Transforming superior canal dehiscence to chronic subjective dizziness: from SCD to CSD.

Patients presenting with chronic dizziness and no identifiable vestibular impairments have been described as having "extravestibular" symptoms, or "psychogenic dizziness." In 2005, Staab and Ruckenstein described a syndrome they referred to as "chronic subjective dizziness" (CSD), which characterized this concept more clearly. According to Staab and Ruckenstein (2003), the primary physical symptoms of CSD are continual nonvertiginous dizziness or subjective imbalance that persists for 3 mo or longer. Patients suffering from CSD often describe their dizziness as a rocking or swaying when sitting or standing. This case study describes a 41-yr-old female who originally presented with complaints of noise-induced vertigo. The patient's history, imaging studies, and balance function examinations led to the diagnosis of a right-sided superior canal dehiscence (SCD). After surgical repair of the dehiscence, the quantitative electrophysiological tests returned to normal. However, the patient's scores on measures of anxiety, depression, and self-perceived dizziness handicap increased significantly postoperatively. This case illustrates the transformation of a peripheral end-organ impairment (i.e., SCD) into a psychiatric condition (i.e., CSD).