Variação da posição do cone medular em pacientes submetidos a rizotomia dorsal seletiva lombar na paralisia cerebral espástica

Abstract

Cerebral Palsy (CP) is a group of permanent disorders of movement and posture development, which cause limitations in neuromotor activities, which are attributed to non-progressive disorders that occur during the period of fetal or infant brain development, contributing to limitations in the child's functionality profile (PEIXOTO et al., 2020). CP has a prevalence of one and a half to three per thousand live births, and can trigger several neurological development disorders, such as cognition, communication, behavior, sensory perception and motor skills (COLVER, 2014; GRAHAM, 2016). Among tone changes, spasticity, characterized by hyperreflexia and hypertonia, is the most commonly observed motor abnormality, with approximately 80% of CP cases incidence (GARFINKLE et al., 2020). CP is often associated with symptoms such as muscle hypertonia, imbalances, coordination difficulties and manual function, reflecting the muscular and neuromuscular changes resulting from brain injury. Although brain damage does not progress, the clinical manifestations of CP may vary as the child grows, leading to a worsening of neuromuscular and functional capacities (RANA et al., 2017). Spasticity is one of the main challenges in the management of children with CP, as it contributes to bone and joint deformities, pain and functional loss (PATEL et al., 2020). Initial therapeutic options include physical therapy, occupational therapy, botulinum toxin injections, intrathecal baclofen and selective dorsal rhizotomy (SDR) (UPADHYAY et al., 2020). RDS, a minimally invasive neurosurgical intervention, has been shown to be effective in improving walking ability and range of motion, correcting spasticity that compromises gait by facilitating movement in the ankle joint (ATESFILIZ et al., 2020). Accurate identification of the position of the conus medullaris is crucial to minimize neurological risks during surgical interventions in the lumbosacral spine, such as selective dorsal rhizotomy. Recent studies highlight that anatomical variations can directly influence surgical results and the incidence of complications (KANG et al., 2020). In Brazil, the RDS surgical technique is still being disseminated, but without defined protocols for the pre-, intra-, and postoperative periods. For the surgical approach, laminoplasty from L1 to L5 with laminectomy of S1 and S2 is commonly performed (ALENCAR et al., 2020). For the precise location of the conus medullaris (CM), it is necessary to perform magnetic resonance imaging (MRI) of the thoracolumbar region in the preoperative period, with the need for contrast or even sedation. This scenario can bring risks and complications that require continuous monitoring of the child, such as adverse effects of sedation, such as respiratory depression and hypoxemia, which can occur in up to 20% of pediatric patients (MALVIYA et al., 2000) or the use of gadolinium contrast, the safety and tolerability of which are not clearly described in the literature (BAKER et al., 2004). Despite advances in neuroimaging, there is a lack of studies that correlate the location of the conus medullaris with demographic variables in Brazilian pediatric populations, which makes it difficult to standardize surgical protocols (SILVA et al., 2019). The hypothesis of this study is to investigate the variation of the termination of the c nus medullaris in patients with spastic CP and compare it with data present in the medical literature. The objective is to elucidate aspects of this variation and contribute to the reduction of invasive neuroimaging procedures, such as MRI, in children eligible for treatments such as RDS L, who routinely undergo imaging exams.