Alterations in CNS activity induced by botulinum toxin treatment in spasmodic dysphonia: an H215O PET study.
Speech-related changes in regional cerebral blood flow (rCBF) were measured using H(2)(15)O positron-emission tomography in 9 adults with adductor spasmodic dysphonia (ADSD) before and after botulinum toxin (BTX) injection and 10 age- and gender-matched volunteers without neurological disorders. Scans were acquired at rest and during production of continuous narrative speech and whispered speech. Speech was recorded during scan acquisition for offline quantification of voice breaks, pitch breaks, and percentage aperiodicity to assess correlations between treatment-related changes in rCBF and clinical improvement. Results demonstrated that speech-related responses in heteromodal sensory areas were significantly reduced in persons with ADSD, compared with volunteers, before the administration of BTX. Three to 4 weeks after BTX injection, speech-related responses were significantly augmented in these regions and in left hemisphere motor areas commonly associated with oral-laryngeal motor control. This pattern of responses was most strongly correlated with the objective measures of clinical improvement (decreases in the frequency of voice breaks, pitch breaks, and percentage aperiodicity). These data suggest a pathophysiological model for ADSD in which BTX treatment results in more efficient cortical processing of sensory information, making this information available to motor areas that use it to more effectively regulate laryngeal movements.
Ali
S Omar
SO
Language Section, Voice, Speech and Language Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Building 10, Room 8S235A, 10 Center Drive, Bethesda, MD 20892, USA.
Thomassen
Michael
M
Schulz
Geralyn M
GM
Hosey
Lara A
LA
Varga
Mary
M
Ludlow
Christy L
CL
Braun
Allen R
AR
D000328:Adult; D018726:Anti-Dyskinesia Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001905:Botulinum Toxins / Q000494:pharmacology* / Q000627:therapeutic use; D001921:Brain / Q000098:blood supply* / Q000187:drug effects; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010700:Phonetics; D049268:Positron-Emission Tomography / Q000379:methods*; D012039:Regional Blood Flow / Q000187:drug effects; D013060:Speech / Q000187:drug effects*; D013068:Speech Production Measurement; D014832:Voice Disorders / Q000188:drug therapy* / Q000503:physiopathology
D018726:Anti-Dyskinesia Agents; D001905:Botulinum Toxins