| Completed | 2 | 299 | Europe | Memantine, Placebo | Merz Pharmaceuticals GmbH | Memory Disorder, Retention Disorder, Cognitive, Subjective Cognitive Impairment, Memory, Concentration or Attention Problems | 08/11 | 09/11 | | |
| Completed | 2 | 7 | Europe | Dextromethorphan (drug used like antitussive), Memantine (drug used in Alzheimer's disease), Placebo (lactose) | University Hospital, Clermont-Ferrand, Dr Malou Navez, Pain Clinic, Saint-Etienne Hopital, Dr Marc Sorel, Pain Clinic, Nemours Hospital, Dr Anne-Margot Duclot, Pain Clinic, Paris Rotschild Hospital, Dr Monique Belon, Pain Clinic, Aurillac Hospital, Dr Marie-Christine Crosmary/Dr Renato Colamarino, Pain Clinic, Vichy Hospital, Dr Mohamed El Ayadi, Pain Clinic, Issoire Hospital, Dr GĂ©raldine Brumauld de Montgazon, Pain Clinic, La Rochelle Hospital | Neuropathic Pain | 06/14 | 09/16 | | |