February 25, 2020 e-Pearl of the Week: Pupillary athetosis

Pupillary athetosis

Pupillary athetosis—or hippus—is bilateral, rhythmic oscillations of the pupil regardless of light intensity.1 It has been hypothesized that it reflects a dysregulation of central parasympathetic nervous system activity.2 Pupillary athetosis usually occurs physiologically in a drowsy state and can range from 0.04 to 2 Hz.3 It is pathologically associated with nonconvulsive status epilepticus, diabetic neuropathy, or myasthenia gravis.4,5 Pathologic hippus is marked by drastic variation of oscillation or amplitude and is a predictor of early mortality in critically ill patients.6

References

  1. Yoss RE, Moyer NJ, HollenhorstRW. Hippus and other spontaneous rhythmic pupillary waves. Am J Ophthalmol, 1970;70:935–941.
  2. Turnbull PR, Irani N, Lim N, Phillips JR. Origins of Pupillary Hippus in the Autonomic Nervous System. Invest Ophthalmol Vis Sci 2017;58:197–203.
  3. McLaren JW, Erie JC, Brubaker RF. Computerized Analysis of Pupillograms in studies of alertness. Invest Ophthalmol Vis Sci 1992;33:671–676.
  4. Centeno M, Feldmann M, Harrison NA, et al. Epilepsy Causing Pupillary Hippus: an Unusual Semiology. Epilepsia 2011;52:93–96.
  5. Fernández-Torre JL, Paramio-Paz A, Lorda-de Los Rios I, Martin-Garcia M, Hernández-Hernández MA. Pupillary Hippus as Clinical Manifestation of Refractory Autonomic Nonconvulsive Status Epilepticus: Pathophysiological Implications. Seizure, 2018;63:102–104.
  6. Denny JC, Arndt FV, Dupont WD, Neilson EG. Increased Hospital Mortality in Patients with Bedside Hippus. Am J Med 2008;121:239–245.

Mirza Usman Baig, Premedical Undergraduate Student (The Honors College at the University of Houston), and Faisal Khan, MD, Consultant Neurologist (Sugar Land Neurology and Sleep, Texas)

Mirza Usman Baig and Dr. Khan report no disclosures.