良性発作性頭位めまい症難治症例の検討―特に原因（病態）の推定とその対応

抄録

Refractory cases of benign paroxysmal positional vertigo (BPPV) are characterized by bilateral onset, frequent recurrence, and various subtypes. Etiology and pathophysiology were assessed in 35 cases of refractory BPPV that required multiple rounds of treatment (>10 times) in 1 year after undergoing the canalith repositioning procedure (CRP). The conditions were investigated based on patients’ clinical courses after undergoing CRP. Additionally, the treatment approaches were evaluated. The suspected causes of refractory BPPV included systemic or local otolith organ damage (97%), CRP failure (71%): lack of effective CRP for BPPV-cupulolithiasis; canalith jam caused by the size and number of otoliths in the semicircular canals, re-entry and canal conversion (34%): habitual head position during sleep with the affected-ear-down, and complications of secondary BPPV and central disorders (31%). The pathological conditions often coexisted. Recommended treatment approaches include measurement of vitamin D and prescription of supplements, extension of the time for maintaining head position at 135° with the healthy-ear-down, tapping of the affected temporal region, and keeping the patients’ heads with the affected-ear-up during sleep on the day of CRP.