MdDS is considered rare, though its exact prevalence is unknown due to underdiagnosis. There are an estimated 150,000 cases of MdDS in the US. It is seen far more often in adult women, with 85% of cases occurring in people born genetically female between the ages 30 and 60. The motion-triggered form is more common, while the spontaneous form is less frequent but increasingly recognized. It is also more common to develop in people who experience migraines, of which the exact cause is also not completely understood.

The exact cause of MdDS is poorly understood. The dominant theory suggests a maladaptation of the brain’s vestibulo-ocular networks that normally help the body adjust to continuous movement. The vestibulo-ocular reflex (VOR) is a rapid eye movement made automatically to counteract head movement, usually when walking and especially during motion in a car, boat, etc. After prolonged exposure to motion, the brain may fail to “recalibrate” once the motion stops (known as proprioception). Functional neuroimaging studies of people with MdDS show abnormal activity in regions involved in balance, motion perception, and sensory integration, particularly the entorhinal cortex and vestibular pathways. Hormonal factors may play a role, as women are disproportionately affected. Stress or migraines can also increase susceptibility.

The hallmark symptom of MdDS is a persistent rocking, swaying, or bobbing sensation (“like being on a boat”) that:

• Worsens when still, such as sitting or lying down

• Improves with passive motion, such as being in a car

• May be triggered by other visual stimuli, such as screens

Additional symptoms may include:

• Unsteadiness or imbalance

• Difficulty concentrating, “brain fog,” or cognitive slowing

• Visual motion sensitivity

• Head pressure or headaches (sometimes associated with migraine)

• Fatigue or sleep disturbances

• Anxiety or depression, often secondary to chronic symptoms

Symptoms usually lessen somewhat when the individual is in motion, which is a key distinguishing feature. It is also not accompanied by tinnitus or vomiting, key factors of other vestibular disorders.

MdDS is diagnosed clinically, as there is no definitive laboratory or imaging test. Diagnosis is typically made by a neurologist or vestibular specialist and requires ruling out other causes of dizziness and balance problems. A characteristic history of symptoms starting after disembarking from passive motion strongly supports the diagnosis.

While no test confirms MdDS, diagnostic evaluations help exclude other conditions:

• Neurological examination to assess balance and coordination

• Videonystagmography (VNG) or electronystagmography (ENG) to evaluate vestibular function

• MRI of the brain to rule out structural abnormalities

• Audiologic testing to exclude inner ear disorders

• Vestibular testing (such as rotary chair testing) may be normal or show nonspecific findings

A detailed symptom history remains the most important diagnostic tool. In 2020, an international organization called the Bárány Society published diagnostic criteria for MdDS in the International Classification of Vestibular Disorders (ICVD) to help distinguish it from other vestibular disorders and increase ease of diagnosis.

There is no universally effective treatment, but several approaches may help reduce symptoms:

• Vestibular rehabilitation therapy (VRT): Results vary; more helpful for motion intolerance than for MdDS itself.

• Optokinetic or visual-vestibular therapy: A specialized treatment retraining the brain’s motion-perception networks; promising results in some patients.

• Medications:

  • Benzodiazepines (e.g., clonazepam) for short-term symptom relief

  • SSRIs or SNRIs for associated anxiety or depression

  • Migraine-directed treatments if migraine features are present

• Neuromodulation techniques:

  • Repetitive transcranial magnetic stimulation (rTMS)

  • Transcranial direct-current stimulation (tDCS)

These are experimental but may benefit select patients.

• Lifestyle management:

  • Stress reduction, sleep optimization, and avoiding triggers

  • Gentle physical activity, such as walking or swimming

A current clinical study for DevRobust treatment of MdDS is underway at Mount Sinai.

Prognosis varies widely. Some individuals recover within weeks or months, especially with early intervention. Others experience chronic, persistent symptoms lasting years. Symptoms may fluctuate and may recur after new exposure to passive motion. While MdDS does not cause physical degeneration, its impact on quality of life can be significant due to its effects on concentration, mobility, and emotional well-being. Appropriate therapy, psychological support, and careful symptom management can greatly improve daily functioning for many patients.

1. Cleveland Clinic - Mal de débarquement syndrome

2. American Brain Foundation - Mal de débarquement syndrome

3. Stanford Medical - Mal de débarquement syndrome, otolaryngology

4. DevRobust treatment for Mal de débarquement syndrome - Mount Sinai

5. Neuroanatomy - Vestibulo-ocular reflex