The Cerebellum

, Volume 17, Issue 2, pp 122–131 | Cite as

The Floccular Syndrome: Dynamic Changes in Eye Movements and Vestibulo-ocular Reflex in Isolated Infarction of the Cerebellar Flocculus

  • Dario Andres Yacovino
  • Manuel Perez Akly
  • Leonel Luis
  • David S. Zee
Original Paper


The cerebellar flocculus is a critical structure involved in the control of eye movements. Both static and dynamic abnormalities of the vestibulo-ocular reflex (VOR) have been described in animals with experimental lesions of the flocculus/paraflocculus complex. In humans, lesions restricted to the flocculus are rare so they can become an exceptional model to contrast with the clinical features in experimental animals or in patients with more generalized cerebellar diseases. Here, we examined a 67-year-old patient with an acute vestibular syndrome due to an isolated infarct of the right flocculus. We evaluated him multiple times over 6 months—to follow the changes in eye movements and vestibular function—with caloric testing, video-oculography and head-impulse testing, and the anatomical changes on imaging. Acutely, he had an ipsilateral-beating spontaneous nystagmus, bilateral gaze-evoked nystagmus, borderline impaired smooth pursuit, and a complete contraversive ocular tilt reaction. The VOR gain was reduced for head impulses directed contralateral to the lesion, and there was also an ipsilesional caloric weakness. All abnormalities progressively improved at follow-up visits but with a considerable reduction in volume of the affected flocculus on imaging. The vestibular and ocular motor findings, qualitatively similar to a previously reported patient, further clarify the “acute floccular syndrome” in humans. We also add new information about the pattern of recovery from such a lesion with corresponding changes in the size of the affected flocculus on imaging.


Vestibulo-ocular reflex (VOR) Magnetic resonance imaging (MRI) Flocculus Cerebellum Acute vestibular syndrome (AVS)  Head impulse test Infarct 



The authors thank Marcelo Duperre for his generous assistance in the production of the manuscript.

Compliance with Ethical Standards

This study was approved by the local review board and the patient gave written informed consent.

Conflicts of Interest

The authors declare that they have no conflict of interest.


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Copyright information

© Springer Science+Business Media, LLC 2017

Authors and Affiliations

  • Dario Andres Yacovino
    • 1
    • 2
  • Manuel Perez Akly
    • 3
    • 4
  • Leonel Luis
    • 5
  • David S. Zee
    • 6
  1. 1.Department of NeurologyDr. Cesar Milstein HospitalBuenos AiresArgentina
  2. 2.Memory and Balance ClinicBuenos AiresArgentina
  3. 3.Department of NeuroradiologyDr. Cesar Milstein HospitalBuenos AiresArgentina
  4. 4.Department of RadiologyItalian HospitalBuenos AiresArgentina
  5. 5.Department of OtolaryngologyHospital Santa Maria, CHLNLisbonPortugal
  6. 6.Departments of Neurology, Otolaryngology-Head and Neck Surgery, Ophthalmology and NeuroscienceJohns Hopkins HospitalBaltimoreUSA

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