**4.2 Cognitive impairments and QOL of DM1**

The mean age of the 60 participants with DM1 (35 men and 25 women) was 47.1 (SD = 10.8), and the mean age at the onset of DM1 was 29.0 (SD = 13.2). Moreover, the mean duration of illness was 17.2 years (SD = 11.4). Also, the mean number of CTG repeats was 1132.2 (SD = 1025.2).

The results indicated that most cognitive functions of DM1 patients were lower than the general population (**Table 1**). In particular, more than half of the patients scored 2 SD lower than the general population for attention and working


**43**

*Cognitive Function and Quality of Life of Muscular Dystrophy*

*Correlation between psychological variables and QOL (Fujino et al. [34]).*

memory (Auditory Detection task, 67% [hit], 60% [correct]), executive function (Position Stroop test, 79%), processing speed (Visual Cancelation task, 91%, Symbol Digit Modalities test, 54%), and visuoconstructive ability (Block Design, 64%). Although patients were markedly impaired on tasks that assessed complex attentional functions (PASAT-2 and Memory Updating 3), they were not severely affected on those assessing simple attentional functions (Digit Span [forward] and Tapping Span [forward]. Certain patients scored 2 SD higher than the general population on psychological factors including apathy (22%), depression (23%),

Factor analysis categorized MDQoL results into Psychosocial relationship factor and Physical functioning and Health factor. The Psychosocial relationship factor was associated with Digit Span (forward, r = 0.39), Tapping Span (forward, r = 0.40), TMT-A (r = −0.38), and Visual Cancelation task (r = −0.48) (**Table 3**). Additionally,

the Psychosocial relationship factor was negatively associated with apathy

(r = o.46), and Auditory Detection task (r = −0.44) (**Table 4**).

have been effective in other neurological conditions [43–45].

**5. Psychopathological features and personality of DM1 patients**

Some studies pointed that depression and fatigue predict psychological and physical QOL in patients with muscular diseases [46, 47]. Additionally, apathy could promote social inhibition and avoidance of social interactions [48]. All of them, in conjunction with each other, lead to the deterioration of the

(r = −0.37), depression (r = −0.52), and fatigue (r = −0.42). Physical Functioning and Health factor was negatively associated with depression (r = −0.66) and fatigue (r = −0.55). Apathy was associated with the FAB (r = −0.47), Visual Cancelation

These results demonstrated that patients with DM1 have specific cognitive impairments including executive dysfunctions, processing speed impairments, attentional problems, and visuoconstructive problems. Improved cognitive abilities in attention and working memory, as well as processing speed, were associated with higher QOL, whereas higher apathy, depression, and fatigue were associated with lower QOL. It is possible that apathy mediates the influence of cognitive functions on the QOL, which suggest that the reduction of apathy might lead to better cognitive performance or vice versa [42]. Cognitive assessment can provide useful information for patients, allowing them to plan support in their daily lives. Cognitive interventions might also contribute to improving the QOL of patients with DM1 because neuropsychological rehabilitation and cognitive remediation

*DOI: http://dx.doi.org/10.5772/intechopen.86222*

and fatigue (15%) (**Table 2**).

**Table 4.**

#### **Table 3.**

*Correlations between cognitive function and QOL (Fujino et al. [34]).*


#### **Table 4.**

*Muscular Dystrophies*

**4.2 Cognitive impairments and QOL of DM1**

CTG repeats was 1132.2 (SD = 1025.2).

The mean age of the 60 participants with DM1 (35 men and 25 women) was 47.1 (SD = 10.8), and the mean age at the onset of DM1 was 29.0 (SD = 13.2). Moreover, the mean duration of illness was 17.2 years (SD = 11.4). Also, the mean number of

The results indicated that most cognitive functions of DM1 patients were lower than the general population (**Table 1**). In particular, more than half of the patients scored 2 SD lower than the general population for attention and working

**42**

**Table 3.**

*Correlations between cognitive function and QOL (Fujino et al. [34]).*

*Correlation between psychological variables and QOL (Fujino et al. [34]).*

memory (Auditory Detection task, 67% [hit], 60% [correct]), executive function (Position Stroop test, 79%), processing speed (Visual Cancelation task, 91%, Symbol Digit Modalities test, 54%), and visuoconstructive ability (Block Design, 64%). Although patients were markedly impaired on tasks that assessed complex attentional functions (PASAT-2 and Memory Updating 3), they were not severely affected on those assessing simple attentional functions (Digit Span [forward] and Tapping Span [forward]. Certain patients scored 2 SD higher than the general population on psychological factors including apathy (22%), depression (23%), and fatigue (15%) (**Table 2**).

Factor analysis categorized MDQoL results into Psychosocial relationship factor and Physical functioning and Health factor. The Psychosocial relationship factor was associated with Digit Span (forward, r = 0.39), Tapping Span (forward, r = 0.40), TMT-A (r = −0.38), and Visual Cancelation task (r = −0.48) (**Table 3**). Additionally, the Psychosocial relationship factor was negatively associated with apathy (r = −0.37), depression (r = −0.52), and fatigue (r = −0.42). Physical Functioning and Health factor was negatively associated with depression (r = −0.66) and fatigue (r = −0.55). Apathy was associated with the FAB (r = −0.47), Visual Cancelation (r = o.46), and Auditory Detection task (r = −0.44) (**Table 4**).

These results demonstrated that patients with DM1 have specific cognitive impairments including executive dysfunctions, processing speed impairments, attentional problems, and visuoconstructive problems. Improved cognitive abilities in attention and working memory, as well as processing speed, were associated with higher QOL, whereas higher apathy, depression, and fatigue were associated with lower QOL. It is possible that apathy mediates the influence of cognitive functions on the QOL, which suggest that the reduction of apathy might lead to better cognitive performance or vice versa [42]. Cognitive assessment can provide useful information for patients, allowing them to plan support in their daily lives. Cognitive interventions might also contribute to improving the QOL of patients with DM1 because neuropsychological rehabilitation and cognitive remediation have been effective in other neurological conditions [43–45].

## **5. Psychopathological features and personality of DM1 patients**

Some studies pointed that depression and fatigue predict psychological and physical QOL in patients with muscular diseases [46, 47]. Additionally, apathy could promote social inhibition and avoidance of social interactions [48]. All of them, in conjunction with each other, lead to the deterioration of the

QOL. Therefore, the psychological interventions for DM1 should incorporate these factors as potential targets for improving patients' QOL.

Minier et al. [49] conducted a systematic literature review of psychopathological features in DM1 and reported that patients with DM1 present mild psychopathological problems, such as interpersonal difficulties, lack of interest, dysphoria, concern about bodily functioning, and hypersensibility. However, they do not present more psychiatric disorders than the general population, except for personality disorders and depression. Moreover, avoidant personality disorder was the most common of several personality disorders among DM1 patients.

### **5.1 Lack of awareness about the illness**

In clinical practice, DM1 patients commonly showed less awareness of the disease distress and its progression. This is named anosognosia or lack of awareness, which can lead to misattributions of symptoms, delay of diagnostic procedures, and low compliance with treatment. The lack of awareness about their illness often is observed in individuals with brain diseases and neurodegenerative disorders, such as Alzheimer's diseases and acquired brain injury. In these disorders, the lack of awareness can be a direct consequence of the underlying pathological process [50]. Research on brain injuries suggests that the prefrontal cortex plays a crucial role in maintaining awareness [51].

Baldanzi et al. [52] conducted a study to estimate the prevalence of disease awareness in 65 adult patients with DM1. The degree of awareness was evaluated by comparing motor impairments using MIRS, patients' complaints about their symptoms, and by comparing INQOL between caregivers. The results indicated that 51.6% of patients were unaware of the disease, and the lack of awareness was most prominent in Independence (52.4%) and Social Relationship (47.6%) domains. Moreover, the lack of awareness was significantly related to failures in cognitive test performance, specifically in the domains of visuospatial memory, cognitive flexibility, and conceptualization. Baldanzi et al. suggested that gaining a better understanding of anosognosia would be useful for the medical management of patients with DM1 and for providing guidance for occupational and social interventions.
