Pseudo-cerebrospinal fluid rhinorrhea

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.

Pseudo-Cerebrospinal Fluid Leaks of the Anterior Skull Base: Algorithm for Diagnosis and Management

Objective  Pseudo-cerebrospinal fluid (CSF) leaks are a rare cause of unilateral, watery rhinorrhea. We proposed a step-wise approach to evaluate these cases. Design  It involves a single-center retrospective cohort study. Setting  The setting is that of a tertiary academic medical center. Participants  Ten patients with diagnosis of pseudo-CSF leak over a 21-year period were evaluated using our proposed algorithm that includes computed tomography, magnetic resonance imaging, nasal endoscopy, β-2 transferrin, intrathecal fluorescein, and surgical exploration of the anterior cranial base. Main Outcome Measures  The occurrence of intracranial infection and resolution of the symptoms were evaluated at a mean follow-up of 94.4 months. Results  Eight patients had history of skull base fracture or surgery. In all patients computed tomography, magnetic resonance imaging, and nasal endoscopy did not show signs of CSF leak. Beta-2 transferrin testing was performed in five patients, being negative in all of them. Intrathecal fluorescein was performed in seven patients, being negative in five and inconclusive in two. Surgical exploration was performed in five patients, definitively ruling out CSF leak. Six patients were treated with intranasal ipratropium, resolving the symptoms in all cases. Conclusion  The presented algorithm provides a step-wise approach for patients with unilateral watery rhinorrhea, allowing to safely ruling out CSF leak.

Serious Complications After Le Fort III Distraction Osteogenesis in Syndromic Craniosynostosis: Evolution of Preventive and Therapeutic Strategies

BACKGROUND

There is a paucity of studies that report complication rates following a subcranial Le Fort III advancement using distraction osteogenesis. The purpose of this study was to identify and describe serious postoperative complications following Le Fort III advancement with distraction osteogenesis, and provide strategies to assist in the resolution of these complications.

METHODS

An observational retrospective study was performed on consecutive patients with Apert, Crouzon, or Pfeiffer syndromes (n = 16) who underwent Le Fort III advancement using distraction osteogenesis between 2008 and 2017. Serious complications were defined as frontal bone loss, cerebrospinal fluid leak, meningitis, seizures, or major blood loss (ie, massive transfusion within the first postoperative day).

RESULTS

Three (18.7%) patients presented serious complications, namely cerebrospinal fluid leak (n = 1; 6.2%), seizures (n = 1; 6.2%) due to a halo-type device trans-pin intracranial migration, and major blood loss (n = 1; 6.2%). Adopting well-delineated interventions, all of these complications were resolved without fatality.

CONCLUSION

A Le Fort III advancement has a significant morbidity rate, with 3 of our patients (18.7%) in this study presenting serious complications. Appropriate management reduced this morbidity, and all complications were resolved without fatality.

Pseudo-Cerebrospinal Fluid Rhinorrhea Resulting from Aberrant Cross-Innervation of Trigeminal and Facial Nerves following Skull Base Surgery

Objectives Pseudo-cerebrospinal fluid (CSF) rhinorrhea is a rare phenomenon, presumed to result from aberrant autonomic reinnervation of the paranasal mucosa following injury to the greater superficial petrosal nerve or periarterial plexus. In this report, we discuss the case of a postoperative patient with pseudo-CSF rhinorrhea exacerbated by chewing and propose a novel mechanism of pseudo-CSF rhinorrhea.

Case Report A 46-year-old man was found to have mastication-induced unilateral clear rhinorrhea following transtemporal resection of a cerebellopontine angle tumor. Computed tomography cisternogram and β-2 transferrin analysis proved negative for any evidence of CSF leak.

Conclusions Pseudo-CSF rhinorrhea exacerbated by mastication has not been previously reported in the literature. We propose aberrant cross-innervation of the trigeminal and facial nerves as the mechanism underlying the patient's condition. Pseudo-CSF rhinorrhea is an important entity to identify following skull base surgery because it may spare patients from the unnecessary invasive procedures and morbidity associated with the management of a presumed CSF leak.

Posttraumatic pseudo-cerebrospinal fluid rhinorrhea

OBJECTIVE AND HYPOTHESIS

Posttraumatic clear rhinorrhea should result in immediate concern for a suspected cerebrospinal fluid (CSF) fistula in patients with skull base injuries, including surgical trauma. However, in addition to CSF rhinorrhea, the differential diagnosis may also include postinjury autonomic dysfunction. Pseudo-cerebrospinal fluid rhinorrhea (PCSFR) is a term used to describe rhinorrhea resulting from injury to preganglionic parasympathetic fibers supplying the sphenopalatine ganglion. This ganglion plays a critical role in this pathway secondary to its anatomic course and physiologic function. Differentiating between PCSFR and true CSF rhinorrhea can be a diagnostic challenge and may result in unnecessary and costly invasive testing and treatment.

CASE STUDY

The authors present an illustrative case of noniatrogenic posttraumatic PCSFR in a previously healthy patient who experienced a head injury in a horseback riding accident.

DISCUSSION

Features of PCSFR include a history of skull base surgery or trauma with involvement of autonomic structures in this region, rhinorrhea within months or years after injury, decreased lacrimation on the involved side, absence of clinical signs of meningitis, and a negative beta2-transferrin test result. Management of PCSFR is aimed at restoring the normal autonomic homeostasis in the nasal cavity. Treatment options include topical medicines such as anticholinergics and the various surgical procedures aimed at disruption of parasympathetic preganglionic fibers proximal to or at the sphenopalatine ganglion.

CONCLUSION

This case and its diagnosis and management provide an additional mechanism of PCSFR, a clinical entity that must be considered in the evaluation of all patients with previous skull base trauma.

Surgical exposure and resection of the vertical portion of the petrous internal carotid artery: anatomic study

OBJECTIVE

The goals were to determine which surgical approaches, i.e., the preauricular subtemporal infratemporal fossa (PSI), postauricular transtemporal (PAT), and/or subtemporal middle fossa (SMF) approaches, provide optimal exposure of the anterior, posterior, medial, and lateral aspects of the vertical segment of the petrous internal carotid artery (VPCA) and to determine the length of the VPCA that can be resected before a vein graft is necessary.

METHODS

Using 22 cadaveric specimens, we compared the length of exposure of the VPCA provided by the PSI, PAT, and SMF approaches. The segment of the VPCA that was exposed with each approach was measured in millimeters and expressed as a percentage of the total length of the VPCA. Resection of the VPCA in 1-mm increments was performed until a graft would be necessary; the total length of the resected segment was recorded in millimeters and was also expressed as a percentage of the total length of the VPCA.

RESULTS

The PSI approach provided average exposures of 14.1 mm (95% of the total exposure possible) of the anterior aspect and 14.3 mm (96%) of the lateral aspect of the VPCA; resection of less than 2.3 mm (16%) of the VPCA could be repaired with an end-to-end anastomosis. The PAT approach provided average exposures of 10.5 mm (71 %) of the lateral aspect and 10.0 mm (76%) of the posterior aspect of the VPCA; resection of less than 2.8 mm of the VPCA could be repaired with an end-to-end anastomosis. The SMF approach provided average exposures of 6.1 mm (45%) of the anterior aspect and 5.4 mm (41 %) of the lateral aspect of the VPCA; resection of less than 2.4 mm (24%) of the VPCA could be repaired with an end-to-end anastomosis.

CONCLUSION

Lesions on the anterior and lateral aspects of the VPCA can be fully exposed with the PSI approach or partially exposed with the less invasive SMF approach. Lesions on the posterior aspect of the artery are best exposed with the PAT approach. Lesions on the medial aspect of the VPCA cannot be exposed unless the VPCA is mobilized in the PSI approach. Resection of less than approximately 2.5 mm (20%) can be repaired with an end-to-end anastomosis, regardless of the approach used.