What is EILO?
EILO, or Exercise Induced Laryngeal Obstruction, refers to airway obstruction triggered by the adduction or closure of the vocal cords during inhalation. This condition was previously known as vocal cord dysfunction.
EILO typically manifests within 1 to 5 minutes after beginning high-intensity exercise. The symptoms resolve within 5 minutes after stopping the activity.
How common is it and who is affected?
Scientific studies indicate that 5% of Olympic-level athletes suffer from EILO, and up to 35% of athletes with breathing complaints may have EILO (Clemm HH). EILO is more common among young and female athletes. Personality traits also seem to play an important role; athletes who are perfectionists appear to be more prone to this condition.
What are the symptoms of EILO?
EILO causes extreme shortness of breath during high-intensity exertion. The discomfort is typically felt in the throat or upper chest. Athletes with EILO may feel like they are breathing through a straw during intense effort. The condition is often mistakenly diagnosed as exercise-induced asthma, as the symptoms are quite similar. However, inhaler medications or steroids prescribed for asthma do not provide relief for EILO. Often, during very intense exercise, a frightening sound can be heard when inhaling. The symptoms quickly disappear after stopping the peak effort. Other symptoms include paleness, feeling faint, or actually fainting. These latter symptoms are likely caused by the dysfunctional breathing pattern often associated with EILO.
What causes EILO?
EILO is triggered during high-intensity exercise. The exact mechanisms that cause this condition are not yet fully understood. It is believed that a combination of factors may be responsible for the symptoms, including sensitivity to irritants, psychological stress, and a dysfunctional breathing pattern. Increased sensitivity to irritants may indicate that neurological processes are involved in the development of EILO. People with EILO show a clear increase in airway resistance in the lungs and an elevated neural drive. The flexibility of the vocal cords and the absolute diameter of the airways may also play a role.
People with EILO should also check for issues such as gastroesophageal reflux, nasal obstructions, or postnasal drip. One study even found a vitamin D deficiency in athletes with EILO, so it may be worthwhile to check for any vitamin D deficiency.
Another possible cause of EILO is improper use of respiratory muscle training. Incorrect breathing patterns may be trained, leading to dysfunctional breathing. Proper respiratory muscle training, with an emphasis on the correct breathing pattern and against low resistance, is always part of the treatment for EILO.
- Work of breathing, airflow resistance, and neural drive
Even during submaximal exertion, athletes with EILO show higher work of breathing (Walsted E) and greater neural respiratory drive. Neural respiratory drive refers to the mechanical load on the respiratory muscles, which is closely linked to the feeling of shortness of breath.
- Psychology, personality traits, and EILO
An athlete's psychological state can significantly contribute to the development of a dysfunctional breathing pattern. This state affects the autonomic nervous system, which in turn can negatively influence breathing. ILO (Idiopathic Laryngeal Obstruction) is a form of vocal cord obstruction not caused by exercise, but it is typically associated with psychological disorders. In contrast, EILO is not associated with psychological disorders.
Several researchers have noted that certain personality traits play a role in the development and severity of EILO. These traits, often associated with a type A personality, include hard work, drive, and a relentless pursuit of success in sports, studies, and work. Other characteristics of type A personalities include hurriedness, multitasking, competitiveness, fast speech, control issues, irritability, and impatience (Olin Tod J).
Expectations, dyspnea, and nocebo
- Dysfunctional breathing pattern and EILO:
Professor Hull J notes that in most of his EILO patients, a dysfunctional breathing pattern is evident. It is unclear whether this pattern is a possible cause of EILO or a consequence of it, but it is clear that this dysfunctional pattern must be treated alongside EILO. The abduction (opening) of the larynx is closely connected to the movement of the diaphragm. Therefore, progressively training the correct movement of the diaphragm is crucial. Often, respiratory muscle training does not focus on the correct breathing movement, which is vital because improper use of this training can exacerbate dysfunctional breathing patterns.
A dysfunctional breathing pattern is important because of the cascade between the diaphragm and vocal cords.
- Bernoulli's Law and EILO
It is possible that the speed of inhalation negatively impacts EILO. Bernoulli's Law states that as the speed of a gas or liquid increases, the pressure exerted by that gas or liquid on the airway walls decreases. The larynx is the narrowest part of the trachea, so airflow at the level of the vocal cords will accelerate. This acceleration leads to a negative pressure, which pulls the vocal cords inward. The faster an athlete breathes, the greater the chance that the airflow will pull the vocal cords inward.
How to treat EILO?
(Clemm Havstad H.)
- Diagnosing EILO and EIB
For accurate testing, athletes are advised to consult with a (sports) pulmonologist who has expertise in EILO.
It is essential to map out and thoroughly test for the various diagnoses that can cause shortness of breath, including EILO, EIB, and DPB. It is also useful to check for potential sinonasal conditions, gastroesophageal reflux, and vitamin D levels.
Testing for EILO:
- Continuous laryngoscopy during maximal exertion.
Testing for EIB:
- Spirometry before and after bronchodilator medication.
- Spirometry before and immediately after a maximal exercise test.
- Asthma provocation test.
Testing for DBP:
- Evaluate the breathing pattern during a VO2max exercise test (with mask).
- Observe the breathing pattern at rest, during submaximal, and maximal exertion.
- Nijmegen Questionnaire.
- Outbreath pause test.
- Hyperventilation provocation test (must be performed in the presence of medical professionals).
- High-intensity sprint interval protocol.
Respiratory education:
Education is a crucial part of the treatment for EILO, EIB, and DBP. These conditions can cause various physical symptoms, such as tension in the throat, tingling, fatigue, dizziness, headaches, etc. Understanding the origin of these symptoms is important in addressing overconcern and anxiety. Eliminating overconcern and anxiety in the early stages is critical for a successful treatment path.
Possible psychological factors should be evaluated and treated.
From my practice experience and literature, it seems clear that psychological aspects and beliefs either play a role in the onset of EILO or in maintaining the condition. The impact of personality, beliefs, and psychological state on the body is often underestimated. Our breathing often reflects our psychological state. Addressing beliefs and psychological conditions is a key step in the recovery process. I approach this through education, breathing exercises, and exercises from Sophrology.
- Evaluate and address lifestyle factors that may contribute to the onset or exacerbation of symptoms
- Rest and sleep.
- Nutrition.
- Stimulating activities versus relaxing activities.
- Breath re-training:
- Exercises to keep the vocal cords open.
- Train breathing awareness.
- Control breathing: abdominal, flank, and chest breathing.
- Breathing pattern exercises at rest.
- Breathing reduction training, breath pauses.
- Advice on breathing strategies during training and competition.
- Adapted respiratory muscle training for DBP and EILO.
- Teach exercises to manage symptoms: EILOBI, slowing down the breathing.
- As a last option, surgery may be considered.
How to distinguish between EILO, EIB, and BPD?
(Emery Michael Scott)
Behavioral predictors of symptom severity in exercise-induced laryngeal obstruction (EILO)
Based on an abstract by: A. Dammann & T. Olin, Denver, USA
Exercise-induced laryngeal obstruction (EILO) is a cause of shortness of breath during exercise, in which the airway at the level of the vocal cords (glottis) or above (supraglottis) temporarily narrows or blocks. In the literature, connections have been suggested between EILO and behavioral or psychological characteristics. In Dammann’s study, the relationship between mood, emotional factors, and EILO was investigated. The study specifically examined the association between EILO and emotions such as anger, sadness, frustration, hopelessness, and nervousness. A total of 219 adolescents and young adults aged 12 to 21 with EILO were studied.
This research by Dammann and Olin shows that young people with EILO not only experience physical symptoms, but that these symptoms are also clearly linked to negative emotions, particularly frustration. The more severe the EILO symptoms, the more negative emotions were reported in the following days. Therefore, treatment of EILO should not only focus on airway symptoms, but also address the mental and emotional aspects.