The inner ear contains the so-called vestibular organ (organ of equilibrium), which is responsible for the sense of balance, for the orientation of the body in space, as well as for the perception of linear and rotational acceleration. The vestibular organ is composed of bony and softer structures. Basically, the vestibular organ consists of three arcuate ducts (arcuates), two outpouchings (sacculus, utriculus) and one duct (ductus endolymphaticus). All these structures are in communication with each other and are filled with the inner ear fluid (endolymph). When the position of the head or the whole body changes, the endolymph moves in relation to the inner ear because of its inertia and excites the sensory cells of the vestibular organ. These transmit the excitation by means of nerves to the brain, where further processing takes place.
In addition to the vestibular organ, the eyes and receptors in the joints and muscles also provide information about the position of the body in space and are therefore also responsible for spatial orientation. If one of these sensory organs provides incorrect sensory stimuli, dizziness can occur.
Possible causes of dizziness can be diseases of the vestibular organ, foreign sensory stimuli, such as during travel on the high seas, as well as diseases of the cardiovascular system. There is also a form of vertigo that can be caused by psychological changes.
Vestibular vertigo:
Darunter versteht man einen Schwindel, der durch Erkrankungen des Gleichgewichtsorgans verursacht wird. Der vestibuläre Schwindel kann in einen peripheren und zentralen Schwindel unterteilt werden. Bei Erkrankungen des Vestibularorgans oder des ableitenden Nervs bezeichnet man den Schwindel als peripher vestibulär. Sind jedoch Veränderungen des Gehirns beziehungsweise des Kleinhirns für den Schwindel verantwortlich, handelt es sich um einen zentralen vestibulären Schwindel. Meistens empfinden die Betroffenen beim vestibulären Schwindel einen Drehschwindel.
Benign paroxysmal positional vertigo:
Diese Erkrankung ist für den Großteil der Schwindelbeschwerden verantwortlich. Hierbei kommt es zur Lösung von kleinsten Kristallen des Vestibularorgans, die sich in weiterer Folge in einem der Bogengänge ablagern und dort die Sinneszellen reizen. Bei Veränderung der Kopf- oder Körperhaltung werden die Kristalle bewegt und führen dadurch zu Schwindelattacken.
Neuritis vestibularis:
This is an inflammation of the nerve that carries information from the inner ear to the brain. Although this is the second most common cause of vertigo and therefore of clinical relevance, it has not yet been possible to clarify how the inflammation occurs. Those affected suffer from violent spinning vertigo and usually feel very ill. The symptoms can last up to four weeks, but usually disappear completely.
Vestibulopathy:
This refers to damage to the organ of balance. In addition to dizziness, sufferers report that objects in the environment move up and down when they walk (oscillopsia), appear blurred and can therefore no longer be easily recognised. The vertigo can be both a swinging and a spinning vertigo that can last from a few hours to over several days. Vestibulopathies can develop as a result of taking certain medications (for example, aminoglycosides, which belong to the group of antibiotics), but also as a result of meningitis. In some cases, no cause for the disease can be found.
Vestibular paroxysmia:
This disorder is characterized by short-lasting, recurrent attacks of vertigo. It usually involves a spinning or swaying vertigo that lasts for a few minutes. It is also typical that the dizziness is caused by certain head postures. The cause of this disease has also not yet been clarified, but it is assumed that the dizziness is caused by an incorrect wiring of the nerve pathways.
Meniére's disease:
In Meniére's disease, excessive accumulation of endolymph in the inner ear occurs for reasons that are not fully understood, resulting in so-called Meniére's seizures, which are characterized by sudden reduction in hearing, severe tinnitus, and spinning vertigo.
Basilaris migraine:
This is a special type of migraine in which there are recurrent migraine attacks characterized by dizziness, vision problems, difficulty walking and standing, and severe headaches.
Stroke and TIA:
In the context of a circulatory disturbance of the cerebellum, symptoms such as dizziness, nausea and vomiting, as well as coordination difficulties with gait and standing unsteadiness, sensory disturbances and speech difficulties may come.
Acoustic neuroma:
This is a benign tumor of the eighth cranial nerve, which transmits sensory information from the auditory and vestibular apparatus to the brain. The tumor arises from altered Schwann's cells, which are responsible for insulating the nerves.
Fracture of the petrous bone:
Accidents or falls can cause fractures of the petrous bone, a bone of the skull that surrounds and protects the vestibular organ. As part of the fractures, the inner ear can be injured, which can lead to vertigo.
Vestibular epilepsy:
This refers to a particular form of epilepsy in which there are seizures as well as dizziness and involuntary, jerky eye movements. Usually the dizziness occurs before the epileptic seizures.
Kinetosis- motion sickness:
Unaccustomed movements during ship travel, rapid car rides, or airplane turbulence can cause excessive irritation of the vestibular organ. Since no fixed points in the environment can be fixed with the eyes when reading in a car, on the high seas, or in an airplane, the brain cannot properly process the stimuli from the vestibular organ, resulting in the complaints of vertigo, as well as nausea and vomiting.
Non-vestibular vertigo:
This form of vertigo is not caused by diseases of the vestibular organ or neurological processing. For example, diseases of the cardiovascular system, such as severe changes in blood pressure (hypertension, hypotension), as well as cardiac arrhythmias, can lead to attacks of vertigo. Other causes of dizziness can be the intake of medicines, drug abuse or metabolic disorders. Common triggers of non-vestibular vertigo include low blood sugar (hypoglycemia) or accelerated breathing (hyperventilation).
Somatoform vertigo:
This is a form of vertigo in which no physical illness is detectable. In most cases, the affected person reports a variety of other complaints in addition to the dizziness, such as shortness of breath or constant fatigue. In most cases, a psychological change in the affected person is the cause of the symptoms. For example, depression or anxiety disorders can cause these symptoms without the affected person even recognizing the mental illness. It is also very typical that those affected visit a number of doctors without ever experiencing any real success in treatment.
Phobic vertigo:
This is the most common somatoform vertigo disorder. People between the ages of 30 and 50 are most likely to suffer from phobic vertigo. Patients report severe staggering vertigo, unsteadiness in walking and standing, often feel dizzy and have a constant fear of falling. The vertigo attacks are mainly triggered by psychological strain and stress, whereby even walking on bridges or even climbing stairs can be causative situations.