Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
While there are many causes of vertigo, the major distinction is between
central causes of vertigo and peripheral causes. Central causes occur because of
an abnormality in the cerebellum of the brain.
Distinguishing between central and peripheral causes for disease is an
important concept in evaluating neurologic problems. The brain and spinal cord
make up the central nervous system while the peripheral nervous system describes
the nerves outside the central area. Sometimes it is easy to make the
distinction, other times it is more difficult to distinguish between central and
peripheral causes. For example, if a person hits their funny bone (elbow) and
develops pain and numbness in their hand, it is mainly due to a direct blow to
the ulnar nerve at the elbow. This is a peripheral nerve problem and most people
would not seek medical care. If however, a person's leg became numb and weak,
the cause may be central (perhaps a stroke in the brain) or there may be a
peripheral cause (sciatica or nerve impingement).
Our orientation in space and, therefore, our balance or equilibrium, is
primarily measured by three sensory systems:
The eye (visual) system
The balance (vestibular) system of the inner ear
The general sensory system including motion, pressure, and position
(proprioception) sensors in joints, muscles, and skin.
These three systems continuously feed information to the brainstem and brain
about our position in space relative to gravity and the world. The brainstem
connects the brain to the spinal cord. The brain, in turn, processes these data
and uses the information to make adjustments of our head, body, joints, and
eyes. When all three sensory systems and the brain are properly functioning, the
final result is a healthy balance system.
Visual input shows the brain where it is in space, what direction it is
facing, what direction it is moving, and whether it is turning or standing
still. Simple tasks like walking and picking up an object are much easier if we
can see our surroundings. Feeling seasick is a problem resulting from a
miscommunication between a healthy visual system and a healthy inner ear
(vestibular) system. In this circumstance, the ears are telling the brain that
there is movement, while the eyes may be seeing the fixed surroundings of the
cabin. Changes in visual acuity, glaucoma, and cataracts are examples of visual
problems that in some individuals may be enough to give them a balance disorder.
Vestibular system
The inner ear, or labyrinth, is located deep to the outer ear and middle ear,
and is encased within petrous portion of the temporal bone of the skull.
Figure 1. Diagram of outer, middle, and inner ear. The outer ear is labeled
in the figure and includes the ear canal. The middle ear includes the eardrum
(tympanic membrane) and three tiny bones for hearing. The bones are called the
hammer (malleus), anvil (incus), and stirrup (stapes) to reflect their shapes.
The middle ear connects to the back of the throat by the Eustachian tube. The
inner ear (labyrinth) contains the semicircular canals and vestibule for
balance, and the cochlea for hearing.
The vestibular structures of the inner ear are the vestibule (which is made
up of the utricle and saccule) and the three semicircular canals. These
structures work somewhat like a carpenter's level (a tool used to show how
"level" a horizontal or vertical surface is) or a gyroscope. Information is sent
by way of the vestibulocochlear nerve to the cerebellum of the brain, the part
that processes information regarding body balance and position. The rest of the
inner ear, the cochlea, is concerned with hearing.
The vestibular system measures linear and rotational movement. A number of
disorders can cause this system to stop working or provide inappropriate
information. These disorders include
Meniere's syndrome, labyrinthitis, benign
paroxysmal positional vertigo, ear infections, tumors, or trauma.
Peripheral sensory system
The sensory system consists of motion, position, and pressure sensors in the
skin, muscles, and joints. These sensors provide important touch and position
information to keep us balanced. For example, if someone pushes you from behind,
a slight increase will occur in the activity of the pressure sensors in the ball
of the feet. As these sensors note the increased pressure, the brain is
notified, and it knows from experience that the body is being pushed forward.
The brain then uses this information to tell the body to shift a small amount of
weight backward to prevent the body from toppling forward.
Brain
The brain processes the information from the three sensory systems. Any
problem that interferes with the proper functioning of the central nervous
system (CNS) can lead to a balance disorder. Unlike the problems associated with
the three sensory input systems discussed above, however, with CNS problems, it
is unusual to have vertigo as the only symptom. The most common causes of
vertigo are peripheral and involve the inner ear or labyrinth.
Some of the most common causes of vertigo are listed below:
Benign paroxysmal positional vertigo (BPPV) may be caused when the crystals
in the inner ear become dislodged and irritate the semicircular canals. Often
the cause is not found but there may be an association with unusual positioning
or movement of the head. It is most frequently seen in people older than 60.
Labyrinthitis may follow a viral infection which causes inflammation within
the middle ear.
Meniere's disease is a group of symptoms associated with vertigo, hearing
loss and tinnitus or ringing in the ears.
Acoustic neuroma is a benign tumor of the ear that can present with vertigo.
Inner ear trauma may be due to a variety of mechanisms. A basilar skull
fracture may damage the labyrinth system directly or a
concussion, where that
area of the skull is shaken and may dislodge some of the inner ear crystals
causing symptoms of vertigo.
The inner ear may also be affected by barotrauma, a condition where pressure
changes may be the causes of damage and vertigo. This type of injury is seen
when an individual dives into water and the air in the external ear canal is
compressed and damages the ear drum, middle, and inner ear. Barotrauma may also
occur as a consequence of diving where an increase of air pressure within the
middle and inner ear can cause structures to rupture. This may cause loss of
hearing if the tympanic membrane ruptures or it may cause vertigo if the round
and oval windows in the inner ear are damaged.
Central causes of vertigo that arise in the brain are much less common.
Strokes, tumors,
seizures, and
multiple sclerosis may be associated with vertigo.
Vestibular migraines describe
migraine headaches associated with vertigo and
are a common cause of balance disorders. Migraine is a blood vessel (vascular)
disease characterized by periodic, usually one-sided, headaches. These headaches
are often preceded for a variable time by associated neurological symptoms,
called the aura. Vertigo may occur in individuals with migraine as part of the
migraine aura or separately. In younger patients, the vertigo may predate the
onset of headaches entirely. A family history of migraine is very common and may
be a clue that a balance disorder may be migraine related.
Vertigo (Dizziness and Vestibular Balance Disorders) - CauseQuestion: How was the diagnosis as to the cause of your vertigo (dizziness and vestibular balance disorders)?
Low blood pressure, also referred to as hypotension, is blood pressure that is so low that it causes symptoms or signs due to the low flow of blood through the arteries and veins. Some of the symptoms of low blood pressure include light-headedness, dizziness, or even fainting if not enough blood is getting to the brain. Diseases and medications can also cause low blood pressure. When the flow of blood is too low to deliver enough oxygen and nutrients to vital organs such as the brain, heart, and kidneys; the organs do not function normally and may be permanently damaged.
A brain tumor can be either benign (non cancerous) or malignant (cancerous), primary, or secondary. Causes and risk factors include age, gender, family history, and exposure to chemicals. Symptoms range from headaches, leg and feet numbness to seizures. Treatment is dependant upon the type and location of the brain tumor.
Dizziness is a symptom that is often applies to a variety of sensations including lightheadedness and vertigo. Causes of dizziness include low blood pressure, heart problems, anemia, dehydration, and more. Treatment of dizziness depends on the cause.
Migraine is usually periodic attacks of headaches on one or both sides of the head. These may be accompanied by nausea, vomiting, increased sensitivity of the eyes to light (photophobia), increased sensitivity to sound (phonophobia), dizziness, blurred vision, cognitive disturbances, and other symptoms. Treatments for migraine headache include therapies that may or may not involve medications.
Panic attacks are sudden feelings of terror that strike without warning. These episodes can occur at any time, even during sleep. A person experiencing a panic attack may believe that he or she is having a heart attack or that death is imminent. The fear and terror that a person experiences during a panic attack are not in proportion to the true situation and may be unrelated to what is happening around them. Most people with panic attacks experience several of the following symptoms: racing heartbeat, faintness, dizzyness, numbness or tingling in the hands and fingers, chills, chest pains, difficulty breathing, and a feeling of loss or control. There are several treatments for panic attacks.
A stroke results from impaired oxygen delivery to brain cells via the bloodstream. A stroke is also referred to as a CVA, or cerebrovascular incident. Symptoms of stroke include: sudden numbness or weakness of the face, arm or leg. Sudden confusion, trouble speaking or understanding. Sudden trouble seeing in one or both eyes, sudden trouble walking, dizziness, or loss of balance, and/or sudden severe headache with no known cause. A TIA, or transient ischemic attack is a short-lived temporary impairment of the brain caused by loss of blood supply. Stroke is a medical emergency.
Multiple sclerosis (MS) is a disease which progressively injures the nerves of the brain and spinal cord, reflected by alterations of virtually every sensory or motor function in the body. The cause of MS is primarily unknown. There are different types of MS including relapsing-remitting MS, primary-progressive MS, and secondary-progressive MS. Symptoms of MS rang from mild to severe and examples include visual disturbances, muscle weakness, spasm, and fatigue. Decreased concentration, memory loss, and impaired judgment. Treatment for MS is generally with medications.
Fainting, also referred to as blacking out, syncope, or temporary loss of consciousness has many causes. Often a person will have signs or symptoms prior to the fainting episode. Diagnosis and treatment depends upon the cause of the fainting or syncope episode.
Middle ear infection or inflammation (otitis media) is inflammation fo the middle ear. There are two types of otitis media, acute and chronic. Acute otitis media is generally short in duration, and chronic otitis media generally lasts several weeks. Seventy-five percent of children in the U.S. suffer from otitis media at some point. Treatment depends upon the type (chronic or acute).
Motion sickness, often referred to as car sickness, sea sickness, or air sickness, is a very common disturbance of the inner ear that is caused by repeated motion. The cause of motion sickness is complex. Symptoms of motion sickness include vomiting, nausea, dizziness, vertigo, sweating, and a feeling of malaise. Treatment of motion sickness include antihistamine medications such as meclizine (Bonine, Antivert, Dramamine), and scopolamine (Transderm Scop) a skin patch.
Orthostatic hypotension symptoms include lightheadedness, weakness, blurred vision, and syncope or passing out. Causes of orthostatic hypotension include dehydration, anemia, medication, blood loss, low blood pressure, heat related illnesses and more. Treatment of orthostatic hypotension depends on the underlying cause.
Trichinosis is a food-borne disease caused by ingesting parasites (roundworms) in undercooked pork or wild-game meat. Symptoms of trichinosis include diarrhea, nausea, muscle aches, itching, fever, chills, and joint pains. Trichinosis usually resolves without treatment, but more severe cases are treated with thiabendazole, albendazole, or mebendazole.
Meniere disease (idiopathic endolymphatic hydrops) is an inner ear disorder with symptoms that include vertigo, tinnitus, hearing loss, and the sensation of ear fullness. Diuretics, anti-vertigo, anti-nausea and low salt diets are the primary treatment for Meniere disease. Surgery may be recommended if the vertigo cannot be controlled with medication.
Balance is a state of body equilibrium or stability. We often take for granted how dependent we are on a healthy balance system. When the system breaks down, however, patients will describe symptoms such as dizziness, vertigo, lightheadedness, or motion sickness.
Arsenic comes in two forms, inorganic and organic. Organic arsenic poisoning is usually not poisonous to humans; however, inorganic arsenic in large enough amounts can lead to shock and death. Symptoms of arsenic poisoning include nausea, abdominal pain, diarrhea, dehydration, dark urine, vertigo, delirium, shock, and death. Treatment for arsenic poisoning includes Hemodialysis and a variety of drugs.
Noise-induced hearing loss may be an acoustic trauma (temporary hearing loss), or permanent due to an acute acoustic trauma. Experts agree that continual exposure to more then 85 dBs (decibels) is dangerous to the ears. Ear plugs and ear muffs can help prevent noise-induced hearing loss as well as decreasing exposure to loud noises.
Hearing loss (deafness) may be present at birth or it may manifest later in life. Deafness may be genetic or due to damage from noise. Treatment of deafness depends upon its cause.
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