Dizziness: when medical imaging becomes an ally in diagnosis
One common symptom, multiple causes
Vertigo is a common reason for consultation in general practice and hospitals. It reflects a disturbance of balance, often experienced as an illusion of movement of the body or the environment, instability, or positional discomfort. Its origin can be peripheral (inner ear, vestibular nerve) or central (brain, brainstem), hence the importance of clearly distinguishing between these two main types to guide treatment. Understanding its origin, its mechanism, as well as the diagnostic and therapeutic pathways, allows for better patient support and helps prevent complications such as falls or chronic anxiety.
Definition and mechanism
Vertigo occurs when there is a conflict between the information sent by the body's balance sensors (inner ear, vision, proprioception) and what the brain normally expects to receive. The vestibular system, located in the inner ear, plays a key role: it perceives head movements, translations and rotations, as well as changes in position, thanks to specialized organs (semicircular canals, otoliths). These signals are transmitted via the vestibular nerve to the brainstem, cerebellum, and the brain centers that coordinate posture, balance, and visual stabilization. If an element of the peripheral or central vestibular system is disrupted (inflammation, injury, infection, altered nerve impulses), integration is impaired, and vertigo can develop.
Epidemiology in Switzerland and around the world
Vertigo affects between 20% and 30% of people aged 18 to 64 and is a frequent reason for seeking medical advice. Prevalence increases with age: older people are particularly susceptible to vestibular disorders, multifactorial imbalances, and an increased risk of falls. In Switzerland, as elsewhere, the majority of cases are due to benign peripheral pathologies, but central causes should always be ruled out if there is any doubt.
Main causes of dizziness
Among the most common peripheral causes, benign paroxysmal positional vertigo (BPPV) occurs when small crystals (otoliths) become dislodged in the inner ear, triggering an illusion of rotation during head movements. Vestibular neuritis is an acute inflammation of the vestibular nerve, often viral, causing intense vertigo, nausea, and unsteadiness without hearing loss. Ménière's disease manifests as attacks combining vertigo, tinnitus, a sensation of pressure in the ear, and fluctuating hearing loss. Central causes, rarer but serious, include brainstem strokes, cerebellar tumors, acoustic neuromas, and certain forms of vestibular migraine.
Clinical signs and associated symptoms
Dizziness can last from a few seconds to several days, depending on the cause. It is often accompanied by nausea, vomiting, sweating, gait disturbances, blurred vision, nystagmus, or postural instability. Some episodes are triggered by head movements, while others occur at rest. The presence of associated neurological signs (visual disturbances, dysarthria, paresthesia) suggests a central nervous system cause, requiring further investigation.
Diagnosis: when imaging becomes essential
Diagnosis is based on medical history, clinical examination (position tests, nystagmus, gait), and sometimes vestibular tests. Imaging is used when symptoms are atypical, prolonged, severe, or when a central cause is suspected. Brain MRI, with sequences focused on the brainstem and cerebellopontine angle, can detect ischemic, tumoral, or inflammatory lesions. CT scans can be used in emergency situations to rule out cerebral hemorrhage.
The role of the CID Lausanne
At the CID Lausanne, the team regularly sees patients for MRI or CT scans related to vertigo of undetermined origin. Thanks to their expertise in neuroradiology, the radiologists analyze in detail the structures involved in balance, including the inner ear, cranial nerves, and cerebellum. Rapid access to examinations, high-quality equipment, and close collaboration with referring physicians ensure a reliable and rapid diagnosis. In some cases, an emergency MRI can prevent delays in treatment for stroke or compressive conditions.
Artificial intelligence as a diagnostic support
The Lausanne CID is progressively integrating artificial intelligence tools into the analysis of neurological MRIs. These technologies allow for faster detection of subtle abnormalities, prioritization of urgent cases, and increased diagnostic reliability, particularly in difficult cases where clinical signs are ambiguous.
Patient journey in Switzerland
In Switzerland, the initial assessment often takes place in primary care. If a peripheral cause is suspected, symptomatic treatment or repositioning maneuvers may suffice. However, any doubt about a central origin or an atypical course warrants referral to an ENT specialist or neurologist, with imaging studies. Imaging centers like the CID are essential links in this care pathway.
Illustrative clinical case
A 65-year-old man with no known neurological history suddenly experienced intense vertigo upon changing position, accompanied by nausea. The absence of auditory or motor symptoms suggested benign paroxysmal positional vertigo (BPPV), which was confirmed by the Dix-Hallpike maneuver. However, a 58-year-old woman with hypertension presented with sudden vertigo accompanied by ataxia and vomiting. An MRI performed at the CID Lausanne revealed a brainstem infarction, requiring immediate hospitalization. These two cases illustrate the diversity of diagnoses and the importance of rapid access to imaging when there is any doubt.
Innovation prospects
Research is progressing towards tools for the objective quantification of vertigo (stabilometry platforms, virtual reality), personalized rehabilitation approaches, and the integration of artificial intelligence to automatically differentiate between vertigo of central and peripheral origin. In parallel, Swiss healthcare systems are working to improve access to advanced imaging throughout the country.
Imaging as a lever for precision
Vertigo requires rigorous evaluation. While the majority of cases involve benign disorders, central or atypical forms necessitate a rapid and accurate diagnosis. The CID Lausanne has established itself as a leading partner for general practitioners, ENT specialists, and neurologists, offering reliable access to brain MRI and CT scans, supported by recognized expertise and the latest innovations in artificial intelligence.
