Clinical-Genetic Features Influencing Disability in Spastic Paraplegia Type 4

The SPAST-HSP phenotypic spectrum in Italian patients confirms a predominantly pure form of HSP with mild-to-moderate disability in 75% of cases, and slight prevalence of men, who appeared more severely affected.

source: Neuro Genetics

Summary

A Cross-sectional Study by the Italian DAISY Network

[Posted 18/May/2022]

AUDIENCE: Neurology, Internal Medicine

KEY FINDINGS: The SPAST-HSP phenotypic spectrum in Italian patients confirms a predominantly pure form of HSP with mild-to-moderate disability in 75% of cases, and slight prevalence of men, who appeared more severely affected. Early-onset cases with intellectual disability were more frequent among patients carrying missense SPAST variants, whereas patients with truncating variants showed a more complicated disease. Both longer DD and altered MEPs are associated with worse disability.

BACKGROUND: Hereditary spastic paraplegias (HSPs) are a group of inherited rare neurologic disorders characterized by length-dependent degeneration of the corticospinal tracts and dorsal columns, whose prominent clinical feature is represented by spastic gait. Spastic paraplegia type 4 (SPG4, SPAST-HSP) is the most common form. We present both clinical and molecular findings of a large cohort of patients, with the aim of (1) defining the clinical spectrum of SPAST-HSP in Italy; (2) describing their molecular features; and (3) assessing genotype-phenotype correlations to identify features associated with worse disability.

DETAILS: A cross-sectional retrospective study with molecular and clinical data collected in an anonymized database was performed. A total of 723 Italian patients with SPAST-HSP (58% men) from 316 families, with a median age at onset of 35 years, were included. Penetrance was 97.8%, with men showing higher Spastic Paraplegia Rating Scale (SPRS) scores (19.67 ± 12.58 vs 16.15 ± 12.61, p = 0.009). In 26.6% of patients with SPAST-HSP, we observed a complicated phenotype, mainly including intellectual disability (8%), polyneuropathy (6.7%), and cognitive decline (6.5%). Late-onset cases seemed to progress more rapidly, and patients with a longer disease course displayed a more severe neurologic disability, with higher SPATAX (3.61 ± 1.46 vs 2.71 ± 1.20, p < 0.001) and SPRS scores (22.63 ± 11.81 vs 12.40 ± 8.83, p < 0.001). Overall, 186 different variants in the SPAST gene were recorded, of which 48 were novel. Patients with SPAST-HSP harboring missense variants displayed intellectual disability (14.5% vs 4.4%, p < 0.001) more frequently, whereas patients with truncating variants presented more commonly cognitive decline (9.7% vs 2.6%, p = 0.001), cerebral atrophy (11.2% vs 3.4%, p = 0.003), lower limb spasticity (61.5% vs 44.5%), urinary symptoms (50.0% vs 31.3%, p < 0.001), and sensorimotor polyneuropathy (11.1% vs 1.1%, p < 0.001). Increasing disease duration (DD) and abnormal motor evoked potentials (MEPs) were also associated with increased likelihood of worse disability (SPATAX score>3).

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Source: Rossi, S., Rubegni, A., Riso, V., et al. (2022). Clinical-Genetic Features Influencing Disability in Spastic Paraplegia Type 4: A Cross-sectional Study by the Italian DAISY Network. Neuro Genetics. 2022; 8(2): e664. Published: April, 2022. DOI: 10.1212/NXG.0000000000000664.



Safety and Efficacy of Single-Dose Primaquine to Interrupt Plasmodium Falciparum Malaria Transmission in Children Compared With Adultsicacy of Single-Dose Primaquine to Interrupt Plasmodium Falciparum Malaria Transmission in Children Compared With Adults

Regardless of malaria transmission intensity and age group, a single dose of 0.25 mg/kg primaquine is safe and efficacious for reducing P falciparum transmission. These findings underscore the need for primaquine formulations suitable for young children, and also provide supportive evidence to expand the use of single low-dose primaquine in regions with a moderate-to-high transmission rate that are threatened by artemisinin partial resistance.

source: The Lancet Infectious Diseases

Summary

A Systematic Review and Individual Patient Data Meta-Analysis

[Posted 15/Sep/2025]

AUDIENCE: Infectious Disease, Pediatric

KEY FINDINGS: Regardless of malaria transmission intensity and age group, a single dose of 0.25 mg/kg primaquine is safe and efficacious for reducing P falciparum transmission. These findings underscore the need for primaquine formulations suitable for young children, and also provide supportive evidence to expand the use of single low-dose primaquine in regions with a moderate-to-high transmission rate that are threatened by artemisinin partial resistance.

BACKGROUND: Adding a single dose of primaquine to artemisinin-based combination therapy (ACT) for the treatment of falciparum malaria can reduce the transmission of Plasmodium falciparum and could limit the spread of artemisinin partial resistance, including in Africa, where the disease burden is greatest. Authors aimed to compare the safety and efficacy of single-dose primaquine plus ACT between young children (aged <5 years) and older children (aged 5 years to <15 years) and adults (aged >=15 years), and between low and moderate-to-high transmission areas.

DETAILS: For this systematic review and individual patient data meta-analysis, authors searched PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, WHO Global Index Medicus, OpenGrey.eu, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform, from database inception to April 3, 2024, with no language restrictions. Authors included prospective studies on efficacy against falciparum malaria that enrolled at least one child younger than 15 years and involved a study group given a single dose of primaquine (<=0.75 mg/kg) plus ACT. Studies involving mass drug administration, healthy volunteers, or patients with severe malaria or mixed (with non-falciparum) infections were excluded. For inclusion in the efficacy analysis, data on transmission potential (as determined by gametocytaemia, infectivity, or both) at enrolment and follow-up (day 3, day 7, or day 14) were required; the safety analysis required data on haemoglobin concentrations or haematocrit values at enrolment and at one or more follow-up visits by day 7, any data on adverse events, or both. After independent screening of the search results by two reviewers, the investigators of eligible studies were invited to contribute individual patient data. Authors quantified day 7 gametocyte carriage, probability of infecting a mosquito, decreases (>25%) in haemoglobin concentration associated with anaemia, and adverse events until day 28 using regression analyses, with random study-site intercepts to account for clustered data. These analyses were registered with PROSPERO, CRD42021279363 (safety) and CRD42021279369 (efficacy). Of 5697 records identified by the search, 30 studies were eligible for analysis. Of these, individual patient data were shared for 23 studies, including 6056 patients from 16 countries: 1171 (19.3%) young children (aged <5 years), 2827 (46.7%) older children (aged 5 years to <15 years), and 2058 (34.0%) adults (aged >=15 years). Adding a single low dose of primaquine (0.2-0.25 mg/kg) to ACTs reduced day 7 gametocyte positivity (adjusted odds ratio [aOR] 0.34, 95% CI 0.22-0.52; p<0.001) and infectivity to mosquitoes over time (aOR per day 0.02, 0.01-0.07, p<0.001). No difference was found in the effect of single low-dose primaquine both on gametocyte positivity in young children compared with older children (1.08, 0.52-2.23; p=0.84) and adults (0.50, 0.20-1.25; p=0.14) and between low-transmission and moderate-to-high transmission settings (1.07, 0.46-2.52; p=0.86), and on infectivity to mosquitoes in young children compared with older children (1.36, 0.07-27.71; p=0.84) and adults (0.31, 0.01-8.84; p=0.50) and between low-transmission and moderate-to-high transmission settings (0.18, 0.01-2.95; p=0.23). Gametocyte clearance was also similar for different ACTs (dihydroartemisinin-piperaquine vs artemether-lumefantrine) when combined with a primaquine target dose of 0.25 mg/kg (1.56, 0.65-3.79; p=0.32 at day 7). However, patients given a primaquine dose of less than 0.2 mg/kg with dihydroartemisinin-piperaquine were more likely to have gametocytaemia than those treated with artemether-lumefantrine (5.68, 1.38-23.48; p=0.016 at day 7). There was no increase in anaemia-associated declines in haemoglobin concentration (>25%) at a primaquine dose of 0.25 mg/kg, regardless of age group, transmission setting, and glucose-6-phosphate dehydrogenase status. The risks of adverse events of grade 2 or higher and of serious adverse events were similar between primaquine and no-primaquine groups, including in young children.

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Source: Yilma, D., Stepniewska, K., Bousema, T., et al. (2024). Safety and Efficacy of Single-Dose Primaquine to Interrupt Plasmodium Falciparum Malaria Transmission in Children Compared With Adults: A Systematic Review and Individual Patient Data Meta-Analysis. The Lancet Infectious Diseases. 2025; 25(9): 965-976. Published: September, 2025. DOI: 10.1016/S1473-3099(25)00078-7.



Reduced Brain Iron and Striatal Hyperdopaminergia in Schizophrenia

The findings suggest that lower levels of non-neuromelanin-bound iron in the SN-VTA contribute to striatal hyperdopaminergia in schizophrenia. Further investigation is warranted to understand the role of low iron in schizophrenia and its potential as a treatment target.

source: Am J Psychiatry

Summary

A Quantitative Susceptibility Mapping MRI and PET Study

[Posted 12/Sep/2025]

AUDIENCE: Psychiatry, Family Medicine

KEY FINDINGS: The findings suggest that lower levels of non-neuromelanin-bound iron in the SN-VTA contribute to striatal hyperdopaminergia in schizophrenia. Further investigation is warranted to understand the role of low iron in schizophrenia and its potential as a treatment target.

BACKGROUND: Neuroimaging studies have independently associated schizophrenia with low iron and elevated dopamine synthesis. While preclinical research demonstrates that midbrain iron deficiency leads to striatal hyperdopaminergia, this relationship has not been studied in schizophrenia. The authors conducted a case-control study to examine differences in tissue magnetic susceptibility, a marker of brain iron, and correlated these with striatal dopamine synthesis capacity.

DETAILS: Magnetic susceptibility in the substantia nigra and ventral tegmental area (SN-VTA) was measured using quantitative susceptibility mapping (QSM) MRI in 159 participants (control subjects, N=80; early-course schizophrenia, N=79, including patients who were antipsychotic-naïve or antipsychotic-free). Because magnetic susceptibility is increased by neuromelanin and reduced by myelin, neuromelanin-sensitive MRI (NM-MRI) and diffusion tensor imaging (DTI) were employed to investigate the influence of neuromelanin and myelin on the QSM findings in 99 participants (control subjects, N=38; schizophrenia patients, N=61). Dopamine synthesis capacity (Ki cer) was then assessed with [18F]-DOPA positron emission tomography in 40 people from the schizophrenia group to test whether low SN-VTA magnetic susceptibility was related to high striatal Ki cer. SN-VTA magnetic susceptibility was lower in patients with schizophrenia than in control subjects (d=-0.66, 95% CI=-0.98, -0.34). This difference remained significant in analyses controlling for mean diffusivity (a DTI measure inversely correlating with myelin concentration) and NM-MRI contrast-to-noise ratios. SN-VTA magnetic susceptibility was significantly inversely correlated with striatal Ki cer, independent of mean diffusivity and NM-MRI contrast-to-noise ratios (r=-0.44). In both analyses, the strongest effects were observed in the ventral SN-VTA.

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Source: Vano, L. J., McCutcheon, R. A., Sedlacik, J., et al. (2024). Reduced Brain Iron and Striatal Hyperdopaminergia in Schizophrenia: A Quantitative Susceptibility Mapping MRI and PET Study. American Journal of Psychiatry. 2025; 182(9): 830–839. Published: September, 2025. DOI: 10.1176/appi.ajp.20240512.



Association of Plasma Alzheimer's Disease Biomarkers with Cognitive Decline in Cognitively Unimpaired Individuals

Mass-spectrometry-based plasma phosphorylated tau217 was associated with cognitively unimpaired to mild cognitive impairment (MCI) progression. Amyloid positron emission tomography (PET) was the strongest predictor of progression to MCI in the MCSA. Plasma had added value to amyloid PET in BioFINDER but not the MCSA. Biomarker performance may vary with cohort and biomarker measurement differences.

source: Alzheimers Dement.

Summary

[Posted 11/Sep/2025]

AUDIENCE: Geriatric, Family Medicine

KEY FINDINGS: Plasma %p-tau217 was associated with progression from CU to MCI in both cohorts, although differences in biomarker associations may be related to differences in the two cohorts.

BACKGROUND: Plasma biomarkers' utility for predicting incident mild cognitive impairment (MCI) remains unclear. Authors evaluated associations of plasma Alzheimer's disease (AD) biomarkers and amyloid positron emission tomography (PET) with transitions from cognitively unimpaired (CU) to MCI in the Mayo Clinic Study of Aging (MCSA) and BioFINDER-2 studies.

DETAILS: Associations of continuous baseline plasma biomarker levels and amyloid PET Centiloid with progression to MCI, adjusting for age, sex, and education, were evaluated with Cox proportional hazards models. The study included 381 MCSA and 584 BioFINDER-2 participants. Amyloid PET and percent phosphorylated to non-phosphorylated tau217 (%p-tau217) were strong predictors of progression to MCI in both cohorts: hazard ratios of 1.49 and 1.23 in the MCSA and 1.72 and 1.65 in BioFINDER, respectively. Amyloid beta 42/40 was a significant predictor in BioFINDER-2 only (hazard ratio 2.20).

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Source: Cogswell, P. M., Wiste, H. J., Therneau, T. M., et al. (2024). Association of Plasma Alzheimer's Disease Biomarkers With Cognitive Decline in Cognitively Unimpaired Individuals. Alzheimers Dement.. 2025; Published: September, 2025. DOI: 10.1002/alz.70625.



Carfilzomib-Lenalidomide-Dexamethasone Versus Lenalidomide-Dexamethasone in Patients With Newly Diagnosed Myeloma Ineligible for Autologous Stem-Cell Transplantation (EMN20)

In the carfilzomib-lenalidomide-dexamethasone group, higher MRD negativity rates were associated with a progression-free survival advantage over lenalidomide-dexamethasone. Toxicities were predictable and generally manageable.

source: The Lancet Haematology

Summary

A Randomised, Open-Label, Multicentre, Phase 3 Trial

[Posted 28/Aug/2025]

AUDIENCE: Hematology, Oncology

KEY FINDINGS: With the limitation of a smaller sample size than planned due to the trial's early interruption, these results, to authors' knowledge, showed for the first-time high rates of MRD negativity with weekly carfilzomib added to lenalidomide-dexamethasone in patients with transplantation-ineligible newly diagnosed multiple myeloma. In the carfilzomib-lenalidomide-dexamethasone group, higher MRD negativity rates were associated with a progression-free survival advantage over lenalidomide-dexamethasone. Toxicities were predictable and generally manageable.

BACKGROUND: Before the introduction of daratumumab-lenalidomide-dexamethasone as a first-line treatment for patients with newly diagnosed transplant-ineligible multiple myeloma, lenalidomide-dexamethasone was a standard of care. Authors aimed to explore whether addition of the second-generation proteasome inhibitor carfilzomib to lenalidomide-dexamethasone improved the rates of measurable residual disease (MRD) negativity and progression-free survival.

DETAILS: EMN20 is a randomised, open-label, multicentre, phase 3 trial comparing weekly carfilzomib-lenalidomide-dexamethasone versus lenalidomide-dexamethasone in patients with newly diagnosed transplant-ineligible multiple myeloma, conducted in 27 centres in Italy. Key inclusion criteria included fit or intermediate-fit status according to the International Myeloma Working Group (IMWG) frailty score, measurable disease according to IMWG criteria, and Eastern Cooperative Oncology Group performance status lower than 3. Patients randomly assigned to the carfilzomib-lenalidomide-dexamethasone group received 28-day carfilzomib-lenalidomide-dexamethasone cycles (carfilzomib 20 mg/m2 intravenously on day 1 for cycle 1, followed by 56 mg/m2 intravenously on days 8 and 15 for cycle 1, then 56 mg/m2 intravenously on days 1, 8, and 15 for cycles 2-12, and 56 mg/m2 intravenously on days 1 and 15 from cycle 13 until 5 years after randomisation; lenalidomide 25 mg orally on days 1-21 until disease progression or intolerance; dexamethasone 40 mg orally on days 1, 8, 15, and 22 until disease progression or intolerance). Patients assigned to the lenalidomide-dexamethasone group received 28-day cycles with lenalidomide-dexamethasone (same dosing and schedule used in the carfilzomib-lenalidomide-dexamethasone group). Primary endpoints were MRD negativity by next-generation sequencing (sensitivity 10-5) after 2 years of treatment and progression-free survival; and were assessed in the intention-to-treat (ITT) population (all patients who were eligible to receive treatment and who were randomly assigned to one of the treatment groups). On Nov 23, 2021, after enrolling 30% of planned patients (101/340), the trial was prematurely stopped due to the introduction of daratumumab-lenalidomide-dexamethasone as a first-line treatment in Italy, which caused the lenalidomide-dexamethasone control group to no longer be considered a standard treatment. This trial is registered with ClinicalTrials.gov, NCT04096066, and study recruitment is complete. Between Nov 14, 2019, and Nov 23, 2021, 82 of 101 enrolled patients were assessed for eligibility and were randomised to receive carfilzomib-lenalidomide-dexamethasone (n=42) or lenalidomide-dexamethasone (n=40). In the ITT population, 35 (43%) of 82 patients were female and 47 (57%) were male. At data cutoff (March 29, 2024), the median follow-up was 35.2 months (IQR 30.3-38.7). The 2-year MRD negativity rates were 25 (60% 95% CI 43-74) of 42 patients with carfilzomib-lenalidomide-dexamethasone versus 0 (0%; 0-9) of 40 patients with lenalidomide-dexamethasone (p<0.0001). Median progression-free survival was not reached (not reached-not reached) with carfilzomib-lenalidomide-dexamethasone versus 20.9 months (15.7-not reached) with lenalidomide-dexamethasone (hazard ratio 0.24 [95% CI 0.11-0.56], p=0.00084). One patient was excluded from the safety analysis because they died before starting treatment. The most frequent grade 3 or worse adverse events were neutropenia (nine [22%] of 41 patients), thrombocytopenia (four [10%]), diarrhoea (four [10%]), cardiac events (three [7%]), infections (three [7%]), and arterial hypertension (two [5%]) with carfilzomib-lenalidomide-dexamethasone, and neutropenia (six [15%] of 40) and skin rash (four [10%]) with lenalidomide-dexamethasone. The most common serious adverse event was SARS-CoV-2-related pneumonia in both the carfilzomib-lenalidomide-dexamethasone group (two [5%] of 41 patients) and lenalidomide-dexamethasone group (three [7%] of 40 patients). Treatment-emergent adverse events leading to death were observed in two patients in the carfilzomib-lenalidomide-dexamethasone (two SARS-CoV-2 infections) and four patients in the lenalidomide-dexamethasone group (one acute myocardial infraction, one heart failure, one septic shock, and one SARS-CoV-2 infection).

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Source: Bringhen, S., Cani, L., Antonioli, E., et al. (2024). Carfilzomib-Lenalidomide-Dexamethasone Versus Lenalidomide-Dexamethasone in Patients With Newly Diagnosed Myeloma Ineligible for Autologous Stem-Cell Transplantation (EMN20): A Randomised, Open-Label, Multicentre, Phase 3 Trial. The Lancet Haematology. 2025; 12(8): e621-e634. Published: August, 2025. DOI: 10.1016/S2352-3026(25)00162-0.



Risdiplam in Presymptomatic Spinal Muscular Atrophy

Infants up to 6 weeks of age with genetically diagnosed SMA who were treated with risdiplam before the development of clinical signs or symptoms appeared to have better functional and survival outcomes at 12 and 24 months than untreated infants in natural history studies. Larger, controlled studies with longer follow-up are needed to further understand the relative efficacy and safety of presymptomatic treatment of SMA with risdiplam.

source: NEJM

Summary

[Posted 28/Aug/2025]

AUDIENCE: Neurology, Pediatric, Neurosurgery

KEY FINDINGS: Infants up to 6 weeks of age with genetically diagnosed SMA who were treated with risdiplam before the development of clinical signs or symptoms appeared to have better functional and survival outcomes at 12 and 24 months than untreated infants in natural history studies. Larger, controlled studies with longer follow-up are needed to further understand the relative efficacy and safety of presymptomatic treatment of SMA with risdiplam.

BACKGROUND: Risdiplam, an oral pre–messenger RNA splicing modifier, is an efficacious treatment for persons with symptomatic spinal muscular atrophy (SMA). The safety and efficacy of risdiplam in presymptomatic disease are unclear.

DETAILS: Authors conducted an open-label study of daily oral risdiplam (with the dose adjusted to 0.2 mg per kilogram of body weight) in infants 1 day (birth) to 42 days of age with genetically diagnosed SMA but without strongly suggestive clinical signs or symptoms. The primary outcome, assessed in infants with two SMN2 copies and a baseline ulnar compound muscle action potential (CMAP) amplitude of at least 1.5 mV, was the ability to sit without support at month 12. Natural history studies have shown that the majority of infants with two SMN2 copies who are untreated would have a severe SMA phenotype (type 1), would never sit independently, would receive permanent ventilation and feeding support, or would die by 13 months of age. Secondary outcomes that were assessed over a period of 24 months included survival, ventilatory support, motor milestones, the development of clinically manifested SMA, feeding, and growth. A total of 26 infants with two, three, or four or more copies of SMN2 were enrolled. After 12 months of treatment, 21 infants (81%) could sit unsupported for 30 seconds, 14 (54%) could stand alone, and 11 (42%) could walk alone. A total of 4 of 5 infants (80%; 95% confidence interval, 28 to 100) with two SMN2 copies and a baseline ulnar CMAP amplitude of at least 1.5 mV were able to sit without support for at least 5 seconds. Three infants were withdrawn from the study by a parent or caregiver after the month 12 visit. Of 23 infants who completed 24 months of treatment, all were alive without the use of permanent ventilation or feeding support. Over a period of 24 months, nine treatment-related adverse events were reported in 7 infants; none of these events were serious.

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Copyright © Massachusetts Medical Society. All rights reserved.

Source: Finkel, R. S., Servais, L., Vlodavets, D., et al. (2024). Risdiplam in Presymptomatic Spinal Muscular Atrophy. N Engl J Med. 2025; 393(7): 671-682. Published: August 13, 2025. DOI: 10.1056/NEJMoa2410120.



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