Poster 11: Emotional Lability and Aggression with Withdrawal of Memantine in Traumatic Brain Injury: A Case Report

Article Outline

• Disclosures
• Patients or Programs
• Program Description
• Setting
• Results
• Discussion
• Conclusions
• Copyright

Keywords: Rehabilitation, Agitation, Traumatic brain injury, Memantine

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Disclosures 

C. C. Groves, None.

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Patients or Programs 

A 25-year-old man 2 years post traumatic brain injury (TBI) with persistent short term memory deficits.

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Program Description 

The patient was a highly functioning man who had reintegrated into his community quite well, was pursuing employment and driving with supervision. His primary cognitive deficit was short term memory loss. The patient had failed a trial of donezepil (Aricept) with respect to memory, therefore memantine (Namenda) was initiated. No clinical improvement was noted with regards to memory. Additionally, no adverse events or behavioral changes were noted with memantine therapy. The patient was on 10 mg bid for approximately 6 months before the medication was weaned. Upon tapering (5 mg twice daily × 7 days, 5 mg daily × 7 days) the patient's emotional lability worsened dramatically with outbursts of rage, and physical displays of aggression and violence. Memantine was therefore reinitiated. (Prior to initiating memantine, the patient had occasional emotional lability with rare anger outbursts, which were well controlled.)

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Setting 

Outpatient traumatic brain injury clinic.

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Results 

Within 24 hours of restarting memantine, the patient's aggression resolved completely. He continues to have occasional difficulty with emotional lability which is once again well controlled and has been for 12 months. He remains on memantine 10 mg bid. The patient continues to have short term memory deficits.

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Discussion 

Memantine was not initiated for behavioral purposes in this patient, however, the dramatic worsening behavioral symptoms described upon weaning memantine—and resolution upon resuming—suggest a potential therapeutic benefit associated with this NMDA receptor antagonist.

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Conclusions 

Memantine is being used more frequently in chronic TBI patients for cognitive deficits but may have a broader use in the TBI population. Memantine's moderate-affinity NMDA receptor antagonist properties, similar to amantadine, may help explain a beneficial effect on emotional lability, agitation, and aggressive behavior frequently encountered in TBI patients. Further research is warranted.