Atypical Lindsay-Hemenway syndrome in a patient with Klippel-Feil syndrome: a new association? Case report and etiopathogenic review

Abstract Introduction Klippel–Feil syndrome is a rare congenital disorder characterized by the fusion of two or more cervical vertebrae. It may be associated with malformations in other systems, including auditory abnormalities. Approximately 30% of patients present with hearing loss; however, the frequency of other hearing disorders remains unknown. Objective To describe the phenotype of Klippel–Feil syndrome and its association with an atypical presentation of Lindsay–Hemenway syndrome. Methods We report the case of a 75-year-old female who has been followed for 14 years for Klippel–Feil syndrome associated with renal malformations. In 2016, she developed progressively debilitating vertigo. Diagnostic tests suggested Lindsay–Hemenway syndrome. Results Imaging studies confirmed type II Klippel–Feil syndrome. The presentation of Lindsay–Hemenway syndrome was atypical, with an insidious onset characterized by vertigo occurring only when turning in bed, followed by progression to chronic instability with recurrent vertigo. The patient also developed an exaggerated vestibulospinal reflex triggered by a sensation of falling due to loss of muscle tone in the lower limbs, as well as mirror movements. Brainstem auditory evoked potential testing revealed left labyrinthine areflexia with preserved hearing, consistent with ischemia of the left anterior vestibular artery, likely associated with Lindsay–Hemenway syndrome. Imaging studies revealed abnormalities that could show chronic ischemia in the left vertebrobasilar territory. Conclusions The description of an atypical Lindsay–Hemenway syndrome in the context of Klippel–Feil syndrome expands its phenotypic spectrum and raises the possibility that chronic ischemia may be an etiological mechanism for Lindsay–Hemenway syndrome.