1. The Effect of Cognitive Fatigue on Language in Multiple Sclerosis Leena Maria Heikkola, Päivi Hämäläinen and Juhani Ruutiainen Åbo Akademi University, Finnish Department, Finland (LMH); University of Queensland, School of Health and Rehabilitation Sciences, Australia (LMH); Masku Neurological Rehabilitation Centre, Finland (PH & JR) Contact Details Leena Maria Heikkola School of Health and Rehabilitation Sciences The University of Queensland St. Lucia QLD 4072, AUSTRALIA (until 31/12/07)‏ Email: l.heikkola@uq.edu.au or lheikkol@abo.fi Introduction Multiple sclerosis (MS) has traditionally been researched from a medico-physical viewpoint, and only during the last decades the cognitive aspects of MS have drawn attention (LaRocca & Kalb 2006), even though up to 50–66 % of MS patients show cognitive difficulty (Peyser et al. 1990). Cognitive fatigue has only recently gained scientific interest, although it is reported to be one of the three most disabling symptoms for persons with MS (Krupp 2004; LaRocca & Kalb 2006). The research on communicative disorders caused by MS has mainly concentrated on the motor disorders of language, while dis- orders due to cognitive disorders have been left untreated (Murdoch & Theodoros 2000). Thus far, no studies have explored the relationship between cognitive fatigue and language in the MS population (Krupp & Elkins 2000). Aims 1. To profile language disorders in the spontaneous speech of MS patients. 2. To explore possible effects of cognitive fatigue on the language of MS patients. Control group (n = 5) is matched for age (mean = 45 yrs; SD = 3.08), education (mean = 14.1 yrs; SD = 1.52) and gender. Procedure Subjects produced spontaneous speech based on picture material previously used in aphasia research, e.g. Frog Stories. Speech was recorded. In addition, subjects were administered neuropsychological test batteries measuring linguistic and cognitive ability. Data will be used as background information for linguistic analysis. Data analysis The speech produced during five different speech tasks were transcribed. The five tasks included three Frog Stories, a 6- piece comic strip and a picture of a campsite. For the pilot study, Visual Analogue Scale (VAS) measuring self- perceived fatigue in speech production at the beginning and at the end of the speech tasks was used to measure the effects of cognitive fatigue on speech. Results and Discussion As a group, the MS patients’ experienced fatigue in speech production increases towards the end during the speech tasks. This is also evident looking at individual patients, except for MS09, see figure 1. Figure 1. Experienced fatigue in speech production in MS patients. In the control group, the experienced fatigue also increases during the speech tasks, see figure 2. However, majority of the controls experience significantly less fatigue compared to the MS patients. Figure 2. Experienced fatigue in speech production in controls. Speech rate decreases slightly towards the end of the speech tasks in MS patients, see figure 3. As a group, the speech rate remains the same in both MS and control group, see figure 4. However, the overall speech rate is significantly lower in the MS group compared to the control group. Figure 3. Speech rate in MS patients. Figure 4. Mean speech rate in the MS group and the control group. Conclusions‏ According to the first hypothesis, the experienced fatigue in speech production seems to increase during, and towards the end of the language tasks both in MS and control group. However, the experienced fatigue is significantly greater in the MS patients. Contrary to the second hypothesis, as a group, MS patients' speech rate does not decrease towards the end of the speech tasks. However, examining individual data, the experienced fatigue in speech production does seems to correlate with a decrease in speech rate. Interestingly, the overall speech rate also seems to correlate with the experienced fatigue. The MS patients show significantly lower speech rates compared to the controls, both as a group, and as individuals. References Krupp, L. B. (2004). Fatigue in multiple sclerosis: A guide in diagnosis and management. New York: Demos. Krupp, L. B. & Elkins, L. E. (2000). Fatigue and declines in cognitive functioning in multiple sclerosis. Neurology 55, 934–939. LaRocca, N. & Kalb, R. (2006). Multiple sclerosis: Understanding the cognitive challenges. New York: Demos. Murdoch, B. & Theodoros, D. (2000). Speech and Language Disorders in Multiple Sclerosis. London and Philadelphia: Whurr Publishers. Peyser, J. M.; Rao, S. M.; LaRocca, N. G. & Kaplan, E. (1990). Guidelines for neuro- psychological research in multiple sclerosis. Arch Neurol 47, 94–97. Hypotheses 1. Experienced fatigue in the speech production of MS patients increases during speech tasks. 2. MS patients' speech rate decreases from the start towards the end during language tasks. Method Participants for the pilot study Five female participants with relapsing-remitting MS. Mean age 45.8 yrs (SD = 4.96 yrs), mean education 15.1 yrs (SD = 1.95 yrs). Future research A bigger group of relapsing- remitting, and a group of secondary progressive MS patients will be included in the study. The language of MS patients will be investigated thoroughly looking at e.g. sentence length and grammatical structures. Neuropsychological test results will be used as background information for qualitatively and quantitatively investigating the relationship between cognitive fatigue and language disorders in MS.