Distinguishing computed tomography findings in patients with empty nose syndrome

This study, conducted by Andrew Thamboo and colleagues, addresses the challenge of diagnosing Empty Nose Syndrome (ENS), a controversial condition often arising after nasal surgeries such as inferior turbinate reduction (ITR). ENS is characterized by a range of debilitating symptoms, including a paradoxical sensation of nasal obstruction despite a clear nasal passage, dryness, pain, and even psychological distress. However, due to the lack of standardized diagnostic criteria, identifying ENS has been challenging for clinicians.

The researchers aimed to determine whether specific radiographic features, particularly those visible on computed tomography (CT) scans, could be used to objectively differentiate ENS patients from those who had undergone ITR but did not develop ENS, as well as from healthy individuals with no history of sinonasal procedures. The study involved analyzing CT scans from three groups: 65 patients diagnosed with ENS, patients with a history of ITR without ENS symptoms, and control patients with no sinonasal disease history.

Key measurements were taken at the level of the nasolacrimal duct, including the thickness of the mucosa in the nasal septum, inferior turbinate, nasal floor, and lateral nasal wall, across different segments of the nasal cavity (anterior, central, and posterior). The study found that the mucosal thickness in the central and posterior segments of the septum was significantly greater in ENS patients compared to both ITR without ENS patients and controls. Specifically, a septal mucosal thickness greater than 2.64 mm in the central nasal region and greater than 1.32 mm in the posterior nasal region were identified as potential markers for ENS, offering high sensitivity and specificity.

The findings support the notion that ENS is a distinct pathophysiological entity with measurable differences in nasal mucosa that can be identified through CT imaging. The study also suggested that the nasal septum, particularly in the central and posterior regions, exhibits dynamic hypertrophy in ENS patients, potentially contributing to their symptoms.

However, the study acknowledges limitations, including the retrospective design and the small sample size, particularly in the ENS group. Moreover, the role of excessive nasal hygiene practices in contributing to mucosal swelling in ENS patients was speculated but not proven. Despite these limitations, the study provides valuable insights into the potential for developing objective diagnostic criteria for ENS, which could greatly benefit patients suffering from this underrecognized condition.

The study did discuss Empty Nose Syndrome (ENS) extensively, highlighting the difficulties in diagnosing the condition and the need for objective criteria. The conclusions emphasize that specific CT findings, particularly related to mucosal thickness in the central and posterior nasal septum, could serve as important diagnostic markers for ENS. This could lead to better recognition and management of the condition, offering hope for patients who suffer from its often debilitating symptoms.

Pathophysiology of Empty Nose Syndrome

This research study, titled "Pathophysiology of Empty Nose Syndrome," conducted by Jeanie Sozansky and Steven M. Houser, delves into the complexities of Empty Nose Syndrome (ENS), a rare but debilitating condition often arising as a complication of turbinate surgery. ENS occurs when the nasal turbinates are partially or completely removed, disrupting normal airflow patterns and impairing the neurosensory mechanisms responsible for detecting nasal airflow. The study aimed to understand the underlying pathophysiology of ENS by reviewing current literature on nasal airflow sensation, nasal patency, and the mechanisms of sensory perception.

**Background:**

ENS was first described in 1994 by Kern and Stenkvist, who identified patients with extensive turbinate resections suffering from paradoxical nasal obstruction—where the nasal passages appear wide open, yet the patient feels congested. The exact cause of this paradoxical sensation remained unclear for many years. Over time, ENS was recognized as a complication of various turbinate surgeries, including total turbinectomy and less invasive procedures like submucosal resection and laser therapy, especially when performed aggressively.

**Key Findings:**

1. **Subjective vs. Objective Nasal Patency:**

Traditional methods for assessing nasal obstruction, such as rhinomanometry and acoustic rhinometry, focus on anatomical measurements and airflow resistance. However, these methods do not correlate well with the subjective sensation of nasal patency. ENS patients often report a blocked sensation despite having wide nasal cavities, which cannot be explained by objective tests alone.

2. **Neurosensory Mechanisms:**

The study highlights the importance of the trigeminal nerve, specifically the TRPM8 receptor, in sensing nasal airflow. TRPM8 is activated by cool air, which is crucial for the sensation of nasal patency. In ENS, the altered airflow patterns reduce the cooling of nasal mucosa, leading to inadequate activation of these receptors. This results in the brain perceiving the nose as obstructed despite the absence of physical blockage.

3. **Airflow Pattern Alterations:**

ENS patients have a disproportionate nasal cavity volume relative to the mucosal surface area, leading to a laminar airflow pattern instead of the necessary turbulent flow. This disruption hinders the air's ability to cool the mucosa, diminishing the activation of cool thermoreceptors and thereby reducing the sensation of nasal patency.

4. **Dyspnea and Respiratory Distress:**

Many ENS patients experience a sensation of breathlessness or dyspnea, which is thought to be linked to the disrupted neurosensory feedback between the nasal passages and the brain. The study found that ENS patients have abnormal brain activation patterns when assessing nasal patency, indicating that the condition affects not just the nose but also the respiratory centers in the brain, contributing to the sensation of suffocation or difficulty breathing.

5. **Neurosensory System Aberrations:**

Beyond the physical alterations in airflow, the study discusses how nerve damage during turbinate surgery can lead to lasting sensory deficits. These deficits might be responsible for the ongoing abnormal sensations in ENS patients. Even if the surgery is technically successful, improper nerve healing can result in the permanent loss of normal nasal sensation, exacerbating ENS symptoms.

**Conclusions:**

The study concludes that ENS is not solely a result of anatomical changes but is heavily influenced by neurosensory dysfunction. The researchers propose that ENS develops due to a combination of impaired airflow patterns and neurosensory system aberrations, which together alter the perception of nasal patency. ENS patients suffer from genuine physiological changes, not just psychological symptoms, and these changes significantly impact their quality of life. The study calls for a more nuanced approach to diagnosing and treating ENS, emphasizing the need for a better understanding of the neurosensory components involved.

**Learnings and Implications:**

The research underscores the complexity of ENS and the importance of preserving nasal structure and function during turbinate surgeries. It suggests that careful surgical planning and consideration of the neurosensory impacts are crucial in preventing ENS. Moreover, the study opens avenues for further research into treatments that could restore normal sensory function or compensate for the loss of turbinate tissue, potentially improving outcomes for ENS patients.

This study is significant in that it shifts the focus from purely anatomical considerations to a more comprehensive understanding of how the nose functions as a sensory organ, particularly in the context of ENS. By doing so, it offers a new perspective on how to approach both the diagnosis and management of this challenging condition.

 

Surgery of the turbinates and “empty nose” syndrome

The research study titled "Surgery of the Turbinates and Empty Nose Syndrome" provides a comprehensive examination of the surgical interventions performed on the nasal turbinates, which are structures within the nasal cavity that play a crucial role in regulating airflow, humidifying, and warming the air we breathe. The study highlights the complexities and challenges associated with turbinate surgery, particularly focusing on the phenomenon known as Empty Nose Syndrome (ENS).

Overview of Turbinate Surgery

Turbinate surgery is often performed to alleviate nasal obstruction caused by conditions such as chronic rhinitis or hypertrophy of the turbinates. The primary goal of these surgical procedures is to improve nasal airflow while preserving the mucosal function of the nasal cavity. However, the study notes that there is no universally accepted surgical technique for turbinate reduction, leading to variability in outcomes and patient experiences.

Empty Nose Syndrome (ENS)

One of the significant concerns raised in the study is the risk of developing Empty Nose Syndrome, a condition that can occur after the resection of turbinates. ENS is characterized by a paradoxical sensation of nasal obstruction despite the nasal passages being physically wide open. Patients with ENS often report a dry nose, crusting, and a feeling of inadequate airflow, which can be distressing and difficult to treat. The study emphasizes that ENS is a surgically irreversible condition, making it crucial for surgeons to carefully consider the extent of turbinate removal during surgery.

Findings from Clinical Studies

The research includes findings from a clinical study conducted at the ENT University Clinic in Ulm, which investigated the airflow dynamics in patients with ENS. Using MRI-based numerical flow simulations, the study found that patients with ENS had significantly higher temperatures of inhaled air at certain points in the nasal cavity compared to healthy individuals. Additionally, the absolute humidity of the air was lower in ENS patients, contributing to the sensation of dryness and increased crust formation. These findings underscore the importance of the nasal turbinates in conditioning inhaled air and maintaining mucosal health.

Conclusions and Lessons Learned

The study concludes that while turbinate surgery can provide relief for many patients suffering from nasal obstruction, it carries the risk of complications such as ENS. The authors stress the need for careful patient selection and thorough preoperative counseling to ensure that patients are aware of the potential risks and benefits of the procedure. Furthermore, the study highlights the importance of preserving as much mucosal tissue as possible during surgery to maintain the natural functions of the nasal cavity.

In summary, the research emphasizes the delicate balance that surgeons must strike between achieving adequate airflow and preserving the integrity of the nasal mucosa. The findings serve as a reminder of the complexities involved in nasal surgery and the need for ongoing research to better understand the long-term effects of turbinate reduction procedures. The study advocates for a more conservative approach to turbinate surgery, prioritizing patient safety and quality of life over aggressive surgical interventions.