Therapeutic advances in SMA.

PURPOSE OF REVIEW: To review the advent of novel therapies and their impact on the field of chromosome 5q-associated spinal muscular atrophy (SMA). RECENT FINDINGS: Antisense oligonucleotides (ASOs) enhancing SMN2 function are delivered intrathecally and small molecules will also be available soon delivered by the oral route; alternatively, systemic injection of viral vectors in order to replace the SMN gene are likely to be available in the future. In summer 2019, it remains the core finding that intrathecally delivered ASOs convincingly change the natural history of the disease in children and that the treatment effect is the better, the earlier ASO treatment is started. Therefore, postnatal screening for deletions and mutations in the SMN gene is presently discussed. Much has to be learnt, however, both on the challenges of the intrathecal mode of delivery and the efficacy of ASOs in adolescent and adult patients. Therapeutic outcome measures mirroring this phenotype are difficult to assess in this group of patients. SUMMARY: Therapeutic advances in 5q-associated SMA have been convincing in the previous years and change the field. This includes newborn screening, changing phenotypes in the treated children, challenges for drug administration in adolescents and adults and the comparison of drug effects. Long-term studies are required.

[Treatment evaluation in patients with 5q-associated spinal muscular atrophy : Real-world experience]. / Therapieevaluation bei Patienten mit 5q-assoziierter spinaler Muskelatrophie : Erfahrungen aus der klinischen Praxis.

Spinal muscular atrophy (SMA) is a progressive autosomal recessive neurodegenerative disease with an incidence of 1:10,000 live births. With a deeper understanding of the molecular basis of SMA in the past two decades, a major focus of therapeutic development has been on increasing the proportion of functionally capable SMN protein by increasing the inclusion of exon 7 in SMN2 transcripts, enhancing SMN2 gene expression, stabilizing the SMN protein or replacing the SMN1 gene. Since June 2017, the antisense oligonucleotide nusinersen/Spinraza® (Biogen GmbH, Ismaning, Germany) has been approved for 5qSMA treatment. Nusinersen modifies premessenger RNA splicing of exon 7, leading to stable SMN protein expression and for the first time an effective disease-modifying treatment is available. In several controlled trials nusinersen showed a favorable benefit-risk profile along with clinically relevant improvements in motor function. The efficacy was most pronounced in presymptomatic patients, which underlines the necessity for a newborn screening program and is the key to start efficient treatment prior to motor neuron death. The repeated intrathecal administration of nusinersen is associated with practical challenges, in particular for patients with severe scoliosis or after spinal straightening surgery. As the vast majority of SMA patients were outside previous study populations regarding age and disease duration, experts complained about a lack of data on efficacy and safety beyond childhood. To fill these gaps a systematic data collection has been initiated by the SMArtCARE initiative, aiming at collecting comprehensive data in the clinical routine, regardless of the patients' individual treatment regimen.

[Spinal Muscular Atrophy - expert recommendations for the use of nusinersen in adult patients]. / Spinale Muskelatrophie ­ Expertenempfehlungen zur Behandlung von erwachsenen Patienten mit Nusinersen.

With Nusinersen, a first causative treatment for 5q-associated spinal muscular atrophy (SMA) has been available in Europe since 2017. Real-world data from neuromuscular clinical centers in Germany increasingly show a therapeutic benefit of nusinersen also in adult SMA patients of both sexes: in many cases, relevant improvements in or at least a stabilization of motor functions are achieved, potentially leading to enhanced autonomy in activities of daily life and to improved quality of living. Even in patients with severe spinal deformities, intrathecal application is usually feasible and safe using imaging modalities. Regular systematic evaluation of the motor status with validated instruments is crucial for adequate monitoring of the therapeutic effects. The documentation in SMA registries enables systematic development of a database for further development of this novel treatment paradigm. Relevant aspects of this novel therapeutic principle were discussed at an experts conference in Frankfurt / Main in February 2019.

Paradoxical increase of neurofilaments in SMA patients treated with onasemnogene abeparvovec-xioi.

Background/Objective: Neurofilament light chain (NfL) has been proposed as a biomarker reflecting disease severity and therapy response in children with spinal muscular atrophy type 1 and 2 (SMA1 and 2). The objective of this study was to examine how serum NfL changes after gene replacement therapy (GRT) with onasemnogene abeparvovec-xioi. Methods: We measured NfL in serum probes from 19 patients (10 SMA 1 and 6 SMA 2; 15 previously treated with nusinersen or risdiplam; 12 male) before and at variable time points after GRT. These values were related to motor scores (CHOP-Intend, HFMSE and RULM). Results: Median age at GRT was 19 months (range 2-46 months). Median NfL of all patients before GRT was 39 pg/ml (range 0-663 pg/ml; normal values <25 pg/ml), increased significantly to 297 pg/ml (range 61-1,696 pg/ml; p<0,002) 1 month after GRT, and decreased to 49 pg/ml (range 24-151 pg/ml) after 6 months. Subjects pre-treated with nusinersen or risdiplam had lower baseline NfL levels than naïve patients (p<0,005), but absolute increases of NfL were similar in both groups. While motor scores were improved in 14 out of 18 SMA patients (78%) 6 months after GRT NfL values differed not significantly from those measured at baseline (p = 0,959). Conclusion: Serum NfL showed a paradoxical transient increase after GRT in both, pre-treated and naïve patients, which may reflect an immunological reaction in the CNS related to transfection of neuronal cells by AAV9. The clinical meaning of this increase should be assessed in future studies. Our findings encourage regular monitoring of NfL in OA treated patients.

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.

Glial fibrillary acidic protein in cerebrospinal fluid of patients with spinal muscular atrophy.

OBJECTIVE: Activated astroglia is involved in the pathophysiology of neurodegenerative diseases and has also been described in animal models of spinal muscular atrophy (SMA). Given the urgent need of biomarkers for treatment monitoring of new RNA-modifying and gene replacement therapies in SMA, we examined glial fibrillary acidic protein concentrations in cerebrospinal fluid (cGFAP) as a marker of astrogliosis in SMA. METHODS: 58 adult patients and 21 children with genetically confirmed 5q-associated SMA from four German motor neuron disease specialist care centers and 30 age- and sex-matched controls were prospectively included in this study. cGFAP was measured and correlated to motor performance and disease severity. Additionally, we compared cGFAP with neurofilament light chain concentrations in cerebrospinal fluid (cNfL). RESULTS: cGFAP concentrations did not differ from controls but showed higher levels in more severely affected patients after adjustment for patients' age. Normalized cNfL values were associated with disease severity. Within 14 months of nusinersen treatment, cGFAP concentrations did not change, while cNfL decreased significantly. INTERPRETATION: cGFAP is not an outstanding biomarker in SMA, but might support the hypothesis that glial activation is involved in SMA pathology. Unlike previously suggested, cNfL may be a promising biomarker also in adult patients with SMA, which should be subject to further investigations.

Validity and reliability of the German multidimensional fatigue inventory in spinal muscular atrophy.

OBJECTIVE: Fatigue is a common and burdensome symptom of spinal muscular atrophy. Given its complex interactions, different dimensions of fatigue need to be investigated. The Multidimensional Fatigue Inventory is a widely used instrument that captures five distinct dimensions. The aim of this study was to investigate the validity and reliability of the German Multidimensional Fatigue Inventory in spinal muscular atrophy and to evaluate the presence of clinically relevant fatigue. METHODS: One hundred and forty adult spinal muscular atrophy patients completed the Multidimensional Fatigue Inventory in a nationwide, multicenter, cross-sectional study. Structural validity was explored using principal component analysis. Cronbach's α was calculated to evaluate internal consistency. Convergent validity was assessed by correlation with a Visual Analog Scale for fatigue and the EuroQol-Five Dimension-Five Level Scale as a measure of quality of life. RESULTS: The original five-component model of the questionnaire constituted an acceptable fit. Internal consistency and convergent validity of general, physical, mental fatigue, and reduced activity were good. We observed a floor effect for mental fatigue. While physical fatigue exceeded the cutoff for clinically relevant fatigue, all dimensions but reduced motivation correlated negatively with quality of life. Age, depression, and ≥4 copies of the survival motor neuron 2 gene were associated with higher general/physical fatigue; unemployed participants reported higher scores for reduced activity/motivation. INTERPRETATION: The Multidimensional Fatigue Inventory is a valid and reliable instrument to assess different dimensions of fatigue in spinal muscular atrophy. Fatigue is a relevant problem in spinal muscular atrophy and its assessment should be incorporated into standard care.

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.

Executive function is inversely correlated with physical function: the cognitive profile of adult Spinal Muscular Atrophy (SMA).

BACKGROUND: Spinal muscular atrophy (SMA) issues from mutations in the survival of motor neuron (SMN) 1 gene. Loss or reduction of the SMN protein results in progressive muscle weakness. Whether this protein deficiency also affects cortical function remains unclear. While no data on adult patients exists so far, prior studies in children with SMA indicate cognitive abilities equal or even superior to healthy controls. This may suggest a possible compensatory-neuropsychological and interactional-process. The goal of this study was to assess the cognitive profile of adult patients with SMA, with a special focus on social cognition as a potential candidate for enhanced cognitive function through compensatory processes. METHODS: In a cross-sectional design, N = 31 adult SMA patients (types II and III) were assessed for language, verbal fluency, memory, visuospatial abilities and executive function with the Edinburgh Cognitive and Behavioural ALS Screen and for social cognition with the Reading the Mind in the Eyes Test. Physical function was evaluated using the Hammersmith Functional Motor Scale Expanded. N = 19 neurologically healthy controls were matched with patients for age, sex and years of education. RESULTS: In none of the abovementioned cognitive domains significant differences between SMA patients and controls were found. Among patients, no differences between type II SMA and type III SMA were detected for any domain. However, a trend towards better social cognition in patients with type II SMA, compared to those with type III SMA was observed. Furthermore, a significant inverse correlation of physical function and executive function was detected: lower motor function was associated with a better executive function. CONCLUSIONS: This study shows cognitive abilities in adult SMA in the normal range for all assessed domains. Thus, reduction of SMN protein has no obvious negative impact on cognitive function. Executive functions are identified as the only cognitive domain correlated with disease severity. Therefore, executive functions may play a role in the adaptation to physical restrictions in SMA, making them a promising target for future research.

Treatment satisfaction in 5q-spinal muscular atrophy under nusinersen therapy.

BACKGROUND: Nusinersen was the first approved disease-modifying therapy for all 5q-spinal muscular atrophy (SMA) patients regardless of age or disease severity. Its efficacy in adults has recently been demonstrated in a large cohort by motor outcome measures, which were only partially suitable to detect changes in very mildly or severely affected patients. Patient-reported outcome measures (PROs) have been suggested as a valuable addition. Here, we aimed to assess treatment satisfaction and investigate whether it may be a useful PRO to monitor SMA patients. METHODS: We enrolled 91 mainly adult 5q-SMA patients treated with nusinersen in a national, multicenter, cross-sectional observational study. 21 patients underwent longitudinal follow up. Patients' satisfaction with treatment in four dimensions (global, effectiveness, convenience, side effects) was assessed by the Treatment Satisfaction Questionnaire for Medication German version 1.4 (TSQM-1.4©) and related to clinical parameters, motor scores, and treatment duration. RESULTS: More than 90% of SMA patients were consistently satisfied over a median treatment duration of 10 months. Highest mean scores were observed in the dimensions 'side effects,' 'global satisfaction,' and 'effectiveness' (93.5 ± 14.8 versus 73.1 ± 21.0 and 64.8 ± 20.6, respectively). Patients' satisfaction with the convenience of treatment was considerably lower (43.6 ± 20.2). Interestingly, satisfaction with the effectiveness was higher in ambulatory (p = 0.014) compared with non-ambulatory patients and directly correlated to motor outcome measures. Five non-ambulatory patients withdrew from therapy. All of them presented with a deterioration of motor outcome measures and reported dissatisfaction with treatment effectiveness and convenience. CONCLUSION: Most patients were satisfied with nusinersen treatment effectiveness. Less severely affected patients indicated higher satisfaction. The TSQM-1.4© helped to identify therapy non-responders, who mainly addressed dissatisfaction with effectiveness and convenience. We suggest introducing the TSQM-1.4© as an additional PRO in SMA into clinical practice.

Serum creatine kinase and creatinine in adult spinal muscular atrophy under nusinersen treatment.

OBJECTIVE: To determine whether serum creatine kinase activity (CK) and serum creatinine concentration (Crn) are prognostic and predictive biomarkers for disease severity, disease progression, and nusinersen treatment effects in adult patients with 5q-associated spinal muscular atrophy (SMA). METHODS: Within this retrospective, multicenter observational study in 206 adult patients with SMA, we determined clinical subtypes (SMA types, ambulatory ability) and repeatedly measured CK and Crn and examined disease severity scores (Hammersmith Functional Motor Scale Expanded, Revised Upper Limb Module, and revised Amyotrophic Lateral Sclerosis Functional Rating Scale). Patients were followed under nusinersen treatment for 18 months. RESULTS: CK and Crn differed between clinical subtypes and correlated strongly with disease severity scores (e.g., for Hammersmith Functional Motor Scale Expanded: (CK) ρ = 0.786/ (Crn) ρ = 0.558). During the 18 months of nusinersen treatment, CK decreased (∆CK = -17.56%, p < 0.0001), whereas Crn slightly increased (∆Crn = +4.75%, p < 0.05). INTERPRETATION: Serum creatine kinase activity and serum creatinine concentration reflect disease severity of spinal muscular atrophy and are promising biomarkers to assess patients with spinal muscular atrophy during disease course and to predict treatment response. The decrease of creatine kinase activity, combined with the tendency of creatinine concentration to increase during nusinersen treatment, suggests reduced muscle mass wasting with improved muscle energy metabolism.

Maximum bite force in patients with spinal muscular atrophy during the first year of nusinersen therapy - A pilot study.

OBJECTIVES: Spinal muscular atrophy is a monogenic disease characterized by progressive spinal and bulbar muscle weakness and atrophy. It is caused by the degeneration of alpha-motoneurons. The recent approval of the antisense oligonucleotide nusinersen highlights the need for reliable clinical tools to evaluate motor function in patients with neuromuscular disorders. Measurement of the bulbar neuromuscular function (e.g., bite force) could be an extension to existing motor scales, sensitive to more nuanced changes, especially in symptomatic patients with severely reduced functional abilities. MATERIALS AND METHODS: Maximum bite force measurement was used to quantify changes of the masticatory function in adult monozygotic female twins with SMA type II. Using piezoelectric transducers, 550 observations were recorded for each patient during the first year of nusinersen therapy. RESULTS: During the application of four loading doses of nusinersen, bite force levels steadily increased and reached a statistically significantly higher level compared to the initial state in both patients. Subsequent maintenance doses coincided with smaller or no statistically significant changes in maximum bite force. CONCLUSIONS: This pilot study indicates that the measurement of maximum bite force may be a useful tool to detect changes of the bulbar function in SMA patients. As such, it may supplement existing scales to identify treatment-related changes in motor function.

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.

Neurofilament light chain in serum of adolescent and adult SMA patients under treatment with nusinersen.

OBJECTIVE: To determine the diagnostic and monitoring value of serum neurofilament light chain (NfL) in spinal muscular atrophy (SMA). METHODS: We measured serum NfL in 46 SMA patients at baseline and over 14 months of treatment with the antisense-oligonucleotide (ASO) nusinersen using the ultrasensitive single molecule array (Simoa) technology. Serum NfL levels of SMA patients were compared to controls and related to cerebrospinal fluid (CSF) NfL, blood-CSF barrier function quantified by the albumin blood/CSF ratio (Qalb) and motor scores (Hammersmith Functional Motor Scale Expanded, HFMSE; Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised, ALSFRS-R). RESULTS: Serum NfL levels of SMA patients were in the range of controls (p = 0.316) and did not correlate with CSF NfL (ρ = 0.302, p = 0.142) or Qalb (ρ = - 0.160, p = 0.293). During therapy, serum NfL levels were relatively stable with notable concentration changes in single SMA patients, however, within the control range. Higher NfL levels were associated with worse motor performance in SMA (baseline: HFMSE ρ = - 0.330, p = 0.025, ALSFRS-R ρ = - 0.403, p = 0.005; after 10 months: HFMSE ρ = - 0.525, p = 0.008, ALSFRS-R ρ = - 0.537, p = 0.007), but changes in motor scores did not correlate with changes in serum NfL. CONCLUSION: Diagnostic and monitoring performance of serum NfL measurement seems to differ between SMA subtypes. Unlike to SMA type 1, in adolescent and adult SMA type 2 and 3 patients, neurodegeneration is not reflected by increased NfL levels and short-term therapeutic effects cannot be observed. Long-term follow-up has to be performed to see if even low levels of NfL might be good prognostic markers.

Nusinersen in adults with 5q spinal muscular atrophy: a non-interventional, multicentre, observational cohort study.

BACKGROUND: Nusinersen is approved for the treatment of 5q spinal muscular atrophy of all types and stages in patients of all ages. Although clinical trials have shown improvements in motor function in infants and children treated with the drug, data for adults are scarce. We aimed to assess the safety and efficacy of nusinersen in adults with 5q spinal muscular atrophy. METHODS: We did an observational cohort study at ten academic clinical sites in Germany. Patients with genetically confirmed 5q spinal muscular atrophy (age 16-65 years) with a homozygous deletion of exons 7, 8, or both, or with compound heterozygous mutations were eligible for inclusion and received nusinersen treatment in accordance with the label for a minimum treatment time of 6 months to a follow-up of up to 14 months. The primary outcome was the change in the total Hammersmith Functional Motor Scale Expanded (HFMSE) score, assessed at months 6, 10, and 14, and based on pre-post comparisons. This study is registered with the German Clinical Trials Register (number DRKS00015702). FINDINGS: Between July 13, 2017, and May 1, 2019, 173 patients were screened, of whom 139 (80%) were eligible for data analysis. Of these, 124 (89%) were included in the 6-month analysis, 92 (66%) in the 10-month analysis, and 57 (41%) in the 14-month analysis; patients with missing baseline HFMSE scores were excluded from these analyses. Mean HFMSE scores were significantly increased compared with baseline at 6 months (mean difference 1·73 [95% CI 1·05-2·41], p<0·0001), 10 months (2·58 [1·76-3·39], p<0·0001), and 14 months (3·12 [2·06-4·19], p<0·0001). Clinically meaningful improvements (≥3 points increase) in HFMSE scores were seen in 35 (28%) of 124 patients at 6 months, 33 (35%) of 92 at 10 months, and 23 (40%) of 57 at 14 months. To 14-month follow-up, the most frequent adverse effects among 173 patients were headache (61 [35%] patients), back pain (38 [22%]), and nausea (19 [11%]). No serious adverse events were reported. INTERPRETATION: Despite the limitations of the observational study design and a slow functional decline throughout the natural disease course, our data provide evidence for the safety and efficacy of nusinersen in the treatment of adults with 5q spinal muscular atrophy, with clinically meaningful improvements in motor function in a real-world cohort. FUNDING: None.

Intrathecal administration of nusinersen in adolescent and adult SMA type 2 and 3 patients.

Spinal muscular atrophy is a genetic motor neuron disease that leads to progressive muscular atrophy and muscle weakness. In December 2016, the Food and Drug Administration, and in June 2017, the European Medicines Agency approved the antisense oligonucleotide nusinersen for treatment of spinal muscular atrophy. Nusinersen has to be repeatedly administered intrathecally. Due to the clinical features of SMA, the application of the ASO by lumbar puncture can be challenging in symptomatic patients considering the frequently observed scoliosis, previous spine fusion surgeries, joint contractures, and respiratory insufficiency. To evaluate safety and feasibility of the intrathecal treatment in adolescent and adult SMA type 2 and 3 patients, we analyzed 93 lumbar punctures, monitored number of lumbar puncture attempts, duration of the procedure, injection site, and needle length. Oxygen saturation during the intervention, medication for sedation and local anesthesia, adverse events related to lumbar punctures, and macroscopic analysis of CSF were recorded. Moreover, we analyzed the use of CT-scans for performing lumbar punctures and its associated radiation exposure. Performing lumbar puncture for the intrathecal administration of nusinersen in adolescent and adult patients with later-onset SMA is feasible and safe, even in patients with complex spinal anatomies and respiratory insufficiency. To guarantee the quality of the procedure, we recommend establishing an experienced interdisciplinary team consisting of neurologists and/or neuropediatricians, anesthesiologists, orthopedic surgeons, and/or neuroradiologists.

Routine Cerebrospinal Fluid (CSF) Parameters in Patients With Spinal Muscular Atrophy (SMA) Treated With Nusinersen.

Background: Nusinersen is an antisense-oligonucleotide (ASO) approved for treatment of 5q-spinal muscular atrophy (SMA). Since the drug cannot cross the blood-brain barrier (BBB), it must be administered into the cerebrospinal fluid (CSF) space repeatedly by lumbar puncture. However, little is known whether ASOs have an impact on CSF routine parameters that may yield information on CSF flow and/or intrathecal inflammation. The objective of this study was to examine CSF routine parameters in SMA patients treated with nusinersen. Methods: Routine CSF parameters [white cell count, total protein, CSF/serum quotients of albumin (Qalb), lactate, and oligoclonal IgG bands (OCB)] of 60 SMA patients (type 1, 2, and 3, aged 7-60 years) were retrospectively analyzed. Results: White cells ranged from 0 to 4/µL in CSF; a singular case of pleocytosis (8/µL) was observed in a patient in parallel with a systemic infection. Total protein and Qalb showed a mild increase from baseline to the following lumbar punctures (except for total protein in CSF at the fourth injection of nusinersen). Lactate levels revealed a stable course. In one patient, positive OCB in CSF were transiently observed. The slight change in total CSF protein and Qalb may be caused by repeated lumbar puncture and/or intrathecal administration of the drug. Conclusion: Our data suggest that a regular examination of routine CSF parameters in patients in which intrathecal ASOs are administered is important to obtain information on possible side effects and to gain further insights into intrathecal processes.

Genotypes and phenotypes of patients with Lafora disease living in Germany.

BACKGROUND: Lafora progressive myoclonus epilepsy (Lafora disease) is a rare, usually childhood-onset, fatal neurodegenerative disease caused by biallelic mutations in EPM2A (Laforin) or EPM2B (NHLRC1, Malin). The epidemiology of Lafora disease in Germany is largely unknown. The objective of this retrospective case series is to characterize the genotypes and phenotypes of patients with Lafora disease living in Germany. METHODS: The patients described in this case series initially had the suspected clinical diagnosis of Lafora disease, or unclassified progressive myoclonus epilepsy. Molecular genetic diagnostics including next generation sequencing-based diagnostic panel analysis or whole exome sequencing was performed. RESULTS: The parents of four out of the 11 patients are nonconsanguineous and of German origin while the other patients had consanguineous parents. Various variants were found in EPM2A (six patients) and in EPM2B (five patients). Eight variants have not been reported in the literature so far. The patients bearing novel variants had typical disease onset during adolescence and show classical disease courses. CONCLUSIONS: This is the first larger case series of Lafora patients in Germany. Our data enable an approximation of the prevalence of manifest Lafora disease in Germany to 1,69 per 10 million people. Broader application of gene panel or whole-exome diagnostics helps clarifying unclassified progressive myoclonus epilepsy and establish an early diagnosis, which will be even more important as causal therapy approaches have been developed and are soon to be tested in a phase I study.

Neurochemical markers in CSF of adolescent and adult SMA patients undergoing nusinersen treatment.

BACKGROUND: There is limited information on neurochemical markers being used to support and monitor the affection of motoneurons in patients with spinal muscular atrophy (SMA). The objective of this study was to examine neurochemical markers in cerebrospinal fluid (CSF) under treatment with the antisense-oligonucleotide (ASO), nusinersen. METHODS: We measured markers of axonal degeneration [neurofilament light chain (NfL) and phosphorylated neurofilament heavy chain (pNfH)] along with basic CSF parameters in 25 adolescent and adult SMA type 2 and 3 patients at baseline and after four intrathecal injections of nusinersen. Neurochemical markers were compared with controls. In addition, neurochemical markers in SMA patients were related to the Hammersmith Functional Rating Scale Expanded (HFMSE). RESULTS: No significant difference in neurofilament (Nf) values was observed between SMA and control group, neither at baseline nor after four injections of nusinersen. NfL, protein and quotients of albumin (Qalb) increased slightly in SMA patients after the fourth injection. The slight increase of NfL could be related to the development of mild CSF flow change. No relations were observed between changes in Nf and HFMSE. CONCLUSION: We assume that Nf levels in CSF in these patients may result from slow disease progression in this stage of disease, pre-existing loss of motoneurons due to long disease duration besides affection of the LMN only. Therefore, we conclude that Nf levels in CSF do not seem useful as diagnostic and monitoring markers in adolescent and adult SMA type 2 and 3 patients.

Antisense oligonucleotides in neurological disorders.

The introduction of genetics revolutionized the field of neurodegenerative and neuromuscular diseases and has provided considerable insight into the underlying pathomechanisms. Nevertheless, effective treatment options have been limited. This changed recently when antisense oligonucleotides (ASOs) could be translated from in vitro and experimental animal studies into clinical practice. In 2016, two ASOs were approved by the United States US Food and Drug Administration (FDA) and demonstrated remarkable efficacy in Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA). ASOs are synthetic single-stranded strings of nucleic acids. They selectively bind to specific premessenger ribonucleic acid (pre-mRNA)/mRNA sequences and alter protein synthesis by several mechanisms of action. Thus, apart from gene replacement, ASOs may therefore provide the most direct therapeutic strategy for influencing gene expression. In this review, we shall discuss basic mechanisms of ASO action, the role of chemical modifications needed to improve the pharmacodynamic and pharmacokinetic properties of ASOs, and we shall then focus on several ASOs developed for the treatment of neurodegenerative and neuromuscular disorders, including SMA, DMD, myotonic dystrophies, Huntington's disease, amyotrophic lateral sclerosis and Alzheimer's disease.