About Dizziness

Overview

Dizziness is a common symptom, experienced at least once a year by 20% of adults. It is more than twice as common in women as in men,

and increases with age. Patients who complain of dizziness describe it in various ways, such as a spinning sensation, a feeling of about to faint, a swaying sensation, a feeling of being about to collapse to one side, a lightheaded feeling in the head, or vertigo.

Because the symptoms are so varied, an accurate diagnosis is often difficult. The main organs associated with dizziness are the ear (peripheral), brain (central), heart, and eyes. Even if dizziness is severe, it may not be due to a serious disease, and even if the intensity is mild, there are cases that require surgery or intensive care, such as abnormalities of the central nervous system,

so an accurate differential diagnosis is necessary.

For diagnosis, it is important to take a history of the situation and sensations the patient experienced at the time of the dizziness. In particular, it is necessary to distinguish between rotational and non-rotational dizziness, and the patient should explain to the doctor the duration of the dizziness, the circumstances of onset, triggering factors, accompanying symptoms, and past medical history. However, in some cases it is difficult for the patient to explain their situation and sensations because of the dizziness, and depending on the case, physical and neurological examinations may worsen the dizziness and make the patient feel worse; nonetheless, for an accurate diagnosis, a detailed history of the symptoms and physical examination are very important.

Cause

There are several ways to classify dizziness. Depending on the cause, it can be broadly divided into central nervous system disorders and peripheral vestibular disorders, and according to symptoms, it can be divided into vertigo (rotational dizziness), syncope (fainting dizziness), and balance disorder. Here, the causes will be classified according to symptoms.

1. Vertigo

The patient complains that they or their surroundings are spinning. The cause can be divided into peripheral and central vestibular disorders. Peripheral refers to abnormalities of the inner ear (cochlea, semicircular canals) and vestibular nerve that maintain balance, while central refers to abnormalities in the cerebrum, cerebellum, brainstem, etc.

1. Peripheral vestibular disorders

Causative diseases include benign paroxysmal positional vertigo, vestibular neuritis, Meniere's disease, labyrinthitis (inner ear inflammation), cholesteatoma, and perilymph fistula. Most patients with acute rotational dizziness are known to have peripheral vestibular disorders, and among them, benign paroxysmal positional vertigo is the most common cause of dizziness. If there is a problem with the inner ear, symptoms such as hearing loss, tinnitus, and ear fullness may accompany the dizziness.

① Benign paroxysmal positional vertigo: Brief, repeated rotational dizziness occurs when the position of the head changes, such as when lying down in bed or getting up, or turning over while lying in bed. The duration of each dizzy spell is usually short, less than 1 minute.

② Vestibular neuritis: Dizziness occurs suddenly, and is usually accompanied by nausea and vomiting, with unsteady walking. The dizziness remains even at rest and may worsen with changes in posture. Symptoms last from several days to several weeks, but most improve within 1 week.

③ Meniere's disease: Tinnitus, ear fullness, and decreased hearing in one ear occur, followed by sudden attacks of rotational dizziness that last from several minutes to several hours. In the early stage of a dizziness attack, nausea and vomiting may accompany the dizziness, similar to vestibular neuritis.

2. Central vestibular disorders

Cases in which dizziness is accompanied by central vestibular dysfunction include vestibular migraine, stroke caused by blockage or rupture of a cerebellar artery,

basilar artery occlusion, vertebral artery dissection, tumors at the skull base, and multiple sclerosis. In particular, cerebellar artery infarction may be accompanied by dizziness, severe postural instability, and hearing loss. If, in addition to dizziness, there is chronically impaired balance, unsteady posture, or hearing loss, a cerebellar artery stroke should be suspected. In particular, if there are visual abnormalities such as double vision or weakness in one arm and leg, a central cause should be suspected.

2. Syncopal dizziness

The patient complains of a feeling of losing consciousness or feeling faint. A drop in cerebral blood flow causes syncope with sudden loss of consciousness for a short period of time, but most cases recover spontaneously. Causes include vasovagal syncope, in which increased parasympathetic activity slows the pulse (bradycardia) and sympathetic activity is suppressed, causing vasodilation and reduced cerebral blood flow, and orthostatic hypotension, in which blood pressure drops when standing up suddenly due to autonomic reflex dysfunction. Heart-related causes include arrhythmia, structural abnormalities of the heart, and decreased cardiac output. Rarely, syncope can also occur with hypoglycemia, which is unrelated to cerebral blood flow.

Orthostatic hypotension is dizziness that occurs when suddenly standing up from a lying or squatting position, as the amount of blood returning to the heart from the legs and viscera decreases, which in turn reduces the amount of blood pumped from the heart back to the brain. It occurs when the sympathetic nervous system does not respond appropriately to postural changes.

If syncope recurs repeatedly for no known reason, psychogenic syncope should be considered. Prodromal symptoms such as a faint feeling before loss of consciousness, dizziness as if about to lose consciousness, vertigo, visual disturbances, and hearing abnormalities are commonly accompanied.

The most common cause of psychogenic syncope is hyperventilation syndrome, and emotional disorders such as anxiety, depression, neurosis, and hysteria are often the cause. In addition, syncope (lightheadedness) may appear as a symptom of fasting hypoglycemia, and syncope (lightheadedness) may occur after exercise in cases of severe anemia. Unrealistic sensations such as feeling like the head is spinning, swaying, feeling faint, feeling like the body is floating,

feeling detached from the body, or fear of falling are reported.

3. Dizziness due to balance disorder

It can occur due to abnormalities in places responsible for motor transmission, such as the cerebellum, frontal lobe of the cerebrum, basal ganglia, and proprioception, or due to medications, Parkinson's disease, alcohol abuse, etc. In rare cases, it can also occur due to hypothyroidism, hypoglycemia, peripheral neuropathy, myopathy, hysteria, and others. There may be no symptoms when lying down or sitting, but this is a type of dizziness in which the person staggers, loses balance, or falls when standing or walking.

So far, I have explained dizziness.

In the next part, we will look at the diagnosis and treatment of dizziness.

Source: National Health Information Portal, Korea Disease Control and Prevention Agency