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Dizziness and Balance Disorders: Other causes of dizziness

Other causes of dizziness

Central dizziness
Vestibular neuritis and labyrinthitis
Perilymphatic fistula
Concussions
Central vertigo
Vertebrobasilar insufficiency (VBI)
Basilar-type migranes
Vascular compression syndromes
Vertebral artery compression

Central dizziness

Central dizziness is related to dysfunction of the central nervous system or brainstem, the computer part of your brain that coordinates movement information from various body systems.  Central dizziness is relatively less common than otologic dizziness; it is most often secondary to aging, small vessel ischemic disease (decrease of blood flow in the brain) and occasionally acute vascular events or other neurologic disease processes involving the cerebellum and brainstem.  This is more common in patients who are older.  Patients with central vertigo are often distressed by disorientation, imbalance or having unsteadiness with ambulation, occasional nausea, illusions of motion, and occasionally fainting (syncope).  Vestibular testing can document central pathology and MRI imaging is also very helpful in delineating this problem.  Vestibular therapy and occasionally medical therapy are often effective with this type of dizziness. Back to Top

Vestibular neuritis or labyrinthitis

Vestibular neuritis, more common than labrynthitis, refers to an inflammatory or irritative condition of the vestibular nerve or the end organs in the labyrinth.  This condition is felt to be caused by a viral infection.  However if there has been a disruption of the blood supply or metabolic change to the nerve or labyrinth, similar changes (to the nerve or labyrinth) will occur.  Vestibular neuritis usually has an acute onset of a spinning sensation (vertigo) with accompanying nausea and sometimes vomiting.  This can be very violent at times and leave one lying face down (prostrate).  It may require bed rest for several days.  There usually is a prior history of an associated viral illness.

With labyrinthitis, a hearing loss is generally expected to be present.  Generally there are two forms of labyrinthitis, suppurative and serous.  Suppurative labyrinthitis often occurs after an ear infection and requires antibiotics and steroids.  Usually a serious hearing loss results.  With serous labyrinthitis, as can happen with postoperative ear surgery, the hearing loss which occurs can resolve with steroids and time.  Technically the fluid in the inner ear is not infected in this condition, but frequently antibiotics are often used post-operatively. 

Diagnosis, treatment and prognosis
Use of vestibular (balance system) testing and imaging help to diagnose these conditions.  Bithermal caloric irrigation (testing of the superior vestibular nerve) or VEMP testing (evaluates the inferior vestibular nerve) will usually demonstrate a unilateral weakness.  An MRI scan may also show inflammatory changes on the nerve (e.g. increased signal intensity changes) with vestibular neuritis and in labyrinthitis.  Initial treatment often involves the use of labyrinthine suppressants.  After the acute phase is over, it is necessary to begin an exercise program of vestibular rehabilitation, which will allow the computer part of the brain to compensate for the irregular information it is receiving from the injured ear.  Most patients recover from severe vertigo and imbalance within 1 week.  However, like Bell’s palsy (which is caused by a virus), the symptoms can be rather protracted (lasting a long time) and residual symptoms may always be present.  However, most patients with vestibular neuritis have complete resolution.  Back to Top

Perilymphatic fistula

What is it and what causes it?
A perilymphatic fistula is an abnormal opening in fluid filled inner ear. Although rare, with increased exertion or severe straining, pressure changes can rupture one of the membranes in the inner ear and cause an abnormal leak of inner ear fluid (perilymph) into the middle ear.  This more commonly occurs around the oval window, but may occur also at the round window.  Head trauma is the most common cause of fistulas, usually involving a direct blow to the ear.  Fistulas may also develop following rapid or profound changes in intracranial or atmospheric pressure, such as may occur with SCUBA diving, or even just dives into a swimming pool.1  It usually will be seen more often in the ears that are congenitally malformed, such as a Mondini Dysplasia (malformed cochlea).  In this instance, the perilymph is mixed with cerebrospinal fluid (CSF).  Patients with the Mondini deformity and other congenital inner ear malformations are at an increased risk for developing recurrent meningitis or perilymphatic fistula.  They are predisposed to develop a CSF leak due to the enlarged cochlear aqueduct or an abnormal connection between the internal auditory canal and the membranous labyrinth.  Fistulas can occur in other congenital circumstances such as a dehiscence (opening) of the superior or posterior semicircular canals.  Cholesteatomas can also erode bone over the horizontal semicircular canal resulting in a fistula.  The bone deshiscenses over the semicircular canals are generally less bothersome than the oval or round window fistulae, as fluid is generally not in direct communication with an air-filled cavity, but a membrane is still present which maintains a seal.  Dehiscence is a very rare condition compared to most other causes of dizziness and hearing loss.  Back to Top

Head injury or concussion

A concussion is defined as an immediate acceleration and deceleration or stopping event, resulting in temporary or permanent damage to the structures of the head.  Concussions are the mildest form of brain injury and the Center for Disease Control (CDC) estimates at least 300,000 sports-related concussions occur in the United States each year.  Many concussions cause only temporary disruption of brain function and resulting problems fade within a week or two.  However, fully 60% of people who sustain a concussion still encounter neurological problems one-month post-injury.  Symptoms can include: disorientation, dizziness, nausea, blurred vision, loss of coordination and concentration, amnesia, and loss of consciousness.  The length of unconsciousness may relate to the severity of the concussion.

Second impact syndrome (SIS)
Second-impact syndrome (SIS) refers to the catastrophic events that may occur when a second concussion occurs while the athlete is still symptomatic and healing from a previous concussion.  The second injury may occur from days to weeks following the first.  Loss of consciousness is not required.  The second impact is more likely to cause brain swelling and other widespread damage, and can be fatal. Back to Top

Repeated Concussions
Even if SIS is not an established problem, there is NO debate that repeat concussions significantly worsen long-term outcomes.  After athletes sustain one concussion, they are three times more likely to sustain a second concussion compared to other players.  Repeat concussions, even when mild, can increase the risk of post-concussive symptoms (PCS) such as headaches, memory loss, difficulty concentrating, etc.  Chances of PCS are even more increased if the second injury occurs too soon, before recovery from the first has taken place.  The higher the rate of concussions, the higher the risk of long-term cognitive dysfunction.

Sports related concussions generally occur in collision/contact sports such as football, ice/field hockey, basketball, and soccer.  However their impact is also seen in sports ranging from baseball to gymnastics and in all recreational sports.  When people think of a concussion, their first instinct is to think of brain trauma, which is not always the case.  There are other structures within the head that are considerably more sensitive and more easily damaged that the brain; the vestibular system is one example. Back to Top

The brain has considerable amount of protection from the bony structure around it, and is generally associated with immediate and severe symptoms.  It does take a certain amount of force to damage the brain, and these injuries are usually seen in high velocity or high impact events.  The vestibular system on the other hand is rather easy to disrupt in general compared to the brain, and there is evidence that a large portion of concussional injuries are actually damage to the inner ear or vestibular system, rather that the brain.  A majority of common symptoms: dizziness, nausea, blurred vision, and coordination and concentration problems that are associated with a concussion can be directly attributed to the vestibular system.  Concussions should be evaluated with the understanding that there are different types of concussions.  No two concussions are the same and they need to be evaluated on individual basis.  Back to Top

The different types of concussions include: vestibular concussions, cerebral concussions, or a combination of both.  Both vestibular and cerebral concussions have similar symptoms, making it sometimes difficult to distinguish between the two.  The key to treating an athlete is differentiating between types of concussions and accurately diagnosing each injury.  The treatment for each type of concussion is often significantly different; incorrect treatment due to improper diagnosis may slow or prevent a full and safe recovery. Back to Top

There are three grades of concussion, based on the symptoms an individual displays after a suspected concussion:

  • Grade 1 concussions are defined by symptoms of transient (short-lived) confusion without amnesia, no loss of consciousness and concussion symptoms and/or mental status abnormalities that resolve in less than 15 minutes.
  • Grade 2 concussions are defined by having transient confusion with amnesia and concussion symptoms and/or mental status abnormalities lasting more than 15 minutes, although there is still no loss of consciousness.
  • Grade 3 concussions are usually quite easy to recognize, and this level of concussion is applied to anyone who experiences loss of consciousness regardless of the length of time and/or the appearance of the player.  Initial treatment for Grade 3 concussion - the most severe and serious of the Grades - calls for the individual to be transported to the nearest hospital.

Diagnosis
The diagnosis of a concussion is made by a combination of historical information, physical examination findings, and diagnostic testing that includes: neuropsychological testing, postural sway analysis, vestibular ocular reflex testing, audio-vestibular testing, and often imaging with a CT or MRI.  Both the central nervous system and vestibular system are evaluated using a combination of testing in the vestibular system, visual system, proprioceptive system, and /or coordination and reflexes.  Central nervous system concussions will often present both objectively and subjectively and demonstrate different patterns than vestibular concussions.  A vestibular concussion will have a very predictable abnormality, showing a specific correlation within a number of the diagnostic tests, allowing for an accurate identification of each injury. Back to Top

Treatment
The treatment for a concussion will vary greatly for each individual, as each injury may be significantly different and can fluctuate in both the severity and duration of symptoms.  As a result, treatment will include stabilization of the injury, medication, rest, or specialized vestibular or visual exercise program.

Prognosis
The aim of treatment is to prevent the symptoms of a concussion from worsening, as they initially do over the first three-day period, and then correcting them from having a negative impact on the athlete’s life.  If a concussion is seen within the acute period (generally the first 12-72 hrs), a majority of the lingering symptoms can be prevented from occurring.  After this acute period, if no treatment is given, the central nervous system and other systems begin to compensate for the injury, creating periods of “good and bad days”.  This cycle can continue for days, months, or years.  A concussion having long lasting effects is commonly referred to as the post-concussion syndrome and can be treated with a similar method – stabilization of the vestibular system and retraining of all the sensory input systems.  The process of retraining a stable vestibular system allows the sensory systems of the body to more effectively coordinate the individual activities with one another and the external environment.  As a result treatment protocols are very individualized and tailored to each patient based on their specific needs.

Occasionally with a very severe blow to the head, the computer part of the brain can be bruised (a contusion) and cause persistent or permanent imbalance.  Initially, it is often helped with the use of medical therapy.  After the acute injury, it is useful to stimulate repair of this system through exercise.  Long term use of some medications is felt to prevent central compensation.  The patient with this type of problem can expect to see slow improvement after the injury. Back to Top

Cervical vertigo

When dizziness or vertigo occurs as a result of neck pathology, the diagnosis is referred to as cervical vertigo.  With cervical vertigo, the symptoms are associated with neck movement.  There should be no associated hearing loss, but only dizziness or lightheadedness with neck movement (usually looking upwards).  Physiologically, there are many potential causes of cervical vertigo including vascular compression of the vertebral artery (due to degenerative changes in the spine), abnormal or loss of sensory input from neck proprioceptors.  Sensory information from the neck is combined with vestibular and visual information to determine the position of the head on the neck and in space(??).  Neck trauma from surgery, blunt trauma, or whiplash injuries are also causative factors.  Diagnosis of cervical vertigo includes hearing and balance testing and vertebral angiography studies (x-ray of the arteries).  Cervical cord compression can also lead to complaints of dizziness, as associated spinal tracts can be affected with neck movements. Back to Top

Vertebrobasilar insufficiency


Vertebrobasilar insufficiency is a condition characterized by poor blood flow to the posterior (back) portion of the brain, which is fed by two vertebral arteries that join to become the basilar artery.  The vertebrobasilar arteries supply oxygen and vital nutrition to parts of the brain responsible for many essential functions.  Decreased blood flow and/or the complete blockage of it (called ischemic events), have serious consequences for brain cells.  A transient ischemic attack (TIA), or “mini-stroke,” is an ischemic event that results in the temporary loss of brain function.  If the resulting loss of brain function is permanent, it is referred to as a stroke (an infarction).  Symptoms of vertebrobasilar insufficiency (VBI) may last for a few minutes or be permanent and include:

  • Partial or complete loss of vision in both eyes
  • Double vision
  • Vertigo (spinning sensation)
  • Numbness or tingling
  • Nausea and vomiting
  • Slurred speech
  • Loss of coordination, dizziness or confusion
  • Trouble swallowing
  • A drop attack — sudden generalized weakness

Studies of the vertebral and basilar arteries can be performed using magnetic resonance angiography (MRA) and standard angiography (X-ray study using injected dye).  A CT or MRI scan of the brain can be used to confirm that a stroke has already occurred.

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Basilar-type Migraine

What is it?
Basilar-type migraine has been described by the Headache Classification Committee of the International Headache Society as a migraine with aura symptoms clearly originating from the brainstem or from both occipital lobes.  The aura phase of the migraine (usually a bilateral visual disturbance) is due to transient brainstem and cerebellar ischemia, which can be mistaken for a transient ischemic attack of the vertebrobasilar circulation.  It rarely has any associated motor weakness, and can affect all age groups as well as both sexes although there is a female predominance.  It is thought that the vertebral and/or basilar arteries or their branches have abnormal reactivity, and are prone to cycles of constriction and dilatation, hence causing the headache and the neurological impairments. 

What happens?
Visual symptoms are followed by varying combinations of ataxia, dysarthria, bilateral vertigo, tinnitus, changing levels of consciousness, bilateral paresthesias of the limbs, face, and tongue, and quadriparesis (complete paralysis of all four limbs).  Other brainstem-related   symptoms less commonly noted include nystagmus, diplopia (double vision), and decreases in hearing.  The symptoms noted in the aura phase of the basilar artery migraine are the result of a combination of disturbances in the cerebellum, brainstem, and occipital lobes, which generally last for less than one hour.  The headache phase of the basilar migraine consists of a severe, throbbing, acute occipital (back of the head) headache.  As with all migraines, Basilar-type migraines can be very debilitating.  Unfortunately, two classes of migraine medications commonly used in other migraines, the ergotamines and the triptans, cannot be used in basilar migraines due to the risk of stroke. 

Diagnosis/classification
The Headache Classification Committee of the International Headache Society has proposed the following for basilar migraine.  An individual must have at least two attacks meeting the following criteria:

Aura symptoms – at least one of the following indicating cortical or brainstem dysfunction:

  • at least one aura symptom develops gradually over five or more minutes and/or different aura symptoms occur in succession over five or more minutes
  • each aura symptom lasts between five to 60 minutes

The patient must demonstrate two or more aura symptoms of the following types:
  • Double vision
  • Visual symptoms in both the temporal and nasal fields of both eyes
  • Dysarthria (impairment or clumsiness in speaking of words)
  • Vertigo
  • Tinnitus
  • Decreased hearing
  • Double vision (diplopia)
  • Ataxia (uncoordinated movement)
  • Bilateral paresthesias (abnormal sensation of numbness, burning, prickly feeling)
  • Bilateral paresis (weakness or loss of movement of the limbs)
  • Decreased levels of consciousness

Headache symptoms
  • a migraine headache that must occur within 60 minutes of the end of the aura, if it
    occurs at all
  • the aura symptoms disappear with the onset of the migraine headache

Infarctions are well-recognized complications of the more common forms of migraine and are among the most frequent causes of strokes in young adults.  Patients with basilar migraines should avoid risk factors such as smoking, and the use of oral contraceptives.

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Vertebral artery compression


The vertebral artery travels through the bones in the neck and supplies circulation to the back of the brain and brainstem.  Rarely, extra movement between the vertebrae and or bone spurs can press on the artery when moving the head or neck.  Vertebral artery compression as described above can cause dizziness, nausea, lightheadedness or even fainting.  Treatment requires surgery to remove the offending bone that compresses the artery.

 

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