Chronic subjective dizziness.

PURPOSE OF REVIEW In 1986, the German neurologists Thomas Brandt and Marianne Dieterich described a syndrome of phobic postural vertigo (PPV) based on clinical observations of patients with nonvertiginous dizziness that could not be explained by then-known neuro-otologic disorders. Subsequent research by an American team led by Jeffrey Staab and Michael Ruckenstein confirmed the core physical symptoms of PPV, clarified its relationship to behavioral factors, and streamlined its definition, calling the syndrome chronic subjective dizziness (CSD). This article reviews the 26-year history of PPV and CSD and places it within the context of current neurologic practice. RECENT FINDINGS Recent investigations in Europe, the United States, Israel, and Japan have validated the primary symptoms of CSD; identified its provoking factors and precipitants; elucidated its long-term clinical course, differential diagnosis, and common comorbidities; developed successful treatment strategies with serotonergic antidepressants, vestibular habituation, and possibly cognitive-behavioral therapy; and raised new hypotheses about pathophysiologic processes that initiate and maintain the disorder. In tertiary neuro-otology centers where it is recognized, CSD is the second most common diagnosis among patients presenting with vestibular symptoms. SUMMARY A quarter century of research has established CSD as a common clinical entity in neurologic and otorhinolaryngologic practice. Its identification and treatment offer relief to many patients previously thought to have enigmatic and unmanageable cases of persistent dizziness. Internationally sanctioned diagnostic criteria for CSD are under development for the first edition of the International Classification of Vestibular Disorders, scheduled for publication in early 2013.