As discussed in the last month’s column, there are many different forms of symptoms, and causes associated with dizziness. Dizziness if described as lightheaded sensation typically has a cardiovascular cause and a spinning sensation is more likely a neurological cause.
One of the most common reasons for many people to experience a lightheaded sensation has to do with a reflex phenomenon known as a vasovagal response. This reflex phenomenon is activated by many triggers in our brain caused by a miscommunication between the heart, vascular system and the brain.
During this phenomenon the heart rate may drop or one’s blood pressure may diminish abruptly leading to a variety of symptoms. Symptoms associated with a vasovagal response include a lightheaded sensation along with skin paleness, nausea, ringing of the ears as and feeling of a hot flash. This occurrence can eventually lead to fainting, commonly referred to as syncope.
Triggers for a lightheaded sensation are different amongst patients. The most common cause for a lightheaded sensation includes standing upright for a long period of time.
Other triggers may include being exposed to the sight of blood, venipuncture, dehydration, a painful stimuli or experiencing a traumatic or exciting encounter. The treatments for this type of dizziness include the avoidance of such triggers as well as keeping a well hydrated state.
Usually vasovagal response has a few seconds of warning with lightheaded sensation before it progresses to syncope. Frequent postural changes, sitting and laying down may increase blood flow to the brain and it may halt the progression of this reflex phenomenon to syncope. It is also important to review medications with a supervising physician in order to recognize medications that may be responsible triggering factors.
Determining the cause of dizziness is vital in treating symptoms effectively. The nature of dizziness as described above and the detailed description and through interview of the patient is crucial in making the right diagnosis. In some cases, the cause may not be clearly understood and if vasovagal phenomenon is suspected, a test called Tilt Table Test can be performed.
This test involves monitoring patients’ electrical rhythm, heart rate, and blood pressure for 30 to 45 minutes to see if vasovagal phenomenon can be recreated. Patients are strapped to a tilt table and placed in an upright position. A drop in blood pressure, dizziness lightheadedness , or syncope are to occur to an individual inclined to a vasovagal response.
Other tests that are typically performed may include Echocardiogram which is an ultrasonography of the heart to evaluate for valvular disease such as Aortic Stenosis, Hypertrophic Cardiomyopathy or markedly thickening of heart muscles, and assessing overall pump function of the heart. A Holter monitor which is a 24-hour electrocardiogram monitoring is also usually done to rule out significant arrhythmias.
The most common neurological cause of dizziness is vertigo. The most familiar symptom associated with vertigo is a spinning sensation which usually occurs from a rapid change in head positions. This spinning sensation is accompanied with either nausea or vomiting.
The cause of this sensation is related to a disequilibrium initiated more commonly in inner ear, called benign positional vertigo or BPV. Usually it may be self-resolving or treated by special maneuvers done by an experienced clinician which involves turning the head in different angles in different positions.
Brain tumors may cause dizziness which usually typical onset is insidious and progressive and signs of increased intracranial pressure such as nausea, vomiting, headache, or visual and other neurological manifestations co-exist. Other neurological causes of dizziness involve inflammation of inner ear and vestibular system, and in rare cases, multiple sclerosis.
Aside from cardiac or neurological causes of dizziness low blood sugar, anemia, or migraine headache should also be taken into account.
Plaque formation with narrowing of the lumen, or obstruction of the carotid arteries which are vessels transferring blood from the aorta to the brain can also create symptoms of dizziness which may be more lightheaded sensation than spinning.
The diagnosis of dizziness relies on a thorough and in-depth interview of the patient by a physician to postulate the most likely cause and selection of the needed tests to prove the diagnosis and rule out the threatening conditions discussed in todays’ and last month’s article.