Clinical features and management of hereditary spastic paraplegia

The Puzzle of Hereditary Spastic Paraplegia: From Epidemiology to Treatment

Inherited neurodegenerative pathology characterized by lower muscle tone and increasing spasticity in the lower limbs is termed hereditary spastic paraplegia (HSP). HSP is associated with changes in about 80 genes and their products involved in various biochemical pathways, such as lipid droplet formation, endoplasmic reticulum shaping, axon transport, endosome trafficking, and mitochondrial function. With the inheritance patterns of autosomal dominant, autosomal recessive, X-linked recessive, and mitochondrial inheritance, HSP is prevalent around the globe at a rate of 1–5 cases in every 100,000 individuals. Recent technology and medical interventions somewhat aid in recognizing and managing the malaise. However, HSP still lacks an appropriate and adequate therapeutic approach. Current therapies are based on the clinical manifestations observed in the patients, for example, smoothing the relaxant spastic muscle and physiotherapies. The limited clinical trial studies contribute to the absence of specific pharmaceuticals for HSPs. Our current work briefly explains the causative genes, epidemiology, underlying mechanism, and the management approach undertaken to date. We have also mentioned the latest approved drugs to summarise the available knowledge on therapeutic strategies for HSP.

Neuroradiological Mimics of Periventricular Leukomalacia

AIM

Periventricular leukomalacia (PVL) is a term reserved to describe white matter injury in the premature brain. In this review article, the authors highlight the common and rare pathologies mimicking the chronic stage of PVL and propose practical clinico-radiological criteria that would aid in diagnosis and management.

METHODS AND RESULTS

The authors first describe the typical brain MRI (magnetic resonance imaging) features of PVL. Based on their clinical presentation, pathologic entities and their neuroimaging findings were clustered into distinct categories. Three clinical subgroups were identified: healthy children, children with stable/nonprogressive neurological disorder, and those with progressive neurological disorder. The neuroradiological discriminators are described in each subgroup with relevant differential diagnoses. The mimics were broadly classified into normal variants, acquired, and inherited disorders.

CONCLUSIONS

The term "PVL" should be used appropriately as it reflects its pathomechanism. The phrase "white matter injury of prematurity" or "brain injury of prematurity" is more specific. Discrepancies in imaging and clinical presentation must be tread with caution and warrant further investigations to exclude other possibilities.

Genetic, clinical and neuroimaging profiles of sporadic and autosomal recessive hereditary spastic paraplegia cases in Chinese

Spastic paraplegias (SPGs) are a group of clinically and genetically heterogeneous neurodegenerative diseases. Mutations in 78 genes have been identified in autosomal dominant hereditary SPG (AD-HSP) and autosomal recessive hereditary SPG (AR-HSP). Compared to familial HSP, much less is known about the genetic and clinical profiles of sporadic SPGs. In this study, we have screened mutations for 18 sporadic SPGs or AR-HSP patients (mainly Northern Chinese) by whole-exome sequencing. We identified 12 mutations in five genes in 9 (50%) patients, including 9 novel ones: SPG5A/CYP7B1 (c.851C > A; c.122 + 2 T > G), SPG11/KIAA1840 (c.1735 + 3_ 1735 + 6del AAGT); SPG7/SPG7 (c.1454G > A; c.1892_ 1906dup GAGGACGGGCCTCGG); SPG39/PNPLA6 (c.1591G > A; c. 2990C > T); SPG15/ ZFYVE26 (c. 4804C > T; c. 4278 G > A). Among all the mutations, 7 were detected in the SPG5A and SPG11. Age at onset was significantly younger in cases with mutations (15.45 ± 6.78 years) than those without mutations (25.56 ± 10.90 years) (P = 0.03). Except for two cases with the SPG5A mutations, all cases presented with complicated SPGs. Three cases carrying mutations in SPG7, SPG15, SPG39 showed symptoms and signs of ataxia. One case carrying the homozygous c.259 + 2 T > C mutation in CYP7B1 showed serum parameters indicating liver impairment. Magnetic resonance imaging showed significantly thinned corpus callosum in cases with SPG11 and SPG15, but not in those with SPG5A, SPG7 or SPG39. In contrast, cerebellar atrophy was prominent in the SPG7 and SPG39 cases. These findings expand the spectrum of genetic, clinical and imaging features of sporadic SPG and AR-HSP, and have important implications in genetic counselling, molecular mechanisms and precise diagnosis of the disease.

Balance rehabilitation with a virtual reality protocol for patients with hereditary spastic paraplegia: Protocol for a clinical trial

BACKGROUND

Neurodegenerative diseases are sporadic hereditary conditions characterized by progressive dysfunction of the nervous system. Among the symptoms, vestibulopathy is one of the causes of discomfort and a decrease in quality of life. Hereditary spastic paraplegia is a heterogeneous group of hereditary degenerative diseases involving the disorder of a single gene and is characterized by the progressive retrograde degeneration of fibers in the spinal cord.

OBJECTIVE

To determine the benefits of vestibular rehabilitation involving virtual reality by comparing pre intervention and post intervention assessments in individuals with hereditary spastic paraplegia.

METHODS

In this randomized controlled clinical trial from the Rebec platform RBR-3jmx67 in which allocation concealment was performed and the evaluators be blinded will be included. The participants will include 40 patients diagnosed with hereditary spastic paraplegia. The interventions will include vestibular rehabilitation with virtual reality using the Wii® console, Wii-Remote and Wii Balance Board (Nintendo), and the studies will include pre- and post intervention assessments. Group I will include twenty volunteers who performed balance games. Group II will include twenty volunteers who performed balance games and muscle strength games. The games lasted from 30 minutes to an hour, and the sessions were performed twice a week for 10 weeks (total: 20 sessions).

RESULTS

This study provides a definitive assessment of the effectiveness of a virtual reality vestibular rehabilitation program in halting the progression of hereditary spastic paraplegia, and this treatment can be personalized and affordable.

CONCLUSION

The study will determine whether a vestibular rehabilitation program with the Nintendo Wii® involving virtual reality can reduce the progressive effect of hereditary spastic paraplegia and serve as an alternative treatment option that is accessible and inexpensive. Rebec platform trial: RBR-3JMX67.

Randomized Trial of Botulinum Toxin Type A in Hereditary Spastic Paraplegia - The SPASTOX Trial

BACKGROUND

Hereditary spastic paraplegia presents spasticity as the main clinical manifestation, reducing gait quality and producing incapacity. Management with botulinum toxin type A (BoNT-A) is not well elucidated. The objective of the current study was to evaluate the efficacy and safety of BoNT-A in patients with hereditary spastic paraplegias.

METHODS

This was a double-blind, randomized, placebo-controlled crossover trial. Each participant was randomly assigned to receive 1 injection session of either BoNT-A (100 IU/2 mL of Prosigne in each adductor magnus and each triceps surae) or saline 0.9% (2 mL). The primary outcome measure was change from baseline in maximal gait velocity, and secondary outcome measures included changes in gait at self-selected velocity, spasticity, muscle strength, Spastic Paraplegia Rating Scale, pain, fatigue, and subjective perception of improvement. We also looked at adverse events reported by the patients.

RESULTS

We enrolled 55 patients, 36 of whom were men and 41 with the pure phenotype. Mean age was 43 ± 13.4 years (range, 19-72 years), mean age of onset waws 27 ± 13.1 years (range, <1 to 55 yars), and mean disease duration was 17 ± 12.7 years (range, 1-62 years). Compared with baseline, we did not find significant differences between groups in primary and secondary outcomes, except for reduction in adductor tone (P = 0.01). The adverse events were transient and tolerable, and their incidence did not significantly differ between treatments (P = 0.17).

CONCLUSIONS

BoNT-A was safe in patients with hereditary spastic paraplegias and reduced the adductor tone, but it was not able to produce functional improvement considering the doses, injection protocol, measures, and instruments used. © 2021 International Parkinson and Movement Disorder Society.

Spinal cord stimulation improves motor function and gait in spastic paraplegia type 4 (SPG4): Clinical and neurophysiological evaluation

INTRODUCTION

Hereditary spastic paraplegia is a heterogeneous group of genetic disorders characterized by degeneration of the corticospinal tracts, coursing with progressive weakness and spasticity of the lower limbs. To date, there are no effective treatments for progressive deficits or disease-modifying therapy for those patients. We report encouraging results for spastic paraparesis after spinal cord stimulation.

METHODS

A 51-year-old woman suffering from progressive weakness and spasticity in lower limbs related to hereditary spastic paraplegia type 4 underwent spinal cord stimulation (SCS) and experienced also significant improvement in motor function. Maximum ballistic voluntary isometric contraction test, continuous passive motion test and gait analysis using a motion-capture system were performed in ON and OFF SCS conditions. Neurophysiologic assessment consisted of obtaining motor evoked potentials in both conditions.

RESULTS

Presurgical Spastic Paraplegia Rating Scale (SPRS) score was 26. One month after effective SCS was initiated, SPRS went down to 15. At 12 months follow up, she experienced substantial improvement in motor function and in gait performance, with SPRS scores 23 (OFF) and down to 20 (ON). There was an increased isometric muscle strength (knee extension, OFF: 41 N m; ON: 71 N m), lower knee extension and flexion torque values in continuous passive motion test (decrease in spastic tone) and improvement in gait (for example, step length increase).

CONCLUSION

Despite being a case study, our findings suggest innovative lines of research for the treatment of spastic paraplegia.

Familiarity with Hereditary Spastic Paraplegia (HSP) and Differentiation of Upper Body Gait Characteristics between Children with HSP and Spastic Diplegic Cerebral Palsy

AIMS

The aim of this two-part, prospective study was to determine therapist familiarity with HSP and examine diagnostic accuracy between individuals with HSP and those with Spastic Diplegic Cerebral Palsy (SD-CP).

METHODS

Part-one surveyed physical therapists (PT) and physical therapist assistants (PTA) throughout Texas to determine familiarity with HSP and its gait deviations. Part-two examined accuracy in differential diagnosis of HSP versus SD-CP using gait analysis and the effects of an educational module on upper body gait deviations observed in individuals with HSP.

RESULTS

Both PTs and PTAs indicated a high degree (≥73.2%) of unfamiliarity with HSP. While a majority of respondents (≥88.7%) indicated use of observational gait analysis in clinical practice, ≥92.5% indicated never receiving instruction on HSP or its associated gait deviations. Whole group analysis revealed diagnostic accuracy increased 21.7% post educational module. In addition, individual case diagnostic accuracy yielded significant improvement in 14 out of 20 cases.

CONCLUSIONS

Physical and occupational therapists are in a unique position to assist with the identification and distinction of HSP from CP. This study demonstrated that brief instruction on common upper body gait deviations seen in individuals with HSP may improve a clinician's ability to distinguish SD-CP from HSP via gait analysis.

Hereditary spastic paraplegia: An "ears of the lynx" magnetic resonance imaging sign in a patient with recessive genetic type 11

Hereditary spastic paraplegias are an uncommon group of monogenic diseases that include 79 types of genetic disorders. The most frequent cause of recessive hereditary spastic paraplegia is a mutation in the spastic paraplegia gene type 11 followed by type 15. This group is usually associated with non-specific clinical features like cognitive decline and may precede the progressive weakness and spasticity of lower limbs. The magnetic resonance imaging hallmark of hereditary spastic paraplegia is thinning of the spinal cord. However, brain magnetic resonance imaging may provide relevant clues for specific hereditary spastic paraplegia subtypes, and thinning of the corpus callosum has been described as the most frequent abnormality in almost one-third of recessive hereditary spastic paraplegias. Moreover, a characteristic abnormality affecting the forceps minor of the corpus callosum has been recently reported as the "ears of the lynx" sign and is highly suggestive of type 11 and 15 hereditary spastic paraplegias. We report a patient who was diagnosed with hereditary spastic paraplegia type 11 by exome genetic testing, presenting the ears of the lynx sign in the first magnetic resonance imaging assessment.

Genetic mutation analysis of hereditary spastic paraplegia: A retrospective study

Hereditary spastic paraplegias are heterogeneous disorders with diversified clinical manifestations, and genetic testing is important for the diagnosis and typing of hereditary spastic paraplegias.Gene panel sequencing containing 55 hereditary spastic paraplegias-related genes was performed to screen the pathogenic genes for hereditary spastic paraplegias. Sanger sequencing was adopted to validate if the family member carried the same pathogenic gene as the proband.Fifteen out of 53 patients carried mutation(s) in the screened hereditary spastic paraplegias-related genes. Among the 23 identified mutations, only one mutation had been previously reported as a pathogenic mutation. In the pedigree of case 6, the proband, his mother and uncle all carried the same novel deletion mutation (c.1459delA) at SPAST gene. Based on the pedigree, the disease was inherited in an AD pattern. In the pedigree of case 53, the family disease may be in an X-linked recessive inheritance pattern. The proband (case 53) carried two novel mutations in ALT1 gene and L1CAM gene (c.2511C>A), respectively. The L1CAM gene is the causative gene for the SPG1 X-linked recessive-hereditary spastic paraplegias.Our data confirm the genetic heterogeneity of hereditary spastic paraplegias, and SPG4/SPAST were the most frequent forms. The pathogenicity of the novel mutations is worth to be further investigated.

Clinical Characterization of 2 Siblings with a Homozygous SPAST Variant

Case series

Patients: —

Final Diagnosis: Hereditary spastic paraplegia type 4

Symptoms: Progressive psychomotor deterioration • mixed seizure patterns • corneal opacity • dysostotic bones • limb spasticity with extensor plantar responses • axial hypotonia

Medication: —

Clinical Procedure: Phenotype-genotype correlation

Specialty: Genetics • Neurology

Hereditary spastic paraplegia: a clinical and epidemiological study of a Brazilian pediatric population

AIMS

To investigate hereditary spastic paraplegia (HSP) in a pediatric Brazilian sample.

METHODS

Epidemiological, clinical, radiological and laboratory data were analyzed in 35 patients.

RESULTS

Simple HSP (HSP-S) was detected in 12 patients, and complicated HSP (HSP-C) was detected in 23 patients. The mean age of onset of symptoms was 2.9 years in HSP-S and 1.6 years in HSP-C (p = 0.023). The disease was more severe in HSP-C. There were no differences in sex, ethnic background, or family history between groups. Intellectual disability was the most frequent finding associated with HSP-C. Peripheral axonal neuropathy was found in three patients. In the HSP-C group, MRI was abnormal in 13 patients. The MRI abnormalities included nonspecific white matter lesions, cerebellar atrophy, thinning of the corpus callosum and the "ear of the lynx sign".

CONCLUSIONS

In children with spastic paraplegia, HSP must be considered whenever similar pathologies, mainly diplegic cerebral palsy, are ruled out.

Neuroimaging in Hereditary Spastic Paraplegias: Current Use and Future Perspectives

Hereditary spastic paraplegias (HSP) are a large group of genetic diseases characterized by progressive degeneration of the long tracts of the spinal cord, namely the corticospinal tracts and dorsal columns. Genotypic and phenotypic heterogeneity is a hallmark of this group of diseases, which makes proper diagnosis and management often challenging. In this scenario, magnetic resonance imaging (MRI) emerges as a valuable tool to assist in the exclusion of mimicking disorders and in the detailed phenotypic characterization. Some neuroradiological signs have been reported in specific subtypes of HSP and are therefore helpful to guide genetic testing/interpretation. In addition, advanced MRI techniques enable detection of subtle structural abnormalities not visible on routine scans in the spinal cord and brain of subjects with HSP. In particular, quantitative spinal cord morphometry and diffusion tensor imaging look promising tools to uncover the pathophysiology and to track progression of these diseases. In the current review article, we discuss the current use and future perspectives of MRI in the context of HSP.

"Ears of the Lynx" MRI Sign Is Associated with SPG11 and SPG15 Hereditary Spastic Paraplegia

BACKGROUND AND PURPOSE

The "ears of the lynx" MR imaging sign has been described in case reports of hereditary spastic paraplegia with a thin corpus callosum, mostly associated with mutations in the spatacsin vesicle trafficking associated gene, causing Spastic Paraplegia type 11 (SPG11). This sign corresponds to long T1 and T2 values in the forceps minor of the corpus callosum, which appears hyperintense on FLAIR and hypointense on T1-weighted images. Our purpose was to determine the sensitivity and specificity of the ears of the lynx MR imaging sign for genetic cases compared with common potential mimics.

MATERIALS AND METHODS

Four independent raters, blinded to the diagnosis, determined whether the ears of the lynx sign was present in each of a set of 204 single anonymized FLAIR and T1-weighted MR images from 34 patients with causal mutations associated with SPG11 or Spastic Paraplegia type 15 (SPG15). 34 healthy controls, and 34 patients with multiple sclerosis.

RESULTS

The interrater reliability for FLAIR images was substantial (Cohen κ, 0.66-0.77). For these images, the sensitivity of the ears of the lynx sign across raters ranged from 78.8 to 97.0 and the specificity ranged from 90.9 to 100. The accuracy of the sign, measured by area under the receiver operating characteristic curve, ranged from very good (87.1) to excellent (93.9).

CONCLUSIONS

The ears of the lynx sign on FLAIR MR imaging is highly specific for the most common genetic subtypes of hereditary spastic paraplegia with a thin corpus callosum. When this sign is present, there is a high likelihood of a genetic mutation, particularly associated with SPG11 or SPG15, even in the absence of a family history.

Hereditary and idiopathic spastic paraparesis: preliminary findings of a single center experience

OBJECTIVES

Hereditary spastic paraplegias (HSP) is a heterogeneous group of inherited neurologic disorders with diversified clinical manifestations. The purpose of this study was to summarize the clinical manifestations of HSP by analyzing the clinical data of 56 HSP patients.

METHODS

A total of 56 HSP patients treated in our hospital from January 2014 to March 2016 were included. Demographic and clinical characteristics of patients were collected. The severity of HSP was assessed by disease severity score.

RESULTS

The patients included 40 males and 16 females. The mean onset age was 17.86 ± 12.56 years (range: 1-47). The mean disease duration was 13.46 ± 12.82 years (range: 1-63). There were 29 pure (51.8%) forms and 27 complicated (48.2%) HSP. The common manifestations included increased deep tendon reflexes in the lower extremities (94.6%), positive Babinski sign (94.6%), increased muscle tone of lower extremities (91.1%), scissors gait (83.9%), ankle clonus (69.6%), reduced muscle strength in the lower extremities (48.2%) and skeletal deformities (37.5%). Reduced cognitive function was the most common manifestation (55.6%) of the complicated HSP patients. The mean disease severity score was significantly higher in males than in females (2.75 ± 0.55 vs. 2.18 ± 1.13, P = 0.013). Patients with a disease duration >30 years had a significantly higher disease severity score than those with disease duration of 1-10 and 21-30 years.

DISCUSSION

We reported the clinical features of HSP from 56 patients in our hospital. Our findings should be helpful for better understanding of clinical features of HSP.

Increased lower limb muscle coactivation reduces gait performance and increases metabolic cost in patients with hereditary spastic paraparesis

BACKGROUND

The aim of this study was to investigate the lower limb muscle coactivation and its relationship with muscles spasticity, gait performance, and metabolic cost in patients with hereditary spastic paraparesis.

METHODS

Kinematic, kinetic, electromyographic and energetic parameters of 23 patients and 23 controls were evaluated by computerized gait analysis system. We computed ankle and knee antagonist muscle coactivation indexes throughout the gait cycle and during the subphases of gait. Energy consumption and energy recovery were measured as well. In addition to the correlation analysis between coactivation indexes and clinical variables, correlations between coactivation indexes and time-distance, kinematic, kinetic, and energetic parameters were estimated.

FINDINGS

Increased coactivity indexes of both knee and ankle muscles throughout the gait cycle and during the subphases of gait were observed in patients compared with controls. Energetic parameters were significantly higher in patients than in controls. Both knee and ankle muscle coactivation indexes were positively correlated with knee and ankle spasticity (Ashworth score), respectively. Knee and ankle muscle coactivation indexes were both positively correlated with energy consumption and both negatively correlated with energy recovery.

INTERPRETATION

Positive correlations between the Ashworth score and lower limb muscle coactivation suggest that abnormal lower limb muscle coactivation in patients with hereditary spastic paraparesis reflects a primary deficit linked to lower limb spasticity. Furthermore, these abnormalities influence the energetic mechanisms during walking. Identifying excessive muscle coactivation may be helpful in individuating the rehabilitative treatments and designing specific orthosis to restrain spasticity.

Translation and validation into Brazilian Portuguese of the Spastic Paraplegia Rating Scale (SPRS)

OBJECTIVE

To translate and validate the Spastic Paraplegia Rating Scale (SPRS) into Brazilian-Portuguese.

METHOD

Two experienced and English-fluent neurologists translated SPRS into Portuguese, creating SPRS-BR. We then assessed inter and intra-rater reliability of this version using coefficients of correlation and variability in a cohort of 30 patients.

RESULTS

Mean age of patients and disease duration were 47.7 ± 10.5 and 17.0 ± 10.6 years, respectively. Twenty-one had pure HSP and SPG4 was the most frequent genotype. Mean Rankin and SPRS-BR scores were 2.2 ± 0.9 and 19.9 ± 9.9, respectively. Mean intra and inter-rater correlation coefficients of SPRS-BR scores were 0.951 and 0.934, whereas coefficients of variation were 11.5% (inter-rater) and 9.9% (intra-rater). Cronbach's alpha for the whole SPRS-BR scale was 0.873.

CONCLUSION

SPRS-BR is a useful, reliable and valid clinical instrument.

Gait Patterns in Patients with Hereditary Spastic Paraparesis

Background

Spastic gait is a key feature in patients with hereditary spastic paraparesis, but the gait characterization and the relationship between the gait impairment and clinical characteristics have not been investigated.

Objectives

To describe the gait patterns in hereditary spastic paraparesis and to identify subgroups of patients according to specific kinematic features of walking.

Methods

We evaluated fifty patients by computerized gait analysis and compared them to healthy participants. We computed time-distance parameters of walking and the range of angular motion at hip, knee, and ankle joints, and at the trunk and pelvis. Lower limb joint moments and muscle co-activation values were also evaluated.

Results

We identified three distinct subgroups of patients based on the range of motion values. Subgroup one was characterized by reduced hip, knee, and ankle joint range of motion. These patients were the most severely affected from a clinical standpoint, had the highest spasticity, and walked at the slowest speed. Subgroup three was characterized by an increased hip joint range of motion, but knee and ankle joint range of motion values close to control values. These patients were the most mildly affected and had the highest walking speed. Finally, subgroup two showed reduced knee and ankle joint range of motion, and hip range of motion values close to control values. Disease severity and gait speed in subgroup two were between those of subgroups one and three.

Conclusions

We identified three distinctive gait patterns in patients with hereditary spastic paraparesis that correlated robustly with clinical data. Distinguishing specific features in the gait patterns of these patients may help tailor pharmacological and rehabilitative treatments and may help evaluate therapeutic effects over time.

Cognitive dysfunction in hereditary spastic paraplegias and other motor neuron disorders

Hereditary spastic paraplegia (HSP) is a diverse group of single-gene disorders that share the predominant clinical feature of progressive lower limb spasticity and weakness. More than 70 different genetic subtypes have been described and all modes of inheritance are possible. Intellectual dysfunction in HSP is frequent in recessive forms but rare in dominant families. It may manifest by either mental retardation and/or cognitive decline. The latter may be subtle, restricted to executive dysfunction or may evolve to severe dementia. The cognitive profile is thought to depend largely on the genetic subtype of HSP, although wide phenotypic variability within the same genetic subtype and also within the same family can be found.

Clinical and Paraclinical Indicators of Motor System Impairment in Hereditary Spastic Paraplegia: A Pilot Study

BACKGROUND

Hereditary spastic paraplegias (HSP) are a composite and genetically heterogeneous group of conditions mainly expressed by the impairment of the central motor system ("pure" forms). The involvement of other components of the central nervous system or of other systems is described in the "complicate" forms. The definition of an investigation protocol capable, by assembling clinical and paraclinical indicators to fully represent the extent of the motor system impairment, would help both the clinical handling of these conditions and contribute to our understanding of their pathogenesis.

METHODS

We applied a clinical and paraclinical protocol which included tools exploring motor and non motor functioning, neurophysiology and MRI to a composite cohort of 70 molecularly defined HSP patients aged 3 to 65, to define for each indicator its significance in detailing the presence and the severity of the pathology.

RESULTS

Clinically increased deep tendon reflexes and lower limb (LL) weakness are constant findings in all patients. The "complicated" forms are characterized by peripheral motor impairment, cognitive and cerebellar involvement. The Spastic Paraplegia Rating Scale efficiently reflects the severity of functional problems and correlates with disease duration. Neurophysiology consistently documents the impairment of the central motor pathway to the LLs. Nevertheless, the upper extremities and sensory system involvement is a frequent finding. MRI diffusion tensor imaging (DTI) highlighted a significant alteration of FA and MD. Combining the sampling of the various portion of the cortico-spinal tract (CST) DTI consistently discriminated patients from controls.

CONCLUSION

We propose a graded clinical and paraclinical protocol for HSP phenotype definition, indicating for each tool the discriminative and descriptive capacity. Our protocol applied to 9 different forms of HSP showed that the functional impairment often extends beyond the CST. The novel DTI approach may add significant elements in disease recognition, staging and mapping.

Mutational analysis of the CYP7B1, PNPLA6 and C19orf12 genes in autosomal recessive hereditary spastic paraplegia

The hereditary spastic paraplegias (HSPs) comprise a group of genetically heterogeneous neurodegenerative diseases. Here, we evaluated the spectrum and frequency of mutations in the CYP7B1, PNPLA6 and C19orf12 genes (causative for the subtypes SPG5A, SPG39 and SPG43, respectively) in a cohort of 63 unrelated HSP patients with suspected autosomal recessive inheritance. Two novel homozygous mutations (one frameshift and one missense mutation) were detected in CYP7B1 (SPG5A), while no disease-causing mutation was identified for SPG39 or SPG43.

Brain-Specific Cytoskeletal Damage Markers in Cerebrospinal Fluid: Is There a Common Pattern between Amyotrophic Lateral Sclerosis and Primary Progressive Multiple Sclerosis?

Many neurodegenerative disorders share a common pathophysiological pathway involving axonal degeneration despite different etiological triggers. Analysis of cytoskeletal markers such as neurofilaments, protein tau and tubulin in cerebrospinal fluid (CSF) may be a useful approach to detect the process of axonal damage and its severity during disease course. In this article, we review the published literature regarding brain-specific CSF markers for cytoskeletal damage in primary progressive multiple sclerosis and amyotrophic lateral sclerosis in order to evaluate their utility as a biomarker for disease progression in conjunction with imaging and histological markers which might also be useful in other neurodegenerative diseases associated with affection of the upper motor neurons. A long-term benefit of such an approach could be facilitating early diagnostic and prognostic tools and assessment of treatment efficacy of disease modifying drugs.