Poster E17, Thursday, August 22, 2019, 3:45 – 5:30 pm, Restaurant Hall
Primary Progressive Aphasia Presenting as a Functional Neurological Disorder for More Than a Decade
Aaron Hauptman1,2, Gretchen Reynolds1,2, Kim Willment1,2, Kirk Daffner1,2;1Brigham and Women's Hospital, 2Harvard Medical School
In 2007, Delis and Wetter proposed the term “Cogniform Disorder” to describe a conversion disorder-like condition within the neurocognitive domain. Broadly, 16% of general neurology outpatients demonstrate symptoms consistent with a DSM-5 diagnosis of functional neurological disorder (FND), previously labelled as conversion disorder. There is little evidence in the literature to guide diagnosis and management of possible FND within cognitive neurology, particularly of patients with insidious or atypical language symptoms. Furthermore, given the heterogeneity in presentation of neurodegenerative language disorders, misdiagnosis is a serious risk, particularly given the possibility of early, atypical or insidious onset. It is important to rule out possible neurodegenerative etiologies of language abnormalities and, even when findings are negative or inconclusive, to monitor closely as subjective symptoms may predate objective or biomarker findings of an underlying neurodegenerative disorder. We present the case of an ambidextrous man first seen at the age of 43 for subjective memory complaints who was subsequently monitored for over 15 years. Symptoms were suggestive of a non-neurodegenerative etiology and he was conceptualized as having underlying language and frontal-executive weaknesses exacerbated in the setting of identified psychosocial stressors, anxiety and a cluster of symptoms most consistent with a diagnosis of FND. Due to persistent complaints of worsening cognitive difficulties, extensive neurological work-up was done for possible contributory conditions or factors, including brain MRI, FDG-PET and lumbar puncture for biomarkers of Alzheimer’s disease, inflammatory etiologies and other causes. All of these were negative. Neuropsychological testing was completed 4 times during his 15 years of follow-up and demonstrated mild language weaknesses and moderate frontal/executive dysfunction, with the language difficulties presumed to be developmental and consistent with this formulation. In the last two years, he complained of worsening language difficulties. His speech was characterized by long response latencies, but otherwise normal language until his final neuropsychological examination in 2018. This neuropsychological testing was most notable for moderate deficits in processing speed and executive functioning. Regarding language, he made atypical spelling errors, mild grammatical errors in written and spoken spontaneous language and errors on phrase repetition. Testing demonstrated intact confrontation naming, comprehension, and low average category fluency. There was no appreciable speech apraxia or articulation deficit. He also demonstrated variable attention and working memory and performed inconsistently across several measures of performance validity. A second brain FDG-PET was repeated, 2 years following his initial normal PET study, and demonstrated abnormal hypometabolism of the left frontal lobe and insula. A repeat brain MRI was then obtained that demonstrated asymmetric atrophic changes of the left inferior frontal gyrus, widening of the left Sylvian fissure and left insular volume loss. These imaging and clinical findings are consistent with a diagnosis of agrammatic/non-fluent variant primary progressive aphasia. This case typifies the challenge of diagnosis of FND within the neurocognitive domain of language. Given the heterogeneity of patient presentations and the frequency of atypical presentations of neurodegenerative language disorders, this case emphasizes the need for close follow-up and ongoing monitoring of patients with neurocognitive complaints.
Themes: Disorders: Acquired, Language Production
Method: Other