When you think of being dizzy, what comes to mind? Light-headedness? Nausea? Headache? A sensation of the room spinning around you? Or the floor tilting under you? Or a feeling of general "spaciness?" The term dizziness can encompass any of these sensations, and getting to the bottom of the cause, and figuring out appropriate treatment, requires some investigation. Many people with chronic headaches experience symptoms of dizziness that too often go untreated. Some patients with dizziness can benefit from physical therapy, and this article will help shed some light on the types of treatment available, and what to expect in terms of improvement.
The term "vertigo" refers to a sensation of spinning, tumbling, falling backward or forward, or of the ground rolling beneath one's feet. The presence of vertigo suggests a vestibular disorder. Sensations of imbalance, lightheadedness and syncope (fainting) are usually due to disorders not within the vestibular system. We will focus here on the causes and treatments available for vertigo. One of the first things your practitioner must determine is whether your symptoms represent peripheral or central nervous system problems.
Peripheral Disorders
Peripheral symptoms are those which involve either the cervical spine (neck) or the peripheral vestibular system, located in the inner ear. The peripheral vestibular system consists of looping canals and spirals which house tiny hair cells and are filled with a syrup-like fluid called endolymph. The movement of endolymph within those canals deflects the hair cells in different directions, depending on the movement of your body or your head. The vestibular nerve then carries the signals from the hair cells to your brain, telling you which way you are moving and how fast. Any problems with this system can result in faulty signals to the brain, causing a sensation of movement when you are actually still.
One disorder that affects the inner ear is called vestibular neuritis. This is inflammation of the vestibular nerve, usually caused by a virus and often preceded by a cold. This disorder usually resolves by itself as the body fights off the virus, and does not require physical therapy treatment. Meniere's Disease is another peripheral vestibular disorder caused by a problem with reabsorbing the fluid in the inner ear. Causes of Meniere's Disease can be viral, traumatic, or idiopathic (which means unknown, or not related to any specific event). Symptoms are usually episodic (come and go), and can range from a mild feeling of fullness in the ear to severe vertigo. In addition, people often complain of tinnitus (ringing in the ear), hearing loss, and balance problems. Treatment may include restriction of salt, water, caffeine and nicotine, as well as medications or possibly surgical procedures. Physical therapy is not generally indicated for Meniere's Disease, as it is episodic, and the episodes are more likely to be aggravated by therapy than helped.
A relatively common peripheral vestibular disorder that is amenable to physical therapy treatment is called Benign Paroxysmal Positional Vertigo (BPPV). In the most common form of this disorder, canalithiasis, small crystals within the canals in the inner ear have broken free of their normal positions and are floating freely in the endolymph, deflecting hair cells and creating faulty sensations of movement. Patients will feel relatively severe symptoms of vertigo with certain movements of the head or changes in position, and these symptoms will last approximately 30-60 seconds, and then fade. The reason for the short duration is that upon movement of the head, the crystals in the endolymph begin to move, and it takes about 30-60 seconds for them to settle down into a new gravity-dependent position. If the symptoms last longer than 60 seconds, it could be a more rare form of the disorder (cupulolithiasis), which means the crystals have reattached themselves in their new position.
Treatment for BPPV involves very specific maneuvers designed to reposition the crystals back into their appropriate positions. Some physicians and some physical therapists are trained in performing these maneuvers which usually only need to be performed once or twice. The maneuvers themselves produce dizziness, but it is short-lived. Following treatment, the patient must minimize head movement for 48 hours, and sleep in a reclined position (not flat or in side-lying) for 2 nights in order to allow the crystals to completely settle back into their positions. Sometimes, if the patient had BPPV for a very long time, further physical therapy may be required to treat any residual dizziness symptoms (this will be described in more detail below).
In addition, the neck can cause dizziness. This is called cervicogenic vertigo. Usually, though not always, this is a result of some sort of injury to the neck. There are nerve roots in the cervical spine which provide information to the central nervous system (the brain) regarding head position. If these nerve roots are affected, vertigo and imbalance can result. Physical therapy is generally the first line of treatment for cervicogenic vertigo, and works to normalize muscle tone, range of motion of the neck, and alignment of the cervical spine.
Central Disorders
Disorders involving the central nervous system can cause vertigo as well. These can include brain stem vascular disease, acoustic neuromas, tumors of the brain stem and cerebellum, multiple sclerosis, vertebrobasilar migraine, stroke, head trauma, and systemic diseases such as those affecting the kidney or thyroid. Vertigo caused by central disorders tends to be more chronic, constant and disabling. Intensity can fluctuate, and the symptoms can be present even at rest. When dizziness is strictly migrainous ("migrainous vertigo"), it occurs in conjunction with migraine headache, but not necessarily when a person is headache-free.
The cerebellum and the vestibular cortex are parts of the brain involved with processing vestibular information. Various nerves (including the vestibular nerve, cervical nerve roots, and ocular nerves) bring information in to these areas of the brain. In addition, motor nerves exit these areas and help to control muscles of the eyes, head and neck, and even hips and legs, to help people adjust their balance based on vestibular information.
In physical therapy, we evaluate chronically dizzy patients for multiple issues. First, we assess risk of falling. If an individual is having frequent falls or near-falls, safety issues must be addressed right away. Assistive devices such as canes or grab-bars may be required, and balance exercises may be instituted. Secondly, we generally begin a program of habituation exercises.
Habituation exercises are important for patients with chronic vertigo, as they have often responded to their symptoms with compensations, both conscious and unconscious. For example, if turning one's head rapidly creates vertigo, an individual will begin to move more slowly in order to avoid it. If walking down the aisle in a grocery store increases symptoms, a person may take care to keep his head stationary and his eyes fixed on a stationary point at some distance, to minimize vestibular input from the eyes. Over time, these compensatory changes in behavior result in less input into the vestibular system overall. Unfortunately, this has the unwanted result in making the vestibular system even more sensitive to input.
To illustrate this phenomenon, think about how your eyes adapt to light and dark. If you exit a dark movie theater after 2 hours, and walk into a bright day, it might feel uncomfortable for a few moments. So instead of letting your eyes adjust, let's say you put on very dark glasses, to minimize that discomfort. And let's say you dimmed your lights at home when you took off the glasses... see where this is going? If you continue this for weeks or months, eventually, the eyes are going to have a very difficult time adapting back to a bright environment. They have adapted to their new (darkened) surroundings.
The same thing happens with the vestibular system. It becomes sensitized. This can even happen in patients with no related central nervous system disorder, who have just been bed-ridden for long periods of time due to other illnesses or injury. Habituation exercises are designed to desensitize the system. Your physical therapist will begin at whatever level is tolerated, and gradually progress the exercises as symptoms improve. Exercises may involve something as basic as keeping your eyes fixed on an object in front of you as you move your head back and forth, or moving your eyes back and forth rapidly from one object to another. They may include walking while moving your head from side to side, or trying to balance on an unstable surface while watching a moving target. Basically, the exercises are customized to each individual patient, with the goal of gradually increasing input into the vestibular system, within the patient's tolerance. The exercises will cause some dizziness symptoms to occur, which can be uncomfortable. But the long-term goal is an overall reduction in symptoms.
Conclusion
Symptoms of vertigo, whether chronic or acute, should be reported to one's treating physician so that they can be thoroughly evaluated. In addition, frequent episodes of falls or near-falls should also be examined to determine if vertigo may be a treatable cause of these problems. In such cases, treatment by physical therapy may be indicated, and should be customized to the individual needs of the patient being referred.
MHNI Physical Therapy Division
