New Spin on Chronic Dizziness

PHILADELPHIA, Feb. 19 -- A look beneath the surface of chronic subjective dizziness, in which there's no clear evidence of vestibular problems, usually comes up with a diagnosis of physiologic ills, psychogenic factors, or a combination.

In a prospective study of 345 men and women with chronic dizziness of uncertain origin, also called chronic subjective dizziness, a University of Pennsylvania team found that all but six had a discernable diagnosis of a psychiatric or neurologic condition.

The diagnoses included primary or secondary anxiety disorders, migraine, traumatic brain injury, neurally mediated dysautonomias, and cardiac dysrhythmias, reported Jeffrey P. Staab, M.D., M.S., and Michael J. Ruckenstein, M.D., in the February issue of Archives of Otolaryngology-Head & Neck Surgery.

"Among non-vertiginous forms of dizziness, one syndrome is particularly vexing to the clinician," the authors wrote. "Patients with this syndrome have chronic nonspecific dizziness, subjective imbalance, and hypersensitivity to motion stimuli, which are exacerbated in complex visual environments (e.g., walking in a busy store, driving in the rain)."

In patients with this condition, neither ear exams nor balance function tests typically reveal any active vestibular dysfunction, leading clinicians to label it psychogenic dizziness possibly related to anxiety, the authors noted.

"Anxiety disorders are known to cause dizziness, but a study of 122 patients with chronic dizziness and anxiety found primary anxiety disorders in only one third of individuals," they wrote. "Most had secondary anxiety precipitated by the medical events responsible for their dizziness."

The authors conducted a study to determine whether they could identify in people with unexplained dizziness specific clinical features leading to a differential diagnosis, so that appropriate treatment could be delivered.

They enrolled 345 men and women, ranging in age from 15 to 89, who were referred to the Penn Balance Center for evaluation of chronic dizziness of uncertain origin lasting at least three months.

The patients were systematically directed, according to the center's diagnostic protocol, through multiple specialty examinations until definitive diagnoses were made.

The evaluations included neurotologic histories and examinations, psychiatric assessments, and systematic screening for other causes of dizziness, including recurrent headaches, head trauma, whiplash injury, seizures, peripheral neuropathy, visual disturbance, dysrhythmias, and autonomic dysfunction.

Patients who screened positive for one of these conditions were referred for additional consultations either within the balance center or to outside specialists such as neurologists, cardiologists, rheumatologists, neuro-ophthalmologists, or physiatrists.

The main study outcome measure was final diagnoses associated with dizziness.

The investigators found that all but six patients referred for evaluation of chronic subjective dizziness eventually were diagnosed with psychiatric or neurologic illnesses.

In all, 206 patients (59.7%) were diagnosed with a primary or secondary anxiety disorder, and 133 (38.6%) were diagnosed with a central nervous system condition.

Migraine was diagnosed as a dizziness source in 57 patients (16.5%), traumatic brain injury was pinpointed in 52 patients (15.1%), and dysautonomia was diagnosed in 24 (7%).

Six of the patients were found to have atrial or ventricular dysrhythmias.

"Because of the study's focus on chronic nonspecific dizziness, patients with migraine who presented to the Balance Center with ongoing episodes of vertigo or ataxia were excluded," the authors noted. "Nevertheless, approximately one third of patients in the migraine group had experienced vertigo or ataxia during headaches in the past. The others had only nonspecific dizziness."

They also found that 44 of 57 patients with migraine (77%) also had clinically significant anxiety, which "often dominated the clinical picture."

The authors concluded that imbalance problems falling under the rubric of "chronic dizziness" may have several common causes requiring different treatments.

"Key diagnostic features were identified in the clinical history for each illness," they wrote. "Careful inquiry about these key features during otologic evaluations may increase diagnostic precision and lead to more specific treatment recommendations for these perplexing patients."