Hyperalgesia in semantic dementia.

M.D., Ph.D. Associate Professor, Faculty of Medicine, Federal University of Goiás, Goiânia GO, Brazil. Coordinator of the Behavioral and Cognitive Neurology Unit of the Hospital das Clínicas, Federal University of Goiás, Goiânia GO, Brazil; Neuropsychologist, Member of Behavioral and Cognitive Neurology Unit of the Hospital das Clínicas, Federal University of Goiás, Goiânia GO, Brazil; Speech Pathologist, Member of Behavioral and Cognitive Neurology Unit of the Hospital das Clínicas, Federal University of Goiás, Goiânia GO, Brazil. There are very few studies addressing pain mechanisms in frontotemporal lobar degeneration (FTLD), as well as the possible contributions that the study of the neurobiological basis of pain in dementia can confer to the knowledge of general pain physiopathology itself. Semantic dementia (SD) is a form of FTLD in which patients progressively lose conceptual knowledge about the world, affecting their ability to understand sensory stimuli such as non-verbal sounds, tastes, and smells. A 60-year-old right-handed, businessman, presented 4 year history of word finding difficulty together with impaired word comprehension. Day-to-day and personal autobiographic memories were unaffected. He did not present depression signs. Patient has developed marked histrionic traits: if brushed by a family member he may react as if in severe pain, an exaggerated reaction to tactile stimuli. He keeps claiming for long time after any bruising, even the very mild ones. Orthopedic investigation resulted negative many times. During physical exam, more precisely during face tapping (to elicit primitive reflexes), he became angry with the manipulation, assumed that behavior as violence, reacting with obscenity and prohibiting me to keep the neurological exam even despite all my warnings that was important to me to continue my job in order to elucidate his health problem. In the neurological exam, except for the alterations in semantic memory, no other abnormalities were seen. His MRI is showed in Figure. A SPECT scan showed bilateral hypoperfusion in temporal lobes. His score on the MMSE was 26/30. Digit Span was 7 forward, 4 backward. His day-to-day memory was unaffected. Constructional ability was preserved. His spontaneous speech was fluent and anomic with normal syntax, phonology and prosody. On verbal fluency he did 3 animals in one minute. Performance on sentence repetition of Boston Diagnostic Aphasia Examination was normal. Comprehension of syntax was normal, however, oral and written comprehension of single words were impaired. Our patient presents an exaggerated reaction to tactile stimuli. Patients with SD were also significantly more likely than