1. Functional Impact of Ankle Clonus Based on Patient Perceptions Chetan P. Phadke 1, 2, 3, Caitlin Davidson 1, Tim Pauley 1, Satyendra Sharma 4, Farooq Ismail 1, 2, Chris Boulias 1, 2 1-Spasticity Research Program, West Park Healthcare Centre; 2-University of Toronto; 3-York University, 4-Sunnybrook Health Sciences Centre, Toronto, Ontario, CANADA Along with spasticity, another clinical sign of UMN syndrome is clonus: an involuntary, rhythmic contraction of a distal muscle or a muscle group that creates an oscillating motion at a characteristic frequency of 5 to 8 Hz 1. It is typically elicited in response to suddenly-applied and subsequently sustained stretch force, holding the muscle(s) in a stretched position at a certain angle 2. In the lower limbs, clonus can be typically elicited in the ankle plantar flexors 3. UMN lesions such as brain lesions (stroke and traumatic brain injury), spinal cord injury (SCI), and multiple sclerosis (MS) 4 impair the ability to execute movements and also result in impaired ability to inhibit excessive tone seen in clonus 5. Patients with the UMN syndrome experience clonus as an uncontrollable tapping, twitching, or muscle spasms, which can potentially interfere with a number of functional activities. The patient perceived functional and emotional impact of clonus, important information for clinicians, has not been fully investigated and remains unclear. INTRODUCTION RESULTS Design: Cross-sectional questionnaire. Setting: Outpatient clinic. Participants (n=18): Average age was 46+16 (see Table 1) Procedures: Clonus was manually assessed by passively dorsiflexing the ankle either by the physiotherapist or physiatrists with >5 years’ experience assessing and treating spasticity. The clonus impact survey asked patients to report subjective assessment of frequency and duration of clonus as well as impact on activities of daily living. The clonus survey items included demographic data, frequency of occurrence, pain, embarrassment, mental stress, ability to stop the clonus, and functional activities such as - sleeping, ambulation, and self-care. subjects were divided into two groups: a) High independence group: BI≥85 (n=8) and b) Low independence group: BI<85 (n=7). Main Outcome Measures: 1) Clonus survey, 2) Barthel Index (BI) METHODS. OBJECTIVES To explore the participant perspectives on the functional and emotional impact of clonus. A secondary objective was to explore the relationship between the impact of clonus and Barthel Index (BI) and explore the differences in functional impact of clonus between brain lesion (stroke, traumatic brain injury, and cerebral palsy), MS, and SCI groups Step length asymmetry - Figure 1: Survey Responses ACKNOWLEDGMENTS We would like to thank all our participants, the West Park Foundation, and the West Park Spasticity Management Clinic staff. Table 1: Patient characteristics 72% of subjects reported experiencing clonus once per day or less, while 28% reported clonus 2-10 times daily Clonus produced impact in both functional and emotional categories (see Figure 1) Functional impact – up to 56% (transfer) and 61% (fatigue) patients and emotional impact – up to 28% (bathing) and 39% (consumed thoughts) patients Significantly greater number of patients (86%) were able to stop clonus in the low independence group than those (25%) in the high independence group (p<0.05) Average age of the MS group (n=5) was 50±8, brain lesion group (n=8) was 55±17, and SCI group (n=4) was 37±10 years Average BI score in the high independence group was 94±7, the low independence group was 41±29 Average BI score in the MS group was 38±53, brain lesion group was 68±32, and SCI group was 77±21 The percentage of patients that reported clonus to be fatiguing was evenly distributed in the high independence (50%) and low independence (57%) groups Clonus showed a trend of occurring during physical tasks in greater number of patients (86%) in the low independence group, than those (25%) in the high independence group (p>0.05) Clonus showed a trend of interfering with transfers in greater number of patients (75%) in the low independence group than those (13%) in the high independence group (p>0.05). DISCUSSION REFERENCES 1.GOTTLIEB, G. L. & AGARWAL, G. C. 1977. Physiological clonus in man. Experimental neurology, 54, 616-21 2.FRAIX, V., DELALANDE, I., PARRACHE, M., DERAMBURE, P. & CASSIM, F. 2008. Action-induced clonus mimicking tremor. Movement disorders : official journal of the Movement Disorder Society, 23, 285-8. 3.MCCLELLAN S, B. F., BOULIS NM, SUTLIFF MH, STOUGH DK, SCHWETZ KM, GOGOL DM, HARRISON M AND PIORO EP 2008. Intrathecal baclofen for spasticity-related pain in amyotropiic lateral sclerosis: efficact and factors associated with pain relief. Muscle & Nerve, 37, 396-398 4.WALSH, E. G. 1976. Clonus: beats provoked by the application of a rhythmic force. Journal of neurology, neurosurgery, and psychiatry, 39, 266-74 5.HIDLER, J. M. & RYMER, W. Z. 1999. A simulation study of reflex instability in spasticity: origins of clonus. IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 7, 327-40 Subject Age (years) Sex Most Impaired Side Etiology Chronicity (years) Barthel Index Score 152FbothMS12NA 262MbothMS30NA 368MleftStroke485 420MbothUnknown790 539FbothCP39100 631MleftTBI695 765MleftStroke-75 851MbothStroke1100 943MbothMS20100 1044MbothSCI170 1137MbothSCI32100 1222MbothSCI-60 1327MleftTBI95 1451FbothMS15 1574MleftStroke1285 1642MleftMS210 1755MleftStroke350 1844MbothSCI0.25NA