Patient-Reported Prevalence of Non-motor Symptoms Is Low in Adult Patients Suffering From 5q Spinal Muscular Atrophy

Exploring variability in cognitive functioning in patients with spinal muscular atrophy: a scoping review

The cognitive functioning of individuals with spinal muscular atrophy (SMA) is not well understood, prompting a call for more research to better grasp cognitive involvement in SMA. This study aims to explore recent findings regarding cognitive outcomes in SMA patients, including correlations between clinical features and cognitive abilities. The investigation seeks to identify commonly used measures for assessing cognitive function in this patient population. A scoping review following the Joanna Briggs Institute methodology examined literature until December 2023. Two databases were searched along with relevant article references using specific terms such as "spinal muscular atrophy," "SMA," "cognitive," "abilities," "functions," "intellective," or "intellectual." Screening focused on titles and abstracts from English language peer-reviewed journals. After the initial research, 1452 articles were identified. Subsequent screening and selection led to the inclusion of 13 articles in the review. Among these studies, four indicated a cognitive trend within the normal range for SMA patients. In four other studies, the majority of patients fell within the normal range. However, smaller proportions were observed to be either above or below the norm compared to the controls. Three studies reported noted cognitive performance below the average, while two showed above-average scores. The scoping review suggests that most SMA patients have cognitive abilities similar to the general population, with types II and III showing even lesser impact. However, certain cognitive domains may be affected in type I patients, highlighting the need for further research to fully understand cognitive involvement in SMA.

Ultrasonic detection of vagus, accessory, and phrenic nerve atrophy in amyotrophic lateral sclerosis: Relation to impairment and mortality

BACKGROUND AND PURPOSE

In amyotrophic lateral sclerosis (ALS), phrenic nerve (PN) atrophy has been found, whereas there is controversy regarding vagus nerve (VN) atrophy. Here, we aimed to find out whether PN atrophy is related to respiratory function and 12-month survival. Moreover, we investigated the relevance of VN and spinal accessory nerve (AN) atrophy in ALS.

METHODS

This prospective observational monocentric study included 80 adult participants (40 ALS patients, 40 age- and sex-matched controls). The cross-sectional area (CSA) of bilateral cervical VN, AN, and PN was measured on high-resolution ultrasonography. Clinical assessments included the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R), the Non-Motor Symptoms Questionnaire, and handheld spirometry of forced vital capacity (FVC). One-year survival was documented.

RESULTS

The CSA of each nerve, VN, AN, and PN, was smaller in ALS patients compared to controls. VN atrophy was unrelated to nonmotor symptom scores. PN CSA correlated with the respiratory subscore of the ALSFRS-R (Spearman test, r = 0.59, p < 0.001), the supine FVC (r = 0.71, p < 0.001), and the relative change of sitting-supine FVC (r = -0.64, p = 0.001). Respiratory impairment was predicted by bilateral mean PN CSA (p = 0.046, optimum cutoff value of ≤0.37 mm2 , sensitivity = 92%, specificity = 56%) and by the sum of PN and AN CSA (p = 0.036). The combination of ALSFRS-R score with PN and AN CSA measures predicted 1-year survival with similar accuracy as the combination of ALSFRS-R score and FVC.

CONCLUSIONS

Ultrasonography detects degeneration of cranial nerve motor fibers. PN and AN calibers are tightly related to respiratory function and 1-year survival in ALS.

[Experience with the use of risdiplam in a familial case of spinal muscular atrophy 5q in patients with a homozygous deletion of the SMN1 gene and the same copy number of the SMN2 gene]

Advances in the treatment of spinal muscular atrophy (SMA) have revolutionized the field. SMA is a rare autosomal recessive neurodegenerative motor neuron disease in which wide phenotypic variability has been described. The rate of increase in neurological deficit and the severity of the disease is mainly determined by the amount of functional SMN (Survival of Motor Neuron) protein. However, the clinical picture may differ significantly in patients carrying homozygous deletions of the SMN1 gene (Survival of Motor Neuron 1) and an identical number of copies of the SMN2 gene (Survival of Motor Neuron 2). A family clinical case of adult patients with spinal muscular atrophy 5q with a homozygous deletion of the SMN1 gene and the same number of copies of the SMN2 gene, having a different clinical picture of the disease, is presented, and the dynamics of the condition against the background of oral pathogenetic therapy is presented.

Cognitive impairment in Chinese adult patients with type III spinal muscular atrophy without disease-modifying treatment

Objective

Spinal muscular atrophy (SMA) is a neurodegenerative disorder characterized by the degeneration of motor neurons in the spinal cord. It remains uncertain whether the cognitive performance of adult patients with SMA is impaired. The objective of this study was to assess the cognitive profile of adult Chinese patients with SMA and the association between clinical features and cognitive ability, particularly executive function.

Methods

This cross-sectional study included 22 untreated adult patients with type III SMA and 20 healthy subjects. The following variables were assessed: general intelligence, memory, attention, language, executive function, depression, anxiety, and other demographic and clinical parameters. In addition, physical function was evaluated using the Hammersmith Functional Motor Scale Expanded (HFMSE), the Revised Upper Limb Module (RULM), and the 6-Minute Walk Test (6MWT).

Results

SMA patients had lower scores than healthy subjects in the Verbal Fluency Test, Stroop effect, Total Errors, Perseverative Responses, Perseverative Errors, and Non-perseverative Errors in the Wisconsin Card Sorting Test, showing impaired abilities of SMA patients in executive function. In the Attention Network Test (ANT), the results indicated that the SMA patients also had selective deficits in their executive control networks. Ambulant patients had better executive function test performance than non-ambulant ones. Compromised executive abilities in patients with SMA were correlated with a younger age at onset, poorer motor function, and higher levels of anxiety and depression.

Conclusion

Our study presented the distribution of cognitive impairment in a Chinese cohort with SMA. Patients with type III SMA showed selective deficits in executive function, which may be associated with disease severity, physical impairment, depression and anxiety. Future cognitive studies, accounting for motor and emotional impairment, are needed to evaluate if executive impairment is driven by specific brain changes or by those confounding factors.

Spinal Muscular Atrophy: An Evolving Scenario through New Perspectives in Diagnosis and Advances in Therapies

Spinal muscular atrophy (SMA) linked to 5q is a recessive motor neuron disease characterized by progressive and diffuse weakness and muscular atrophy. SMA is the most common neurodegenerative disease in childhood with an incidence of approximately 1 in 6000-10,000 live births, being long considered a leading cause of hereditary mortality in infancy, worldwide. The classification of SMA is based on the natural history of the disease, with a wide clinical spectrum of onset and severity. We are currently in a new therapeutic era, that, thanks to the widespread use of the newly approved disease-modifying therapies and the possibility of an early administration, should lead to a deep change in the clinical scenario and, thus, in the history of SMA. With the aim to achieve a new view of SMA, in this review we consider different aspects of this neuromuscular disease: the historical perspective, the clinical features, the diagnostic process, the psychological outcome, innovation in treatments and therapies, the possibility of an early identification of affected infants in the pre-symptomatic phase through newborn screening programs.

Cognitive performance of adult patients with SMA before and after treatment initiation with nusinersen

BACKGROUND

Spinal muscular atrophy (SMA) is a genetic neuromuscular disease caused by mutations of the SMN1 gene. Deficient SMN protein causes irreversible degeneration of alpha motor neurons characterized by progressive muscle weakness and atrophy. Considering that SMA is a multi-systemic disorder and SMN protein was found to be expressed in cortical structures, the cognitive profile of adult patients with SMA has recently been of particular interest. With nusinersen, a novel, disease-modifying drug has been established, but its effects on neuropsychological functions have not been validated yet. Aim of this study was to investigate the cognitive profile of adult patients with SMA during treatment initiation with nusinersen and to reveal improvement or deterioration in cognitive performance.

METHODS

This monocentric longitudinal study included 23 patients with SMA type 2 and 3. All patients were assessed with the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) before and after 14 months of treatment initiation with nusinersen. Additionally, motor function was evaluated by Hammersmith Functional Motor Scale Expanded (HFMSE), Revised Upper Limb Module (RULM) and Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R).

RESULTS

Of the treatment-naive patients, only three were below the age- and education-matched cut-off for cognitive impairment in the ECAS total score. Significant differences between SMA type 2 and 3 were only detected in the domain of Language. After 14 months of treatment, patients showed significant improvement of absolute scores in all three ALS-specific domains, in the non-ALS-specific domain of Memory, in both subscores and in the ECAS total score. No associations were detected between cognitive and functional outcome measures.

CONCLUSIONS

In some adult patients with SMA abnormal cognitive performance in ALS-specific functions of the ECAS was evident. However, the presented results suggest no clinically significant cognitive changes during the observed treatment period with nusinersen.

The complex syndrome of functional neurological disorder

BACKGROUND

Patients with functional neurological disorders (FND) often present with multiple motor, sensory, psychological and cognitive symptoms. In order to explore the relationship between these common symptoms, we performed a detailed clinical assessment of motor, non-motor symptoms, health-related quality of life (HRQoL) and disability in a large cohort of patients with motor FND. To understand the clinical heterogeneity, cluster analysis was used to search for subgroups within the cohort.

METHODS

One hundred fifty-two patients with a clinically established diagnosis of motor FND were assessed for motor symptom severity using the Simplified Functional Movement Disorder Rating Scale (S-FMDRS), the number of different motor phenotypes (i.e. tremor, dystonia, gait disorder, myoclonus, and weakness), gait severity and postural instability. All patients then evaluated each motor symptom type severity on a Likert scale and completed questionnaires for depression, anxiety, pain, fatigue, cognitive complaints and HRQoL.

RESULTS

Significant correlations were found among the self-reported and all objective motor symptoms severity measures. All self-reported measures including HRQoL correlated strongly with each other. S-FMDRS weakly correlated with HRQoL. Hierarchical cluster analysis supplemented with gap statistics revealed a homogenous patient sample which could not be separated into subgroups.

CONCLUSIONS

We interpret the lack of evidence of clusters along with a high degree of correlation between all self-reported and objective measures of motor or non-motor symptoms and HRQoL within current neurobiological models as evidence to support a unified pathophysiology of 'functional' symptoms. Our results support the unification of functional and somatic syndromes in classification schemes and for future mechanistic and therapeutic research.

Health-Related Quality of Life in Spinal Muscular Atrophy Patients and Their Caregivers-A Prospective, Cross-Sectional, Multi-Center Analysis

Spinal muscular atrophy (SMA) is a disabling disease that affects not only the patient’s health-related quality of life (HRQoL), but also causes a high caregiver burden (CGB). The aim of this study was to evaluate HRQoL, CGB, and their predictors in SMA. In two prospective, cross-sectional, and multi-center studies, SMA patients (n = 39) and SMA patient/caregiver couples (n = 49) filled in the EuroQoL Five Dimension Five Level Scale (EQ-5D-5L) and the Short Form Health Survey 36 (SF-36). Caregivers (CGs) additionally answered the Zarit Burden Interview (ZBI) and the Hospital Anxiety and Depression Scale (HADS). Patients were clustered into two groups with either low or high HRQoL (EQ-5D-5L index value <0.259 or >0.679). The latter group was mostly composed of ambulatory type III patients with higher motor/functional scores. More severely affected patients reported low physical functioning but good mental health and vitality. The CGB (mean ZBI = 22/88) correlated negatively with patients’ motor/functional scores and age. Higher CGB was associated with a lower HRQoL, higher depression and anxiety, and more health impairments of the CGs. We conclude that patient and CG well-being levels interact closely, which highlights the need to consider the health of both parties while evaluating novel treatments.

Spinal muscular atrophy

Spinal muscular atrophy (SMA) is a neurodegenerative disorder caused by mutations in SMN1 (encoding survival motor neuron protein (SMN)). Reduced expression of SMN leads to loss of α-motor neurons, severe muscle weakness and often early death. Standard-of-care recommendations for multidisciplinary supportive care of SMA were established in the past few decades. However, improved understanding of the pathogenetic mechanisms of SMA has led to the development of different therapeutic approaches. Three treatments that increase SMN expression by distinct molecular mechanisms, administration routes and tissue biodistributions have received regulatory approval with others in clinical development. The advent of the new therapies is redefining standards of care as in many countries most patients are treated with one of the new therapies, leading to the identification of emerging new phenotypes of SMA and a renewed characterization of demographics owing to improved patient survival.

Quality of Life in SMA Patients Under Treatment With Nusinersen

Background: Spinal Muscular Atrophy (SMA) is a severe neurodegenerative disease, characterized by progressive muscle weakness and atrophy. The approval of the antisense oligonucleotide (ASO) nusinersen now provides an effective pharmacological approach with the potential to slow down or stop disease progression with a potentially major impact on patients' well-being.

Objective: This study evaluates quality of life (QoL) in pediatric and adult patients over the course of therapy with nusinersen.

Methods: Twenty-six SMA patients treated with nusinersen were evaluated regarding global QoL (gQoL), health-related QoL (HRQoL) and depressiveness. Assessments were conducted three times over the first 6 months of treatment. Applied were different questionnaires: the Anamnestic Comparative Self-Assessment (ACSA) for gQoL, the Short Form-36 Health Survey (SF-36) for HRQoL in adult patients and the ALS Depression Inventory 12 Items (ADI-12) for depressiveness. The sample was matched with 22 healthy controls.

Results: Despite severe physical restrictions, patients reported high levels of QoL and low levels of depressiveness at study entry. Early disease onset and low levels of physical functioning were associated with better gQoL and lower levels of depressiveness. A significant decrease of gQoL in patients was evident over the course of the study. Still, adult patients reported a significant increase in perceived health.

Conclusions: Our study provides first insight that SMA patients experience a gQoL superior to healthy controls at start of therapy. This might indicate patients' high hopes and expectations toward treatment. gQoL returns to a level similar to that of healthy controls over the course of therapy.

Cognitive Performance of Patients with Adult 5q-Spinal Muscular Atrophy and with Amyotrophic Lateral Sclerosis

Motor neuron diseases, such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS), share several clinical similarities while differing substantially in etiology, disease onset and progression. Cognitive dysfunction, a clinically relevant non-motor feature in a substantial proportion of ALS patients, has been less frequently investigated in SMA. In this prospective multicenter cross-sectional study, cognitive function was assessed by the Edinburgh Cognitive (and Behavioural) ALS Screen (ECAS) and a German vocabulary test (Wortschatztest, WST) in 34 adult patients with SMA types 2-4 and in 34 patients with ALS. Demographic and clinical parameters were assessed to identify factors that potentially influence cognitive function. While SMA and ALS patients were comparable in the vocabulary test, on average, SMA patients performed better than ALS patients in the cognitive domains of memory, language and executive function. Better cognitive abilities in SMA patients seemed to be related to the early onset, rather than the extent or the duration, of their physical handicap. Future studies should focus on disease-specific cognitive functions in SMA.

[New treatments for spinal muscular atrophy]

5‑q-associated spinal muscular atrophy (SMA) has so far been a causally untreatable disease, which leads to severe, progressive physical restrictions due to the loss of spinal motor neurons. However, the monogenetic cause of the relatively short coding "survival motor neuron" (SMN) 1 gene sequence and the presence of almost identical gene copies, the SMN2 genes, offer favorable conditions for the development of new therapeutic approaches. While previously only supportive and palliative therapies could be used, new disease-modifying drugs are now available for the first time. Nusinersen, an antisense oligonucleotide (ASO), is the first drug that has received approval in Germany to treat SMA. Further therapeutic approaches such as the so-called "small molecules" or the gene replacement therapy are currently still being tested in clinical studies or are already waiting for approval by the European Medicines Agency (EMA). In this article, the most important disease-modifying drugs of SMA, the associated studies and their challenges are presented.

Health, wellbeing and lived experiences of adults with SMA: a scoping systematic review

BACKGROUND

Spinal muscular atrophy (SMA) is a neurodegenerative disease that has a substantial and multifaceted burden on affected adults. While advances in supportive care and therapies are rapidly reshaping the therapeutic environment, these efforts have largely centered on pediatric populations. Understanding the natural history, care pathways, and patient-reported outcomes associated with SMA in adulthood is critical to advancing health policy, practice and research across the disease spectrum. The aim of this study was to systematically review research investigating the healthcare, well-being and lived experiences of adults with SMA.

METHODS

In accordance with the Preferred Reported Items for Systematic Reviews and Meta-Analysis guidelines, seven electronic databases were systematically searched until January 2020 for studies examining clinical (physical health, natural history, treatment) and patient-reported (symptoms, physical function, mental health, quality of life, lived experiences) outcomes in adults with SMA. Study risk of bias and the level of evidence were assessed using validated tools.

RESULTS

Ninety-five articles met eligibility criteria with clinical and methodological diversity observed across studies. A heterogeneous clinical spectrum with variability in natural history was evident in adults, yet slow declines in motor function were reported when observational periods extended beyond 2 years. There remains no high quality evidence of an efficacious drug treatment for adults. Limitations in mobility and daily activities associated with deteriorating physical health were commonly reported, alongside emotional difficulties, fatigue and a perceived lack of societal support, however there was no evidence regarding effective interventions.

CONCLUSIONS

This systematic review identifies the many uncertainties regarding best clinical practice, treatment response, and long-term outcomes for adults with SMA. This comprehensive identification of the current gaps in knowledge is essential to guide future clinical research, best practice care, and advance health policy with the ultimate aim of reducing the burden associated with adult SMA.