Experimentally induced Chiari-like malformation with myeloschisis in chick embryos

Myelomeningocele: the evolution of care over the last 50 years

PURPOSE

Myelomeningocele (MMC) is one of the representative anomalies in the field of pediatric neurosurgery. During the 50 years of ISPN history, MMC had a tremendous changes in its incidence, clinical management and outcome with advanced understanding of its pathogenesis. We reviewed the changes in MMC during the period.

METHODS

We reviewed the literature review and collected our experiences.

RESULTS

During the 50 years, major changes happened in many aspects of MMC including incidence, pathoembryogenesis, folate deficiency, prevention, prenatal diagnosis, mode of delivery, treatment policy with ethical considerations, clinical treatment including fetal surgery, latex allergy, retethering, management outcome, multidisciplinary team approach, and socioeconomic and family issues.

CONCLUSIONS

There was a great advance in the management and research of MMC during the 50 years. It is a monumental achievement of pediatric neurosurgeons and colleagues of the related fields.

Chiari III malformation: a comprehensive review of this enigmatic anomaly

INTRODUCTION

Chiari III is one of the rarest of the Chiari malformations and is characterized by a high cervical or low occipital encephalocele and osseous defect with or without spinal cord involvement and may include many of the anatomical characteristics seen in the Chiari II malformation. Herein, we provide a comprehensive review of this rare anomaly as well as a translation of Chiari's original description.

METHODS

We review all reported cases of Chiari III malformation found in the extant literature.

CONCLUSIONS

Out of 57 reported cases of Chiari III malformation, encephaloceles were in a high cervical/low occipital position in 23, 8 were in a high cervical position, 17 were in low occipital position, and the position in 9 cases was not reported. The pathogenesis of Chiari III malformation remains unclear. The majority of patients have concomitant hydrocephalus. Brain parts occurring in the sac from the most to least common include the following: cerebellum, occipital lobe, and parietal lobe. The severity of symptoms is correlated with the amount of brain structures within the encephalocele. Neurologic functional outcomes have been varied and depend on the neurological status of the patient before surgery.

Experimental models of spinal open neural tube defect and Chiari type II malformation

INTRODUCTION

Experimental animal models are essential for investigation of the pathoembryogenesis, pathophysiology, and management strategy of spinal open neural tube defect (ONTD) and its associated anomalies including Chiari type II malformation. Genetic, chemical/nutrient, and surgical models have been widely used for a variety of purposes. The aim of this article is to review the representative animal models of spinal ONTD and associated Chiari type II malformation with respect to their advantages and disadvantages.

DISCUSSION

Among them, the surgical model was described in detail because it is familiar to neurosurgeons and it is used for evaluations of prenatal repair of spinal ONTDs. The surgical model also has advantages because it allows quantitative analysis of the lesions. A description of our previous studies on spinal ONTDs using a chick surgical model is presented as an example.