Chiari 1 Malformation Surgery: Comparing Non-violation of the Arachnoid versus Arachnoid Opening and Thermocoagulation of the Tonsils.

OBJECTIVE: Evidence is lacking concerning the myriad surgical techniques for type 1 Chiari malformation. This study evaluated the impact of arachnoid violation with tonsil thermocoagulation during surgical craniovertebral junction decompression. METHODS: The evaluation included aspects of the neurologic examination and parameters of cerebrospinal fluid flow on magnetic resonance imaging during preoperative and postoperative periods. All patients underwent craniovertebral junction decompression and opening of the dura mater. Patients were divided into 2 study groups. Patients in group 1 did not undergo arachnoid violation. Patients in group 2 underwent tonsil manipulation and systematic opening of the fourth ventricle outlet. RESULTS: There were 16 patients enrolled in each group (total of 32 patients). Regarding clinical improvement, there were no significant differences between groups in the postoperative period. Group 2 had more adverse events (relative risk 2.45, 95% confidence interval 1.55-3.86). In terms of cerebrospinal fluid flow parameter analyses, patients in group 1 achieved better results (P < 0.05). CONCLUSIONS: For treatment of symptomatic type 1 Chiari malformation, craniovertebral junction decompression with arachnoid preservation (i.e., without tonsillar manipulation) seems more suitable than the addition of arachnoid opening and thermocoagulation of the tonsils.

The pathogenesis of Chiari I malformation and syringomyelia.

OBJECTIVE: The pathogeneses of Chiari malformation type I and syringomyelia are incompletely understood. In this article, the authors attempt to review the current theories on the pathogeneses of Chiari I malformation and syringomyelia. METHODS: A literature review for articles pertaining to Chiari I malformation or syringomyelia before August 2010 was conducted; in addition, the author's own experience in treating Chiari I malformation and syringomyelia is included. RESULTS: Chiari I malformation has been defined radiographically as cerebellar tonsillar herniation or ectopia 5 mm or greater below the foramen magnum. By this narrow definition, Chiari I malformation (i.e. cerebellar tonsillar herniation or ectopia 5 mm or greater below the foramen magnum) likely encompasses a heterogeneous grouping of disorders caused by different mechanisms. Molecular and genetic studies have been helpful in furthering our understanding of Chiari I malformation. CONCLUSION: A review of the pathogeneses of Chiari I malformation and syringomyelia is reported.

National Institutes of Health Chiari Research Conference: state of the research and new directions.

OBJECTIVE: To establish the current Chiari knowledge base and develop recommendations for future research. METHODS: Chiari malformation: state of the research and new directions was a two-day, National Institutes of Health sponsored conference. The agenda included review presentations and working groups tasked with developing specific, achievable research recommendations. Content for both the review presentations and working groups was divided into six areas: pathophysiology, symptoms and diagnosis, engineering and imaging analysis, treatment, pediatric issues, and related conditions. RESULTS: The articles in this issue represent the knowledge base that was developed at the conference, plus subsequent literature reviews. There are significant gaps in the understanding of Chiari malformation, including a clinically relevant definition of Chiari, confusing terminology, subjective diagnostic criteria, and a well-accepted standard of care. These knowledge gaps are not surprising given the relative lack of Chiari research compared to similar neurological conditions and the preponderance of case reports in the published Chiari literature. The lack of understanding, and research, regarding Chiari translates directly into negative patient experiences and outcomes. CONCLUSIONS: Implementation of the recommendations developed at the conference would not only further expand the current understanding of the condition, but would likely have a significant, positive impact on patient experiences and outcomes.

Posterior fossa measurements in patients with and without Chiari I malformation.

PURPOSE: To determine if there is a correlation between cerebellar tonsillar descent in patients with and without Chiari I malformation and three skull morphometric measurements: clivus length, anteroposterior diameter of the foramen magnum, and Boogard's angle. METHODS: Cerebellar tonsillar descent, clivus length, anteroposterior diameter of the foramen magnum, and Boogard's angle were measured in mid-sagittal T1-weighted magnetic resonance images of 188 patients. The study included 81 patients with Chiari I malformations (CMI). Without identifiable pathology, 107 patients served as a comparison group. Two-sample t-tests were used to assess for significance. A Pearson correlation matrix was constructed to assess the strength of linear dependence between measured parameters for the study population. RESULTS: A negative correlation was found between tonsillar herniation and clivus length (r = -0.30, P < 0.001), while a positive correlation was found between tonsillar herniation and foramen magnum size (r = 0.15, P = 0.0431), and Boogard's angle (r = 0.23, P = 0.0014). Clivus length was shorter (P = 0.0009) in CMI patients (4.02 cm ± 0.45) than comparison patients (4.23 cm ± 0.42). In addition, the anteroposterior diameter of the foramen magnum was wider (P = 0.0412) (3.74 cm ± 0.40 compared to 3.63 ± 0.30) and Boogard's angle was larger (P = 0.0079) (123.58 degrees ± 8.27 compared to 120.62 degrees ± 6.79) with CMI. CONCLUSION: A greater degree of cerebellar tonsillar herniation is associated with a shorter clivus length, a wider anteroposterior diameter of foramen magnum, and a wider Boogard's angle.

Posterior fossa morphometry in symptomatic pediatric and adult Chiari I malformation.

The linear dimensions and volume of the posterior fossa, and the length of the supra-occiput and the clivus in children with Chiari I malformations (CMI) were studied. A statistical relationship between patient demographics, radiological features, posterior fossa and occipital bone morphometry in the study and control groups was investigated. The results of 21 pediatric patients was compared to those of a matched control group. The posterior fossa volume (PFV) of an adult CMI group was also studied. Linear measurements were used to calculate the length of the occipital bone, spherical PFV and intracranial volume (ICV) using pre-operative MRI and CT scans. A PFV to ICV ratio was obtained to standardize the comparison. The volumetric measurement in the pediatric study group was also compared to the adult CMI group. The antero-posterior dimension, width, and volume of the posterior fossa and the PFV to ICV ratio in pediatric CMI patients was significantly lower than in the control group (p<0.05). There was no statistical difference in the length of the clivus and the supra-occiput between the two pediatric groups. The difference in the PFV to ICV ratio between pediatric and adult CMI patients was not statistically significant. Thus, the authors provide a simple, yet accurate, and reproducible method of comparison of posterior fossa volume in patients with CMI in different age groups, based on linear measurements. There is no significant difference between the length of the occipital bone at the base of the skull in pediatric CMI patients and the normal pediatric population. Development of the clivus due to late fusion of the sphenoid and occipital synchondroses in the second decade could result in manifestation of the disease in adulthood in CMI patients who were asymptomatic as children.

Cefalea recurrente pospunción dural en una paciente con síndrome de Chiari tipo I no conocido / Recurrent postdural puncture headache in a woman with undiagnosed Chiari I malformation

Objetivo: Identificar el riesgo de complicaciones neurológicas de la anestesia espinal en los pacientes con un síndrome de Chiari tipo I preexistente y diferenciarlo del llamado “Chiari I adquirido” causado por un síndrome de hipotensión intracraneal, radiológicamente difícil de distinguir del anterior. Caso clínico: Mujer de 37 años, que tras recibir una punción dural durante la realización de una epidural analgésica para el parto, presentó cefalea pospunción dural (CPPD) recurrente. Se practicó resonancia magnética (RM) cerebral que puso de manifiesto malformación de Chiari tipo I (desplazamiento caudal de las amígdalas cerebelosas por el orificio magno) y engrosamiento difuso de las meninges. Aunque no lo había manifestado con anterioridad a la realización de la técnica epidural, la paciente presentaba cefaleas crónicas que se exacerbaban con las maniobras de Valsalva. La paciente fue tratada con analgésicos, cafeína y corticoides, y quedó asintomática. Tras 6 meses de seguimiento se realizó una nueva RM de control donde se observó la persistencia de los cambios anatómicos que definen el síndrome de Chiari tipo I, pero ausencia de las alteraciones meníngeas. Discusión: Tras una punción dural se puede producir el llamado “síndrome de hipotensiónin tracraneal”, motivado por la alteración del flujo y presiones del líquido cefalorraquídeo entre los compartimientos craneal y espinal. La pérdida continua de líquido cefalorraquídeo por el orificio de la punción originaría un gradiente de presión negativa que “empuja” las amígdalas cerebelosas hacia el orificio magno. ¿Es más acusado el cambio de presiones en aquellos pacientes con alteraciones previas, como el síndrome de Chiari? ¿Justifica la persistencia de una CPPD, a pesar del tratamiento? (...) (AU)

Objective: To identify the risk of neurological complications of spinal anesthesia inpatients with preexisting Chiari I malformation and to differentiate this entity from“ acquired Chiari I malformation”, caused by intracranial hypotension. These two entities can be difficult to distinguish radiologically. Case report: After undergoing dural puncture for epidural analgesia during delivery, a37-year-old woman developed recurrent postdural puncture headache (PDPH). Cerebral magnetic resonance imaging (MRI) revealed Chiari I malformation (displacement of the cerebellar tonsils into the foramen magnum) and diffuse dural gadolinium enhancement. The patient had experienced chronic headaches exacerbated by Valsalva’s maneuver before receiving epidural analgesia but had not reported these symptoms. She was treated with analgesics, caffeine and corticosteroids, which resolved the symptoms. After 6 months of follow-up, a second MRI scan revealed the persistence of the anatomical alterations characteristic of Chiari I malformation but without meningeal alterations. Discussion: After dural puncture, “intracranial hypotension syndrome” can occur, caused by alteration of cerebrospinal fluid (CSF) flow and pressure between the cranial and spinal compartments. Continuous CSF leak through the puncture site would cause a negative pressure gradient that would “push” the cerebellar tonsils toward the foramen magnum. Is the pressure change more marked in patients with prior alterations, such as Chiari malformation? Is the previous malformation the cause of the recurrent headache, despite treatment? Conclusion: Thorough clinical evaluation is required before spinal anesthesia is administered since severe neurological complications can occur in patients with undiagnosed Chiari malformations (AU)

Síndrome de apnea central del sueño como primera manifestación de malformación de Chiari tipo I / Central sleep apnea syndrome as the first sign of type I Chiari malformation

Introducción: La malformación de Chiari tipo I consiste en el descenso de las amígdalas cerebelosas a través del foramen magno. Con frecuencia es asintomática, pero puede presentar clínica por afectación de cerebelo, troncoencéfalo, porción superior de la médula cervical y pares craneales bajos. Objetivo: Se presenta nuestra experiencia de 16 años con 16 casos de malformación de Chiari tipo I; sólo en 2 existen síntomas atribuibles a la anomalía de Chiari tipo I, y en una de ellas la primera manifestación clínica consistió en un trastorno respiratorio durante el sueño. Caso clínico: Niña de 15 años con tos crónica diaria, agravada con el ejercicio, de 5 años de duración. La madre observaba desde hacía 1 año que al dormir la niña roncaba y realizaba repetidamente pausas de apnea. Tenía cefaleas ocasionales e hipersomnolencia diurna. Las exploraciones física y neurológica fueron normales, salvo ausencia de reflejo nauseoso bilateral. El estudio polisomnográfico nocturno evidenció un patrón seudoperiódico con alternancia de pausas de apnea con ciclos de respiraciones profundas, con graves repercusiones gasométricas y sobre la frecuencia cardíaca. La resonancia magnética mostró anomalía de Chiari tipo I. La ventilación mecánica no invasiva supuso una mejoría clínica y gasométrica en la paciente. Discusión: La descompresión quirúrgica es discutida. Está indicada de forma precoz, antes de que aparezca daño neurológico irreversible. Se asocia con una reducción significativa en el número de apneas centrales y microdespertamientos. Se recomienda en casos sintomáticos o en casos con progresión radiológica de la anomalía de Chiari o de la siringomielia asociada (AU)

Introduction: Type I Chiari malformation consists on the caudal displacement of cerebellar tonsils through the foramen magnum. It is often asymptomatic, although it may display symptoms as a result of cerebellum, brainstem, high cervical spinal cord or the lower cranial nerve, involvement. Objective: We report our experience over the last 16 years. We have identified 16 patients with type I Chiari malformation. Only 2 cases showed common type I Chiari symptoms and just one had respiratory disorder as the first clinical sign. Clinical case: A 15 year old girl presented with a 5 years history of chronic daily cough aggravated by the exercise. Snoring and sleep apnea had been noted by her mother for 1 year. The girl eventually suffered from migraine and diurnal hypersomnolence. The physical and neurological examination was normal with the only exception being the absence of bilateral nauseous reflex. A nocturnal polysomnography study demonstrated a pseudoperiodic pattern with apnea pauses associated to cycles of deep breathing, resulting in severe gasometric repercussion and bradycardia. Magnetic resonance imaging of the brain showed Chiari I malformation. Non-invasive mechanical ventilation treatment significantly improved the clinical symptoms and gasometric analysis. Discussion: Surgical posterior fossa decompression is discussed. Early decompression before appearance of irreversible neurological damage is recommended. It is associated with a significant reduction in the number of central apneas and sleep arousals. Surgical intervention is recommended in symptomatic patients and in cases of radiographic Chiari malformation or syrinx progression (AU)

Factores de riesgo y complicaciones más frecuentes del puerperio: estudio realizado en el Hospital Materno Infantil Mariana de Jesús / Risk factors and most frequent complications of puerperium: study realized at the Mariana de Jesus Maternal-infant hospital

Cuando existen un nivel socio-económico bajo, una mala conducta obstétrica, o condiciones hospitalarias inadecuadas las infecciones junto con las hemorragias constituyen las principales complicaciones y causas de morbimortalidad durante el puerperio en nuestro medio. Se realizó un estudio prospectivo, longitudinal, descriptivo que tuvo como objetivo conocer las patologías del puerperio, incidencia y factores de riesgo para el desarrollo de las mismas. De las 723 pacientes que acudieron al hospital materno-infantil Mariana de Jesús, solo el 2,21 por ciento (16 pacientes), presentaron complicaciones durante su puerperio. Por tal motivo la atención médica debe ir encaminada tanto a la prevención como al tratamiento de las numerosas alteraciones que pueden presentarse...

[Study on galactorrhea-amenorrhea syndrome (GAS) with special reference to normoprolactinemic GAS].

In order to clarify the mechanism(s) which causes galactorrhea and amenorrhea in patients with Galactorrhea-Amenorrhea Syndrome (GAS) (Group A, n = 20), composed of Chiari-Frommel Syndrome (CFS) (Subgroup I, n = 3), Argonz-del Castillo Syndrome (ADCS) (Subgroup II, n = 5) and Drug-induced Galactorrhea-Amenorrhea (DIG) (Subgroup III, n = 12), we analysed basal plasma prolactin (PRL) and gonadotropin levels and their responsiveness to TRH and LH-RH, respectively in GAS patients. In addition, another group of galactorrhea patients without amenorrhea (Group B, n = 29) was selected, and further divided into three subgroups; subgroup I (n = 7) with persisting postpartum lactation, subgroup II (n = 7) of idiopathic galactorrhea, and subgroup III (n = 15) induced by drug administration. There were found unexpectedly high frequencies of normoprolactinemic patients (less than 23.7 ng/ml) in 40% of GAS (66.7% in CFS, 40% in ADCS, and 33.3% in DIG). The PRL responsiveness to TRH, evaluated by % delta PRL (peak PRL - basal PRL/basal PRL X 100), tended to be high in ADCS and DIG (group after discontinuation of drugs) compared with those of normal subjects (n = 12) and patients with primary hypothyroidism (n = 21). PRL response was almost normal in CFS or DIG (group during drug administration). Basal level of plasma gonadotropin in GAS was comparable to that of normal subjects. However, responsiveness of gonadotropin to LH-RH in GAS tended to be high compared with that of normal subjects. The patients in group B (subgroup I-III) demonstrated almost parallel responses of PRL and gonadotropin, respectively, to those of corresponded subgroups in group A. From the present results, we concluded that; 1) It seems likely that frequency of normoprolactinemic patients in GAS (Group A) is surprisingly high. 2) A still unclarified mechanism(s) for the occurrence of galactorrhea, not explained solely by plasma radioimmunoassayable PRL level and/or hyperresponsiveness of PRL to stimuli, may operate on a considerably large number of group A patients. 3) Decreased gonadotropin secretion at pituitary level seems not to be a main cause of menstrual abnormality in group A patients. 4) The same mechanism(s) as in group A patients may cause galactorrhea in group B patients.