[Abstract Title]. - Society for Neuroscience

Authors: *M. L. MAKHLOUF 1,2,3 , N. SHARMA 4,8,3 , T. J. MULTHAUPT-BUELL 4 , J.
KUSTER 4 , R. E. HILLMAN 1,5,6,3 , A. J. BLOOD 2,4,3,7 ;
1 Dept. of Hlth. Sci. and Technol., Harvard-MIT, Cambridge, MA; 2 Athinoula A. Martinos Ctr.
for Biomed. Imaging, Charlestown, MA; 3 Harvard Med. Sch., Boston, MA; 4 Dept. of Neurol.,
5 Ctr. for Laryngeal Surgery and Voice Rehabil., 6 Dept. of Surgery, 7 Dept. of Psychiatry,
Massachusetts Gen. Hosp., Boston, MA; 8 Brigham and Women's Hosp., Boston, MA
Abstract: Spasmodic dysphonia (SD) is a disabling neurological disorder characterized by
involuntary contractions of one or more muscles of the larynx during speech. SD is classified as
a focal laryngeal form of the movement disorder, dystonia. Currently there is no specific test for
SD and the disorder is often misdiagnosed as muscle tension dysphonia. We have previously
shown an abnormal microstructural asymmetry medial to the pallidum in hand and cervical
dystonia patients (Blood et al., 2006). To test whether this abnormality may be a biomarker for
focal dystonia more generally, we investigated brain microstructure in SD. Diffusion tensor
imaging (DTI) was used to screen for white matter abnormalities in regions between the
pallidum and thalamus in two SD patients. Scanning was performed when botulinum toxin
treatment was least effective (i.e. just before the patient‟s next set of injections). A region of
interest (ROI) analysis was performed in which 20 a priori ROIs were drawn on the fractional
anisotropy (FA) maps for each hemisphere and for each patient. Both SD patients exhibited an
abnormal hemispheric asymmetry in a focal region where the ansa lenticularis fibers are known
to project between the pallidum and thalamus. These findings indicate that a microstructural
abnormality previously observed in focal hand and cervical dystonia patients may also exist in
SD patients, suggesting the abnormality may be a potential biomarker for multiple forms of focal
dystonia.
Reference: Blood AJ, Tuch DS, Makris N, Makhlouf ML, Sudarsky LR, Sharma N. White matter
abnormalities in dystonia normalize after botulinum toxin treatment. NeuroReport 2006;
17(12):1251-5.
Disclosures: M.L. Makhlouf, None; N. Sharma, None; T.J. Multhaupt-Buell, None; J.
Kuster, None; R.E. Hillman, None; A.J. Blood, None.
Poster
249. Dyslexia, SLI, and Other Disorders of Cognition and Behavior
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 249.1/U20
Topic: C.05.e. Other
Support: K. Leroy Irvis Fellowship