Spontaneous Cerebrospinal Fluid Leak in a Patient with Asymptomatic Idiopathic Intracranial Hypertension.

BACKGROUND: Spontaneous cerebrospinal fluid (CSF) leaks occur when there is a tear in the dura mater. Spontaneous CSF leaks are rare, and often associated with conditions like intracranial hypertension, connective tissue disorders, or congenital defects in the dura mater. CASE REPORT: The patient was a 66-year-old woman who presented to the Emergency Department with clear, positional nasal discharge from her left nostril for 1 week. She had a history of chronic headaches, which seemed to have been relieved around the time of onset of her rhinorrhea. Diagnostic imaging, including computed tomography and magnetic resonance imaging scans, confirmed the presence of a CSF leak and a left temporal meningoencephalocele. The patient subsequently underwent surgical repair of the leak and ventriculoperitoneal shunt placement, and was discharged home in stable condition. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Early detection of CSF leaks require a thorough history and physical examination, and is crucial in preventing potentially life-threatening complications such as meningitis and intracranial abscesses.

Using Ipratropium Bromide Nasal Spray Response as a Screening Tool in the Diagnostic Workup of Cerebrospinal Fluid Rhinorrhea.

OBJECTIVES: Unilateral clear thin rhinorrhea (UCTR) can be concerning for a nasal cerebrospinal fluid (CSF) leak. Beta-2 transferrin electrophoresis has been the gold standard for initial non-invasive confirmatory testing for CSF rhinorrhea, but there can be issues with fluid collection and testing errors. Ipratropium bromide nasal spray (IBNS) is highly effective at reducing rhinitis-related rhinorrhea, and should presumably not resolve CSF rhinorrhea. This study assessed whether different clinical features and IBNS response helped predict presence or absence of CSF rhinorrhea. METHODS: A prospective cohort study was conducted where all patients with UCTR had nasal fluid tested for beta-2 transferrin, and were prescribed 0.06% IBNS. Patients were diagnosed with CSF rhinorrhea or other rhinologic conditions. Clinical variables like IBNS response (rhinorrhea reduction), positional worsening, salty taste, postoperative state, female gender, and body-mass index were assessed for their ability to predict CSF rhinorrhea. Sensitivity, specificity, and predictive values and odds ratios were calculated for all clinical variables. RESULTS: Twenty patients had CSF rhinorrhea, and 53 had non-CSF etiologies. Amongst clinical variables assessed for predicting CSF absence or presence, significant associations were shown for IBNS response (OR = 844.66, p = 0.001), positional rhinorrhea worsening (OR = 8.22, p = 0.049), and body-mass index ≥30 (OR = 2.92, p = 0.048). IBNS response demonstrated 96% sensitivity and 100% specificity, and 100% positive and 91% negative predictive values for predicting CSF rhinorrhea. CONCLUSIONS: In patients with UCTR, 0.06% IBNS response is an excellent screening tool for excluding CSF rhinorrhea, and should be considered in the diagnostic workup of CSF rhinorrhea. LEVEL OF EVIDENCE: 2 Laryngoscope, 134:56-61, 2024.

Reliability of High-resolution Gadolinium-enhanced MR Cisternography and Gasket-seal Technique for Management of Anterior Skull Base Defects.

PURPOSE: Precise preoperative localization of anterior skull base defects is important to plan surgical access, increase the success rate and reduce complications. A stable closure of the defect is vital to prevent recurrence of cerebrospinal fluid (CSF) rhinorrhea. The purpose of this retrospective case series was to evaluate the reliability of a new high-resolution gadolinium-enhanced compressed-sensing SPACE technique (CS T1 SPACE) for magnetic resonance (MR) cisternography to detect cerebrospinal fluid leaks of the anterior skull base and to assess the long-term success rate of the gasket-seal technique for closure of skull base defects. METHOD: All patients with spontaneous or postoperative cerebrospinal fluid rhinorrhea and defects of the anterior skull base presenting to the Departments of Otorhinolaryngology and Neurosurgery between 2019 and 2020, receiving a computed tomography (CT) cisternography and MR cisternography (on a 3T whole-body MR scanner using a 64-channel head and neck coil) with CS T1 SPACE sequence and closure of the defect with the gasket-seal technique, were enrolled in the study. For the cisternography, iodinated contrast agent (15 ml Solutrast 250 M®), saline (4 mL) mixed with a 0.5 mL of gadoteridol was injected into the lumbar subarachnoid space. RESULTS: A total of four patients were included in the study and MR cisternography with CS T1 SPACE sequence was able to precisely localize CSF leaks in all patients. The imaging results correlated with intraoperative findings. All defects could be successfully closed with the gasket-seal technique. The mean follow-up was 35.25 months (range 33-37 months). CONCLUSION: MR cisternography with CS T1 SPACE sequence could be a promising technique for precise localization of CSF leaks and the gasket-seal technique resulted in good closure of the CSF fistula in this case series.

Extraordinary Complication of COVID-19 Swab Testing: CSF Rhinorrhea.

Coronavirus disease 2019 (COVID-19) is a highly contagious disease that has reached pandemic status. The diagnosis of COVID-19 is made using the polymerase chain reaction test to evaluate a swab taken from the naso/oro-pharyngeal area. Since COVID-19 is still a pandemic, it is thought that the use of this diagnostic test will be on the agenda for a while. A patient with COVID-19 symptoms presented with unilateral cerebrospinal fluid rhinorrhea after a nasopharyngeal swab test. Although nasopharyngeal swabs are taken very frequently, the complication rate is very low. However, life-threatening complications can be observed on rare occasions, and care should be taken.

Spontaneous skull base cerebrospinal fluid leak during pregnancy: a case report and review of the literature.

BACKGROUND: Idiopathic intracranial hypertension can lead to dural defects and spontaneous leakage of cerebrospinal fluid (CSF) from the skull base. Skull base CSF leaks are rarely reported in pregnancy but pose unique challenges for obstetricians and anesthesiologists. CASE PRESENTATION: A 31-year-old G4P1021 at 14 weeks developed debilitating headaches and CSF rhinorrhea. Brain imaging revealed a bony defect of the sphenoid sinus with a meningoencephalocele and a partially empty sella, consistent with CSF leakage from a skull base defect. The patient was neurologically stable without signs of meningitis; thus, management was focused on symptomatic alleviation. A planned cesarean section was performed at 38 weeks under spinal anesthesia. The patient had spontaneous marked improvement of her symptoms postpartum. CONCLUSION: Pregnancy may exacerbate skull base CSF leaks, requiring careful management with a multidisciplinary team. Neuraxial anesthesia can safely be performed in pregnant individuals with spontaneous skull base CSF leakage, but further studies are needed to determine the safest mode of delivery in these patients.

Analysis of the Causes and Experience in the Diagnosis and Treatment of Meningocele Caused by Sternberg's Canal of the Sphenoid Sinus: Two Case Reports and a Review of the Literature.

OBJECTIVE: The present study aimed to improve the diagnosis and treatment outcome of cerebrospinal fluid (CSF) rhinorrhea caused by patent meningoencephalocele of Sternberg's canal of the sphenoid sinus by analyzing the clinical data and imaging features of two rare cases of this disease and by reviewing the relevant literature for possible etiology, diagnoses, and treatments. METHODS: Together with the relevant literature, we retrospectively studied the clinical and imaging data of two patients (mother and child) with CSF rhinorrhea caused by patent meningoencephalocele of Sternberg's canal of the sphenoid sinus, analyzed their diagnostic and treatment procedures, and proposed a potential, feasible treatment method. RESULTS: On the 2nd day after surgery, the expansive sponge and iodoform gauze in the nasal cavity were removed in both patients, and the lumbar subarachnoid drainage was removed 3 days after the operation, as no nasal discharge was observed. One week after the operation, head magnetic resonance imaging (MRI) showed that the abnormal tissue in the sphenoid sinus had disappeared, and no accumulation of the CSF was observed. Both patients were discharged after 2 weeks. At the time of discharge, both patients were without nasal drip, fever, headache, and other discomforts, and they had grade 5 muscle strength in their extremities, with normal muscle tension. CONCLUSION: CSF rhinorrhea is usually caused by secondary factors. Spontaneous CSF rhinorrhea caused by encephalocele of the skull base due to congenital dysplasia of the skull base is very rare and easily misdiagnosed. The presence of brain tissue or CSF signal in the sphenoid sinus on preoperative MR images is an important imaging feature of the disease. Conditional cisternography can be used to further detect CSF leaks. Endoscopic transnasal transsphenoidal repair of CSF leaks combined with short-term postoperative lumbar subarachnoid drainage is an effective treatment method. According to previous literature, the possible causes of meningoencephalocele with patent Sternberg's canal of the sphenoid sinus include abnormal development of the sphenoid sinus or the craniopharyngeal canal and bone defects of the skull base. There are no related reports on patent meningoencephalocele caused by Sternberg's canal in direct blood relatives, such as mother-son; therefore, the possibility of this disease having a genetic origin should be considered in future studies on its pathophysiological mechanisms.

Cerebrospinal Fluid Rhinorrhea as the First Symptom of Metastatic Prostate Adenocarcinoma.

The most common cause of cerebrospinal fluid (CSF) rhinorrhoea is damage to the skull base with a dura mater's rupture due to an accident or an iatrogenic injury. This applies to over 96% of cases. Other possibilities that can lead to CSF leakage are neoplasms of the nasal cavity, paranasal sinuses, and nasopharynx. Although prostate cancer spreads to bones, cranial metastases to paranasal sinuses are extremely rare. We present a case of an 83-year-old patient with CSF leakage due to infiltrating metastatic prostate cancer. Cerebrospinal fluid rhinorrhea turned out to be the first symptom of prostate cancer metastasis. Diagnostic and treatment strategies are presented in the discussion.

Individual SNOT-22 Items Aid in Differentiating Between Spontaneous Cerebrospinal Fluid Rhinorrhea and Chronic Rhinosinusitis Without Nasal Polyps.

OBJECTIVES: Spontaneous cerebrospinal fluid (CSF) rhinorrhea is a diagnostic challenge due to its overlapping symptomatology with other sinonasal diseases. The objective of this study was to investigate whether items on the sinonasal outcome test (SNOT)-22 could suggest a diagnosis of spontaneous CSF rhinorrhea versus chronic rhinosinusitis without nasal polyps (CRSsNP). METHODS: A multi-institutional retrospective chart review of patients with spontaneous CSF rhinorrhea and a control group of CRSsNP patients was performed. Individual SNOT-22 scores and domain scores were compared. RESULTS: One hundred fifteen patients were included in both cohorts. Of the patients in the CSF rhinorrhea group, 48% were misdiagnosed as chronic rhinosinusitis (CRS) prior to the correct identification of a CSF leak. On bivariate analysis, the CSF rhinorrhea group scored significantly higher on the SNOT-22 for runny nose (P < .001) and was more likely to designate this symptom as most important (P < .001). The CRSsNP group scored significantly higher in nasal blockage (P < .001), thick nasal discharge (P < .001), facial pain/pressure (P < .001), and in the ear/facial (P < .001) and rhinologic (P = .003) domains. Multivariable logistic regression revealed that runny nose (P < .001) was most predictive of spontaneous CSF rhinorrhea while nasal blockage (P < .001), thick nasal discharge (P < .001), and facial pain/pressure (P = .001) were predictive of CRSsNP after adjusting for relevant confounders. No significant difference was observed in total SNOT-22 scores between groups (P = .676). CONCLUSIONS: Spontaneous CSF rhinorrhea is commonly misdiagnosed as other sinonasal pathologies. However, individual SNOT-22 items can help aid in suggesting a CSF leak. Spontaneous CSF rhinorrhea should be suspected in patients who have high SNOT-22 scores for runny nose and report this symptom as most important, but have lower scores related to the other cardinal symptoms of CRS.

Case report: Meningoencephalocele and recurrent bacterial meningitis in chronic idiopathic intracranial hypertension.

BACKGROUND: Meningoencephalocele is a rare malformation caused by congenital and acquired lesions. The association between recurrent bacterial meningitis and meningoencephaloceles with cerebrospinal fluid (CSF) leak is reported in the literature. We report a rare case of meningoencephalocele secondary to chronic idiopathic intracranial hypertension as a result of hospitalization repeatedly for meningitis due to the lack of CSF leak. CASE PRESENTATION: This study presents a case of a patient with a decade of recurrent meningitis. With clinical symptoms and imaging examination with chronic idiopathic intracranial hypertension, this patient was diagnosed with meningoencephalocele. With the treatment of acetazolamide to decrease CSF product, the patient had no recurrence of meningitis over the 6-months follow-up period. CONCLUSION: In patients with recurrent intracranial infections but no history of immunodeficiency, cranial trauma, or neurosurgery, the possibility of meningitis should be considered appropriately, even in the absence of CSF otorrhea or rhinorrhea.

Diagnosis and Localization of Cerebrospinal Fluid Rhinorrhea: A Systematic Review.

BACKGROUND: Cerebrospinal fluid (CSF) rhinorrhea results from abnormal communications between the subarachnoid and sinonasal spaces. Accurate preoperative diagnosis and localization are vital for positive clinical outcomes. However, the diagnosis and localization of CSF rhinorrhea remain suboptimal due to a lack of accurate understanding of test characteristics. OBJECTIVE: This systematic review aims to assess the diagnostic accuracy of various tests and imaging modalities for diagnosing and localizing CSF rhinorrhea. METHODS: A systematic review of the MEDLINE and EMBASE databases was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Our search identified 4039 articles-53 cohort studies and 24 case series describing 1622 patients were included. The studies were heterogeneous and had a wide range of sensitivities and specificities. Many specificities were incalculable due to a lack of true negative and false positive results, thus precluding a meta-analysis. Median sensitivities and specificities were calculated for cohort studies of the following investigations: high-resolution computed tomography (HRCT) 0.93/0.50 (sensitivity/specificity), magnetic resonance cisternography (MRC) 0.94/0.77, computed tomography cisternography (CTC) 0.95/1.00, radionuclide cisternography (RNC) 0.90/0.50, and contrast-enhanced magnetic resonance cisternography (CEMRC) 0.99/1.00, endoscopy 0.58/1.00, topical intranasal fluorescein (TIF) 1.00/incalculable, intrathecal fluorescein (ITF) 0.96/1.00. Case series were reviewed separately. Etiology and site-specific data were also analyzed. CONCLUSION: MR cisternography is more accurate than high-resolution CT at diagnosing and localizing CSF rhinorrhea. CT cisternography, contrast-enhanced MR cisternography, and radionuclide cisternography have good diagnostic characteristics but are invasive. Intrathecal fluorescein shows promising data but has not been widely adopted for purely diagnostic use. Office endoscopy has limited data but does not sufficiently diagnose CSF rhinorrhea independently. These findings confirm with current guidelines and evidence.

Usefulness of imaging studies for diagnosing and localizing cerebrospinal fluid rhinorrhea: A systematic review and meta-analysis.

BACKGROUND: Our aim in this study was to determine the usefulness of diagnosis by imaging studies for the localization of cerebrospinal fluid (CSF) rhinorrhea. METHODS: PubMed, SCOPUS, Embase, Web of Science, and Cochrane Library databases were searched up to July 2021. True and false positive and negative data were collected along with the characteristics of each study. Methodologic quality was assessed using the QADAS-2 tool. RESULTS: Sixteen studies involving 472 patients were included. The diagnostic odds ratio (DOR) of imaging studies was 13.6195 (95% confidence interval [CI], 7.4756-24.8129; I2  = 28.1%). The area under the summary receiver-operating characteristic curve was 0.712. Sensitivity, specificity, negative predictive value, and positive predictive value were 0.8507 (0.7773-0.9029), 72.1%; 0.7827 (0.6865-0.8556), 26.8%; 0.5828 (0.4398-0.7132), 67.4%; and 0.9407 (0.8935-0.9678), 59.1%, respectively. In the subgroup analysis, there were significant differences for sensitivity (computed tomography [CT], 0.7421; computed tomography cisternography [CTC], 0.8872; magnetic resonance imaging [MRI], 0.8365; magnetic resonance cisternography [MRC], 0.8565; intrathecal gadolinium magnetic resonance cisternography [GaMRC], and 0.9307; radionuclide cisteronography [RNC], 0.7097; p = 0.0481) and for negative predictive value among imaging modalities (CT, 0.3028; CTC, 0.4848; MRI, 0.4658; MRC, 0.7465; GaMRC, 0.8611; and RNC, 0.5263; p = 0.0046). There were no significant differences among imaging modalities for specificity, positive predictive value, or DOR (p > 0.05). CONCLUSION: Imaging studies can be used in the diagnosis of CSF rhinorrhea. Gadolinium magnetic resonance cisternography showed the highest diagnostic accuracy. MRC showed fair diagnostic accuracy without intrathecal injection.

An uncommon etiological factor for aspiration pneumonitis caused by spontaneous sphenoid sinus meningoencephalocele with cerebrospinal fluid rhinorrhea: a case report.

BACKGROUND: Aspiration pneumonitis is an inflammatory disease of the lungs which is difficult to diagnose accurately. Large-volume aspiration of oropharyngeal or gastric contents is essential for the development of aspiration pneumonitis. The role of cerebrospinal fluid (CSF) rhinorrhea is often underestimated as a rare etiological factor for aspiration in the diagnosis process of aspiration pneumonitis. CASE PRESENTATION: We present a case of a patient with 4 weeks of right-sided watery rhinorrhea accompanied by intermittent postnasal drip and dry cough as the main symptoms. Combined with clinical symptoms, imaging examination of the sinuses, and laboratory examination of nasal secretions, she was initially diagnosed as spontaneous sphenoid sinus meningoencephalocele with CSF rhinorrhea, and intraoperative endoscopic findings and postoperative pathology also confirmed this diagnosis. Her chest computed tomography showed multiple flocculent ground glass density shadows in both lungs on admission. The patient underwent endoscopic resection of meningoencephalocele and repair of skull base defect after she was ruled out of viral pneumonitis. Symptoms of rhinorrhea and dry cough disappeared, and pneumonitis was improved 1 week after surgery and cured 2 months after surgery. Persistent CSF rhinorrhea caused by spontaneous sphenoid sinus meningoencephalocele was eventually found to be a major etiology for aspiration pneumonitis although the absence of typical symptoms and well-defined risk factors for aspiration, such as dysphagia, impaired cough reflex and reflux diseases. CONCLUSIONS: We report a rare case of aspiration pneumonitis caused by spontaneous sphenoid sinus meningoencephalocele with CSF rhinorrhea, which can bring more attention and understanding to the uncommon etiology for aspiration, so as to make more accurate diagnosis of the disease and early surgical treatment.

Surgical Correction of a Clivus Cerebrospinal Fluid Fistula: A Technical Report.

BACKGROUND: Cerebrospinal fistulas of the clivus region often result from previous surgical intervention at the skull base. The localization and size of the fistula determine the appropriate treatment strategy. When flap closure is not possible, the microsuture technique with autograft placement provides a favorable outcome. METHODS: We present a technical report on the application of the microsuture technique for clivus region cerebrospinal fluid fistula closure in a patient with previous chordoma treatment and nonspecific coronavirus disease 2019 complications. RESULTS: The application of the microsuture technique resulted in stable remission of the fistula and complete regression of the clinical manifestations. CONCLUSIONS: The microsuture technique for clivus region fistula closure is a potentially valuable alternative to vascularized flap closure.

International Consensus Statement: Spontaneous Cerebrospinal Fluid Rhinorrhea.

BACKGROUND: The association between spontaneous cerebrospinal fluid (CSF) leak/rhinorrhea and idiopathic intracranial hypertension (IIH) has been increasingly recognized over the last years. However, considerable variability of opinion regarding the assessment, investigations, and management of patients with spontaneous CSF rhinorrhea remains. METHODS: A consensus group was formed from experts from Europe, Asia, Australia, South and North America. Following literature review and open discussions with members of the panel, a set of 61 statements was produced. A modified Delphi method was used to refine expert opinion with 3 rounds of questionnaires and a consensus group meeting in Santo-Rhino meeting in September 2019. RESULTS: Fifty statements (82% of total) on spontaneous CSF leak and IIH reached consensus. In 38 of 50 statements, the median response was 7 (strongly agree) and in the 12 remaining statements the median response was 6 (agree). Eleven statements were excluded because they did not reach consensus and one new statement was added during SantoRhino meeting. The final statements refer to patient history and clinical examination ("History taking should include presence of headache, tinnitus and visual defects"), investigations (role of Thin Slice Computed Tomography and CISS/FLAIR sequences in Magnetic Resonance Imaging), principles of management (watchful waiting or measures to reduce ICP are supplementary but cannot subsitute surgical closure), surgical technique, intraoperative, early postoperative and long term management. CONCLUSION: We present fifty consensus statements on the diagnosis, investigation, and management of spontaneous CSF rhinorrhea based on the currently available evidence and expert opinion. Although by no means comprehensive and final, we believe they can contribute to the standardization of clinical practice. Early diagnosis, prompt surgical closure of the defect, assesment for and treatment of potentially co-existing idiopathic intracranial hypertension in a comprehensive multidisciplinary approach are essential in order to successfully manage spontaneous CSF rhinorrhea, reduce associated morbidity and prevent recurrence.

Transorbital Endoscopic Approach for Repair of Frontal Sinus Cerebrospinal Fluid Leaks: Case-Series.

OBJECTIVES: To highlight the feasibility and evaluate the outcomes of the transorbital endoscopic approach (TOEA) in the management of frontal sinus cerebrospinal fluid (CSF) leaks. STUDY DESIGN: Retrospective case series. METHODS: The database of patients with frontal sinus CSF leaks managed with TOEA from January 2017 through December 2019 at our institution was reviewed. Two videos of clinical case examples are presented. RESULTS: Sixteen patients (10 males, 6 females, mean age 53; range 21-61 years) underwent TOEA through the superior eyelid corridor for the repair of frontal sinus CSF leak. The most common etiology of the CSF leak was trauma (nine cases; 56.3%), followed by injury from iatrogenic causes in six cases (37.5%), and spontaneous leak in one case (6.2%). Average defect size was 8.8 mm (range 2.0-20.8 mm). Ten patients were revision cases who had undergone prior nontransorbital CSF leak repair at outside institutions. All patients underwent successful repair via TOEA without postoperative complications. Complete resolution was maintained in all cases. Mean follow-up period was 11 months (range 6-22 months). CONCLUSIONS: TOEA is a safe minimally disruptive alternative for definitive management of frontal sinus CSF leak in well-selected primary or revision cases. Further studies are necessary to define its indications and outcomes. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1753-1757, 2021.

Spontaneous CSF Leaks and IIH: A Flawless Connection? An Experience With 167 Patients.

OBJECTIVES: Spontaneous cerebrospinal fluid (CSF) leaks are a rare but insidious clinical entity. In the recent literature, their pathogenesis has been linked with idiopathic intracranial hypertension (IIH). Considering a worse surgical outcome compared to traumatic leaks, a medical treatment of the underlying IIH has been suggested in order to prevent relapses. Nevertheless, some aspects of this rare pathology remain unclear. We report our long experience in the management of spontaneous CSF leaks. METHODS: A retrospective evaluation of all patients with spontaneous CSF leaks treated from 1998 to 2018 in a tertiary referral center was carried out. All patients received surgery without any adjuvant routine medical treatment. Epidemiological and clinical data were reviewed. A telephone survey was conducted to investigate IIH-related symptoms in this population. RESULTS: One hundred sixty-seven patients and 195 procedures were included in the study. The total rate of failure after surgical treatment was 9%. Eight patients suffered a relapse in the same site (4%, 8 of 195), whereas seven patients experienced a relapse in a different site (4%, 7 of 167). Twenty-nine percent of the population interviewed referred at least one IIH-related symptom. CONCLUSION: Spontaneous CSF leaks represent a complex pathology that need a multidisciplinary evaluation. Surgical treatment seems to guarantee favorable results in most of the patients. Despite this, a not negligible percentage of patients experienced a relapse during a long-term follow-up. Further studies are needed to reach a deeper understanding of the presentation and course of this particular condition. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E401-E407, 2021.

Chemotherapy associated dural sinus thrombosis presenting as a cerebrospinal fluid leak.

Despite the well documented increased risk of thrombosis in patients with cancer and during chemotherapy, cerebral venous sinus thrombosis (CVT) remains a rare entity. We present a rare case of cerebrospinal fluid (CSF) rhinorrhoea secondary to a left transverse sinus thrombus which occurred 2 years previously during chemotherapy for breast cancer. The patient underwent a three-layer repair using Neuro-Patch, septal cartilage and middle turbinate pedicle flap and was started on acetazolamide. There was no recurrence at 1-year follow-up. Raised intracranial pressure secondary to cerebral venous occlusion can erode the base of skull and predispose to CSF leaks. Despite the theoretical risk, there have been no cases reported where CSF leaks have occurred following chemotherapy induced CVT. We describe the first case and discuss pathophysiology and management.