug activity. Though efficacy varies by shunt model, low numbers preclude conclusions regarding model superiority. CSF flow scintigraphy studies reliably assess drug distribution.

IMMU-15. QUANTIFYING INTRATHECAL DRUG DELIVERY UTILIZING PROGRAMMABLE VENTRICULOPERITONEAL SHUNTS

BackgroundProgrammable ventriculoperitoneal (pVP) shunts are increasingly utilized for intraventricular chemotherapy, radioimmunotherapy, and/or cellular therapy. Shunt adjustments allow optimization of thecal space drug concentrations with minimization in the peritoneum. Drug delivery quantification using several types of pVP shunts has not been reported. MethodsWe performed a retrospective analysis on patients with CNS tumors and pVP shunts at Memorial Sloan Kettering Cancer Center from 2003–2020, noting shunt model. CSF flow through the pVP shunt was evaluated using In-111-DTPA scintigraphy at approximately 4 hours and 24 hours after injection. pVP shunts were calibrated pre-injection to minimize peritoneal flow and re-calibrated to baseline setting 4–5 hours following injection. Scintigraphy studies quantified ventricular-thecal and peritoneal drug activity at these 2 time points. ResultsTwenty-one CSF flow studies were administered to 15 patients, ages 1–27 years. Diagnoses included medulloblastoma (N=10), metastatic neuroblastoma (N=3), pineoblastoma (N=1), and choroid plexus carcinoma (N=1). pVP shunt models included Aesculap Miethke proGAV (N=3), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 5), and Sophysa Polaris (N= 1). All 21 studies (100%) demonstrated ventriculo-thecal drug activity. 29% (6 of 21) of the studies had no peritoneal uptake visible by imaging. 73% (16 of 21) of the studies had minimal peritoneal uptake (<12%), and 24% (5 of 21) demonstrated moderate peritoneal uptake (12–37%). pVP shunt models measuring minimal to no peritoneal uptake included: Aesculap Miethke proGAV (N=2), Aesculap Miethke proGAV2.0 (N=3), Codman HAKIM (N=2), Codman Certas Plus (N=1), Medtronic STRATA (N= 3), and Sophysa Polaris (N= 1). ConclusionsSuccessful drug delivery to the ventriculo-thecal space can be accomplished using pVP shunts: 80% of studies have minimal (<12%) peritoneal drug activity. Though efficacy varies by shunt model, low numbers preclude conclusions regarding model superiority. CSF flow scintigraphy studies reliably assess drug distribution.

Multi-modality imaging evaluation of the dorsal arachnoid web.

Dorsal arachnoid web (DAW) is a rare intradural abnormality which is associated with progressive myelopathy. Our objective was to review multi-modality imaging techniques demonstrating the scalpel sign appearance in evaluation of DAW. We retrospectively reviewed various imaging modalities of patients found to have DAW at our institution during January 2015 to February 2020. Five patients underwent surgical decompression with pathological correlation. The remaining patients were presumptively diagnosed based on the characteristic finding of scalpel sign. Clinical data were evaluated and correlated to imaging findings. All imaging modalities demonstrated the characteristic scalpel sign. Sixteen patients (10 females, and six males) with multi-imaging modalities were evaluated. Their mean age was 52 year (range 23-74 years). Fifteen patients underwent conventional spine MRI. Further high-resolution MR imaging techniques, e.g. 3D T2 myelographic sequence, were utilized with two patients. MRI spine CSF flow study was performed to evaluate the flow dynamic across the arachnoid web in one patient. Eight patients were evaluated with CT myelogram. Syrinx formation was discovered in seven (44%) patients; five (71%) of them underwent surgical resection and decompression. Two patients underwent successful catheter-directed fenestration of the web with clinical improvement. We found a statically significant positive correlation between the degree of cord displacement and compression with syrinx formation (r = 0.55 and 0.65 with p-value of 0.03 and 0.009, respectively). DAW has characteristic scalpel sign independent of imaging modality. Multi-modality imaging evaluation of DAW is helpful for evaluation and surgical planning.

Cerebrospinal Fluid Dynamics Study: A Unique Tool for Management of Chiari 1 Malformation Patients

Background and Aim: Chiari I malformation(CIM) is defined as descent of cerebellar tonsils 5mm or more below the foramen magnum, with or without associated syrinx. Degree of tonsillar descent has a poor correlation with the progression of disease and symptomatology. Abnormal CSF dynamics at foramen magnum is the main pathophysiological factor responsible for the progression of tonsillar descent, syrinx formation and hence symptomatology. The aim of this study is to correlate CSF dynamic changes with the clinicoradiological profile of CIM patients. Methods and Materials/Patients: A prospective longitudinal study was done in 25 patients of CIM out of which 24 patients underwent standard midline suboccipital craniectomy with augmented duraplasty and 1 patient had ventriculoperitoneal shunt surgery for hydrocephalus. CSF flow study was done in sagittal as well as in axial sections at the level of foramen magnum using cine flow magnetic resonance imaging (MRI). Clinical and radiological assessment in reference to CSF flow parameters was done before and after decompression surgery. Results: After suboccipital decompression 23 out of 24 patients had relief in their symptoms and 1 patient had progressive syringomyelia. Postoperative MRI scan at 3months showed round shaped tonsils in all 24 patients. Ten out of 11 patients with syrinx had reduction in diameter of syrinx cavity. Peak CSF flow velocities reduced significantly (p value &lt; 0.05) in the postoperative period and correlated well with the clinicoradiological improvement. Conclusion: Abnormal CSF flow dynamics is responsible for the progression of disease and symptomatology in CIM patients. Cine flow MRI is a useful tool in the management of CIM patients both for proper selection of surgical candidates and in post-operative follow-up.

SCIDOT-37. ASSESSING CEREBROSPINAL FLUID FLOW DYNAMICS IN PEDIATRIC PATIENTS WITH CENTRAL NERVOUS SYSTEM TUMORS

Abstract BACKGROUND The incidence of abnormal CSF flow dynamics in the pediatric population with CNS tumors prior to intraventricular therapy has not been described. METHODS We performed a single-institution, retrospective review of patients with primary or metastatic CNS tumors treated between 2003–2018 (15 years).. Patients underwent 111-indium diethylene triamine pentaacetic acid injection into the CSF intraventricular space followed by nuclear medicine imaging at 90 minutes, 4, 24, and 48 hours (if required). CSF flow was classified as normal, delayed, asymmetric or obstructed. RESULTS 278 CSF flow studies were performed in 224 patients, 202(90%) &lt;18 years of age. 116(52%) patients had metastatic CNS neuroblastoma, 57(25%) had medulloblastoma, and 51(23%) had other CNS histologies. Of the 278 studies, 237(85%) were normal, 9(3%) required neurosurgical intervention, 25(9%) were delayed, and 7(3%) were asymmetric. CONCLUSIONS Abnormal CSF flow and necessity of neurosurgical intervention must be considered when attempting to ensure appropriate intraventricular therapy in the pediatric population.

P.007 Familial idiopathic normal pressure hydrocephalus in a Canadian family

Background: Idiopathic Normal-pressure hydrocephalus (iNPH) is characterized by cognitive impairment, gait disturbance, enlarged ventricles with/without cerebral atrophy, with/without urinary incontinence, and normal cerebrospinal fluid pressure. Familial iNPH is very rarely described in the literature. A Canadian family with more than one generation of iNPH has never been described. Methods: Patient 1: 50-year-old female presented with wide-based and magnetic gait, multiple falls with subsequent freezing. LP with large volume tap was performed. Patient had ventriculo peritoneal (VP) shunt surgery. Patient 2: 52 year male (brother): Presented with long-standing cognitive impairment and fatigue. Montreal Cognitive Assessment (MOCA) was performed. Whole exome sequencing(WES) of both siblings as well as an unaffected first cousin was done. The father and grandmother of both patients was diagnosed with iNPH. Results: Patient 1: Opening pressure on LP was 22 cm-H2O. She responded well to large volume tap. She had VP shunt resulting in improved gait. Patient 2: Opening pressure on LP was 16cm-H2O. CSF flow study was slow for age indicative of NPH. MoCA score was 25/30. WES of patients and unaffected first cousin is underway. Conclusions: We present an undescribed Canadian family with iNPH in more than one generation. WES is underway for better understanding of genetic predesposition and inheritance of familial iNPH

P.122 Foramen magnum decompression of Chiari malformation using minimally invasive tubular retractors

Background: A surgical technique for foramen magnum decompression of Chiari malformation I in 11 patients is described. Methods: We used minimally invasive tubular retractors (METRx Quadrant) attached to a flexible arm to keep the retractor in a fixed position, while allowing flexible angulation under fluoroscopic guidance. Despite the small surgical opening, this approach allowed access to a wide working area, minimized soft tissue exposure, and optimized extent of decompression. For some patients, only the outer layer of dura was opened, but in cases where clinically indicated, a duraplasty was performed. Results: Postoperative CT head demonstrated satisfactory bony removal, and MRI with CSF flow study showed restoration, or significant improvement to CSF flow around the foramen magnum. There was a low incidence of post-operative complications, and the average length of hospital stay was around 1 day (1.2). For 10 out of 11 patients; their symptoms completely resolved on last follow-up, and for those who had syringomyelia, they demonstrated a radiological evidence of syrinx reduction or resolution. Conclusions: Based on our experience with this technique in foramen magnum decompression of Chiari malformation I, minimally invasive tubular retractor is a useful tool, providing the surgeon with enhanced visualization of the operative field, while reducing potential damage to tissue, and optimizing surgical outcomes.

Role of MRI CSF Flowmetry in Evaluation of Hydrocephalus in Pediatric Patients

Background: phase contrast MR imaging is a rapid, simple and non-invasive technique which is sensitive to even small CSF flows, and can be used to evaluate CSF flow both qualitatively and quantitatively. Cine phase contrast MR images show CSF flow in a dynamic, more easily appreciable, and in a more pleasing manner, allowing the delineation of obstruction, if present, along the portions of CSF pathway where obstruction is common (foramen of Monro, acqueduct of Sylvius) Patients and Methods: the study includes 20 patients from the pediatric population with ventriculomegaly (diagnosed by a radiological report) referred from Ain Shams Pediatric Hospital, Neurosurgery department at Ain Sahms University, clinic, and outpatients. Control group of 20 pediatric patients of matched age group underwent CSF flow study to obtain normal reference values. These patients had no hydrocephalus and came to our institute to undergo MRI for other neurological causes. CSF flowmetry was added to their study after obtaining oral informed consent from their parents. Results: our study included 20 patients, 8 males and 12 females, with age range 2 months - 12 years and average age 3.5 years old. All patients included were diagnosed with hydrocephalus by a previous radiological report. All patients underwent conventional MRI brain and CSF flowmetry. Patients were given diagnosis based on findings of conventional MR images, and were categorized into groups according to their underlying etiologies. 9 patients had aqueductal stenosis, 4 patients had atrophy, 2 patients had communicating hydrocephalus, 2 patients had Arnold Chiari malformation, 1 patient had Dandy-Walker variant, 1 patient had obstruction at foramen of Monro, and 1 had obstruction at foramen of Magendi. CSF flowmetry was added to evaluate the cause of hydrocephalus. Conclusion: phase contrast MR imaging is a rapid, simple and non-invasive technique which is sensitive to even small CSF flows, and can be used to evaluate CSF flow both qualitatively and quantitatively, and could be used in conjunction with conventional MRI in assessment of cases of hydrocephalus.

Dynamic cervicomedullary cord compression and alterations in cerebrospinal fluid dynamics in children with achondroplasia: review of an 11-year surgical case series.

Achondroplasia may be associated with compression at the cervicomedullary junction. Determining which patients are at greatest risk for neurological complications of cervicomedullary compression can be difficult. In the current study the authors reviewed their records to determine the incidence and clinical significance of dynamic cervicomedullary stenosis and obstruction of CSF flow along with surgical outcomes following posterior fossa decompression. The authors reviewed 34 consecutive cases involving symptomatic children with achondroplasia undergoing cervicomedullary decompression performed by a single surgeon over 11 years. Of these patients, 29 had undergone preoperative dynamic MRI of the cervicomedullary junction with cine (cinema) CSF flow studies; 13 of these patients underwent postoperative dynamic MRI studies. Clinical outcomes included changes in polysomnography, head circumference percentile, and fontanel characteristics. Radiographic outcomes included changes in dynamic spinal cord diameter, improvement in CSF flow at the foramen magnum, and change in the Evans ratio. Patients were predominantly female, with a mean age at presentation of 6.6 years and mean follow-up of 3.7 years (range 1-10 years). All patients had moderate to excellent improvement in postoperative polysomnography, slight decrease in average head circumference percentile (from 46.9th percentile to 45.7th percentile), and no subjective worsening of fontanel characteristics. The Evans ratio decreased by 2%, spinal cord diameter increased an average of 3.1 mm, 5.2 mm, and 0.2 mm in the neutral, flexed, and extended positions, respectively, and CSF flow improved qualitatively in all 3 positions. There were no postoperative infections, CSF leaks, or other major complications. None of the patients undergoing initial foramen magnum decompression performed at our medical center required reoperation. Patients with achondroplasia and symptomatic cervicomedullary compression have increased risk of dynamic stenosis at the foramen magnum evident upon dynamic cine MRI. Operative decompression may be offered with low risk of complications or need for reoperation.

Normal pressure hydrocephalus: Treatable dementia, missed diagnosis—The Launceston Prevalence Study

Normal Pressure Hydrocephalus (NPH) is one of the few treatable forms of dementia, but it is notoriously difficult to diagnose in the elderly. It is often treated by the insertion of ventriculo-peritoneal shunt with significant improvement in the cognitive, gait and urinary functioning. Most studies suggest the condition is rare but there are few studies addressing the prevalence of the condition. We have, therefore, investigated the prevalence of NPH amongst patients with cognitive impairment attending the Memory Disorders Clinic in Launceston. Three hundreds and fifty five consecutive patients were recruited from the Memory Disorders Clinic at the Launceston General Hospital since 2010. The diagnosis of NPH was based on the presence of memory impairment or dementia, and/or balance/gait disorder and the presence of prominent ventricles regardless of cerebral atrophy on MRI of the brain. All patients with NPH were investigated by CSF Flow Study. One hundred and sixty four men and 191 women participated in the study, mean age 73 years (range 32–95 years), mean MMSE score 23 (range 0–30). 190 (54%) patients were diagnosed with mild cognitive impairment, of whom 54 (28%) had underlying anxiety and depression, 23 (12%) had NPH and 9 (5%) had Parkinsonism.165 (46%) were diagnosed with dementia, of whom 77 (47%) had Alzheimer's disease, 33 (20%) had NPH, 20 (12%) had mixed dementia, 9 (5%) had vascular dementia and 26 (16%) were diagnosed with other forms of dementia including Parkinsonism, Lewy Body Disease, Gertsmann Syndrome, and Frontal Lobe Dementia. NPH is probably more common than previously thought. This is important because many patients without shunting might be condemned for years of disabilities and institutionalisation.

Prognostic utility of neuraxis imaging in leptomeningeal metastasis (LM): A retrospective case series.

2037 Background: Correlate imaging of the central nervous system that includes both brain and spine MRI and radio-isotope cerebrospinal fluid [CSF] flow studies with survival in a retrospective case series of patients with LM. Methods: 240 adult patients with LM (125 non-brain solid tumor patients with positive CSF cytology; 40 non-brain solid tumor patients with negative CSF cytology and MRI consistent with LM; 50 lymphoma and 25 leukemia patients with positive CSF flow cytometry), all considered appropriate for LM-directed treatment, underwent prior to treatment brain and entire spine MRI and radio-isotope CSF flow studies. Results: Median overall survival was significantly shortened in patients with large volume MRI defined disease (defined as measurable tumor &gt; 5 x 10 mm in orthogonal diameters) and in patients with non-corrected CSF flow obstruction irrespective of primary tumor histology. Additionally, cause of death differed wherein patients with large volume of disease or uncorrected obstructed CSF flow more often died of progressive LM disease whereas patients with normal or small volume disease and patients with normal or re-established CSF flow more often died of progressive systemic disease. Conclusions: Neuraxis imaging utilizing brain and spine MRI as well as radio-isotope CSF flow studies appears to have prognostic significance and may be predictive of median overall survival in this large cohort of patients with LM all of whom were considered for treatment with LM.

Interpretation and value of MR CSF flow studies for paediatric neurosurgery

Imaging techniques may be underutilised when clinicians are unaware of the technique or do not recognise its potential. Phase-contrast MR imaging (PC-MRI) is a rapid, simple and non-invasive technique that is sensitive to CSF flow. It demonstrates a mechanical coupling between cerebral blood and CSF flow throughout the cardiac cycle. Neurosurgeons should be able to request this procedure routinely as part of an MRI request. This paper gives an overview of the indications, technical requirements, technique and interpretation, using image examples. Indications for CSF flow studies include assessment and functionality of shunt treatment in patients with hydrocephalus; hydrocephalus associated with achondroplasia; Chiari I malformation; confirmation of aqueductal stenosis; and determining patency of a third ventriculostomy.

Interpretation and value of MR CSF flow studies for paediatric neurosurgery

Imaging techniques may be underutilised when clinicians are unaware of the technique or do not recognise its potential. Phase-contrast MR imaging (PC-MRI) is a rapid, simple and non-invasive technique that is sensitive to CSF flow. It demonstrates a mechanical coupling between cerebral blood and CSF flow throughout the cardiac cycle. Neurosurgeons should be able to request this procedure routinely as part of an MRI request. This paper gives an overview of the indications, technical requirements, technique and interpretation, using image examples. Indications for CSF flow studies include assessment and functionality of shunt treatment in patients with hydrocephalus; hydrocephalus associated with achondroplasia; Chiari I malformation; confirmation of aqueductal stenosis; and determining patency of a third ventriculostomy.

Comprehensive neuraxis imaging in leptomeningeal metastasis: a retrospective case series.

Quantify imaging abnormalities in a retrospective case series of patients with leptomeningeal metastasis (LM). A total of 240 adult patients with LM (125 nonbrain solid tumor patients with positive cerebrospinal fluid [CSF] cytology; 40 nonbrain solid tumor patients with negative CSF cytology and positive MRI; and 50 lymphoma and 25 leukemia patients with positive CSF-flow cytometry) underwent brain and entire spine MRI and radioisotope CSF-flow studies prior to treatment. MRI was more often abnormal in solid tumors (40 CSF defined and 100% in MRI defined) compared with hematologic cancers (16-20%; p = 0.03). Similarly, CSF-flow studies was more often abnormal in solid tumors (25-28%) compared with hematologic cancers (10-20%; p = 0.04). MRI and flow-study abnormalities altered therapy in a third of solid tumors and 15% of hematologic cancers. Although imaging abnormalities are less often seen in hematologic cancers compared with solid tumor LM, imaging abnormalities frequently result in treatment alteration.

Neuraxis imaging in leptomeningeal metastasis: A retrospective case series.

2046 Background: (and Objective) Leptomeningeal metastasis (LM) is a central nervous system metastatic complication of cancer that affects the entire neuraxis. Quantify imaging (brain and spine MRI and radio-isotope cerebrospinal fluid [CSF] flow study) abnormalities in a retrospective case series of patients with LM. Methods: 240 adult patients with LM (125 non-brain solid tumor patients with positive CSF cytology; 40 non-brain solid tumor patients with negative CSF cytology; 50 lymphoma and 40 leukemia patients with positive CSF flow cytometry) underwent prior to treatment brain and entire spine MRI and radio-isotope CSF flow studies (FS). Results: Neuraxis MRI in pathologically defined patients was more often normal in hematologic tumors (80-84%) compared to solid tumors (60%). Similarly, FS was more often normal in hematologic tumors (90-92%) compared to solid tumors (72-75%). However, neuraxis MRI and FS abnormalities (i.e. CSF flow obstruction; nodular subarachnoid or parenchymal disease; hydrocephalus) altered therapy by requiring CSF diversion, site specific radiotherapy, systemic chemotherapy or recommending no further therapy in one third of CSF cytology positive solid tumors and 15% of CSF flow cytometry positive hematologic tumors. Conclusions: Notwithstanding less frequent imaging abnormalities in hematologic tumors, similar to solid tumors imaging abnormalities frequently result in treatment alteration for patients with LM. Consequently, neuraxis imaging is recommended in both tumor categories in patients being considered for LM-directed and in particular intra-CSF chemotherapy treatment.