ABSTRACT
Objective:To explore the diagnostic value of ultrasound in posterior fossa anomalies (PFA) at 11-13 + 6 gestational weeks by measuring brainstem (BS), brainstem-to-occipital bone (BSOB) diameter and BS/BSOB ratio. Methods:A total of 209 normal fetuses (control group) were randomly selected from Beijing Obstetrics and Gynecology Hospital, Capital Medical University, between March 2018 and November 2021. Reference ranges for BS, BSOB diameter and BS/BSOB ratio were obtained on the mid-sagittal view of the fetal profile and the relationship of three parameters and crown-rump length (CRL) was investigated. The intra- and inter-observer reliabilities were determined by intraclass correlation coefficient (ICC) in 30 normal fetuses. Fourteen fetuses diagnosed with PFA in the same period including 10 cases of cystic posterior fossa malformations (cPFM) and 4 cases of open spine bifida (OSB) were retrospectively selected to compare BS, BSOB diameter and the BS/BSOB ratio with control group.Results:BS and BSOB diameters were successfully obtained in all control fetuses (100%), and the intra- and inter-observer reliabilities for BS and BSOB diameters were good (ICC=0.877, 0.846 and 0.939, 0.895). In the control group, BS and BSOB diameter linearly correlated with CRL ( r=0.867, 0.794; all P<0.001), while the BS/BSOB ratio was 0.75 (0.71, 0.79). There were significant differences of BSOB diameter and BS/BSOB ratio between control group and PFA group (all P<0.05). Except for one isolated vermian hypoplasia (VH), the BSOB diameters in 9 (90%) cases of cPFM were above the 95th percentile of the calculated normal range and were below the 5th percentile in 4(100%) cases of OSB.Except for one isolated VH, the BS/BSOB ratio in 9 (90%) cases of cPFM was below the 5th percentile of the calculated normal range. The BS/BSOB ratio in 4 (100%) cases of OSB was above the 95th percentile of the calculated normal range. Conclusions:The measurements of BS and BSOB diameter are feasible with good repeatability. Abnormal BSOB diameter and BS/BSOB ratio are suggestive for PFA. The posterior fossa of isolated VH can be normal in the first trimester.
ABSTRACT
RESUMEN Se revisó la literatura existente sobre la Malformación de Chiari Tipo I en el adulto, haciendo énfasis en su diagnóstico imagenológico y tratamiento médico-quirúrgico. La malformación de Chiari es una enfermedad poco frecuente. Representa entre el 1 y el 4 % de todas las patologías neuroquirúrgicas. El diagnóstico se realiza meses y hasta años después de comenzada la sintomatología y se confirma en el 100 % de los casos con resonancia magnética de cráneo. El tratamiento es quirúrgico en los pacientes sintomáticos, siendo controversial en aquellos oligosintomáticos o con diagnóstico casual. La cirugía siempre debe realizarse con el apoyo de monitoreo neurofisiológico, que puede ser determinante en la técnica quirúrgica a emplear. La mortalidad asociada a la cirugía es muy baja, oscilando entre el 0 y 0,5 % según la mayoría de las series. Lo más importante es la selección de los pacientes para el tratamiento quirúrgico. No debe asumirse una actitud expectante en espera de un deterioro neurológico que justifique la cirugía, cuando ésta se hace a tiempo los resultados son mejores y con un mínimo de complicaciones (AU).
ABSTRACT The existent literature on Type I Chiari Malformation in adults was reviewed, making emphasis in its imaging diagnosis and medico-surgical treatment. Chiari malformation is a few frequent disease. It represents between 1 % and 4 % of all the neurosurgery pathologies. The diagnosis is made up months and even years after the beginning of the symptoms and it is confirmed by cranial magnetic resonance in the 100 % of the cases. The treatment is surgical in symptomatic patients, and it is controversial in the oligosymptomatic ones and in those with casual diagnosis. The surgery should be performed with the support of neurophysiological monitoring that might be determinant in the surgical technique to use. The mortality associated to the surgery is low, ranging from 0 and 0.5 % in most of the series. The most important thing is the choice of the patients for the surgical treatment. The neurological deterioration should not be expected to justify the surgery; when the surgery is carried out on time the results are better and with the minimum of complications (AU).
Subject(s)
Humans , Adult , Arnold-Chiari Malformation/surgery , Arnold-Chiari Malformation/diagnosis , Arnold-Chiari Malformation/etiology , Arnold-Chiari Malformation/physiopathology , Arnold-Chiari Malformation/diagnostic imaging , Syringomyelia , Cranial Fossa, Posterior/abnormalities , Decompressive Craniectomy , Surgical Procedures, Operative , Magnetic Resonance Spectroscopy/methods , Intracranial Hypertension , HydrocephalusABSTRACT
Se revisó la literatura existente sobre la Malformación de Chiari Tipo I en el adulto, haciendo énfasis en su diagnóstico imagenológico y tratamiento médico-quirúrgico. La malformación de Chiari es una enfermedad poco frecuente. Representa entre el 1 y el 4% de todas las patologías neuroquirúrgicas. El diagnóstico se realiza meses y hasta años después de comenzada la sintomatología y se confirma en el 100% de los casos con Resonancia magnética de cráneo. El tratamiento es quirúrgico en los pacientes sintomáticos, siendo controversial en aquellos oligosintomáticos o con diagnóstico casual. La cirugía siempre debe realizarse con el apoyo de monitoreo neurofisiológico, que puede ser determinante en la técnica quirúrgica a emplear. La mortalidad asociada a la cirugía es muy baja, oscilando entre el 0 y 0,5% según la mayoría de las series. Lo más importante es la selección de los pacientes para el tratamiento quirúrgico. No debe asumirse una actitud expectante en espera de un deterioro neurológico que justifique la cirugía, cuando ésta se hace a tiempo los resultados son mejores y con un mínimo de complicaciones (AU).
The aim of this article is reviewing the existent literature on Type I Chiari malformation in adults and making emphasis in its imaging diagnosis and medico-surgical treatment. Chiari malformation is a few frequent diseases. It represents 1-4 % of all the neurosurgical diseases. The diagnosis is made months and even years after the beginning of the symptoms and it is confirmed by cranial magnetic resonance in the 100 % of the cases. The treatment is surgical in symptomatic patients, and it is controversial in the oligosymptomatic ones and in those with casual diagnosis. The surgery should be performed with the support of neurophysiological monitoring that might be determinant in the surgical technique to use. The mortality associated to the surgery is low, ranging from 0 and 0.5 % according to most of the series. The most important thing is the choice of the patients for the surgical treatment. The neurological deterioration should not be expected to justify the surgery; when the surgery is carried out on time the results are better and with the minimum of complications (AU).