Article Text

Download PDFPDF

Rapid ping-pong eye deviation following a recovery from carbon dioxide narcosis
  1. Shuichiro Neshige1,2,
  2. Ohno Narumi1,
  3. Shiro Aoki1 and
  4. Hirofumi Maruyama1,2
  1. 1Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan
  2. 2Epilepsy Center, Hiroshima University Hospital, Hiroshima, Japan
  1. Correspondence to Dr Shuichiro Neshige; s-neshige{at}

Statistics from


A 70-year-old woman with a history of panic disorder was admitted to the emergency room for loss of consciousness from carbon dioxide (CO2) narcosis due to atelectasis following lobectomy for lung cancer. After mechanical ventilation, the carbon dioxide partial pressure (PCO2) and consciousness levels improved, but she was immobile, showing reduced responsiveness to the environment. While neurological tests for motor function yielded normal results, she did not attempt to move voluntarily. Although her language comprehension was preserved, she did not speak spontaneously. Even though she could breathe, she remained ventilator-dependent. Spontaneous breathing trials induced severe tachypnoea; thus, tracheostomy was performed. Multiple clinical examinations, including blood and cerebrospinal fluid testing and brain imaging, were normal. Electroencephalography showed background slowing. The PCO2 level remained within normal values during these conditions. Therefore, the cause of her ventilator dependence was unclear. The only neurological abnormality was rapid ‘ping-pong’ eye deviations: an oculomotor disturbance characterised by involuntary, rapid, alternating gaze between right and left (video 1). These movements were pronounced under psychological stress, such as during neurological examination, but they completely disappeared when she was relaxed, for example, when watching television or spending time alone. Based on these findings, she was diagnosed with catatonia and functional saccadic oculomotor disturbance.1 This manifestation gradually disappeared after 2-month liaison psychiatry therapy with antianxiety drugs. Acute catatonia should be suspected when a patient fails to withdraw from mechanical ventilation without evidence of a respiratory deficit. The absence of a neurological abnormality other than an oculomotor disturbance may assist in confirming the diagnosis, especially in patients with a history of psychiatric disorders.2

Video 1

Learning points

  • Catatonia reduces a patient’s responsiveness to the environment, leading to an immobile condition.

  • Spontaneous breathing trials can fail because of severe catatonia.

  • Functional saccadic oculomotor disturbance is a neurological sign of catatonic stupor.



  • Contributors SN: conceptualised study; interpreted of the data; drafted the manuscript for intellectual content. ON: interpreted of the data; revised the manuscript for intellectual content. SA: interpreted of the data; revised the manuscript for intellectual content. HM: revised the manuscript for intellectual content.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.