Approach to Management of Cerebrospinal Fluid Rhinorrhea: Institutional Based Protocol

Abstract

The role of otolaryngologist in the management of CSF rhinorrhea is expanding. It is prudent to evaluate all cases of CSF leak, understand the etiological causes and formalize a working approach to management of such cases to yield better outcome. A retrospective descriptive study of 39 cases of proven CSF rhinorrhea treated at a tertiary care center between January 2014 to August 2019. The data retrieved were analyzed for age, gender, weight, etiology, recurrence of the disease, history of meningitis, nasal or neurosurgical intervention in past, imaging inform of CT and MR cisternography as and when required. This was aimed at understanding the various etiological types of CSF rhinorrhea and work out a management approach. The patients with skullbase tumors who presented with CSF Rhinorrhea were excluded from the study sample. There were 18 cases of spontaneous CSF rhinorrhea and 20 cases of traumatic CSF rhinorrhea. The mean BMI of spontaneous gp was 32.9 ± 2.46 kg/m² while in traumatic group was 25.7 ± 2.94 kg/m² and difference was statistically significant. None of the spontaneous CSF rhinorrhea cases showed features of raised ICP preoperatively either clinically or on imaging except empty sella in 14 of 18 cases. 6 of 18 cases of spontaneous category while 01 of 20 cases in traumatic had recurrence and the recurrence rate was significantly (p < 0.05) higher in spontaneous group. In traumatic group 7 were iatrogenic, 8 were occult traumatic and rest were acute traumatic. 4 of traumatic and 1 spontaneous group had history of meningitis and the incidence was 12.8% in our study group. Early identification and localization of CSF fistula is necessary to reduce morbidity and mortality associated with it. Risk of meningitis is high in CSF rhinorrhea especially in traumatic group. The etiology of CSF rhinorrhea has a bearing on the management and spontaneous CSF rhinorrhea has higher rate of recurrence.

Introduction

Cerebrospinal fluid (CSF) rhinorrhea is the flow of CSF into the nose due to the breach in the intervening layers of mucosa, bone, dura and arachnoid membrane. It serves as the potential passage of infection from the nasal cavity to the brain and can lead to meningitis and other intracranial infections, it can also lead to pneumo-cephalus [1].

According to Ommaya et al. [2] CSF rhinorrhea is classified into traumatic and atraumatic type based on etiology. 80% of all CSF leak is due to nonsurgical trauma mostly in form of close head injury, 16% is iatrogenic and 4% is spontaneous. CSF rhinorrhea can be direct through the defect in anterior skullbase which is the commonest site for nonsurgical traumatic CSF leak or indirect from the middle or posterior skullbase coming into the nasal cavity through the Eustachian tube. Most of the traumatic CSF fistulas normally resolve by conservative management with a resolution rate of 85% in 7–10 days [3]. The once that don’t resolve are primarily due to necrosis of bony edge, de-vascularization of tissue, wound contracture or infection [4]. The non-traumatic CSF rhinorrhea also called as Spontaneous CSF rhinorrhea is caused due to congenital skullbase malformation, skullbase defect due to tumors, and idiopathic intracranial hypertension (IIH) where cause cannot be ascertained [5].

Despite abundance of literature on CSF fistula still there is paucity of literature to describe a working approach to management of CSF Rhinorrhea. It is important to identify the cause of leak, location of leak, optimize the treatment with less likely chances of failure and complications. Thus, an institutional based retrospective analysis was done for all patients who reported to Department of ENT at tertiary care center with CSF rhinorrhea. A stratification was done on basis of identification of location, cause, extent of defect, treatment instituted and complications in order to develop a protocol for management for CSF Rhinorrhea.

Materials and Methods

A retrospective study of all the patients with proven CSF rhinorrhea that reported to Department of ENT of Tertiary care hospital between January 2014 and August 2018 were included in the study. These patients’ nasal secretions tested positive for Beta-2-Transferrin and were included in the study. Their management data were retrieved from the Departmental archives without disclosing the patients’ identity. The data retrieved were for age, gender, weight, etiology, history of meningitis, nasal or neurosurgical intervention in past, imaging inform of CT and MR cisternography as and when required. The location, size of defect, type of closure done and post-operatively complication if any were also noted.

The patients with skullbase tumors who presented with CSF Rhinorrhea were excluded from the study sample. Patients managed surgically were given intrathecal fluorescein dye preoperatively. We used fluorescein dye in the concentration of 0.3 ml of 10% fluorescein in 10 ml of CSF injected intrathecal over 5–7 min, 30–40 min prior to the start of surgery. The fluorescein dye was used to aid in localizing the CSF fistula and ensure proper seal intraoperatively. The dye was not used in pediatric patients and patients with history of drug allergy. On identification of sight of leak, the mucosa was cleared off from the bony margin and depending on the size of defect the closure was done. The defect with size of 5 mm or less were closed by bath plug technique, size greater than 6 mm were closed in layers using various autologous materials like facia-lata, fat, cartilage, naso-septal flaps. The patients were kept on 3 monthly follow-ups for a period of 1 year.

Statistical analysis of spontaneous and traumatic CSF rhinorrhea were done separately using the descriptive data. The mean ± standard deviation was taken out for various factors and a Chi square with 95% confidence interval (CI) was done to compare the two groups (Statistical significance was considered when value < 0.05%). The statistical analysis was performed using SPSS version 20 (IBM, US).

Results

There were 39 patients who tested positive for CSF rhinorrhea in the period between January 2014 to May 2018. The patients were in the age range of 4–67 years with a mean age of 34 years. 03 Cases of acute traumatic CSF rhinorrhea responded to conservative management in the 07 days’ duration while 01 of spontaneous CSF fistula resolved prior to surgical management. Rest of the 35 patients had undergone 36 surgical repairs for CSF rhinorrhea. Out of the 39 cases 19 were cases of atraumatic CSF rhinorrhea and rest were traumatic/iatrogenic cases as shown in Fig. 1. The commonest site of defect was seen in cribriform fossa in both cases of spontaneous and traumatic CSF Rhinorrhea (Fig. 2).

Fig. 1.

Etiology of CSF Rhinorrhea (N = 39)

Fig. 2.

Location of defect with the etiology of CSF Rhinorrhea managed surgically (n = 36)

All the patients of Spontaneous CSF Rhinorrhea were females except congenital CSF rhinorrhea (Congenital Encephalocoele) which was seen in a male child. All the patients of Spontaneous CSF leak were overweight with a BMI range from 28 to 36 kg/m² (with a mean BMI of 32.9 ± 2.46 kg/m²) as compared to traumatic CSF leak with BMI range from 21 to 32.6 kg/m² (with a mean BMI of 25.7 ± 2.94 kg/m²) which was statistically significant between the two groups (Table 1). All patients of non- congenital spontaneous CSF rhinorrhea were subjected to fundoscopy and visual field assessment, however none showed features of IIH during the preoperative workup. The imaging in form of CT Scan/MRI for all spontaneous CSF leak patients were evaluated for features of IIH and finding of empty sella (Fig. 3) was seen in 14 out of 18 cases while in traumatic/Iatrogenic CSF leak group none had empty sella which was statistically significant (Table 1). 04 of 20 cases of traumatic CSF Rhinorrhea and 01 of the 19 cases spontaneous CSF leak had a history of one or more episodes of bacterial meningitis. So, the incidence of meningitis before definitive management in the present study was 5/39 (12.8%). 8 of the 20 cases of traumatic CSF rhinorrhea were categorized as occult traumatic as they presented with history of trauma, more than 3 months prior to presentation.

Table 1.

Demographic data of patients of spontaneous and traumatic CSF rhinorrhea

S. No.	Category	Spontaneous CSF rhinorrhea	Traumatic CSF rhinorrhea	P value
1	Age in years (Mean ± SD)	39.44 ± 8.2	33 ± 10	0.045
2	Female (%)	100	35	< 0.001
3	BMI	32.9 ± 2.4	25.7 ± 3	< 0.001
4	Empty sella on imaging (%)	77.8	0	< 0.001
5	Recurrencea (%)	33	5	0.024

^aRecurrence of CSF fistula at primary site or another site

Fig. 3.

Empty sella (arrow in green) with Meningocoele (arrow in red) on MRI in spontaneous CSF rhinorrhea

The size of defect in skullbase with maximum diameter was assessed on NCCT scan/CT cisternography in various categories (Table 2). Eight cases were managed by fat bath plug technique; rest were managed by multilayer closure including pedicled nasoseptal flap (Fig. 4).

Table 2.

Size of defect with etiology of CSF Rhinorrhea

S. No.	Etiology	Size of defect (mm)
1.	Spontaneous/atraumatic
(a)	Congenital (syncipital encephalocoele)	10
(c)	Others	2–12
2.	Traumatic	4–12
3.	Iatrogenic	4–25

Fig. 4.

A case of meningoencephalocoele NCCT scan, a preoperative, b postoperative, c endoscopic view (green arrow shows the pedicled nasoseptal flap)

In the spontaneous CSF rhinorrhea category 6 of 18 cases (33%) had undergone surgery of CSF fistula more than once within a duration ranging from 08 to 48 months, this included one case of the recurrence initially managed by the author while one case in the traumatic group had undergone surgery for recurrence, thus the chances of recurrence was higher in spontaneous group and was statistically significant (p < 0.05) (refer Table 1). All patients of spontaneous CSF fistula were routinely managed by Tab Acetazolamide for 2 weeks postoperatively.

This enabled us to formulate an Institutional based protocol for management of CSF Rhinorrhea (Fig. 5).

Fig. 5.

Algorithm for management (Mx) of CSF rhinorrhea

Discussion

CSF Rhinorrhea is the osteo-dural breach resulting in the communication of cranial cavity to the nasal cavity. Most of these patients present with unilateral watery rhinorrhea, which gets aggravated on straining. There are various tests for identification of CSF, the most reliable test is the B2-Transferrin test with sensitivity of nearly 100% and specificity of 95% which is considered as the gold standard test [6], another alternative is the B-trace protein with a comparable sensitivity and specificity. However, in absence of these tests glucose oxidase test can be used but the test has low predictive value, hence we used the B2-transferrin test for confirmation of CSF rhinorrhea.

CSF fistula increases the chances of ascending meningitis. The streptococcus pneumoniae is the commonest causative organism for ascending meningitis in cases of CSF fistula and the overall incidence of meningitis associated with CSF fistula in various studies ranges from 10 to 30.6% [7–10] and in the present study the incidence was 12.8%. The risk of ascending meningitis is more with traumatic than spontaneous CSF leak as seen in the present study the incidence of bacterial meningitis in traumatic CSF rhinorrhea was 4/20 (20%) and spontaneous CSF rhinorrhea was 1/19 (5%) which is in agreement with Daudia et al. which showed comparable risk association [7]. The risk of meningitis before surgical repair is 1.3% per day in the first 2 weeks, 7.4% per week in the 1st month after trauma [9]. Hence to reduce the morbidity and mortality associated with ascending meningitis the author recommends pneumococcal vaccinations in some high-risk patients as per the pneumococcal vaccination guideline of CDC 2019 and Table 3 [11, 12]. However, the role of prophylactic antibiotic is controversial and not recommended in management of CSF Rhinorrhea [13, 14].

Table 3.

Recommendation for pneumococcal vaccination in CSF fistula

1.	In cases of recurrent CSF fistula
2.	Patients of Skullbase tumors being worked up for surgical resection with likely chances of dural breach
3.	Patients of CSF fistula with immunocompromised status
4.	Congenital CSF fistula
5.	Patients with CSF fistula with history of meningitis

The acute and delayed traumatic CSF rhinorrhea are initially managed by conservative approach with absolute bed rest, head elevation, stool softeners, cough suppressants to reduce intracranial pressure and aid in closure of defect. According to Bell et al. [15] and Yilmazler et al. [16] the success rate of conservative management in acute traumatic CSF fistula is around 80–85% over 7 days, however in the present series the spontaneous cessation was 3/12 (25%) cases of acute traumatic CSF rhinorrhea which is far less than reported in other studies. The low rate of response to conservative management can be explained by the fact these cases are primarily from the series of referral from neurosurgery to otolaryngologist (referral bias).

The traumatic CSF rhinorrhea has been classified according to latency of occurrence into acute/early onset, delayed and occult/late onset type. In acute/early onset type, the patient presents with CSF rhinorrhea within first 2 days of trauma, delayed type presents with onset of leak at least 1 week after trauma and the late onset/occult types presents with CSF leak 3 months after trauma [17]. According to various authors 50% starts in first 2–3 days while 70% within the 1st week, while almost all traumatic CSF leaks occur within 3 months of trauma [18]. However in the present study we see 8/20 (40%) cases of occult CSF rhinorrhea, out of which 4 cases reported with one or more episodes of meningitis and one with pneumocephalocoele. According to various literature the incidence of late onset CSF fistula ranges from 1.6 to 16% [19, 20] however the occurrence is higher than is generally recognized, most of these cases present with recurrent intracranial complications. The cause of late onset CSF leak is enlarging skullbase defect, remodeling of bone around the defect or transient rise in intracranial pressure due to straining, sneezing, coughing in an already weak skullbase defect with mucosal seal. A high level of suspicion is required to identify patients of occult/late onset CSF fistula, there are situations when patients may present with post-traumatic recurrent meningitis without active leak, the author recommends evaluation of such patients who has history of trauma with high resolution CT scan for identification of defect. If identification of bony defect is made, the closure of defect should be attempted using intrathecal fluorescein dye.

The atraumatic CSF rhinorrhea is divided into spontaneous and congenital. The cause of spontaneous CSF rhinorrhea is multifactorial but recent studies attribute it to intracranial hypertension [21–23]. However, the identification of raised intracranial pressure during spontaneous CSF rhinorrhea is debatable. All the patients in the present study were evaluated by imaging and fundoscopy for features of IIH preoperatively. 14/18 (77.8%) cases had empty sella syndrome but no other features of IIH on MRI, a similar finding on imaging has been reported by Chaaban et al. [24]. None of the patients of spontaneous CSF leak had papilledema on fundoscopy which is in agreement with the findings reported by Aaron et al. [25] Another plausible explanation is that most of the spontaneous CSF fistula is seen in middle aged obese female with radiological evidence of empty sella syndrome which is also a common finding in IIH [26] and can be correlated in the present study (Fig. 6). Recent evidence has made us to realize the elevated intracranial pressure (ICP) causes remodeling and thinning of bones in the anterior cranial fossa and areas of temporal bone resulting in CSF fistula. This CSF fistula gives relief to intracranial tension and hence alleviates the frank manifestation of IIH. The intracranial pressure surge is a matter of concern after the surgical closure of the CSF fistula, this leads to higher failure rate of surgical repair. Teachey et al. [27] conducted a study with large sample size to compare the outcome for endoscopic surgery for closure of spontaneous CSF fistula with and without ICP controlled and found that the success rate of 92.82% with active ICP control and 81.87% without control. The ICP can be controlled by conservative method using Carbonic anhydrase inhibitor (Tab Acetazolamide) which reduces intracranial fluid pressure, or by invasive methods using Lumber drain or ventriculo-peritoneal shunt (VP Shunt). Both are the standard of care however the conservative approach of ICP control is the preferred choice of management for postoperative patients. Tablet Acetazolamide in the dosage of 500 mg twice daily for first week followed by lower dosage to 250 mg twice daily for second week was given in all cases of spontaneous CSF leak post-surgery. There was 100% success rate in closure of primary defect in spontaneous CSF leak with ICP control in the immediate post-operative period in the present study however one patient had a recurrence at a new location after a period of 8 months.

Fig. 6.

Endoscopic view of intrathecal fluorescein dye aiding in identification of skullbase defect

The repair of CSF fistula was performed with intrathecal administration of fluorescein dye in all 34 of 35 patients (except the congenital encephalocoele). The dye aided with 100% accuracy in identification of CSF fistula site (Fig. 6) and confirmation of closure of fistula while performing Valsalva test. The use of intrathecal fluorescein dye is controversial; it is used in many centers for diagnostic as well as therapeutic CSF fistula repair however it’s not approved by FDA for intrathecal use and no standardization of dosage is yet done [28]. In our study, we did not observe any major complication except transient headache in 4/34 patients.

The limitations of the present study are the non-availability of CSF pressure during the surgical management of spontaneous CSF rhinorrhea and a longer duration of follow-up is required assess the long-term outcome.

Conclusion

CSF Rhinorrhea is relatively rare and potentially life threatening condition which needs early identification and management to prevent morbidity and mortality associated with it. It is important to confirm CSF leak and identify the site of defect. The etiology of leak has a bearing on the approach to evaluation and treatment. The traumatic CSF leak can be managed by conservative approach initially followed by surgical closure of defect and have a better prognosis. While spontaneous CSF rhinorrhea is widely associated with obesity and IIH but causal relationship remains poorly understood. The management of spontaneous CSF rhinorrhea does not only entail closure of defect but also requires ICP monitoring and has higher rate of recurrence.

Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical Approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed Consent

Informed consent was obtained from individual participants included in the study.