os textos aqui apresentados são redigidos em desacordo com o Acordo Ortográfico #AO90







terça-feira, 23 de agosto de 2011

da minha experiência vertiginosa - para quem não sabe o que é...

Vertigo: Related Terms
Objective Vertigo, Pathological Vertigo, Physiological Vertigo, Subjective Vertigo, Vertiginous Syndrome


Differential Diagnoses

Acute cerebellar lesions
Brain stem ischemia or infarctions
Cerebellopontine angle lesions
Cervical spondylosis
Hyperventilation
Panic disorders
Parkinson's disease
Perilymphatic fistula
Seizures
Stroke
Syncope
Vertebral basilar artery insufficiency
Vitamin B12 deficiency


Specialists: Neurologist, Otolaryngologist


Comorbid Conditions:

Central nervous system tumors
Diabetes
Immune system disorders
Lupus erythematosis
Multiple sclerosis
Post-traumatic stress disorder
Rheumatoid arthritis
Sjögren's syndrome
Stroke


Factors Influencing Duration

Duration depends on the type of vertigo, the underlying cause for the vertigo, the individual's age and response to treatment, and the extent, if any, of complications. Acute vertigo is self-limited with a duration of a few days. Chronic vertigo may persist indefinitely.


Definition

Though sometimes inaccurately called "dizziness," vertigo occurs because of a disturbance in the system for balance in the body (vestibular system). Vertigo is a unique symptom related to specific diseases of the nervous system (central nervous system: pathologic vertigo) or a mismatch in the body's normal systems of balance and position (peripheral nervous system: physiologic or positional vertigo). Vertigo is a rotating sensation giving individuals the false impression that their surroundings are spinning or moving. Examples of physiologic vertigo are seasickness, carsickness, and height vertigo.
A sudden (acute) attack of vertigo is usually due to inflammation of the semicircular canals of the inner ear (nonspecific labyrinthitis), possibly of viral origin. Generally, the attack is self-limited. Ongoing (chronic) vertigo occurs almost daily and usually indicates the presence of a serious disease.
The principal causes of vertigo are Ménière's disease, adverse reactions to drugs (gentamicin, anticonvulsant intoxication, certain antibiotics, etc.), toxins (notably alcohol intoxication), vestibular neuronitis, multiple sclerosis, vestibular migraine, an abnormal connection between the inner and middle ear spaces (perilymphatic fistula), and an imbalance created by certain head positions or movement (benign paroxysmal positional vertigo, or BPPV). Head trauma, upper respiratory infection, hypothyroidism, and diabetes may be associated with the disease. Since balance is partially maintained by receptors in the neck that sense position in space, trauma to the neck can also cause vertigo. Tumors can occur on the nerve for hearing in the ear (acoustic neuromas).
Autoimmune disorders such as rheumatoid arthritis, dry eye syndrome (Sjögren's syndrome), ulcerative colitis, Wegener's granulomatosis, scleroderma, allergies, systemic lupus erythematosus, and Cogan's syndrome may cause symptoms including vertigo. Autoimmune damage can be confined to the labyrinth, causing vertigo and hearing loss as isolated symptoms. Steroids and other hormones affect the peripheral vestibular system involved in balance, which may be one mechanism contributing to the symptom of vertigo.

Risk: Females may be at slightly greater risk than males for benign paroxysmal positional vertigo (BPPV).

Incidence and Prevalence: Dizziness is the third most common complaint for persons seeking outpatient care. Overall, the prevalence of dizziness, imbalance, and vertigo in the general population is 5% to 10%, rising to 40% for those over age 40 (Hamid).

BPPV is estimated to be the most common single cause of vertigo in the US (Li). Approximately 3,000 acoustic neuromas occur each year in the US. Vertigo is present with migraines in about 30% of individuals (Hamid).



Source: Medical Disability Advisor



Diagnosis

History: The individual's primary complaint usually is a sudden sensation that surroundings are spinning or moving (vertigo). Headache, nausea and vomiting, and blurred vision due to jerking eye movements (nystagmus) are common if inflammation of the semicircular canals of the inner ear (labyrinthitis) is the cause. The individual may report problems after use of prescription or other types of drugs. Vertigo may also occur within 24 hours after alcohol intake. Sudden onset may occur while the individual is lying on one side or looking up, with symptoms sometimes resolving in less than a minute. Movement may cause vertigo. It is important to determine if symptoms are those of true vertigo, or lightheadedness and fainting (syncope).

The individual may complain of vertigo after flying or after a prolonged drive in the mountains. Individuals with vertigo caused by sudden rupture of a part of the inner ear (round window of the cochlea) may report symptoms following intense physical exertion such as calisthenics or scuba diving. Other general complaints may include hearing loss, ringing in the ears (tinnitus), falling, or temporary (transient) blindness.

In vertigo originating from the central nervous system, the individual may report a more gradual onset with less intense symptoms.

Physical exam: An active or resolving upper respiratory infection with runny nose, nasal congestion, sore throat, and cough may be evident. Exam may reveal the presence of jerky eye movements (nystagmus). Individuals may have hearing loss on audiogram, eye movement difficulties, facial weakness, or difficulty speaking. Observations of the individual engaged in heel-to-toe walking and touching the nose or standing while the eyes are closed (Romberg's sign) could reveal an unsteady gait, difficulty maintaining equilibrium, and a poor sense of orientation in space. Special positioning maneuvers designed to bring on symptoms (Dix-Hallpike test and Nylan-Barany maneuvers) may be helpful.


Tests: For definitive diagnosis of the underlying cause of vertigo, tests include audiometry, equilibriometry, brain CT scan, and specific testing of the balancing function of the inner ear (caloric stimulation, electronystagmography and posturography). A rare diagnosis of perilymphatic fistula is confirmed with exploratory perforation of the eardrum (tympanotomy). A vascular analysis (angiography) may be needed to determine possible blood flow abnormalities. Neck x-ray or MRI may be indicated to evaluate for musculoskeletal trauma as a cause for vertigo (cervicogenic vertigo) or acoustic neuroma. Three-dimensional analysis of eye movement helps determine the type of nystagmus (infrared nystagmography), which in turn may localize the neurological abnormality causing the vertigo.


Source: Medical Disability Advisor



Treatment

Treatment involves finding and eliminating the cause of vertigo. For example, cerebellopontine angle tumors may be surgically removed, and autoimmune disorders and multiple sclerosis may be treated with appropriate medications. If no neurologic or metabolic defect can be identified, bed rest for 2 to 3 days is effective as the principal treatment in most cases. For those with benign paroxysmal positional vertigo (BPPV), bed rest often involves maintaining the head in a specific position in order to alleviate symptoms that may occur with position changes. In addition, antivertiginous and/or antinausea drugs may be prescribed. Life style changes, pain relievers, or medications aimed at reducing migraine symptoms may be needed for individuals with headaches; however, eliminating medications with potential vertiginous side effects is a first line of treatment.

Positional vertigo is inconvenient but rarely a serious problem unless the individual's occupation depends on good balance or certain physical maneuvers. In this case, even short episodes of vertigo may be disruptive since the most common treatment is to avoid positions or activities that cause the symptoms.

Individuals with Ménière's disease may be treated with diet or diuretics to reduce fluid in the ears. Decompression chamber therapy also may help restore correct pressure balances in the inner ear. In some conditions, short-term use of steroids may relieve inflammation of nerves in the inner ear. Specific maneuvers or physical therapy may be recommended for certain types of positional vertigo.

Various surgical options may be considered in extreme, unresolved cases of vertigo, including relief of pressure in the inner ear (endolymphatic sac surgery, cochleosacculotomy, and microvascular decompression), removal of certain sensory tissue and nerve fibers (labyrinthectomy), sectioning selected nerves (middle cranial fossa, retrolabyrinthine, retrosigmoid, translabyrinthine), pulling away (avulsion) a selected nerve (singular neurectomy), and sealing the inner ear semicircular canal (posterior semicircular canal occlusion).

Source: Medical Disability Advisor

Sem comentários: