Dizziness in Postural Tachycardia Syndrome and the Link with Vestibular Migraine

Ruby Sekhon¹Nicholas Gall²Carolyn Ainsworth¹Louisa Murdin^1*

• ¹Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
• ²Kings College Hospital, London, United Kingdom

Postural tachycardia syndrome (PoTS) is a chronic condition characterised by an increase in heart rate on standing and recognised to be associated with dizziness and migraine. This study sought to investigate the multifaceted nature of dizziness in PoTS from a vestibular perspective, including the relationship with vestibular migraine.A retrospective review of 80 patients with confirmed PoTS, attending a tertiary Neurootology clinic, was conducted to evaluate standardised detailed assessments (validated symptom questionnaires, history/physical examination, neuro-otological diagnostics (including video head impulse test (VHIT) videonystagmography (VNG) and caloric testing) and management. The PoTS cohort was also compared with an age and sex matched control group of dizzy patients.80 patients were included (mean age 35.3 years ± 12.1; 93% female). 84% had migraine and 30% had vestibular migraine. Clincial examination of static and dynamic balance was most frequently abnormal. VHIT was abnormal in 2%, VNG canal paresis and directional preponderance was abnormal in 19% and 22% respectively. 49% of cases were offered migraine management advice and 58% were offered vestibular rehabilitation. The PoTS group showed higher rates of vestibular symptoms including vertigo, unsteadiness, and positional vertigo, and high Disability Rating Scores.Our findings reflect the challenges of distinguishing dizziness phenotypes in PoTS, in particular vestibular migraine. This study illustrates the importance of judicious clinical enquiry to investigate the presence of non-orthostatic dizziness mechanisms, such as vestibular migraine, for which evidence-based management exists, and recommend further research to elucidate the multifaceted nature of PoTS associated dizziness.