Jürgen Konczak1, Joshua E Aman2, Yu-Wen Chen3, Kuan-yi Li4, Peter J Watson3. 1. Human Sensorimotor Control Laboratory, University of Minnesota, Minneapolis, Minnesota. Electronic address: jkonczak@umn.edu. 2. Human Sensorimotor Control Laboratory, University of Minnesota, Minneapolis, Minnesota. 3. Department of Speech-Language-Hearing Sciences, University of Minnesota, Minneapolis, Minnesota. 4. Department of Occupational Therapy, Graduate Institute of Behavioral Sciences, Healthy Aging Center, Chang Gung University, Taoyuan, Taiwan.
Abstract
OBJECTIVES: Focal dystonia of the head and neck are associated with a loss of kinesthetic acuity at muscles distant from the dystonic sites. That is, while the motor deficits in focal dystonia are confined, the associated somatosensory deficits are generalized. This is the first systematic study to examine, if patients diagnosed with spasmodic dystonia (SD) show somatosensory impairments similar in scope to other forms of focal dystonia. METHODS: Proprioceptive acuity (ability to discriminate between two stimuli) for forearm position and motion sense was assessed in 14 spasmodic dystonia subjects and 28 age-matched controls using a passive motion apparatus. Psychophysical thresholds, uncertainty area (UA), and a proprioceptive acuity index (AI) were computed based on the subjects' verbal responses. RESULTS: The main findings are as follows: first, the SD group showed significantly elevated thresholds and UAs for forearm position sense compared with the control group. Second, 9 of 14 dystonia subjects (64%) exhibited an AI for position sense above the control group maximum. Three SD subjects had a motion sense AI above the control group maximum. CONCLUSIONS: The results indicate that impaired limb proprioception is a common feature of SD. Like other forms of focal dystonia, spasmodic dystonia does affect the somatosensation of nondystonic muscle systems. That is, SD is associated with a generalized somatosensory deficit.
OBJECTIVES:Focal dystonia of the head and neck are associated with a loss of kinesthetic acuity at muscles distant from the dystonic sites. That is, while the motor deficits in focal dystonia are confined, the associated somatosensory deficits are generalized. This is the first systematic study to examine, if patients diagnosed with spasmodic dystonia (SD) show somatosensory impairments similar in scope to other forms of focal dystonia. METHODS: Proprioceptive acuity (ability to discriminate between two stimuli) for forearm position and motion sense was assessed in 14 spasmodic dystonia subjects and 28 age-matched controls using a passive motion apparatus. Psychophysical thresholds, uncertainty area (UA), and a proprioceptive acuity index (AI) were computed based on the subjects' verbal responses. RESULTS: The main findings are as follows: first, the SD group showed significantly elevated thresholds and UAs for forearm position sense compared with the control group. Second, 9 of 14 dystonia subjects (64%) exhibited an AI for position sense above the control group maximum. Three SD subjects had a motion sense AI above the control group maximum. CONCLUSIONS: The results indicate that impaired limb proprioception is a common feature of SD. Like other forms of focal dystonia, spasmodic dystonia does affect the somatosensation of nondystonic muscle systems. That is, SD is associated with a generalized somatosensory deficit.
Authors: Joyce K H Tang; Neil Mahant; Danny Cunic; Robert Chen; Elena Moro; Anthony E Lang; Andres M Lozano; William D Hutchison; Jonathan O Dostrovsky Journal: Exp Neurol Date: 2007-01-19 Impact factor: 5.330
Authors: Christy L Ludlow; Charles H Adler; Gerald S Berke; Steven A Bielamowicz; Andrew Blitzer; Susan B Bressman; Mark Hallett; H A Jinnah; Uwe Juergens; Sandra B Martin; Joel S Perlmutter; Christine Sapienza; Andrew Singleton; Caroline M Tanner; Gayle E Woodson Journal: Otolaryngol Head Neck Surg Date: 2008-10 Impact factor: 3.497