The causes of dizziness according to the decreasing incidence are;
1) Benign paroxysmal positional vertigo (BPPV) 20%
2) Vestibular 15%
3) Migraine and motion sensitivity 15%
4) Anxiety and depression 10%
5) Meniere's disease 7%
6) Cerebellar disease 6%
7) Transient ischemic attacks 5%
8) Orthostatic hypotension 4%
So BPPV would be the most likely explanation in her case. An MRI with the gadolinium contrast should be done to rule out a condition called as acoustic neuroma. MRI with gadolinium enhancement is particularly useful in detecting smaller intracanalicular tumors such as acoustic neuromas. It is also recommended for identifying sclerotic and demyelinating white matter lesions characteristic of multiple sclerosis. So that can be another investigation considered by her doctor. Chronic dizziness associated with the floating, rocking and light headedness and is induced by eye movements (head being still) should be also investigated or correlated to anxiety and depression, if all the medical imaging, blood work and examination is negative. If she is on any medications, their side effects also should be ruled out for lightheadedness, as drugs are quite a common cause for this symptom. Dizziness may be provoked by only certain movements, such as standing up after lying down for at least 10 minutes in orthostatic hypotension, or may occur after vertical or oblique head movements, such as lying down, turning over in bed, or sitting up in benign paroxysmal positional vertigo (BPPV). Simply moving the eyes with the head stationary causes dizziness and there is no eye movement disorder (ocular misalignment or an internuclear ophthalmoparesis), then dizziness is likely to be the result of anxiety. When dizziness occurs without provocation (spontaneous) and is vestibular (ear disorder) in origin, it frequently is exacerbated by head movements.
Internal ear disease vertigo is termed true vertigo in which one feels rotational movement of self or the surroundings. The false vertigo or nonvertigo has feeling of light-headedness, unsteadiness, motion intolerance, imbalance, etc. Often, dizziness can be a multisensory disorder due to any combination of peripheral neuropathy, visual impairment, and musculoskeletal disease. Many patients who have thyroid dysfunction can present with dizziness as an initial complaint. In individuals who have migraine, dizziness and vertigo can occur as part of the aura or separately. Spells usually last approximately an hour but can last several hours or days in patients who have severe symptoms. Most patients who have migraines have a long history of recurring symptoms. So that too should be assessed as a cause if she a history of migraine.
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