Cutaneous and subcutaneous blood flow rates in paraplegic humans investigated by 133Xenon wash-out. Methodological considerations

Summary. In a methodological study including 14 paraplegics and seven normal controls cutaneous and subcutaneous blood flow rates were investigated by ¹³³Xenon wash-out after atraumatic labelling. In paraplegics, areas suffering pressure sores were included. The method was found applicable for the authors' purposes. In seven paraplegics median (95% confidence limits) cutaneous blood flow was 5–2 (2–4–8–5) ml (100 g min)“¹ and subcutaneous 4–3 (2–0–13–2) ml (100 g min)^-1. This did not differ from normal controls. In seven paraplegics with ischial pressure sores a trend for increased cutaneous blood-flow rates from areas adjacent to sores was obvious (P= 0–06). During 704 head-up tilt, elimination-rate constants were reduced by a factor of 0–54 (0–50–0–70). A proximal blockade or infiltration of the ¹³³Xenon depots with lidocaine did not inhibit employment of the method. The proximal block did not alter the local blood flow rate, but infiltration increased it in both paraplegics and normal individuals. Intra- and interdepot coefficients of variation were about 11% and 40% respectively. Interindividual coefficients of variation varied between 25% and 46%.     

Autonomic cardiovascular control and sports classification in Paralympic athletes with spinal cord injury

Purpose To investigate the relationship between the classification systems used in wheelchair sports and cardiovascular function in Paralympic athletes with spinal cord injury (SCI). Methods 26 wheelchair rugby (C3–C8) and 14 wheelchair basketball (T3‐L1) were assessed for their International Wheelchair Rugby and Basketball Federation sports classification. Next, athletes were assessed for resting and reflex cardiovascular and autonomic function via the change (delta) in systolic blood pressure (SBP) and heart rate (HR) in response to sit-up, and sympathetic skin responses (SSRs), respectively. Results There were no differences in supine, seated, or delta SBP and HR between different sport classes in rugby or basketball (all p?>?0.23). Athletes with autonomically complete injuries (SSR score 0‐1) exhibited a lower supine SBP, seated SBP and delta SBP compared to those with autonomically incomplete injuries (SSR score?>1; all p?2?=^?1.63, p?=?0.20). Conclusion We provide definitive evidence that sports specific classification is not related to the degree of remaining autonomic cardiovascular control in Paralympic athletes with SCI. We suggest that testing for remaining autonomic function, which is closely related to the degree of cardiovascular control, should be incorporated into sporting classification.

• Implications for Rehabilitation

• Spinal cord injury is a debilitating condition that affects the function of almost every physiological system.

• It is becoming increasingly apparent that spinal cord injury induced changes in autonomic and cardiovascular function are important determinants of sports performance in athletes with spinal cord injury.

• This study shows that the current sports classification systems used in wheelchair rugby and basketball do not accurately reflect autonomic and cardiovascular function and thus are placing some athletes at a distinct disadvantage/advantage within their respective sport.

     

Physical therapists’ perceptions about patients with incomplete post-traumatic paraplegia adherence to recommended home exercises: a qualitative study

Background

The overall purpose of physical therapy for patients with spinal cord injury is to improve health-related quality of life. However, poor adherence is a problem in physical therapy and may have negative impact on outcomes.

A nonstop variant in REEP1 causes peripheral neuropathy by unmasking a 3′UTR‐encoded,aggregation‐inducing motif

Single‐nucleotide variants that abolish the stop codon (“nonstop” alterations) are a unique type of substitution in genomic DNA. Whether they confer instability of the mutant mRNA or result in expression of a C‐terminally extended protein depends on the absence or presence of a downstream in‐frame stop codon, respectively. Of the predicted protein extensions, only few have been functionally characterized. In a family with autosomal dominant Charcot‐Marie‐Tooth disease type 2, that is, an axonopathy affecting sensory neurons as well as lower motor neurons, we identified a heterozygous nonstop variant in REEP1. Mutations in this gene have classically been associated with the upper motor neuron disorder hereditary spastic paraplegia (HSP). We show that the C‐terminal extension resulting from the nonstop variant triggers self‐aggregation of REEP1 and of several reporters. Our findings support the recently proposed concept of 3′UTR‐encoded “cryptic amyloidogenic elements.” Together with a previous report on an aggregation‐prone REEP1 deletion variant in distal hereditary motor neuropathy, they also suggest that toxic gain of REEP1 function, rather than loss‐of‐function as relevant for HSP, specifically affects lower motor neurons. A search for similar correlations between genotype, phenotype, and effect of mutant protein may help to explain the wide clinical spectra also in other genetically determined disorders.     

Autosomal dominant hereditary spastic paraplegia with axonal sensory motor polyneuropathy maps to chromosome 21q 22.3

Aim: Hereditary spastic paraplegia (HSP) are a genetically and clinically heterogeneous group of disorders. At present, 19 autosomal dominant loci for HSP have been mapped. We ascertained an American family of European descent segregating an autosomal dominant HSP associated with peripheral neuropathy. Methods: A genome wide scan was performed with 410 microsatellite repeat marker (Weber lab screening set 16) and following linkage and haplotype analysis, fine mapping was performed. Established genes or loci for HSP were excluded by direct sequencing or haplotype analysis. Results: All established loci for HSP were excluded. Fine mapping suggested a locus on chromosome 21q22.3 flanked by markers D21S1411 and D21S1446 with a maximum logarithm of odds score of 2.05 and was supported by haplotype analysis. A number of candidate genes in this region were analyzed and no disease-producing mutations were detected. Conclusion: We present the clinical and genetic analysis of an American family with autosomal dominant HSP with axonal sensory motor polyneuropathy mapping to a novel locus on chromosome 21q22.3 designated SPG56.     

Proteolipid protein modulates preservation of peripheral axons and premature death when myelin protein zero is lacking

Protein zero (P0) is the major structural component of peripheral myelin. Lack of this adhesion protein from Schwann cells causes a severe dysmyelinating neuropathy with secondary axonal degeneration in humans with the neuropathy Dejerine‐Sottas syndrome (DSS) and in the corresponding mouse model (P0^null‐mice). In the mammalian CNS, the tetraspan‐membrane protein PLP is the major structural myelin constituent and required for the long‐term preservation of myelinated axons, which fails in hereditary spastic paraplegia (SPG type‐2) and the relevant mouse model (Plp^null‐mice). The Plp‐gene is also expressed in Schwann cells but PLP is of very low abundance in normal peripheral myelin; its function has thus remained enigmatic. Here we show that the abundance of PLP but not of other tetraspan myelin proteins is strongly increased in compact peripheral myelin of P0^null‐mice. To determine the functional relevance of PLP expression in the absence of P0, we generated P0^null*Plp^null‐double‐mutant mice. Compared with either single‐mutant, P0^null*Plp^null‐mice display impaired nerve conduction, reduced motor functions, and premature death. At the morphological level, axonal segments were frequently non‐myelinated but in a one‐to‐one relationship with a hypertrophic Schwann cell. Importantly, axonal numbers were reduced in the vital phrenic nerve of P0^null*Plp^null‐mice. In the absence of P0, thus, PLP also contributes to myelination by Schwann cells and to the preservation of peripheral axons. These data provide a link between the Schwann cell‐dependent support of peripheral axons and the oligodendrocyte‐dependent support of central axons. GLIA 2016;64:155–174     

创伤性高位截瘫患者气管切开术的临床分析

目的 探讨创伤性高位截瘫患者气管切开术方法,总结注意事项,减少并发症.方法 回顾我院2007年1月-2011年12月收治的21例创伤性高位截瘫手术患者,均在颈椎术前常规行气管切开术,插管麻醉完成颈椎手术后,更换带气囊气管套管,送重症监护室观察7d.结果 21例均成功完成气管切开术,2例术中出现呼吸困难,1例术后脱管,均抢救成功.结论 为创伤性高位截瘫患者行气管切开术是安全的.术前正确评估手术风险,做好应急抢救准备,可以降低手术风险,减少术后并发症.