Numerous psychopathological syndromes have been attributed to posttraumatic stress, both at the time of the trauma and many years later. To date, however, there is little literature on pseudodementia as a delayed traumatic stress response. The authors present a case history of a 50-year-old woman who developed severe cognitive impairment following retrieval of previously forgotten memories of childhood sexual abuse. Her cognitive condition deteriorated rapidly and dramatically. Neuropsychological assessment and clinical presentation led to a diagnosis of frontotemporal dementia (vs. corticobasal degeneration). Detailed neurologic and medical evaluations could not identify any underlying physical cause. Her condition progressively worsened over 9 months, at which point memantine, an N-methyl-D-aspartate receptor antagonist, was begun. The patient regained full functioning over the next year. Although an organic cause could not be ruled out, it was likely that recovery of traumatic memories was contributory to the patient's condition, as ongoing psychotherapy had begun 1 year into the course. If additional cases with similar presentations are reported, such cases would corroborate the notion that persistent, severe, and reversible cognitive impairment constitutes a previously unrecognized and atypical posttraumatic response.