De Beukelaer Nathalie, Bar-On Lynn, Hanssen Britta, Peeters Nicky, Prinsen Sandra, Ortibus Els, Desloovere Kaat, Van Campenhout Anja
KU Leuven Department of Rehabilitation Sciences, Leuven, Belgium.
Clinical Motion Analysis Laboratory, University Hospitals Leuven, Leuven, Belgium.
Front Neurol. 2021 Feb 26;12:635032. doi: 10.3389/fneur.2021.635032. eCollection 2021.
Hereditary spastic paraplegia (HSP) is a neurological, genetic disorder that predominantly presents with lower limb spasticity and muscle weakness. Pediatric pure HSP types with infancy or childhood symptom onset resemble in clinical presentation to children with bilateral spastic cerebral palsy (SCP). Hence, treatment approaches in these patient groups are analogous. Altered muscle characteristics, including reduced medial gastrocnemius (MG) muscle growth and hyperreflexia have been quantified in children with SCP, using 3D-freehand ultrasound (3DfUS) and instrumented assessments of hyperreflexia, respectively. However, these muscle data have not yet been studied in children with HSP. Therefore, we aimed to explore these MG muscle characteristics in HSP and to test the hypothesis that these data differ from those of children with SCP and typically developing (TD) children. A total of 41 children were retrospectively enrolled including (1) nine children with HSP (ages of 9-17 years with gross motor function levels I and II), (2) 17 age-and severity-matched SCP children, and (3) 15 age-matched typically developing children (TD). Clinically, children with HSP showed significantly increased presence and severity of ankle clonus compared with SCP ( = 0.009). Compared with TD, both HSP and SCP had significantly smaller MG muscle volume normalized to body mass ( ≤ 0.001). Hyperreflexia did not significantly differ between the HSP and SCP group. In addition to the observed pathological muscle activity for both the low-velocity and the change in high-velocity and low-velocity stretches in the two groups, children with HSP tended to present higher muscle activity in response to increased stretch velocity compared with those with SCP. This exploratory study is the first to reveal MG muscle volume deficits in children with HSP. Moreover, high-velocity-dependent hyperreflexia and ankle clonus is observed in children with HSP. Instrumented impairment assessments suggested similar altered MG muscle characteristics in pure HSP type with pediatric onset compared to bilateral SCP. This finding needs to be confirmed in larger sample sizes. Hence, the study results might indicate analogous treatment approaches in these two patient groups.
遗传性痉挛性截瘫（HSP）是一种神经系统遗传性疾病，主要表现为下肢痉挛和肌肉无力。婴儿期或儿童期起病的小儿单纯型HSP在临床表现上与双侧痉挛性脑瘫（SCP）患儿相似。因此，这些患者群体的治疗方法类似。分别使用三维徒手超声（3DfUS）和仪器化的反射亢进评估方法，对SCP患儿的肌肉特征改变进行了量化，包括腓肠肌内侧头（MG）肌肉生长减少和反射亢进。然而这些肌肉数据尚未在HSP患儿中进行研究。因此，我们旨在探究HSP患儿的这些MG肌肉特征，并检验这些数据与SCP患儿和正常发育（TD）儿童的数据不同这一假设。总共回顾性纳入了41名儿童，包括：（1）9名HSP患儿（年龄9 - 17岁，粗大运动功能水平为I级和II级），（2）17名年龄和严重程度匹配的SCP患儿，以及（3）15名年龄匹配的正常发育儿童（TD）。临床上，与SCP患儿相比，HSP患儿踝阵挛的出现率和严重程度显著增加（P = 0.009）。与TD儿童相比，HSP患儿和SCP患儿的MG肌肉体积与体重的比值均显著更小（P≤0.001）。HSP组和SCP组之间反射亢进无显著差异。除了观察到两组在低速以及高速和低速拉伸变化时的病理性肌肉活动外，与SCP患儿相比，HSP患儿在拉伸速度增加时往往表现出更高的肌肉活动。这项探索性研究首次揭示了HSP患儿存在MG肌肉体积不足。此外，在HSP患儿中观察到了与速度相关的反射亢进和踝阵挛。仪器化的损伤评估表明，小儿起病的单纯型HSP与双侧SCP相比，MG肌肉特征改变相似。这一发现需要在更大样本量中得到证实。因此，研究结果可能表明这两个患者群体的治疗方法类似。
