Dizziness
Dizziness does not a represent a specific illness but rather the symptom of countless diseases of completely different origin. For instance, sleep deprivation, fluctuation of blood pressure and blood glucose level, viral infections, diseases of the vestibular system, brain tumor, disturbances of blood supply, injuries to the skull, concussion, eye disorders, sclerosis of the cervical vertebrae, etc.
Due to this bewilderingly complex picture, the symptom of dizziness requires complex medical investigation (with the involvement of an ear-nose-throat (ENT) specialist, a neurologist, and an internist).
Types of dizziness
Vertigo represents a condition where the patient actually feels that the world is spinning around him or her. This spinning movement always has a specific direction. The other forms of dizziness, such as unsteadiness (the patient walks wobbly, feels unstable, and fears losing balance) or feeling fainting (pre-syncope), that is a sensation of weakness, are often described as light-headedness.
The investigation of dizziness
First, it is important to clarify what the patient actually means by referring to dizziness. The physician can be helped in establishing whether the symptoms result from the disease of the vestibular system or other organs. If the examination suggests the disorder of the vestibular system, the next step is to decide whether the vestibular apparatus itself or the central nervous system can be found in its background.
Therefore, a specialist checks the visible parts of the ear to look for signs of an infection or injury, and a hearing test is also performed. The examination involves tests of standing and walking with closed eyes. Their results can be informative of the condition of the vestibular system. With examination of the ocular movements, the presence of abnormal rhythmic eye movements (nystagmus) is screened. If the patient's general condition makes it possible, the development of nystagmus is also tested by triggers (changes in the position of the head or posture, or caloric stimulation).
If a central nervous system disorder is suspected in the background, the investigation of the cerebral arteries, EEG, CT and MRI scans are also required.
Spinning dizziness (vertigo)
The vestibular organ consist of three annular (semi-circular canals) and two saccular (the utricle and the saccule) organelles. Its sensory cells send information about your body position and movements toward your vestibular centre in the medulla, which coordinates the tone of our muscles according to these stimuli. This way it regulates your posture and makes it possible to maintain a straight body position while standing or walking. The vestibular system is connected to the ocular muscles; therefore, you can follow the objects of your environment even upon turning your head. When the information, provided by the aforementioned organs is not completely harmonized, dizziness will develop. Vertigo is the most frequent form of dizziness (representing about 19% of all cases). It is caused by the disorder of the vestibular organ or its connection to the central nervous system in 80% of the cases. Changing the position of the head, such as sitting up or moving may worsen the symptoms sometimes leading to nausea and vomiting. Vertigo is usually accompanied by nystagmus.
Causes and treatment of the vertigo
Benign paroxysmal, positional vertigo (BPPV) represents harmless episodes of spinning dizziness, which are provoked by changes in the position of the head.
It develops, when the calcium carbonate crystals (otoliths) of the inner ear dislodge and migrate to the semi-circular canals, they stimulate the sensory cells of the canals. Dizziness typically develops upon turning the head, and characteristically it is of spinning nature, and it subsides in 15–20 seconds.
The symptoms are especially severe, when the patient turns in bed, or sits up in the morning. The disease is benign, and it resolves soon despite the alarming symptoms.
The treatment of the BPPV focuses on repositioning of the dislodged otolith from the symptomatic location to a new place where it does not cause irritation and can be absorbed over time. The most effective methods of treatment are special manoeuvres (Epley manoeuvre, Brandt–Daroff manoeuvre, Semont manoeuvre, and Lempert manoeuvre), which are sometimes complemented by medications. These exercises have to be performed till the patient cannot trigger the development of vertigo with changing the position of the head any longer. In dedicated patients, frequent exercising proves successful usually in 3–4 weeks.
Inflammation of the inner ear (acute vestibular neuronitis or labyrinthitis) may elicit intensive vertigo of abrupt onset, which can last for several days causing nausea and vomiting. The symptoms can be so severe that they may even confine the patient to bed for some days. Fortunately, vestibular neuronitis, usually spontaneously, resolves within a couple of days. With vestibular exercises, the recuperation process can be facilitated. Although the exact reason of the disease is unknown, a viral infection is suspected to be in the background.
Meniere's disease is caused by the accumulation of surplus fluid in the inner ear. The disease can appear at any age and typically causes episodes of vertigo, which last from 30 minutes to an hour. Furthermore, sensation of fullness, buzzing or ringing in the ear (tinnitus), and sometimes loss of hearing can develop. The cause of the disease is unknown. In its treatment, besides anti-dizziness medications administered in high doses, urine production has to be supported. Therefore, introduction of diuretics, changes in dietary habits, and aiming at low salt intake are recommended. Sometimes even surgical treatment may be considered as an option.
In the case of vestibular migraine-evoked vertigo, primarily migraine-trigger factors should be prevented. According to medical recommendations, the consumption of some specific food should be avoided. A decrease in stress level and a proper sleep schedule may also be helpful.
Medicinal treatment is also important in the alleviation of the symptoms of dizzy patients, and they might be helped to return to normal life. The applicable medications consist of vasodilators, antiepileptics and antiemetics.
Drugs which target the vestibular organ are used both for therapeutic and preventive purposes.