Hereditary spastic paraplegia (HSP) represents a genetically heterogeneous group of neurodegenerative disorders characterized by progressive axonal degeneration of corticospinal upper motor neurons, leading to lower limb-predominant spasticity and weakness. To date, 83 HSP subtypes have been reported, exhibiting either pure or complicated phenotypes. Among these, spastic paraplegia type 64 (SPG64) is an ultra-rare form of complicated HSP caused by biallelic variants in ENTPD1, which encodes an ectonucleotidase involved in purine metabolism. In this study, we report a proband presenting with neurodevelopmental regression, dysmorphic features and sensorimotor polyneuropathy, followed comprehensively for 6 years. Genetic analysis identified a novel homozygous NM_001776:c.1174C>T;p.Gln392Ter variant in ENTPD1. A literature review reveals that 39 individuals with SPG64 have been reported, with clinical manifestations including cognitive decline (38/39), speech abnormalities (30/39) and brain malformations (16/31). However, aspects of the full phenotypic spectrum remain to be fully characterized. Notably, this case represents the first documented patient with long-term follow-up, providing valuable clinical insights into disease progression over time. Neuroimaging in the proband demonstrated the involvement of the posterior limb of the internal capsule and the 'ear of the lynx' sign, which was not previously reported in SPG64. Furthermore, the presence of sensorimotor polyneuropathy supports that neuropathy may be a previously unappreciated component of SPG64. Our findings highlight the importance of deep phenotyping and long-term follow-up in fully understanding the nature of this unique HSP subtype.

HSP-SPG11 and HSP-ZFYVE26 are autosomal-recessive forms of hereditary spastic paraplegias (HSPs). As therapeutic trials emerge, validated biomarkers are critically needed. To evaluate plasma neurofilament light chain (pNfL) as a biomarker for neurodegeneration and disease progression. We analyzed pNfL levels in 57 patients (36 HSP-SPG11, 21 HSP-ZFYVE26) and matched controls using single-molecule array technology. Longitudinal clinical and biomarker data were collected over 5 years. Baseline pNfL levels were significantly elevated in patients: 33.85 pg/mL (IQR 25.15-47.38) in HSP-SPG11, 46.70 pg/mL (IQR 29.95-54.84) in HSP-ZFYVE26, and 4.90 pg/mL (IQR 3.48-6.90) in controls (P < 0.001). No significant difference was observed between HSP-SPG11 and HSP-ZFYVE26. In matched pair analysis, pNfL showed inverse correlation with age (ρ = -0.463, P < 0.001). Baseline pNfL did not predict future clinical progression. Elevated pNfL reflects early neuroaxonal injury in HSP-SPG11 and HSP-ZFYVE26; however, it could not be used as a surrogate for disease progression. © 2025 International Parkinson and Movement Disorder Society.

An increasing number of cases of comorbid hereditary spastic paraplegia (HSP) and multiple sclerosis (MS) have been described. We report a patient with the SPG3A form of HSP and features of relapsing-remitting MS (RRMS). We took this opportunity to review the current literature of co-occurring MS and HSP. The patient underwent clinical, laboratory and neuroimaging evaluations. We performed a literature search for cases of HSP and MS. The 2017 McDonalds Criteria for MS were retrospectively applied to the selected cases. A 34-year-old woman, presenting a molecular diagnosis of SPG3A, complained subacute sensory-motor symptoms. Spinal MRI disclosed T2-hyperintense lesions at C2, T6 and T4 level, the latter presenting contrast-enhancement. CSF analysis showed oligoclonal bands. She was treated with intravenous high-dose steroids, with symptom resolution. The literature review yielded 13 papers reporting 20 possible cases of MS and HSP. Nine patients (5 M, median age 34) met the 2017 McDonald criteria. Five (25%) received a diagnosis of RRMS and four (20%) of primary progressive MS. Brain MRI showed multiple WM lesions, mostly periventricular. Six of seven cases (85.7%) had spinal cord involvement. Oligoclonal bands were found in 6/8 (75%) patients. Seven patients (77.7%) improved/stabilized on immunotherapy. This is the first description on the association between SPG3A type of HSP and MS. This report adds to the other reported cases of co-occurring HSPs and MS. Although it remains unclear if this association is casual or causal, clinicians should be aware that an HSP diagnosis does not always exclude a concomitant MS.

We aimed to identify healthcare needs, expectations, utilization, and the experienced treatment effects in a population of Dutch patients with hereditary spastic paraplegia (HSP). We distributed an online questionnaire among 194 adult persons with HSP in the Netherlands, of which 166 returned a fully completed version. After applying predefined exclusion criteria, 109 questionnaires from persons with pure HSP were analysed. Healthcare needs and expectations were primarily focused on the relief of muscle stiffness and reduction of balance and gait impairments (65-80%), but many participants also expressed needs regarding relief of non-motor symptoms (e.g. pain, fatigue), emotional problems, impaired sleep and self-care capacity, and participation problems (> 60%). Remarkably, despite these frequent needs, relatively few participants (< 33%) expected to be able to improve in these additional domains. Rehabilitation physicians and physiotherapists were more frequently consulted than neurologists and occupational therapists, respectively. Physiotherapy was the most often proposed non-pharmacological intervention (85%), followed by orthopedic footwear (55%) and splints (28%). Approximately one third of the participants was never offered any pharmacological (spasmolytic) treatment. Spasmolytic oral drugs, injections, and intrathecal baclofen were given to 41%, 26%, and 5% of the participants, respectively. Independent of the type of pharmacological intervention, 35-46% of these participants experienced decreased spastiticy and improved general fitness. Other experienced effects differed per type of intervention. Based on this web-based survey in the Netherlands, there seems to be ample room for improvement to meet and attune the healthcare needs and expectations of people with HSP concerning both their motor and non-motor symptoms and functional limitations. In addition, the provision of adequate information about non-pharmacological and pharmacological interventions seems to be insufficient for many patients to allow shared decision making. These conclusions warrant a more pro-active attitude of healthcare providers as well as an interdisciplinary approach for a substantial proportion of the HSP population, also involving professionals with a primary occupational and/or psychosocial orientation.

Hereditary spastic paraplegia type 11 (SPG11) is the most common subtype of autosomal recessive hereditary spastic paraplegia (HSP), to date, there are more than 181 different KIAA1840 gene mutations detected, and yet the genetic landscape of SPG11 is far from complete. To find the clinical and genetic characteristics of SPG11, we performed a reanalysis of the clinical features and genotype-phenotype correlations in all reported studies exhibiting SPG11 mutations. A total of 339 patients were collected, their mean age at onset was 13.10 ± 3.65 years, with initial symptoms like gait disturbance (107/195, 54.87%) and mental retardation (47/195, 24.10%). Cognitive decline (228/270, 84.44%) was the most common complex manifestation stepped by dysarthria (134/195, 68.72%), neuropathy (112/177, 63.28%), amyatrophy, sphincter disturbance (60/130, 46.15%) and ataxia (90/194, 46.39%). The most common brain MRI abnormality is thinning of the corpus callosum (TCC) (173/190, 91.05%), followed by periventricular white matter changes (130/158, 82.28%), cerebral or cerebellar cortical atrophy (55/107, 51.40%). The mutational spectrum associated with KIAA1840 gene is wide, and frameshift mutations are the most common type followed by nonsense mutations. Our reanalysis demonstrated that SPG11 exhibited significant clinical and genetic heterogeneity, and no clear genotype-phenotype correlation was observed. There is no mutational hot spot in the KIAA1840 gene, which emphasizes the need to analyse the whole gene in clinical practice. In addition to conventional genetic testing methods, further mRNA analysis should be conducted on some cases to yield a definitive diagnosis.