68Ga-DOTA PET for Diagnosis of Spinal Cerebrospinal Fluid Leaks

Spontaneous intracranial hypotension due to spinal cerebrospinal fluid (CSF) leakage causes substantial disease burden. In many patients, the course is protracted and refractory to conservative treatment, requiring targeted therapy. We propose PET of the CSF space with 68Ga-DOTA as a state-of-the-art approach to radionuclide cisternography (RC) and validate its diagnostic value. Methods: This study is a retrospective analysis of patients with suspected intracranial hypotension due to spinal CSF leaks and who underwent whole-body PET/CT at 1, 3, and 5 h after intrathecal lumbar injection of 68Ga-DOTA. Two independent raters unaware of the clinical data analyzed all scans for direct and indirect RC signs of CSF leakage. Volume-of-interest analysis was performed to assess the biologic half-life of the tracer in the CSF space and the ratio of decay-corrected activity in the CSF space at 5 and 3 h (simplified marker of tracer clearance). Comprehensive stepwise neuroradiologic work-up served as a reference; additional validation was provided by surgical findings and follow-up. Results: Of 40 consecutive patients, 39 patients with a working diagnosis of intracranial hypotension due to a spinal CSF leak (spontaneous, n = 31; postintervention, n = 8) could be analyzed. A spinal CSF leak was verified by the neuroradiologic reference method in 18 of 39 patients. As the only direct and indirect diagnostic signs, extrathecal tracer accumulation at the cervicothoracic junction (67% sensitivity and 90% specificity) and lack of activity over the cerebral convexities (5 h; 94% sensitivity and 67% specificity) revealed a high diagnostic value for spinal CSF leaks. Their combination provided little improvement (71% sensitivity and 95% specificity). Additional quantitative analyses yielded no benefit (94% sensitivity and 53% specificity for biological half-life; 94% sensitivity and 58% specificity for the ratio of total radioactivity within the CSF space at 5 and 3 h). The location of direct signs (extrathecal tracer accumulation) did not correlate with verified sites of spinal CSF leakage. Conclusion: We propose CSF PET with 68Ga-DOTA as a novel, fast, and convenient approach to RC for verification but not localization of spinal CSF leaks with high sensitivity and specificity. CSF PET may fulfill an important gatekeeper function for stratifying patients toward escalation (ruling in) or deescalation (ruling out) of diagnostic and therapeutic measures. Further prospective studies are needed to validate the present results and determine the potential of the methods to reduce the burden to patients.

Patterns of cerebrospinal fluid (CSF) distribution in patients with spontaneous intracranial hypotension: Assessed with magnetic resonance myelography

BACKGROUND

Diagnosis of spontaneous intracranial hypotension (SIH) relies on the ability of medical staff to recognize cerebrospinal fluid (CSF) leakage at the spine. However, difficulties with interobserver discrepancy sometimes occurred while reading magnetic resonance myelography (MRM) because clear image definition was lacking. In this study, we tried to determine which pattern of CSF distribution is more reliable for diagnosis of CSF leakage by using MRM.

METHODS

From January 2012 to August 2014, 19 SIH patients and 27 healthy controls (HC) were recruited into our study; 10 of the 19 patients were recovered (SIH-R) after treatment. Whole spine MRM was performed using the 3D-SPACE (three-dimensional sampling perfection with application-optimized contrasts using different flip-angle evolutions) sequence, and interpreted by two experienced neuroradiologists. Two 4-point classification systems of CSF distribution were used to evaluate the three-dimensional maximum intensity projection (3D MIP) and the thin-slice axial multiplanar reconstruction (MPR) images, respectively.

RESULTS

The interobserver agreement between the two readers interpreting the 3D MIP and thin-slice axial MPR MRM were moderate to good (κ=0.60-0.78). Grade 3 of 3D MIP and Type D of axial MPR MRM were only noticed in the SIH. Overall, Grade 3 of MIP and Type D of MPR showed significant difference (p<0.008) between the SIH and the HC in the whole spine. Type C at the T-spine was more frequently noted in the SIH than in the HC (p<0.038). By using "Grade 3", "Type D", "Type D and Type C at T-spine" as the diagnostic criteria of CSF leakage, the sensitivity, specificity, positive predict value (PPV), and negative predict value (NPV) were all > 70%.

CONCLUSION

Grade 3 on 3D MIP and Type D on axial MPR MRM were definite criteria of MRM for localizing CSF leakage, and Type C in the T-spine was a probable leakage sign with high sensitivity and NPV.

Imaging Signs in Spontaneous Intracranial Hypotension: Prevalence and Relationship to CSF Pressure

BACKGROUND AND PURPOSE

Patients with spontaneous intracranial hypotension often exhibit low CSF pressure and changes on brain MR imaging and/or evidence of CSF leak on myelography. We investigated whether individual imaging signs of spontaneous intracranial hypotension correlate with measured CSF pressure and how frequently these 2 markers of spontaneous intracranial hypotension were concordant.

MATERIALS AND METHODS

We performed a retrospective, cross-sectional study of 99 subjects with spontaneous intracranial hypotension. Prevalence of brain and myelographic imaging signs of spontaneous intracranial hypotension was recorded. CSF pressure among subjects with or without individual imaging signs was compared by using a 2-tailed t test and ANOVA. Concordance between low CSF pressure (≤6 cm H2O) and imaging was defined as the presence of the sign in a subject with low CSF pressure or absence of the sign when pressure was not low.

RESULTS

Dural enhancement, brain sagging, and venous distension sign were present in 83%, 61%, and 75% of subjects, respectively, and myelographic evidence of CSF leak was seen in 55%. Marginal correlations between CSF pressure and brain sagging (P = .046) and the venous distension sign (P = .047) were found. Dural enhancement and myelographic evidence of leak were not significantly correlated with CSF pressure. Rates of concordance between imaging signs and low CSF pressure were generally low, ranging from 39% to 55%.

CONCLUSIONS

Brain and myelographic signs of spontaneous intracranial hypotension correlate poorly with CSF pressure. These findings reinforce the need to base the diagnosis of spontaneous intracranial hypotension on multiple diagnostic criteria and suggest the presence of patient-specific variables that influence CSF pressure in these individuals.

[Headhache secondary to intracranial hypotension in a Lumbar Spinal Stenosis Surgery]

Intracraneal hypotension headache is a well known syndrome in neurosurgery practice. In most cases cerebrospinal fluid leaks are caused by medical interventions, such as lumbar puncture, peridural anesthesia and surgical interventions on the spine. Clinical symptoms tipically show orthostatic headache that resolves in supine position, and other symptoms like neck tightness, vertigo and diplopia. RMI diagnostic confirms paquimeningeal enhancement and subdural hygromas. Conservative treatment usually includes bed resting, hydratation and administration of caffeine or glucocorticoids, resolving spontaneously in one to four months. The importance of the diagnosis lies in the differential diagnosis with other causes of headache, as symptomatic limiting factor in the rehabilitation of the patient and the same favorable prognosis.

[Intracranial hypotension syndrome: a review of the magnetic resonance findings]

INTRODUCTION

Intracranial hypotension syndrome (IHS) is a syndrome with a variable aetiology and clinical presentation that is, in most cases, caused by leakage of cerebrospinal fluid (CSF) through the thecal sac. Orthostatic headache associated to the typical magnetic resonance imaging (MRI) findings, secondary to depletion of CSF, is the key to a correct diagnosis.

AIMS

To show the imaging findings that, within a suitable clinical context, allow this condition to be identified and diagnosed.

DEVELOPMENT

Decreased CSF volume plays an important role in IHS, which leads to an increase in the compensatory volume of blood, essentially dependent on the venous system. MRI is a sensitive technique in the diagnosis of IHS. Yet, separate findings are unspecific. The MRI findings include diffuse and homogeneous dural enhancement, the presence of small bilateral subdural collections, caudal displacement of the encephalic structures (pseudo-Chiari), dilatation of the cortical and medullar veins, and the recent sign of venous distension. This last sign is a highly sensitive finding of IHS, which tends to disappear following the patient's clinical improvement even before the disappearance of the pachy-meningeal enhancement, and could be used as a marker for response to treatment.

CONCLUSIONS

IHS is a condition that is difficult to diagnose clinically for which several typical MRI findings have been reported; both neurologists and radiologists must be familiar with these findings.

[Case report of paradoxical overdrainage of cerebrospinal fluid]

The authors describe a case of paradoxical lumboperitoneal overdrain of cerebrospinal fluid (CSF) with severe CSF hypotension syndrome in horizontal position of the patient and immediate cessation in vertical position. Ligation and then removal of lumboperitoneal shunt lead to rapid and stable disappearance of overdrain syndrome as well as concurrent left-side radicular pain syndrome in the leg.

[Case of cerebrospinal fluid hypovolemia possibly due to acceleration of cerebrospinal fluid absorption]

The authors present a case of a 31-year-old man suffering from intractable cerebrospinal fluid hypovolemia (CSFH), in whom autologous epidural blood patch at the cervical, thoracolumbal, and sacral sites was not effective. Repeated radionuclide cisternography reproducibly demonstrated "early accumulation of radioactivity in the bladder", "cystic accumulation of radioactivity at the sacral site" and "less activity than expected over the cerebral convexities"; but computerized tomography myelography did not demonstrate CSF leakage but detected a sacral cyst. These repeated radionuclide cisternography findings suggested unusually rapid uptake of tracer by the circulation but did not always CSF leakage. The finding of strong accumulation of radioactivity in the sacral cyst might mean the opposite CSF flow against normal caudal-cranial flow. The formation of this abnormal cranial-caudal CSF flow could be produced with CSF leakage or abnormal absorption at the caudal site, where the cyst existed in the patient. Therefore, it is not unreasonable to suppose that the sacral cyst appeared to be responsible for development of CSFH in the patient. The possibility of acceleration of cerebrospinal fluid absorption in the sacral cyst was proposed for the cause of CSFH if CSF leakage was denied.

Trigeminal Neuralgia in Wind Musicians

The author reports 3 patients with trigeminal neuralgia whose pain was triggered by musical performance. Use of the muscles of embouchure activated the trigger zone when playing the clarinet, saxophone, flute, piccolo, trombone, or whistling. In each case, the location of the trigger zone was perioral, regardless of which division of the trigeminal nerve emanated pain. Trigeminal neuralgia is a particularly disabling affliction when it occurs in wind musicians.

Spontaneous cerebrospinal fluid hypovolaemia: a therapeutic dilemma?

Spontaneous intracranial hypotension is characterized by orthostatic headaches in conjunction with reduced cerebrospinal fluid volume (CSF) and characteristic imaging findings. We report the clinical course of six consecutive patients with spontaneous intracranial hypotension who were followed between 4 months and 2.5 years. The characteristic orthostatic headaches were present in five patients. Diffuse pachymeningeal enhancement on brain magnetic resonance imaging (MRI) was evident in all cases. CSF detected elevated protein content in three of six patients. In only two of our six patients a first epidural blood patch resulted in complete symptom resolution lasting 4 months and 1 year. Four patients received a second epidural blood patch and one patient also received a third. In four patients, follow-up brain MRI revealed re-occurrence of the typical MRI features and all of them suffered from orthostatic symptoms at this time. Only four patients are free of complaints after an average follow-up period of 10 months. Symptom relief within 7 days from an epidural blood patch is accepted to be diagnostic for spontaneous intracranial hypotension. However, our data illustrate that the clinical course of the syndrome is very unstable and the epidural blood patch is less effective than widely accepted.

Tracer clearance in radionuclide cisternography in patients with spontaneous intracranial hypotension

We semiquantitatively analysed radionuclide cisternography in three patients with spontaneous cerebrospinal fluid (CSF) leakage diagnosed by typical symptoms and magnetic resonance imaging findings before and several months after treatment with epidural blood patch. Radioactivity in the whole CSF space was measured immediately after and at 1, 5, 7 and 24 h after intrathecal injection of (111)In-diethylenetriaminepentaacetic acid (DTPA). Initial findings included the vague appearance of leakage in the thoracic spine in two patients, early bladder filling at 1 h in one and a lack of tracer filling into the high cranial convexity in all three. The radioactivity count rapidly decreased within several hours after injection and reached 20% of the initial value at 24 h. In contrast, no rapid decrease was observed after treatment and more than 50% of tracer remained at 24 h after injection. Semiquantitative analysis of tracer clearance may provide additional information in the diagnosis of CSF leakage, especially with no obvious qualitative findings.

Exploration de l’hypotension de liquide cérébro-spinal à l’étage rachidien en IRM

We propose studying signs of cervicothoracic CSF hypotension by MRI. Axial T1-weighted GRE sequence with and without saturation bands positioned above and below the selected image plane, MR venography and MR Angiography with contrast administration are helpful to confirm the venous nature of the epidural thickening and to make the differential diagnosis with infectious or neoplastic epiduritis.

Spontaneous intracranial hypotension: case report

Spontaneous intracranial hypotension is a well defined entity, however it is characterised by a relevant clinical heterogeneity. The main feature is orthostatic headache, often accompanied by other symptoms. The diagnosis is easily made in the presence of orthostatic headache, excluding an obvious aetiology of low cerebrospinal fluid (CSF) pressure, and often there is no evidence of direct or indirect CSF leak.

[Spontaneous intracranial hypotension]

Spontaneous intracranial hypotension is an infrequent clinical entity characterized by orthostatic headache, low cerebrospinal fluid pressure, and magnetic resonance imaging findings of diffuse pachymeningeal gadolinium enhancement without previous history of head trauma or lumbar puncture. A 24 year-old healthy woman was referred after having daily headaches for two weeks. She described a headache that occurred soon after assuming an upright position and disappeared after resuming a recumbent position. The cerebrospinal fluid showed pleocytosis primarily lymphocitic, raised protein content and an opening pressure of 20 mm H2O. Magnetic resonance imaging of the head showed diffuse pachymeningeal gadolinium enhancement. Radioisotope cisternography using 99mTc-DTPA confirmed the cerebrospinal fluid leak in the thoracic region. With conservative treatment the patient improved in a few days and the headache disappeared. Radiological findings, together with a compatible clinical condition, help to establish the diagnosis of spontaneous intracranial hypotension and avoid the use of unnecessary clinical investigations.

Detection of cerebrospinal fluid leakage in intracranial hypotension with radionuclide cisternography and blood activity monitoring

Radionuclide cisternography is an indispensable examination to detect cerebrospinal fluid (CSF) leakage in patients suspected of having spontaneous intracranial hypotension (SIH). However, it sometimes fails to demonstrate the site of CSF leakage, and in such cases, early bladder visualization is utilized for the diagnosis of SIH as an indirect finding. The aim of this work is to improve the diagnostic ability of radionuclide cisternography and to reevaluate the reliability of early bladder visualization as an indirect finding of CSF leakage.

METHODS

We obtained serial images during the first hour after injection as well as the following time points in 4 patients with SIH and 5 with normal pressure hydrocephalus (NPH) as a control. We also performed blood sampling over time to measure blood radioactivity concentrations.

RESULTS

All 4 patients with SIH demonstrated leakage, 2 of 4 within one hour after injection. Bladder visualization was observed falsely in 4 of 5 patients with NPH, considered to be the result of a lumbar puncture complication. In this false bladder visualization, blood radioactivity showed a more rapid raise and fall than in CSF leakage of SIH.

CONCLUSIONS

The combination of radionuclide cisternography, including early time points and blood sampling, may enable accurate diagnosis of SIH.

Intracranial hypotension due to leakage of cerebrospinal fluid: could myelography be a therapeutic option?

Spontaneous intracranial hypotension (SIH) is an uncommon condition caused by cerebrospinal fluid leakage. We report of a 29-year-old woman with typical symptoms in whom initial cranial MRI and CT were normal . A clinical diagnosis of SIH, but the symptoms did not resolve with conservative therapy or a lumbar epidural blood patch. Repeat MRI revealed (indirect) findings consistent with SIH but failed to directly demonstrate a cerebrospinal fluid fistula. Subsequent CT myelography revealed leakage of contrast medium into the epidural space bilaterally along the nerve roots at C3-7. Following the myelography the patient reported dramatic clinical improvement with complete resolution of symptoms. The adhesive quality of the myelographic contrast medium might have precipitated closure of the meningeal tears. Myelography may be not only of diagnostic value but also therapeutic in SIH.

Intérêt du blood-patch pour le traitement de l’hypotension intracrânienne spontanée

OBJECTIVE

Spontaneous intracranial hypotension (SIH) is a rare syndrome. It is due most often to a spinal meningeal leak. Symptoms due to SIH are often difficult to treat and epidural blood-patch (BP) has been proposed. The aim was to evaluate the effects and the problems associated with lumbar blood-patch to treat SIH.

STUDY DESIGN

Case series.

PATIENTS AND METHODS

The diagnosis of SIH was made in six consecutive patients on clinical signs and radiological findings (CT-scan and MRI). A lumbar BP (L1-L2 level) was performed as soon as possible after diagnosis. A maximum of three procedures was allowed in case of failure of the initial BP.

RESULTS

BP was effective and well tolerated for five patients (3 immediately after BP, 2 others patients needed 2 and 3 BP). In one patient, an incomplete response was observed and was related to a large CFS leak diagnosed by CT-myelogram.

CONCLUSION

When the diagnosis of spontaneous intracranial hypotension is confirmed, a repeated blood patch lumbar procedure can be efficient to treat these patients.

[Extraordinary high cerebrospinal fluid protein in two cases of intracranial hypotension syndrome]

Intracranial hypotension is a rare cause of chronic headache. Although there is still debate about the aetiology, it is believed that the syndrome is caused by low cerebrospinal fluid volumes due to dural leakage. Such leakages can occur spontaneously after lumbar puncture or surgical or traumatic opening of the dura. In magnetic resonance contrast imaging, diffuse meningeal enhancement can be seen; usually the pressure at the cerebrospinal opening is lower than normal. Sometimes a pleocytosis and, in most cases, increased protein content can be identified in the CSF. These protein levels most frequently range between 0.5 g/l and 2 g/l. Here we describe two patients with typical clinical signs and neuroradiological alterations of intracranial hypotension syndrome but with extraordinarily high CSF protein levels (8.3 g/l and 9.63 g/l). On the basis of these findings, the putative causes of elevated CSF protein contents are discussed.

Spontaneous cerebrospinal fluid leak syndrome: report of 18 cases

We examined a group of 18 consecutive patients with spontaneous cerebrospinal fluid leak syndrome (SCSFLS) and investigated clinical, MRI, radioisotope findings and therapeutic outcome of this syndrome.

Low cerebrospinal fluid pressure syndromes

Only 12 years ago the first report on pachymeningeal gadolinium enhancement in low-pressure headaches appeared in the literature. In this short interval the enormous impact of MRI on so-called "spontaneous intracranial hypotension" and "low-pressure head-aches" has become obvious. A much broader clinical and imaging spectrum of the disease is now recognized and a substantially larger number of patients is diagnosed. In the past decade there has been remarkable progress in understanding this disorder and its associated cerebrospinal fluid (CSF) dynamics. Some of the older concepts or presumptions have been challenged while novel observations continue to appear in the literature. We are still in the learning phase.

CSF hypovolemia vs intracranial hypotension in "spontaneous intracranial hypotension syndrome"

OBJECTIVES

To investigate the role of CSF hypovolemia in spontaneous intracranial hypotension (SIH) syndrome because so-called SIH syndrome sometimes lacks intracranial hypotension.

METHODS

Ten women (aged from 28 to 49 years) with characteristic orthostatic headache without a previous history of dural tear were investigated. In addition to gadolinium (Gd)-enhanced brain MRI, spinal MRI with and without Gd enhancement was performed.

RESULTS

Gd-enhanced brain MRI demonstrated diffuse pachymeningeal enhancement in all patients. Sagittal T2-weighted spinal MRI revealed a variable amount of CSF in the extradural space in all patients. Sagittal T2-weighted MRI or axial Gd-enhanced T1-weighted MRI showed dilated epidural veins located in the high cervical portion in each patient. The intensity of dilatation of the epidural veins correlated significantly with the amount of CSF in the epidural space. This suggested that the Monro-Kellie doctrine was applicable in this circumstance.

CONCLUSIONS

Since some patients with SIH syndrome have normal CSF pressure and since a downward displacement of the brain due to a reduction of the buoyant action of CSF may induce symptoms, CSF hypovolemia, not intracranial hypotension, may be the cause. Based on the Monro-Kellie doctrine, detecting leaked CSF and venous engorgement (epidural vein dilatation and pachymeningeal enhancement) is an important clue to diagnose so-called SIH syndrome. Dilatation of epidural veins suggests CSF hypovolemia in appropriate conditions.

Delayed gadolinium enhancement in epidural space of the cervicothoracic spine in a patient with spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) due to a spinal cerebrospinal fluid leak is a rare but increasing cause of postural headache. Its extravasated epidural fluid collection tends to be non-enhanced or mildly enhanced on enhanced magnetic resonance (MR) imaging. The mild enhancement of the epidural fluid in SIH is usually attributed to fenestrated neovascularization provoked by an inflammatory component, such as blood, of the fluid collection. In this report, we present a case of SIH with a prominent delayed enhancement of the spinal epidural fluid collection on MR imaging. Subsequent vertebral angiography revealed that this delayed enhancement was related to contrast extravasation from a torn anterior meningeal branch of the right vertebral artery. Therefore, we suggest that contrast extravasation from a torn meningeal vessel may be a possible cause of the enhancement in the spinal epidural fluid of SIH.

Spinal radiological findings in nine patients with spontaneous intracranial hypotension

Cranial magnetic resonance imaging (MRI) findings in spontaneous intracranial hypotension (SIH) are well known, while spinal studies have received less attention. Radiological spinal findings in nine patients with SIH are presented, looking for possible characteristic features. Five of the nine patients had histories of previous minor trauma, one of previous surgery; in three patients possible relevant preceding events were completely absent. All nine patients had cervical, seven thoracic, and four lumbar spine MRI studies; post-contrast studies were obtained in seven cases, MRI myelograms in five. Radioisotope myelocisternography was performed in four patients and myelo-CT in four. Epidural fluid collections were found in seven patients. In six cases the dural sac had collapsed, with a festooned appearance; intense epidural enhancement on post-contrast studies demonstrated marked dilatation of the epidural venous plexus. In three cases an irregular root sleeve suggested a possible point of cerebrospinal fluid (CSF) leakage. Myelo-CT demonstrated the CSF fistula in two cases, radioisotope myelocisternography in three. The pattern of spinal abnormalities is different from that seen in cranial MRI for anatomical reasons: in the spinal canal the dura is not adherent to the bone; therefore, collapse of the dural sac and dilatation of epidural venous plexus occur, rather than subdural hematomas. In most cases the search for the dural tear is difficult. Radioisotope cisternography is probably the most sensitive examination for documenting the leakage of CSF out of the subarachnoid space; myelo-CT may precisely demonstrate the point of the CSF fistula, whereas MRI may only suggest it.

Neuroimaging features of spontaneous intracranial hypotension

We reviewed the cranial MRI and radionuclide cisternograms of four adults with postural headache indicating spontaneous intracranial hypotension (SIH). All four underwent clinical and radiological follow-up. MRI showed diffuse, thin meningeal enhancement; bilateral subdural fluid collections; and morphological abnormalities secondary to "sagging" of the brain. Radionuclide cisternography revealed direct or indirect signs of leakage of cerebrospinal fluid (CSF) along the spinal axis, and the symptoms resolved after the leak treated by epidural injection of blood at a level indicated by the cisternogram. The diffuse meningeal enhancement decreased but persisted on follow-up MRI, although the patients were asymptomatic. All morphologic abnormalities resolved during 3-5 months follow-up.

Spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) is typically manifested by orthostatic headaches that may be associated with one or more of several other symptoms, including pain or stiffness of the neck, nausea, emesis, horizontal diplopia, dizziness, change in hearing, visual blurring or visual field cuts, photophobia, interscapular pain, and occasionally face numbness or weakness or radicular upper-limb symptoms. Cerebrospinal fluid (CSF) pressures, by definition, are quite low. SIH almost invariably results from a spontaneous CSF leak. Only very infrequently is this leak at the skull base (cribriform plate). In the overwhelming majority of patients, the leak is at the level of the spine, particularly the thoracic spine and cervicothoracic junction. Sometimes, documented leaks and typical clinical and imaging findings of SIH are associated with CSF pressures that are consistently within limits of normal. Magnetic resonance imaging of the head typically shows diffuse pachymeningeal gadolinium enhancement, often with imaging evidence of sinking of the brain, and less frequently with subdural fluid collections, engorged cerebral venous sinuses, enlarged pituitary gland, or decreased size of the ventricles. Radioisotope cisternography typically shows absence of activity over the cerebral convexities, even at 24 or 48 hours, and early appearance of activity in the kidneys and urinary bladder, and may sometimes reveal the level of the leak. Although various treatment modalities have been implemented, epidural blood patch is probably the treatment of choice in patients who have failed an initial trial of conservative management. When adequate trials of epidural blood patches fail, surgery can offer encouraging results in selected cases in which the site of the leak has been identified. Some of the spontaneous CSF leaks are related to weakness of the meningeal sac, likely in connection with a connective tissue abnormality.

Radionuclide cisternography in spontaneous intracranial hypotension with simultaneous leaks at the cervicothoracic and lumbar levels

This case report clearly illustrates defined simultaneous cerebrospinal fluid leaks at the cervicothoracic and upper lumbar areas. A 53-year-old woman without a remarkable medical history was hospitalized for sudden onset of severe headache. The headache lasted more than 1 week and standing or sitting positions exaggerated the symptoms, although it was relieved when the patient was recumbent. Radionuclide cisternography was performed using 150 MBq (4 mCi) Tc-99m DTPA. It revealed two cerebrospinal fluid leaks from the cervicothoracic junction bilaterally and the left side of the upper lumbar area. Epidural blood patching was tried at the lumbar level (L1-L2) and showed only a transient effect. A second trial of this method at the level of C7-T1 performed 2 days later resulted in immediate improvement of the symptoms without recurrence. The simultaneous cerebrospinal fluid leaks were detected successfully with radionuclide cisternography using Tc-99m DTPA, which provided a useful guideline for treatment despite the limitations of delayed scanning.

Diagnosis of spontaneous intracranial hypotension by using magnetic resonance myelography. Case report

The authors describe a case of spontaneous intracranial hypotension in which the leakage site was determined by using magnetic resonance (MR) myelography. This technique demonstrated the route of cerebrospinal fluid (CSF) leakage, whereas other methods failed to show direct evidence of leakage. Magnetic resonance myelography is a noninvasive method that is highly sensitive in detecting CSF leakage. This is the first report in which a site of CSF leakage was detected using MR myelography.

[Intracranial hypotension]

A CLINICAL DIAGNOSIS: Headache which appears in the upright position and subsides in the reclining position is suggestive of intracranial hypotension Brain magnetic resonance imaging can eliminate an intracranial tumoral process. In most cases, contrast images after gadolinium injection show a diffuse hypersignal of all the meninges including the falx cerebri and the tentorium cerebelli.

SPONTANEOUS OR SECONDARY

This clinical presentation is sufficient for diagnosis. Occurring after a recent neurosurgical procedure, the intracranial hypotension is termed secondary. Inversely, is no known cause can be identified, the condition is termed spontaneous.

CEREBROSPINAL FLUID

If the clinical manifestations are somewhat doubtful, a spinal tap can reveal the very low pressure of the cerebrospinal fluid (CSF) although it is advisable to avoid further loss of fluid.

CSF LEAK

It is generally accepted that intracranial hypotension results from leakages of CSF through a breach in the dura mater caused by untreated trauma to a particularly fragile area due to a meningocele or an arachnoid cyst for example. Occasionally, the CSF leak can be evidenced with isotopic labeling used to visualize the breach and guide therapy.

TREATMENT

By analogy with the spinal tap syndrome, a blood-patch with autologous blood is usually proposed as first line medical treatment. Prognosis is generally good.