Chapter 17 Hereditary spastic paraparesis

Gait analysis patterns and rehabilitative interventions to improve gait in persons with hereditary spastic paraplegia: a systematic review and meta-analysis

Background

Hereditary spastic paraplegias (HSPs) are a group of inheritance diseases resulting in gait abnormalities, which may be detected using instrumented gait analysis. The aim of this systematic review was 2-fold: to identify specific gait analysis patterns and interventions improving gait in HSP subjects.

Methods

A systematic review was conducted in PubMed, Cochrane Library, REHABDATA, and PEDro databases, in accordance with reporting guidelines of PRISMA statement and Cochrane's recommendation. The review protocol was recorded on the PROSPERO register. Patients with pure and complicated HSP of any age were included. All types of studies were included. Risk of bias, quality assessment, and meta-analysis were performed.

Results

Forty-two studies were included: 19 were related to gait analysis patterns, and 24 were intervention studies. The latter ones were limited to adults. HSP gait patterns were similar to cerebral palsy in younger subjects and stroke in adults. Knee hyperextension, reduced range of motion at knee, ankle, and hip, reduced foot lift, and increased rapid trunk and arm movements were reported. Botulinum injections reduced spasticity but uncovered weakness and improved gait velocity at follow-up. Weak evidence supported intrathecal baclofen, active intensive physical therapy (i.e., robot-assisted gait training, functional exercises, and hydrotherapy), and functional electrical stimulation. Some improvements but adverse events were reported after transcranial magnetic stimulation, transcutaneous spinal direct current stimulation, and spinal cord stimulation implant.

Conclusion

Knee hyperextension, non-sagittal pelvic movements, and reduced ROM at the knee, ankle, and hip represent the most peculiar patterns in HSP, compared to diplegic cerebral palsy and stroke. Botulinum improved comfortable gait velocity after 2 months. Nonetheless, interventions reducing spasticity might result in ineffective functional outcomes unveiling weakness. Intensive active physical therapy and FES might improve gait velocity in the very short term.

Novel genotype-phenotype and MRI correlations in a large cohort of patients with SPG7 mutations

Objective

To clinically, genetically, and radiologically characterize a large cohort of SPG7 patients.

Methods

We used data from next-generation sequencing panels for ataxias and hereditary spastic paraplegia to identify a characteristic phenotype that helped direct genetic testing for variations in SPG7. We analyzed MRI. We reviewed all published SPG7 mutations for correlations.

Results

We identified 42 cases with biallelic SPG7 mutations, including 7 novel mutations, including a large multi-exon deletion, representing one of the largest cohorts so far described. We identified a characteristic phenotype comprising cerebellar ataxia with prominent cerebellar dysarthria, mild lower limb spasticity, and a waddling gait, predominantly from a cohort of idiopathic ataxia. We report a rare brain MRI finding of dentate nucleus hyperintensity on T2 sequences with SPG7 mutations. We confirm that the c.1529C>T allele is frequently present in patients with long-standing British ancestry. Based on the findings of the present study and existing literature, we confirm that patients with homozygous mutations involving the M41 peptidase domain of SPG7 have a younger age at onset compared to individuals with mutations elsewhere in the gene (14 years difference, p < 0.034), whereas c.1529C>T compound heterozygous mutations are associated with a younger age at onset compared to homozygous cases (5.4 years difference, p < 0.022).

Conclusions

Mutant SPG7 is common in sporadic ataxia. In patients with British ancestry, c.1529C>T allele represents the most frequent mutation. SPG7 mutations can be clinically predicted by the characteristic hybrid spastic-ataxic phenotype described above, along with T2 hyperintensity of the dentate nucleus on MRI.

Effects of superficial heating and insulation on walking speed in people with hereditary and spontaneous spastic paraparesis: A randomised crossover study

OBJECTIVES

Cooling of the lower limb in people with Hereditary and Spontaneous Spastic Paraparesis (pwHSSP) has been shown to affect walking speed and neuromuscular impairments. The investigation of practical strategies, which may help to alleviate these problems is important. The potential of superficial heat to improve walking speed has not been explored in pwHSSP. Primary objective was to explore whether the application of superficial heat (hot packs) to lower limbs in pwHSSP improves walking speed. Secondary objective was to explore whether wearing insulation after heating would prolong any benefits.

METHODS

A randomised crossover study design with 21 pwHSSP. On two separate occasions two hot packs and an insulating wrap (Neo-G™) were applied for 30minutes to the lower limbs of pwHSSP. On one occasion the insulating wrap was maintained for a further 30minutes and on the other occasion it was removed. Measures of temperature (skin, room and core), walking speed (10 metre timed walk) and co-ordination (foot tap time) were taken at baseline (T1), after 30 mins (T2) and at one hour (T3).

RESULTS

All 21 pwHSSP reported increased lower limb stiffness and decreased walking ability when their legs were cold. After thirty minutes of heating, improvements were seen in walking speed (12.2%, P<0.0001, effect size 0.18) and foot tap time (21.5%, P<0.0001, effect size 0.59). Continuing to wear insulation for a further 30minutes gave no additional benefit; with significant improvements in walking speed maintained at one hour (9.9%, P>0.001) in both conditions.

CONCLUSIONS

Application of 30minutes superficial heating moderately improved walking speed in pwHSSP with effects maintained at 1hour. The use of hot packs applied to lower limbs should be the focus of further research for the clinical management of pwHSSP who report increased stiffness of limbs in cold weather and do not have sensory deficits.

[Hereditary spastic paraplegia: up to date]

Hereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous group of neurodegenerative disorders that are clinically characterized by progressive spasticity and weakness of the lower limbs. HSP genetic loci are designated SPG1-72 in order of their discovery. In 206 Japanese families with autosomal dominant HSP, SPG4 was the most common form, accounting for 38%, followed by SPG3A (5%), SPG31 (5%), SPG10 (2%), and SPG8 (1%). We have identified novel mutations in the C12orf65 gene and the LYST gene in several Japanese families with autosomal recessive HSP. JASPAC will facilitate gene discovery and mechanistic understanding of HSP. The future challenge will be the establishment of treatment of HSP.

Muscle paresis and passive stiffness: key determinants in limiting function in Hereditary and Sporadic Spastic Paraparesis

BACKGROUND

People with Hereditary and Sporadic Spastic Parapresis (SP) walk with a stiff legged gait characterised by a lack of knee flexion.

OBJECTIVE

We investigated the relationship between lower limb strength and stiffness and knee flexion during swing phase while walking in 20 people with SP and 18 matched controls.

METHODS

Maximal isometric strength was measured using a dynamometer. Passive stiffness and spasticity was assessed during motor-driven slow (5°/s) and fast (60°/s) stretches at the ankle and knee while the subject was relaxed or preactivating the muscle. Walking was assessed using 3D motion analysis.

RESULTS

Isometric muscle strength was decreased in people with SP with over a 50% reduction in strength being found in the ankle dorsiflexors. Passive stiffness, assessed during slow stretches, was 35% higher in the plantarflexors in people with SP (P<0.05). Faster stretches induced large stretch evoked muscle activity and over a 110% increase in stiffness at the ankle and knee in people with SP reflecting the presence of spasticity (P<0.05). However, stretch reflex size and stiffness was similar between the groups following identical stretches of the pre-activated muscle (P>0.05). Lower knee flexion during swing phase was associated with reduced knee flexion velocity at the end of stance phase which in turn was associated with reduced plantarflexor strength and increased passive stiffness in the knee extensors.

CONCLUSIONS

The relative importance of muscle paresis and passive stiffness in limiting walking in SP suggests that these impairments should be the target of future therapies.