Cognitive Rehabilitation for Multiple Sclerosis Patients With Executive Dysfunction

Accumulating data suggest that Multiple Sclerosis (MS) patients suffer from various cognitive impairments (Amato, Ponziani, Pracucci, Bracco, Siracusa & Amaducci, 1995; Truelle, Palisson, Le Gall, Stip & Derouesne,1987; Callanan, 1989; Maurelli, Marchioni, Cerretano, Bosone, Bergamaschi, Citterio, Martelli, Sibilla & Savoldi, 1992; Zakzanis, 2000). Yet, only a few studies have focused on intervention techniques that aim to improve the cognitive functioning of MS patients. Jonnsson (Jonnsson, Korfitzen, Heltberg, Ravnborg & Byskov-Ottosen, 1993) reported that although the effects of short-term (46 days) neuropsychological training on cognitive measures were not unequivocal, the results of the Beck Depression Inventory seemed to confirm the beneficial effects of the neuropsychological treatment. The present study reports the effects of cognitive rehabilitation over a period of six months, with approximately 24 therapeutic sessions. We focused our intervention on executive functions, since they are commonly reported as one of the cognitive impairments typical in MS patients. Executive functions encompass cognitive processes, such as attention and working memory and also metacognitive control processes, such as the evaluation of a task’s difficulty, planning and choosing the right strategies, anticipating results, and monitoring the ongoing process (Flavell, 1985). Thus, the metacognitive processes are essential for successful executive functions. Metacognitive dysfunction may be described as a decrease in the use of efficient processing strategies to select, discriminate, organize, and structure incoming information, as well as a reduced ability to access previous knowledge and to apply knowledge and skills flexibly to a variety of situations (Toglia, 1991). These metacognitive control processes are considered to be associated with prefrontal cortex functions (Shallice, 1988; Shallice & Burgess, 1991). Hence, executive functions are typically assessed using neuropsychological tests that were found to be sensitive to the evaluation of frontal lobe functions, such as the Wisconsin Card Sorting Test (WCST) (Bryan & Luszcz, 2000). It has been demonstrated that MS patients fail to use an efficient strategy in the WCST (Beatty, Goodkin, Monson & Beatty, 1989; Arnett, Rao, Grafman, Bernardin, Luchetta, Binder, & Lobeck, 1997; Beatty & Monson, 1996; Arnett, Rao, Bernardin, Grafman, Yetkin & Lobeck, 1994; Foong, Rozewicz, Quaghebeur, Davie, Kartsounis, Thompson, Miller & Ron, 1997). MS patients were also found to be impaired on other executive function measures, including temporal-ordering, semantic encoding, the Tower of Hanoi test, and word fluency tasks (Amato et al, 1995; Beatty et al, 1989; Arnett et al, 1997; Archibald & Fisk 2000). A specific difficulty with applying an efficient working strategy in a verbal recognition task was also reported (Carroll, Gates & Roldan, 1984). In a former study (Birnboim, 2004), we tested 76 MS patients using the Strategy Application Test (SAT), (Levine et al, 1998; Birnboim, 2004) which aims to measure the ability to apply and maintain a working strategy for efficient execution of tasks. Strategies are sequences of activities aimed towards reaching goals efficiently and effectively (Nickerson, Perkins & Smith, l985). Ten of the MS patients with very poor results on the SAT who also were able to commit to six months of cognitive rehabilitation were selected for the current study. The aim of this study was to explore the effectiveness of cognitive rehabilitation for MS patients with executive function impairments. The Metacognitive therapeutic approach was used in the neuro-rehabilitation (Birnboim, 1995) (see description in Methods). According to this approach, the final goal of the intervention is to improve the patient’s functioning in his/her daily life. However, we cannot expect patients with cognitive impairments to transfer and incorporate the strategies learned in the clinic to daily life without the therapist’s guidance and encouragement. Thus, the intervention must encompass the patient’s relevant activities outside the clinic, and the main measure of the intervention’s success should be the degree to which changes are incorporated in daily life. The two case reports illustrate the intervention principles and techniques.