Positional alcohol nystagmus

Positional Alcohol Nystagmus (PAN) is a condition characterized by an involuntary rhythmic eye movement that occurs when a person's head is positioned at different angles, especially after consuming alcohol. This phenomenon is a specific form of nystagmus, which in general refers to the uncontrollable movement of the eyes, often described as shaking or wobbling eyes. PAN is particularly induced or exacerbated by the intake of alcohol, which affects the vestibular system in the inner ear, responsible for maintaining balance and spatial orientation.

Causes and Mechanism

The primary cause of Positional Alcohol Nystagmus is the consumption of alcohol. Alcohol can alter the density of the blood and bodily fluids, including the endolymph fluid in the inner ear, which plays a crucial role in the body's balance system. When alcohol enters the bloodstream, it diffuses into the endolymph, changing its density. This discrepancy in density affects the ear's semicircular canals, which are sensitive to rotation and movement, leading to an imbalance in the signals sent to the brain about the body's position. As a result, the brain, attempting to correct these imbalances, induces the eyes to move in a specific pattern, leading to nystagmus.

PAN can be divided into two phases based on the direction of eye movement relative to the consumption of alcohol:

• PAN I: Occurs shortly after drinking, where the eyes tend to beat away from the ground when the person is lying on their side. This phase is thought to result from the direct effects of alcohol on the vestibular system.
• PAN II: Occurs several hours after drinking, as the alcohol begins to wear off, where the eyes beat towards the ground. This phase is attributed to the differential effects of alcohol and its withdrawal from the vestibular system.

Symptoms

The most noticeable symptom of Positional Alcohol Nystagmus is the involuntary eye movement, which individuals might not always perceive themselves but can be observed by others. Other symptoms may include:

• Dizziness
• Vertigo
• Balance problems
• Nausea
• Visual disturbances

Diagnosis

Diagnosis of PAN involves a clinical examination, where a healthcare provider observes the eye movements in various head positions. This may be done using the Dix-Hallpike test or the head impulse test. A detailed history of alcohol consumption prior to the onset of symptoms is also crucial for diagnosis.

Treatment and Management

The primary treatment for Positional Alcohol Nystagmus is to reduce or eliminate alcohol consumption. In cases where PAN leads to significant discomfort or risk of injury due to balance issues, certain medications may be prescribed to alleviate symptoms. Vestibular rehabilitation therapy may also be recommended to help improve balance and reduce vertigo.

Prevention

Preventing Positional Alcohol Nystagmus primarily involves moderating alcohol intake or abstaining from alcohol altogether. Understanding the impact of alcohol on the vestibular system and the potential for inducing nystagmus can help individuals make informed decisions about alcohol consumption.