PGR - 2 Neuropsychology’s Role in Identifying Functional Neurological Disorder

Abstract

Objective To outline the usefulness of neuropsychological evaluation in identifying functional neurological disorder. Functional neurological disorder accounts for an estimated 16% of neurology referrals and is a “crisis of neurology” (Edwards & Bhatia, 2012). Adolescents with a history of neurologic compromise, including autoimmune disorders, are at increased risk for comorbid functional neurological disorder (Reuber, Mitchell, Howlett, Crimlisk, & Grünewald, 2005). Method 16-year-old female with a history of Hoshimoto’s encephalopathy referred by her neurologist. Following diagnosis and treatment, she developed a constellation of symptoms, including wide set gait, nystagmus, incontinence, and dystonic episodes. She also reported lapses in memory that lasted a few minutes at a time. During these episodes, she forgot who her mother was and forgot details about her home, which resulted in panic. Results Two neuropsychological evaluations were completed over two years. Psychometric intelligence declined by two standard deviations compared to previous testing one year before. Her performance on memory tasks declined dramatically as well. Despite these declines, there was no decline in activities of daily living. She failed embedded and stand-alone performance validity measures (RDS = 4; TOMM = 29, 30, 28). These findings were described to her neurologist and psychiatrist and we discussed the importance of identifying functional symptoms in the context of her medical history. Conclusions Our evaluation identified significant discrepancies between neuropsychological performance and daily cognitive functioning. The memory lapses she described were inconsistent with any known etiology or illness. Neuropsychological evaluation identified symptoms of a functional nature and assisted in appropriate treatment planning.