Cognitive performance in patients with Myasthenia Gravis: an association with glucocorticosteroid use and depression

Frequency and Correlates of Mild Cognitive Impairment in Myasthenia Gravis

BACKGROUND

Antibodies against acetylcholine receptors (AChRs) can also target nicotinic AChRs that are present throughout the central nervous system, thus leading to cognitive dysfunctions in patients with myasthenia gravis (MG). However, the presence of cognitive impairment in MG is controversial, and the factors that may influence this risk are almost completely unknown. In this study, the frequency of mild cognitive impairment (MCI) in MG, as well as the clinical, immunological, and behavioral correlates of MCI in MG were evaluated.

METHODS

A total of 52 patients with MG underwent a comprehensive assessment including motor and functional scales, serological testing, and neuropsychological and behavioral evaluation.

RESULTS

The frequency of MCI was 53.8%, and the most impaired cognitive domains were, in order, visuoconstructive/visuospatial skills, memory, and attention. After multivariate analysis, only pyridostigmine use was inversely associated with the presence of MCI, while a trend toward a positive association between MCI and disease severity and arms/legs hyposthenia was found. Correlation analyses showed that daily doses of prednisone and azathioprine significantly correlated with depressive symptomatology, while disease severity significantly correlated with depressive symptomatology and sleep disturbance.

CONCLUSIONS

The presence of MCI is rather frequent in MG and is characterized by multidomain amnestic impairment. Such preliminary data need further confirmation on larger case series.

Prevalence of depression and anxiety among myasthenia gravis (MG) patients: A systematic review and meta-analysis

OBJECTIVE

Myasthenia gravis (MG) people experience adverse psychiatric outcomes, which may impact on their life and disturb their daily activity. Depression and anxiety are identified as significant psychiatric problems that MG people face. However, there is no sufficient epidemiological information about depression and anxiety-based publication. Due to this limitation, the aim of this study was to review the prevalence of depression and anxiety in MG patients.

METHODS

Original and international databases were searched to find papers about the estimation of anxiety and depression. Random-effects analysis was used for calculating the proportions of anxiety and depression. For estimating anxiety and depression based the severity, instruments, type of studies, and study regions, subgroup analysis was performed.

RESULTS

38 studies met inclusion criteria and entered study. The pooling of the prevalence of depression was found at 36%, (95% CI 28% to 45%). Also, prevalence of anxiety was found at 33%, (95% CI 25% to 42%). Prevalence of depression based on mild, moderate, and severe level was 27%, 14%, and 9%, respectively.

CONCLUSIONS

Anxiety and depression are a major concern among MG individuals. The estimation of both anxiety and depression are high even when compared to other autoimmune diseases. It seems depression and anxiety are important issues and more attention needs to be paid to these psychiatric disorders.

Association Between Myasthenia Gravis and Memory: A Systematic Review and Meta-Analysis

Objective: The studies have produced contradictory results regarding the association between myasthenia gravis (MG) and cognitive function, especially for the cognitive domains of memory. This meta-analysis was dedicated to exploring the association between MG and memory, which was represented by the immediate recall and delayed recall.

Methods: Using the random effects models, this study analyzed memory in MG based on data from the studies retrieved from four electronic databases from inception to February 2021. Disease severity was graded according to the Myasthenia Gravis Foundation of America (MGFA) classification. We defined ocular myasthenia gravis (OMG) (MGFA Grade I) as Class I, mild, and moderate generalized myasthenia gravis (GMG) (MGFA Grade IIa, IIb, IIIa, and IIIb) as Class II.

Results: In total, eight studies of 274 patients and 211 healthy controls were included. The significant associations were found between MG and memory. Compared with the healthy control group, the patients with MG performed significantly worse in the terms of immediate recall [standardized mean difference (SMD) = −0.65, 95% CI = −0.97 to −0.33, P < 0.001, I² = 64.1%] and delayed recall (SMD = −0.49, 95% CI = −0.88 to −0.1, P < 0.05, I² = 76.3%). Compared with the patients with Class I MG, those with Class II MG did not have significantly different scores in immediate recall (SMD = −0.07, 95% CI = −0.35 to 0.21, P = 0.614, I² = 0%) and delayed recall (SMD = 0.63, 95% CI = −0.29 to 1.55, P = 0.178, I² = 87.9%).

Conclusion: The patients with MG showed lower memory performance, such as both immediate and delayed recall ability. There was no association between the severity of MG and memory. Future studies should address whether these associations are casual and modifiable.