Morphology, Not Only Volume: A Study on Empty Nose Syndrome and Inferior Turbinates

The research study titled *"Morphology, Not Only Volume: A Study on Empty Nose Syndrome and Inferior Turbinates"* explores the relationship between the volume and morphological patterns of the remnant inferior turbinates (ITV) and the severity of symptoms in patients with Empty Nose Syndrome (ENS). ENS is a complex and often underdiagnosed condition that causes significant discomfort for those who suffer from it. Despite having a seemingly patent airway, patients with ENS experience a paradoxical sensation of nasal obstruction, along with a variety of other symptoms that can severely impact their quality of life.

### Objectives and Background

The primary aim of the study was to assess how the ITV and the morphological phenotype of the inferior turbinates influence the severity and manifestation of ENS symptoms. Previous studies have largely focused on the anatomical changes in the nasal cavity following turbinectomies as the cause of ENS. However, this study sought to go beyond simply measuring the volume of the remnant turbinates, exploring how their shape and distribution within the nasal cavity might affect patient outcomes.

### Methods

The study enrolled 54 patients who had previously undergone inferior turbinectomies and met specific criteria for ENS diagnosis, including a positive cotton test and high scores on the ENS 6-Item Questionnaire (ENS6Q). The patients were evaluated using several subjective assessment tools: ENS6Q, Sino-Nasal Outcome Test-25 (SNOT-25), Beck Depression Inventory-II (BDI-II), and Beck Anxiety Inventory (BAI). Computed tomography (CT) scans were used to measure the ITV by carefully analyzing finely cut images of the nasal cavity using ImageJ, a Java-based image processing program.

The researchers also categorized the patients into two distinct morphological groups based on the distribution of their remnant turbinates: **torpedo type** (balanced tissue volume) and **pistol type** (posterior dominance).

### Results

The study found several key results:

1. **Correlation Between ITV and Symptoms**: Contrary to what might be expected, patients with a higher volume of remnant inferior turbinates (ITV) did not have reduced symptoms. In fact, a positive correlation was observed between ITV and ENS-specific symptoms, particularly in the SNOT-25 domain.

2. **Morphological Differences**: Patients classified as the pistol type (with posterior dominance of turbinate tissue) had a higher burden of rhinologic symptoms compared to those in the torpedo type. This suggests that not just the volume, but the specific morphological distribution of the remnant turbinates, significantly affects symptom severity.

3. **Nasal Resistance**: There was no significant correlation between nasal resistance and ITV in either morphological type. This indicates that traditional methods of measuring nasal resistance may not be effective in evaluating ENS severity or predicting symptom burden.

4. **Psychological Impact**: Despite the complex interplay between physical and psychological symptoms in ENS patients, the study found no significant correlation between ITV and psychological assessment scores (BDI-II and BAI). This highlights that factors other than the physical presence of turbinate tissue, such as neurosensory function or patient perception, may contribute to the psychological aspects of ENS.

### Conclusions

The study concludes that the severity of ENS symptoms cannot be fully explained by the volume of remnant turbinate tissue alone. The shape and distribution of this tissue play a crucial role in determining symptom severity. Patients with a pistol type of turbinate morphology, characterized by a posterior concentration of tissue, tend to experience more severe rhinologic symptoms, even if their nasal resistance appears normal.

The findings suggest that treatment approaches for ENS should consider the specific morphological characteristics of the patient's nasal cavity, rather than focusing solely on restoring tissue volume. Moreover, the lack of correlation between nasal resistance and symptom severity calls into question the effectiveness of traditional objective measurements in diagnosing and managing ENS.

### Key Takeaways and Future Directions

- **Morphology Matters**: The study highlights the importance of considering the shape and distribution of remnant turbinate tissue in assessing ENS symptoms. This could influence future surgical and non-surgical treatment strategies aimed at alleviating ENS symptoms.

  

- **Limitations of Traditional Measurements**: The study challenges the reliance on nasal resistance measurements for ENS evaluation, suggesting the need for more sophisticated diagnostic tools that can better capture the nuances of ENS symptomatology.

- **Complex Pathophysiology**: The pathophysiology of ENS is complex, involving not just anatomical changes, but also neurosensory dysfunction and possibly psychological factors. This underscores the need for a multidisciplinary approach to diagnosis and treatment.

- **Future Research**: Further research is needed to explore the role of neurosensory mechanisms, including nerve function and thermoreceptor activity, in the development and progression of ENS. Computational fluid dynamics (CFD) studies could also provide deeper insights into how changes in nasal airflow patterns contribute to ENS symptoms.

In summary, this study provides valuable insights into the multifaceted nature of ENS, emphasizing the need for personalized treatment strategies that take into account the unique morphological and functional characteristics of each patient’s nasal anatomy.