Association between upper and lower respiratory disease among patients with primary ciliary dyskinesia: an international study.

Introduction: Nearly all patients with primary ciliary dyskinesia (PCD) report ear-nose-throat (ENT) symptoms. However, scarce evidence exists about how ENT symptoms relate to pulmonary disease in PCD. We explored possible associations between upper and lower respiratory disease among patients with PCD in a multicentre study. Methods: We included patients from the ENT Prospective International Cohort (EPIC-PCD). We studied associations of several reported ENT symptoms and chronic rhinosinusitis (defined using patient-reported information and examination findings) with reported sputum production and shortness of breath, using ordinal logistic regression. In a subgroup with available lung function results, we used linear regression to study associations of chronic rhinosinusitis and forced expiratory volume in 1 s (FEV1) accounting for relevant factors. Results: We included 457 patients (median age 15 years, interquartile range 10-24 years; 54% males). Shortness of breath associated with reported nasal symptoms and ear pain of any frequency, often or daily hearing problems, headache when bending down (OR 2.1, 95% CI 1.29-3.54) and chronic rhinosinusitis (OR 2.3, 95% CI 1.57-3.38) regardless of polyp presence. Sputum production associated with daily reported nasal (OR 2.2, 95% CI 1.20-4.09) and hearing (OR 2.0, 95% CI 1.10-3.64) problems and chronic rhinosinusitis (OR 2.1, 95% CI 1.48-3.07). We did not find any association between chronic rhinosinusitis and FEV1. Conclusion: Reported upper airway symptoms and signs of chronic rhinosinusitis associated with reported pulmonary symptoms, but not with lung function. Our results emphasise the assessment and management of upper and lower respiratory disease as a common, interdependent entity among patients with PCD.

Redox Imbalance in Nasal Epithelial Cells of Primary Ciliary Dyskinesia Patients.

Background: Primary Ciliary Dyskinesia (PCD) represents a rare condition marked by an abnormal mobility pattern of cilia and flagella, resulting in impaired mucociliary clearance. This deficiency leads to recurrent infections and persistent inflammation of the airways. While previous studies have indicated heightened oxidative stress levels in the exhaled breath condensate of pediatric PCD patients, the assessment of oxidative stress within the affected respiratory tissue remains unexplored. Aims: To assess the oxidative status of human nasal epithelial cells (NECs) in PCD patients. Methods: Thirty-five PCD patients and thirty-five healthy control subjects were prospectively included in the study. Levels of reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione (GSH), intracellular Ca2+, plasma membrane potential, and oxidative damage in lipids and proteins were measured. In addition, apoptosis and mitochondrial function were analyzed by flow cytometry in NECs. Results: NECs from PCD patients showed reduced levels of apoptosis (p = 0.004), superoxide anion (O2-, p = 0.018), peroxynitrite (ONOO-, p = 0.007), nitric oxide (NO, p = 0.007), mitochondrial hydrogen peroxide (mtH2O2, p < 0.0001), and mitochondrial superoxide anion (mtO2-, p = 0.0004) and increased mitochondrial mass (p = 0.009) compared to those from healthy individuals. No significant differences were observed in oxidized proteins (p = 0.137) and the oxidized/reduced lipid ratio (p = 0.7973). The oxidative profile of NEC cells in PCD patients, according to their ciliary motility, recurrent otitis, recurrent pneumonia, atelectasis, bronchiectasis, and situs inversus, showed no statistically significant differences in the parameters studied. Conversely, patients with chronic rhinosinusitis exhibited lower levels of ONOO- than PCD patients without this condition, with no significant differences related to other symptoms. Conclusions: Our findings strongly suggest the presence of a redox imbalance, specifically leaning toward a reductive state, in PCD patients.

Sinonasal disease among patients with primary ciliary dyskinesia: an international study.

Background: Sinonasal symptoms are a common feature of primary ciliary dyskinesia (PCD); however, literature about their severity and frequency, particularly during the life course, is scarce. Using baseline data from the Ear, nose and throat (ENT) Prospective International Cohort of PCD patients, we describe sinonasal disease in PCD. Methods: We included participants who had a routine sinonasal examination during which they completed a symptoms questionnaire. We compared frequency of reported symptoms and examination findings among children and adults, and identified characteristics potentially associated with higher risk of sinonasal disease using ordinal regression. Results: 12 centres contributed 384 participants; median age was 16 years (IQR 9-22), and 54% were male. Chronic nasal problems were the most common feature, reported by 341 (89%). More adults (33; 24%) than children (10; 4%) described hyposmia. Quality of life was moderately affected by rhinosinusitis among 136 participants with completed SNOT-22 questionnaires (median score 31; IQR 23-45). Examinations revealed nasal polyps among 51 of 345 participants (15%) and hypertrophic inferior nasal turbinates among 127 of 341 participants (37%). Facial pain was detected in 50 of 342 participants (15%). Nasal polyps, hypertrophic turbinates, deviated septum and facial pain were found more commonly in adults than children. The only characteristic associated with higher risk of sinonasal disease was age 10 years and older. Conclusions: Based on our findings, regular sinonasal examinations are relevant for patients with PCD of all ages. There is a need for improved management of sinonasal disease supported by evidence-based guidelines.

Characteristics of Otologic Disease Among Patients With Primary Ciliary Dyskinesia.

Importance: Otologic disease is common among people with primary ciliary dyskinesia (PCD), yet little is known about its spectrum and severity. Objective: To characterize otologic disease among participants with PCD using data from the Ear-Nose-Throat Prospective International Cohort. Design, Setting, and Participants: This cross-sectional analysis of baseline cohort data from February 2020 through July 2022 included participants from 12 specialized centers in 10 countries. Children and adults with PCD diagnoses; routine ear, nose, and throat examinations; and completed symptom questionnaires at the same visit or within 2 weeks were prospectively included. Exposures: Potential risk factors associated with increased risk of ear disease. Main Outcomes and Measures: The prevalence and characteristics of patient-reported otologic symptoms and findings from otologic examinations, including potential factors associated with increased risk of ear inflammation and hearing impairment. Results: A total of 397 individuals were eligible to participate in this study (median [range] age, 15.2 [0.2-72.4] years; 186 (47%) female). Of the included participants, 204 (51%) reported ear pain, 110 (28%) reported ear discharge, and 183 (46%) reported hearing problems. Adults reported ear pain and hearing problems more frequently when compared with children. Otitis media with effusion-usually bilateral-was the most common otoscopic finding among 121 of 384 (32%) participants. Retracted tympanic membrane and tympanic sclerosis were more commonly seen among adults. Tympanometry was performed for 216 participants and showed pathologic type B results for 114 (53%). Audiometry was performed for 273 participants and showed hearing impairment in at least 1 ear, most commonly mild. Season of visit was the strongest risk factor for problems associated with ear inflammation (autumn vs spring: odds ratio, 2.40; 95% CI, 1.51-3.81) and age 30 years and older for hearing impairment (41-50 years vs ≤10 years: odds ratio, 3.33; 95% CI, 1.12-9.91). Conclusion and Relevance: In this cross-sectional study, many people with PCD experienced ear problems, yet frequency varied, highlighting disease expression differences and possible clinical phenotypes. Understanding differences in otologic disease expression and progression during lifetime may inform clinical decisions about follow-up and medical care. Multidisciplinary PCD management should be recommended, including regular otologic assessments for all ages, even without specific complaints.

Molecular and Clinical Predictors of Quality of Life in Chronic Rhinosinusitis with Nasal Polyps.

(1) Background: Factors influencing the quality of life (QoL) of patients with chronic rhinosinusitis with nasal polyposis (CRSwNP) are poorly understood. We set out to determine the predictive factors on patients' QoL using the Sino-Nasal Outcome Test-22 (SNOT-22); (2) Methods: An ambispective analysis of data from patients diagnosed with CRSwNP in our institution. All the patients underwent a nasal polyp biopsy and completed the SNOT-22 questionnaire. Demographic and molecular data as well as the SNOT-22 scores were collected. Patients were classified in six subgroups considering the presence of asthma, non-steroidal drugs (NSAID) intolerance and corticosteroid resistance; (3) Results: The mean SNOT-22 score was 39. Considering the clinical parameters, the SNOT-22 value was significantly associated with NSAID intolerance (p = 0.04) and the endoscopic polyp score (p = 0.04). A high SNOT-22 value was also correlated with high tissue eosinophilia (p = 0.01) and high IL-8 expression; (4) Conclusions: Eosinophilia, IL-8 expression and NSAID intolerance can be used as predictors of worse QoL in patients with CRSwNP.

The disease-specific clinical trial network for primary ciliary dyskinesia: PCD-CTN.

Primary ciliary dyskinesia (PCD) is a rare genetic disorder characterised by impaired mucociliary clearance leading to irreversible lung damage. In contrast to other rare lung diseases like cystic fibrosis (CF), there are only few clinical trials and limited evidence-based treatments. Management is mainly based on expert opinions and treatment is challenging due to a wide range of clinical manifestations and disease severity. To improve clinical and translational research and facilitate development of new treatments, the clinical trial network for PCD (PCD-CTN) was founded in 2020 under the framework of the European Reference Network (ERN)-LUNG PCD Core. Applications from European PCD sites interested in participating in the PCD-CTN were requested. Inclusion criteria consisted of patient numbers, membership of ERN-LUNG PCD Core, use of associated standards of care, experience in PCD and/or CF clinical research, resources to run clinical trials, good clinical practice (GCP) certifications and institutional support. So far, applications from 22 trial sites in 18 European countries have been approved, including >1400 adult and >1600 paediatric individuals with PCD. The PCD-CTN is headed by a coordinating centre and consists of a steering and executive committee, a data safety monitoring board and committees for protocol review, training and standardisation. A strong association with patient organisations and industrial companies are further cornerstones. All participating trial sites agreed on a code of conduct. As CTNs from other diseases have demonstrated successfully, this newly formed PCD-CTN operates to establish evidence-based treatments for this orphan disease and to bring new personalised treatment approaches to patients.

Study protocol: the ear-nose-throat (ENT) prospective international cohort of patients with primary ciliary dyskinesia (EPIC-PCD).

INTRODUCTION: Primary ciliary dyskinesia (PCD) is a rare, genetic, multiorgan disease with an estimated prevalence of 1 in 10 000. It affects mainly the upper and lower airways due to impaired mucociliary clearance. Almost all patients have sinonasal or otologic (ear-nose-throat, ENT) problems, although the ENT clinical phenotype may present great variability. Despite that, data on PCD ENT manifestations are scarce and based on small single-centre studies. To date, we know little about the spectrum and severity of PCD ENT disease, its association with lung disease, its course over life and its determinants of prognosis.This study protocol describes the aims and methods of the first prospective, observational, multinational cohort study focusing on ENT disease in patients with PCD. METHODS AND ANALYSIS: The ENT prospective international cohort of patients with PCD (EPIC-PCD) is a prospective standardised observational clinical cohort set up as a multinational multicentre study, embedded into routine patient care. It aims to longitudinally characterise ENT disease in patients with PCD and its association with lung disease, and to identify determinants of its prognosis. Patients of all ages, diagnosed with PCD who undergo an ENT clinical assessment at least once a year at one of the participating centres will be invited to participate. Collected data include diagnostic test results, results of ENT examinations, lung function measurements, information on management of ENT disease and patient-reported data on clinical symptoms and health-related quality of life (QoL). Data are collected using the standardised PCD-specific FOLLOW-PCD form and the validated QoL-PCD questionnaire. ETHICS AND DISSEMINATION: The study has been reviewed and approved by the Human Research Ethics Committees at all participating centres, based on local legislation. The results of the study will be published in scientific journals, presented at scientific conferences and disseminated to participants and national patient organisations. TRIAL REGISTRATION: NCT04611516.

High-Speed Video Microscopy for Primary Ciliary Dyskinesia Diagnosis: A Study of Ciliary Motility Variations with Time and Temperature.

Primary ciliary dyskinesia (PCD) is a rare disease resulting from a defect in ciliary function that generates, among other issues, chronic upper and lower respiratory tract infections. European guidelines recommend studying ciliary function (pattern (CBP) and frequency (CBF)), together with characteristic clinical symptoms, as one of the definitive tests. However, there is no "gold standard". The present study aims to use high-speed video microscopy to describe how CBF and CBP alter over time and at different temperatures to reduce the error rate in the diagnosis of PCD. Samples of nasal epithelium from 27 healthy volunteers were studied to assess CBF and CBP at 0, 3, 24, 48, and 72 h, at room temperature and 4 °C. It was observed that CBF increased while CBP became dyskinetic, both at room temperature and at 4 °C, as time passed, especially after 3 h. In order to preserve all ciliary function parameters and to perform a reliable analysis to improve the diagnostic process of PCD, analysis should be performed within the first 3 h of sample collection, preferably in reference centers.

New Laboratory Protocol to Determine the Oxidative Stress Profile of Human Nasal Epithelial Cells Using Flow Cytometry.

Several studies have shown the importance of oxidative stress (OS) in respiratory disease pathogenesis. It has been reported that the nasal epithelium may act as a surrogate for the bronchial epithelium in several respiratory diseases involving OS. However, the sample yields obtained from nasal biopsies are modest, limiting the number of parameters that can be determined. Flow cytometry has been widely used to evaluate cellular OS profiles. It has the advantage that analyses can be performed using a small amount of sample. Therefore, we aimed to set up a new method based on flow cytometry to assess the oxidative profile of human nasal epithelial cells which could be used in research on respiratory diseases. Levels of total nitric oxide, superoxide anion, peroxynitrite, and intracellular peroxides were measured. Reduced thiol levels, such as antioxidant-reduced glutathione and oxidative damaged lipids and proteins, were also analysed. The intracellular calcium levels, plasma membrane potential, apoptosis, and percentage of live cells were also studied. Finally, a strategy to evaluate the mitochondrial function, including mitochondrial hydrogen peroxide, superoxide anion, mitochondrial mass, and membrane potential, was set up. Using small amounts of sample and a non-invasive sampling technique, the described method enables the measurement of a comprehensive set of OS parameters in nasal epithelial cells, which could be useful in research on respiratory diseases.

IFT46 Expression in the Nasal Mucosa of Primary Ciliary Dyskinesia Patients: Preliminary Study.

BACKGROUND: Primary ciliary dyskinesia (PCD) is characterised by an imbalance in mucociliary clearance leading to chronic respiratory infections. Cilia length is considered to be a contributing factor in cilia movement. Recently, IFT46 protein has been related to cilia length. Therefore, this work aims to study IFT46 expression in a PCD patients cohort and analyse its relationship with cilia length and function, as it was not previously described. MATERIALS AND METHODS: The expression of one intraflagellar transport (IFT46) and two regulating ciliary architecture (FOXJ1 and DNAI2) genes, as well as cilia length of 27 PCD patients, were measured. PCD patients were diagnosed based on clinical data, and cilia function and ultrastructure. Gene expression was estimated by real-time RT-PCR and cilia length by electron microscopy in nasal epithelium biopsies.Results and conclusions: While IFT46 expression was only diminished in patients with short cilia, FOXJ1, and DNAI2 expression were reduced in all PCD patient groups compared to controls levels. Among the PCD patients, cilia were short in 44% (5.9 ± 0.70 µm); nine of these (33% from the total) patients' cilia also had an abnormal ultrastructure. Cilia length was normal in 33% of patients (6.4 ± 0.39 µm), and only three patients' biopsies indicated decreased expression of dynein.

A Ciliary Motility Index for Activity Measurement in Cell Cultures With Respiratory Syncytial Virus.

BACKGROUND: The respiratory epithelium is frequently infected by the respiratory syncytial virus, resulting in inflammation, a reduction in cilia activity and an increase in the production of mucus. METHODS: In this study, an automatic method has been proposed to characterize the ciliary motility from cell cultures by means of a motility index using a dense optical flow algorithm. This method allows us to determine the ciliary beat frequency (CBF) together with a ciliary motility index of the cells in the cultures. The object of this analysis is to automatically distinguish between normal and infected cells in a culture. RESULTS: The method was applied in 2 stages. It was concluded from the first stage that the CBF is not a good enough indicator to discriminate between the control and infected cultures. However, the ciliary motility index does succeed in discriminating between the control and infected cultures using the t test with a value t = 6.46 and P < .001. In the second stage, it has been shown that the ciliary motility index did not differ significantly between patients, and the analysis of variance test gives α = 0.05, F = 1.61, P = .20. A threshold for this index has been determined using a receiver operating characteristics analysis that gives an area under the curve of 0.93. CONCLUSIONS: We have obtained a ciliary motility index that is able to discriminate between control and infected cultures after the eighth postinfection day. After infection, there is a rapid cilia loss of the cells and the measured CBF corresponds to the remaining noninfected cells. This is why the CBF does not discriminate between the control and the infected cells.

X-linked primary ciliary dyskinesia due to mutations in the cytoplasmic axonemal dynein assembly factor PIH1D3.

By moving essential body fluids and molecules, motile cilia and flagella govern respiratory mucociliary clearance, laterality determination and the transport of gametes and cerebrospinal fluid. Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder frequently caused by non-assembly of dynein arm motors into cilia and flagella axonemes. Before their import into cilia and flagella, multi-subunit axonemal dynein arms are thought to be stabilized and pre-assembled in the cytoplasm through a DNAAF2-DNAAF4-HSP90 complex akin to the HSP90 co-chaperone R2TP complex. Here, we demonstrate that large genomic deletions as well as point mutations involving PIH1D3 are responsible for an X-linked form of PCD causing disruption of early axonemal dynein assembly. We propose that PIH1D3, a protein that emerges as a new player of the cytoplasmic pre-assembly pathway, is part of a complementary conserved R2TP-like HSP90 co-chaperone complex, the loss of which affects assembly of a subset of inner arm dyneins.

MUC4 impairs the anti-inflammatory effects of corticosteroids in patients with chronic rhinosinusitis with nasal polyps.

BACKGROUND: Current evidence suggests that membrane-tethered mucins could mediate corticosteroid efficacy, interacting with glucocorticoid receptor (GR) in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Mucin 4 (MUC4)-tethered mucin is expressed in nasal polyp (NP) epithelial cells and upregulated under inflammatory conditions. Moreover, MUC4ß has the capacity to interact with other intracellular proteins. We hypothesized that MUC4 modulates corticosteroid efficacy of patients with CRSwNP. OBJECTIVE: We sought to analyze the role of MUC4 in corticosteroid effectiveness in different cohorts of patients with CRSwNP and elucidate the possible mechanisms involved. METHODS: Eighty-one patients with CRSwNP took oral corticosteroids for 15 days. Corticosteroid resistance was evaluated by using nasal endoscopy. Expression of MUC4 and MUC4ß was evaluated by means of real-time PCR, Western blotting, and immunohistochemistry. BEAS-2B knockdown with RNA interference for MUC4 (small interfering RNA [siRNA]-MUC4) was used to analyze the role of MUC4 in the anti-inflammatory effects of dexamethasone. RESULTS: Twenty-two patients had NPs resistant to oral corticosteroids. MUC4 expression was upregulated in these patients. In siRNA-MUC4 BEAS-2B airway epithelial cells dexamethasone produced higher anti-inflammatory effects, increased inhibition of phospho-extracellular signal-regulated kinase 1/2, increased mitogen-activated protein kinase phosphatase 1 expression, and increased glucocorticoid response element activation. Immunoprecipitation and immunofluorescence experiments revealed that MUC4ß forms a complex with GRα in the nuclei of NP epithelial cells from corticosteroid-resistant patients. CONCLUSION: MUC4ß participates in the corticosteroid resistance process, inhibiting normal GRα nuclear function. The high expression of MUC4 in patients with CRSwNP might participate in corticosteroid resistance.

Evaluation of Mucociliary Clearance by Three Dimension Micro-CT-SPECT in Guinea Pig: Role of Bitter Taste Agonists.

Different image techniques have been used to analyze mucociliary clearance (MCC) in humans, but current small animal MCC analysis using in vivo imaging has not been well defined. Bitter taste receptor (T2R) agonists increase ciliary beat frequency (CBF) and cause bronchodilation but their effects in vivo are not well understood. This work analyzes in vivo nasal and bronchial MCC in guinea pig animals using three dimension (3D) micro-CT-SPECT images and evaluates the effect of T2R agonists. Intranasal macroaggreggates of albumin-Technetium 99 metastable (MAA-Tc99m) and lung nebulized Tc99m albumin nanocolloids were used to analyze the effect of T2R agonists on nasal and bronchial MCC respectively, using 3D micro-CT-SPECT in guinea pig. MAA-Tc99m showed a nasal mucociliary transport rate of 0.36 mm/min that was increased in presence of T2R agonist to 0.66 mm/min. Tc99m albumin nanocolloids were homogeneously distributed in the lung of guinea pig and cleared with time-dependence through the bronchi and trachea of guinea pig. T2R agonist increased bronchial MCC of Tc99m albumin nanocolloids. T2R agonists increased CBF in human nasal ciliated cells in vitro and induced bronchodilation in human bronchi ex vivo. In summary, T2R agonists increase MCC in vivo as assessed by 3D micro-CT-SPECT analysis.

Gene mutations in primary ciliary dyskinesia related to otitis media.

Otitis media with effusion (OME) is the most common cause of conductive hearing loss in children and is strongly associated with primary ciliary dyskinesia (PCD). Approximately half of the children with PCD require otolaryngology care, posing a major problem in this population. Early diagnosis of PCD is critical in these patients to minimise the collateral damage related to OME. The current gold standard for PCD diagnosis requires determining ciliary structure defects by transmission electron microscopy (TEM) or clearly documenting ciliary dysfunction via digital high-speed video microscopy (DHSV). Although both techniques are useful for PCD diagnosis, they have limitations and need to be supported by new methodologies, including genetic analysis of genes related to PCD. In this article, we review classical and recently associated mutations related to ciliary alterations leading to PCD, which can be useful for early diagnosis of the disease and subsequent early management of OME.

Primary ciliary dyskinesia assessment by means of optical flow analysis of phase-contrast microscopy images.

Primary ciliary dyskinesia implies cilia with defective or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis and male infertility. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency (CBF) and beat pattern. In this paper, we present a method to determine CBF of isolated cells through the analysis of phase-contrast microscopy images, estimating cilia motion by means of an optical flow algorithm. After having analyzed 28 image sequences (14 with a normal beat pattern and 14 with a dyskinetic pattern), the normal group presented a CBF of 5.2 ± 1.6 Hz, while the dyskinetic patients presented a 1.9 ± 0.9 Hz CBF. The cutoff value to classify a dyskinetic specimen was set to 3.45 Hz (sensitivity 0.86, specificity 0.93). The presented methodology has provided excellent results to objectively diagnose PCD.

Ciliary motility activity measurement using a dense optical flow algorithm.

Persistent respiratory syncytial virus (RSV) infections have been associated with the exacerbation of chronic inflammatory diseases, including chronic obstructive pulmonary disease (COPD). This virus infects the respiratory epithelium, leading to chronic inflammation, and induces the release of mucins and the loss of cilia activity, two factors that determine mucus clearance and the increase in sputum volume. In this study, an automatic method has been established to determine the ciliary motility activity from cell cultures by means of optical flow computation, and has been applied to 136 control cultures and to 144 RSV-infected cultures. The control group presented an average of cell surface with cilia motility per field of 41 ± 15 % (mean ± standard deviation), while the infected group presented a 11 ± 5 %, t-Student p<0.001. The cutoff value to classify a infected specimen was <17.89 % (sensitivity 0.94, specificity 0.93). This methodology has proved to be a robust technique to evaluate cilia motility in cell cultures.

[A simple and reliable technique for the treatment of rhinoliquorrhoea from small defects: Free nasal mucosa overlay graft]. / Una técnica simple y segura para el tratamiento de las rinolicuorreas por pequeños defectos: colgajo libre de superposición «overlay¼ de mucosa nasal.

INTRODUCTION: Cerebrospinal fluid leaks to the sinonasal cavities (rhinoliquorrhoea) represent a process with diagnostic and therapeutic difficulties. The endoscopic transnasal approach is the method of choice, but with many possible variants. The purpose of this paper was to make a critical review of our diagnostic and therapeutic protocol used for 11years. MATERIAL AND METHODS: We operated on 31patients. The diagnosis was based on the biochemical analysis of rhinorrhoea, CT and MRI. TREATMENT: endoscopic nasal surgery after preoperative intrathecal injection of 5% fluorescein (2cc). Closure was performed using a free overlay graft from middle turbinate mucosa. RESULTS: Two patients had meningitis as the first sign. All patients were diagnosed by biochemical analysis of rhinorrhoea. CT and MRI gave clear evidence of the leakage location. The skull base defect was always less than 1cm. Fluorescein allowed clear visualisation of the fistulous area without other instruments and produced no side effects. One patient had a postoperative frontal abscess, which evolved favourably. All fistulas were closed and there was only one recurrence at 10years, which debuted as pneumococcal meningitis. DISCUSSION AND CONCLUSIONS: Our surgical protocol, based on the use of intrathecal fluorescein and free grafting of middle turbinate mucosa overlay onto the fistulous area, achieves successful long-term results in the management of rhinoliquorrhoea secondary to small skull base defects.