NIVALDO ALONSO
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Cirurgia, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
4 resultados
Resultados de Busca
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- Cranial Fossa Volume and Morphology Development in Apert Syndrome(2020) LU, Xiaona; FORTE, Antonio Jorge; WILSON, Alexander; STEINBACHER, Derek M.; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.Background: Apert syndrome causes normal or enlarged intracranial volume overall as patients grow. This study aimed to trace the segmental anterior, middle, and posterior cranial fossae volume and structural morphology in these patients, to help discern a more focused and individualized surgical treatment plan for patients with Apert syndrome. Methods: This study included 82 preoperative computed tomographic scans (Apert, n = 32; control, n = 50) divided into five age-related subgroups. The scans were measured using image processing and three-dimensional modeling software. Results: The middle cranial fossa volume was increased and was the earliest change noted. It was increased by 45 percent (p = 0.023) compared with controls before 6 months of age and remained increased into adulthood (161 percent, p = 0.016), with gradually increasing severity. The anterior and posterior cranial fossae volumes also increased, by 35 percent (p = 0.032) and 39 percent (p = 0.007), respectively. Increased depth of cranial fossae contributed most to the increase in volumes of patients with Apert syndrome, with correlation coefficients of 0.799, 0.908, and 0.888 for anterior, middle, and posterior cranial fossa, respectively. The intracranial volume was increased 12 percent (p = 0.098) across the entire test age range (0 to 26 years old), but only had statistical significance during the age range of 6 to 18 years (22 percent, p = 0.001). Conclusions: Malformation of the middle cranial fossa is an early, perhaps the initial, pivotal cranial morphologic change in Apert syndrome. Increased cranial fossae depth is an inherent characteristic of the maldevelopment. Normalization of cranial volume and circumference overall may not achieve a normal skull structure, as it does not correct regional craniocerebral disproportion.
- Respective Roles of Craniosynostosis and Syndromic Influences on Cranial Fossa Development(2021) LU, Xiaona; FORTE, Antonio Jorge; WILSON, Alexander T.; PARK, Kitae Eric; ALLAM, Omar; ALPEROVICH, Michael; STEINBACHER, Derek M.; ALONSO, Nivaldo; PERSING, John A.Background: Little is known about the detailed growth of the cranial fossae, even though they provide an important structural connection between the cranial vault and the facial skeleton. This study details the morphologic development of isolated cranial vault synostosis and associated syndromes on cranial fossa development. Methods: A total of 125 computed tomographic scans were included (nonsyndromic bicoronal synostosis, n = 36; Apert syndrome associated with bicoronal synostosis, n = 24; Crouzon syndrome associated with bicoronal synostosis, n = 11; and controls, n = 54). Three-dimensional analyses were produced using Materialise software. Results: The regional anterior and middle cranial fossae volumes of nonsyndromic bicoronal synostosis are characterized by significant increases of 43 percent (p < 0.001) and 60 percent (p < 0.001), respectively, and normal posterior cranial fossa volume. The cranial fossae depths of nonsyndromic bicoronal synostosis were increased, by 37, 42, and 21 percent (all p < 0.001) for anterior, middle, and posterior cranial fossae, respectively, accompanying the shortened cranial fossae lengths. The volume and morphology of all cranial fossae in Apert syndrome nearly paralleled nonsyndromic bicoronal synostosis. However, Crouzon syndrome had reduced depths of cranial fossae, and more restricted fossa volumes than both Apert syndrome and nonsyndromic bicoronal synostosis. Conclusions: Cranial vault suture synostosis is likely to be more influential on cranial fossae development than other associated influences (genetic, morphologic) in Apert and Crouzon syndromes. Isolated Apert syndrome pathogenesis is associated with an elongation of the anterior cranial fossa length in infants, whereas in Crouzon syndrome, there is a tendency to reduce cranial fossa depth, suggesting individual adaptability in cranial fossae development related to vault synostosis.
- Influence of Nonsyndromic Bicoronal Synostosis and Syndromic Influences on Orbit and Periorbital Malformation(2022) LU, Xiaona; FORTE, Antonio Jorge; DINIS, Jacob; JUNN, Alexandra; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.Background: Oculoorbital disproportion in patients with craniosynostosis has similarities and dissimilarities between syndromic and nonsyndromic cases. The authors hypothesized that these two conditions have specific individual influences as they relate to development of the orbital and periorbital skeletons. Methods: A total of 133 preoperative computed tomography scans (nonsyndromic bicoronal synostosis, n = 38; Apert syndrome bicoronal synostosis subtype, n = 33; Crouzon syndrome bicoronal synostosis subtype, n = 10; controls, n = 52) were included. Craniometric and volumetric analyses related to the orbit and periorbital anatomy were performed. Results: Orbital cavity volume was mildly restricted in nonsyndromic bicoronal synostosis (7 percent, p = 0.147), but more so in Apert and Crouzon syndromes [17 percent (p = 0.002) and 21 percent (p = 0.005), respectively]. The sphenoid side angle in Apert syndrome was wider than when compared to Crouzon syndrome (p = 0.043). The ethmoid side angle in Apert patients, however, was narrower (p = 0.066) than that in Crouzon patients. Maxilla anteroposterior length was more restricted in Apert syndrome than Crouzon syndrome (21 percent, p = 0.003) and nonsyndromic cases (26 percent, p < 0.001). The posterior nasal spine position was retruded in Crouzon syndrome (39 percent, p < 0.001), yet the anterior nasal spine position was similar in Apert and Crouzon syndromes. Conclusions: Orbit and periorbital malformation in syndromic craniosynostosis is likely the combined influence of syndromic influences and premature suture fusion. Apert syndrome expanded the anteriorly contoured lateral orbital wall associated with bicoronal synostosis, whereas Crouzon syndrome had more infraorbital rim retrusion, resulting in more severe exorbitism. Apert syndrome developed maxillary hypoplasia, in addition to the maxillary retrusion, observed in Crouzon syndrome and nonsyndromic bicoronal synostosis patients.
- Association of Regional Cranial Base Deformity and Ultimate Structure in Crouzon Syndrome(2019) LU, Xiaona; FORTE, Antonio Jorge; SAWH-MARTINEZ, Rajendra; WU, Robin; CABREJO, Raysa; STEINBACHER, Derek M.; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.Background: Considerable craniofacial features of Crouzon syndrome are attributed to the dysmorphology of the cranial base. As cephalometric studies have focused mainly on the facial deformity, rather than the cranial base, the underlying cause of deformity is not as well understood. Therefore, the authors compared the cranial base development of Crouzon syndrome to controls to trace the timing of deformity in the cranial base and face, to analyze their temporal correlation. Methods: Ninety computed tomographic scans were included (Crouzon, n = 36; controls, n = 54) and divided into five age subgroups. Craniofacial cephalometric measurements were analyzed by Materialise software. Results: The overall cranial base length in Crouzon syndrome compared with controls decreased 8 percent (p = 0.014) on average. The posterior cranial fossa shortening accounted for most of this reduction. The cranial base displaced with the distances from basion, sella, and ethmosphenoid to posterior nasal spine shortened by 21%, 18%, and 16%, respectively (all p < 0.01) during life. Although the cranial base angle on intracranial surface remains normal, the angles on facial surface narrowed were reduced. Conclusions: The cranial base deformity of Crouzon syndrome consists of the whole skull base and particularly anterior skull base shortening early, leading to a compensatory widened anterior skull base. However, when this widening did not compensate fully for the rapid enlargement of the brain, the posterior skull base displaced inferiorly and became kyphotic. The cranial base deformity develops sequentially anterior to posterior in a probable cascade of influence pattern.