Vertigo

Vertigo

Vertigo is a distressing condition which can accompany several medical conditions. It can be mildly uncomfortable, or it can be severe and totally disabling. It can accompany the common cold, or it can be due to other underlying problems. By definition, it is the sensation of a spinning movement. When the person affected feels like he is moving, it is called subjective vertigo. When he feels as if the environment around him is moving, it is called objective vertigo.
The mechanism for balance is a delicately arranged combination of the sensors in the middle ears, and the brain mechanisms which interpret their signals. When the spinning sensation comes from abnormal function in the middle ear sensing mechanism, it is called peripheral vertigo.
When it occurs from a faulty brain mechanism, it is called central vertigo. Since one purpose of the mechanism is to keep the eyes focused while the head is moving, there is a complex pathway to the eye movement center called the vestibular-ocular reflex -- this is called Barneys test. Barneys test is performed by laying the person on their back with shoulders on the edge of the examining table and head lying backwards with the patient trying to look over their head. The doctor sits on a stool and tells the patient not to move the skull at all. He places his finger one foot from the nose then tells the patient not to move the skull and tells the patient to look at the tip of the doctor's finger. He then takes his hand far right quickly and stops at the very edge of visual field and looks at the patient's eye, holds the finger for 10 seconds. He then repeats this to the opposite side.
If the person is normal, the eyes look right and left. However if the patient is positive for Barneys when the finger is brought to the far edge right and left of the patient's head the eye oscillates -- it goes back and forth, right and left 2-5 times per second at this extreme right and left. This is called nystagmus. The nystagmus only occurs to the side where the inner ear's semi-circular canals are irritated and define the cause of peripheral vestibular labyrinthitis or vertigo and it shows the side of the affecting problem. When there is vertigo, most of the time there is abnormal eye movement called nystagmus which can be observed and used in the diagnostic process.
The sensing organs for balance lie within the middle ear and consist of the semicircular canals, the otolith organs of the utricle, and the saccule. The 8th cranial nerve carries signals of movement to areas of the brain including the cerebellum based on movement of the fluid within these organs. A number of things can affect the balance organs. There can be infection within them, there can be too much fluid, or there can be a tiny stone bouncing around within, giving errant signals. The nerve can become inflamed or a tumor can develop just involving the nerve.
One very uncomfortable condition of the peripheral organ is Meniere 's disease. It is thought to arise from too much endolymph fluid. It causes temporary hearing loss, progressive ringing in the ear, and the severe spinning sensation of vertigo and often progresses to deafness. It tends to come on very rapidly, and then can completely go away for periods of time. The most common form of peripheral vertigo is BPPV, or benign positional paroxysmal vertigo. It is usually initiated by rapid head movements, can be caused by an infection or a stone. It can usually be treated with medicines like meclizine, and often clears up with special head positioning movements and exercises.
The brain mechanisms which can cause vertigo are found largely in the cerebellum. One particular condition which can lead to central vertigo in this area is cardiovascular disease where there are problems with blood flow. The most severe form of this would be a stroke either from too little blood flow or a focal hemorrhage. These symptoms seem to be more persistent and less specifically severe than peripheral vertigo. The problem is that things which cause central vertigo can lead to severe disability and death. Whereas, peripheral disease causes are not usually life-threatening. The diagnostic tests for central vertigo might be a CT scan or MRI, and treatment might be directed toward reducing cardiovascular risks. There are symptoms of central vertigo which can be ominous and need immediate evaluation such as double vision, difficulty with speech, difficulty with movement of the arms and legs, changes in level of consciousness, or severe headache.
Some other causes of central vertigo might be that which precedes a migraine headache. Sometimes vertigo can be psychogenic caused by severe stress effects of anxiety and depression upon the brain. Sometimes it can be a symptom of neurodegenerative disorders like multiple sclerosis or certain trauma. The Sarin gas attack victims in the Tokyo subway had very specific vertigo episodes after the injuries sustained in that event. The vertigo attacks of the Gulf War Syndrome victims are likewise thought to be due to brain injuries from neurotoxins.
So what's the take-home message? Well, vertigo is a common symptom usually caused by self-limited illnesses like viral infections, though there can be many other causes. There are effective treatments in pills or patches which can control the symptoms. A person needs to be careful when having vertigo so as not to fall or be involved in an auto accident. Rest and no movement are essential foundations of treatment. Most cases of vertigo can be managed by the primary care physician, though; some will need to be referred to a neurologist or an ear/nose/throat specialist (ENT). There are warning signs with vertigo which need urgent evaluation, particularly when they suggest a stroke. There are other treatment modalities, particularly with peripheral vertigo, which can bring long-lasting relief of symptoms, like diuretics for Meniere's or positioning exercises or maneuvers for BPPV. All in all, it's probably best to see your doctor right away if you have vertigo.
John Drew Laurusonis, M.D.