Presented at the 2013 AAPM Annual Meeting « Back

Using the 10-Point Clock Drawing Test as a Tool for Assessing Cognitive Dysfunction in Patients Undergoing Outpatient Ketamine Infusions for Chronic Pain

Karen Slocum, MD MPH, karenrusak@gmail.com¹, Aaron L. Reposar, MS IV¹, May L. Chin, MD², chinm@gwu.edu, Richard Amdur, PhD³, (1) George Washington University, Arlington, Virginia, (2) George Washington University Medical Center, Washington, D.C. (3) Medical Faculty Associates, Washington, D.C.

Introduction: Chronic pain patients with severe refractory pain may benefit from ketamine infusions. Ketamine is an NMDA antagonist. The NMDA receptor plays an important role in central sensitization and in CNS functions such as learning and memory. We used the 10-point clock drawing test, a validated instrument for assessing cognitive dysfunction, to evaluate whether ketamine infusions result in cognitive dysfunction. We compared 10-point clock scores before and after ketamine infusions over three consecutive days. Materials and Methods: Following approval from the Institutional Review Board, we completed a retrospective chart review for patients who were administered outpatient ketamine infusions along with the 10-point clock drawing test between July 2011 and June 2012. Data reviewed included dose of ketamine infusion, with age, gender, and weight as static covariates, and 10-point clock score pre- and post-infusion on three consecutive days. Results: We identified 31 patients receiving 88 outpatient ketamine infusions for chronic pain syndromes including complex regional pain syndrome (CRPS), neuropathic pain, migraine headaches, and chronic abdominal pain. We found no effect of infusion number, age, gender, or weight on the clock scores. The ketamine dose ranged from 0.2 mg/kg/hr to 1 mg/kg/hr over four hours. Pearson's correlation (r) for the doses each day did not show significant associations with clock scores. Conclusions: Outpatient ketamine infusions on three consecutive days in chronic pain patients did not affect cognitive function as assessed by the 10-point clock drawing test. References: 1) Sheetal P, Anitescu M. Efficacy of Outpatient Ketamine Infusions in Refractory Chronic Pain Syndromes: A 5-Year Retrospective Analysis. Pain Medicine. 2012; 13:263-269. 2) Morgan CJ, Curran HV. Acute and Chronic Effects of Ketamine Upon Human memory: a review. Psychopharmacology. 2006 Nov; 188(4): 408-24. 3) Manos P.J. The Utility of the Ten-Point Clock Test as a Screen for Cognitive Impairment in General Hospital Patients. General Hospital Psychiatry. 1997; 19: 439-444.

Funding: None

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