Anterior Sacral Meningocele: A New Classification and Treatment Using the Dorsal Transsacral Approach.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Anterior sacral meningocele (ASM) is a rare disorder. We reviewed 11 cases of congenital ASM and classified them into three types based on the anatomy and relationship between the cyst and sacral nerve roots. SUMMARY OF BACKGROUND DATA: The cohort with ASM is relatively large; the classification is novel and has not been previously reported. METHODS: Eleven consecutive patients with ASM who underwent surgery between February 2014 and January 2019 were retrospectively analyzed. They included four males and seven females. The dorsal transsacral approach was adopted in all cases. The follow-up time was at least 3 months. RESULTS: We attempted to classify ASM into three types. Of the 11 cases, six were caudal type, two were paraneural type, and three were nerve-root type. The meningocele was ligated after exploring no nerve involvement, in Type I and II. For Type III, the herniating sac and involved nerve roots were ligated when the nerve roots were indicated as nonfunctional on neurophysiological monitoring; otherwise, the sacral nerve roots were protected and imbricated on the residual sac like a hand-in-glove, and sutured to reconstruct the nerves sleeve. Eight cases were accompanied by tethered cord syndrome (TCS); spinal cord detethering was done with one-stage operation. Ten patients' presenting symptoms improved at 3 to 6 months' follow-up; notably, constipation significantly improved. Only one case accompanied by an epidermoid cyst had a second laparoscopic surgery by a general surgeon. CONCLUSION: Aim of surgical treatment is to obliterate the communication between the subarachnoid space and herniated sac, detether the spinal cord, and resect the congenital tumor. The new classification helps to recognize the relationship between the meningocele and sacral nerve roots, and subsequently adopt different surgical strategies. We consider the dorsal transsacral approach relatively feasible, safe, and with lower complication. LEVEL OF EVIDENCE: 4.

Intrasphenoidal Encephalocele with Spontaneous Cerebrospinal Fluid Rhinorrhea in Idiopathic Intracranial Hypertension: Need for Clarity in Terminology and Imaging Delineation.

BACKGROUND: Magnetic resonance imaging plays an important role in identification of any underlying structural cause in spontaneous cerebrospinal fluid (CSF) leaks-either rhinorrhea or otorrhea. Sphenoid bone defects have been reported in those presenting as idiopathic intracranial hypertension with or without CSF rhinorrhea. Sphenoid lateral recess defect with intrasphenoidal encephalocele is one of the uncommon causes of spontaneous CSF leakage. Many classifications of basal encephaloceles have been used along with associated predisposing anatomic factors for the CSF leak. CASE DESCRIPTION: We report 2 cases of spontaneous CSF rhinorrhea in 2 middle-aged females and had intrasphenoidal encephalocele on imaging using 3-dimensional magnetic resonance cisternography and computed tomography. CONCLUSIONS: We discuss the various classification systems of sphenoidal encephaloceles and review the terminology and comprehensive imaging details to be included in reporting such cases for appropriate treatment planning.

Hernias encefálicas. Clasificación, neuropatología y problemas medicolegales / Brain herniations. Classification, Neuropathology and medico-legal problems

Las hernias cerebrales son la causa inmediata del fallecimiento en muchas lesiones neurológicas. Algunos protocolos recientes de actuación neuroquirúrgica han originado nuevas modalidades, como por ejemplo en el llamado síndrome del trefinado. Se requiere, pues, una revisión actualizada del tema, máxime cuando tiene importantes implicaciones medicolegales. Nuestro objetivo es revisar las clasificaciones, adaptarlas a los avances en Neurorradiología y Neurocirugía, y analizar su problemática medicolegal. La actualización de la clasificación y un conocimiento detallado de la fisiopatología de las hernias cerebrales constituyen la mejor orientación para la resolución de problemas forenses en lo relativo a etiología, causalidad y secuelas de las lesiones encefálicas (AU)

Brain herniation is the immediate cause of death in most of neurological lesions. Some recent neurosurgical protocols have promoted new kinds of herniation, like those that occur in the so-called syndrome of the threphined. Therefore, an up-to-date revision of this subject is required in regard of its important medico-legal implications. Our aim is to review the present classifications, adapting them to Neuroimaging and Neurosurgical advances, and analyzing the medical-legal issues of brain herniation. The problems extend not only to Pathology, but also to Clinical Forensic subjects. An up-to-date classification and a more detailed knowledge of the brain herniations physiology and pathology are the best tools to address their forensic problems, in particular those related with etiology, causation and sequels of brain lesions (AU)

John Howship (1781-1841) and growing skull fracture: historical perspective.

In the late 18th and early 19th centuries, Dr. John Howship, a pioneering British surgeon, described the clinical features and pathophysiology of various surgical disorders of the human body. His critical contributions to pediatric neurosurgery came in 1816 when he first described the features of an important childhood condition following head trauma, what he referred to as parietal bone absorption. This condition as depicted by Dr. Howship was soon to be christened by later scholars as traumatic cephalhydrocele, traumatic meningocele, leptomeningeal cyst, meningocele spuria, fibrosing osteitis, cerebrocranial erosion, and growing skull fracture. Nevertheless, the basic features of the condition as observed by Dr. Howship were virtually identical to the characteristics of the above-mentioned disorders. This article describes the life and accomplishments of Dr. Howship and his contributions to the current understanding of growing skull fracture.

Spontaneous lateral sphenoid cephaloceles: anatomic factors contributing to pathogenesis and proposed classification.

SUMMARY: Spontaneous lateral sphenoid cephaloceles arise from bony defects in the lateral sphenoid, in the absence of predisposing factors such as trauma, surgery, mass, or congenital skull base malformation. We reviewed CT and MR imaging findings and clinical data of 26 patients with spontaneous lateral sphenoid cephaloceles to better understand anatomic contributions to pathogenesis, varying clinical and imaging manifestations, and descriptive terminology. Two types of spontaneous lateral sphenoid cephaloceles were identified. In 15 of 26 patients, a type 1 spontaneous lateral sphenoid cephalocele was noted, herniating into a pneumatized lateral recess of the sphenoid sinus, and typically presenting with CSF leak and/or headache. In 11 of 26 patients, a type 2 spontaneous lateral sphenoid cephalocele was noted, isolated to the greater sphenoid wing without extension into the sphenoid sinus, presenting with seizures, headaches, meningitis, cranial neuropathy, or detected incidentally. All patients had sphenoid arachnoid pits, and 61% of patients had an empty or partially empty sella, suggesting that altered CSF dynamics may play a role in their genesis.

Nasal encephaloceles: a review of etiology, pathophysiology, clinical presentations, diagnosis, treatment, and complications.

INTRODUCTION: Encephaloceles are considered by most to be a type of neural tube defect characterized by a herniation of the brain and meninges through structural weaknesses in the bony structures of the skull. DISCUSSION: Many different types of encephaloceles have been classified according to the location of the bony defect. Basal and frontoethmoidal encephaloceles constitute a nasal subclass of encephaloceles, which are herniations from the skull base and ethmoid bone, respectively. Basal encephaloceles are usually occult and can herniate into nasal structures causing obstruction. Frontoethmoidal encephaloceles usually present as a protrusion that is visible at birth and enlarges during crying. Both of these entities are rare with an incidence ranging from 1 in 5,000 to 1 in 40,000 live births around the world with the majority of cases localized in Southeast Asia. CONCLUSION: Although cases have been recorded since the sixteenth century, there is still a scarcity of knowledge on the exact causes and factors associated with the development of the disease. Many studies have determined these to be caused by a combination of genetic and environmental factors. Most cases are non-life-threatening and the preferred method of treatment is surgical removal after diagnosis is confirmed with computerized tomography or magnetic resonance imaging. Prognosis is generally positive, especially in the subset of patients with frontoethmoidal encephaloceles.

Sincipital encephaloceles.

An encephalocele is a protrusion of the cranial contents beyond the normal confines of the skull through a defect in the skull and the facial bones. Encephaloceles are classified according to their contents, site of exit through the skull/facial bones, and the path traversed through the face. Sincipital encephaloceles are the most common variety seen in the Asian population. Sincipital encephaloceles have been classified by Suwanwela and Suwanwela (1972) into frontoethmoidal, interfrontal, and those associated with craniofacial clefts. Correction of encephaloceles can be done in 1 stage or multiple stages and consists of excision of the encephalocele sac, repair of the bony defect, correction of hypertelorism/telecanthus, and correction of associated deformities such as trigonocephaly and the "long nose."

Spontaneous encephaloceles of the temporal lobe.

Encephaloceles are pathological herniations of brain parenchyma through congenital or acquired osseus-dural defects of the skull base or cranial vault. Although encephaloceles are known as rare conditions, several surgical reports and clinical series focusing on spontaneous encephaloceles of the temporal lobe may be found in the otological, maxillofacial, radiological, and neurosurgical literature. A variety of symptoms such as occult or symptomatic CSF fistulas, recurrent meningitis, middle ear effusions or infections, conductive hearing loss, and medically intractable epilepsy have been described in patients harboring spontaneous encephaloceles of middle cranial fossa origin. Both open procedures and endoscopic techniques have been advocated for the treatment of such conditions. The authors discuss the pathogenesis, diagnostic assessment, and therapeutic management of spontaneous temporal lobe encephaloceles. Although diagnosis and treatment may differ on a case-by-case basis, review of the available literature suggests that spontaneous encephaloceles of middle cranial fossa origin are a more common pathology than previously believed. In particular, spontaneous cases of posteroinferior encephaloceles involving the tegmen tympani and the middle ear have been very well described in the medical literature.

Encefalocele anterior / Anterior encephalocele

Diagnóstico y clasificación de esta anomalía, que consiste en el defecto abierto del tubo neural, y aparece tempranamente en el desarrollo embrionario.(AU)

Are encephaloceles neural tube defects?

OBJECTIVE: Encephalocele is classified as a neural tube defect, but questions have been raised regarding whether its epidemiological characteristics are similar to those of other neural tube defects. DESIGN: We compared characteristics of temporal trends in, and the impact of folic acid grain fortification on, the prevalence of encephalocele, spina bifida, and anencephaly using data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects surveillance system. Prevalences of encephalocele, spina bifida, and anencephaly were compared by maternal age, gender, race, birth weight, ascertainment period (1968-1981, 1982-1993, or 1994-2002), and fortification period (1994-1996 [prefortification] and 1998-2002 [postfortification]) using prevalence ratios with 95% confidence intervals. Temporal trends were assessed using Poisson and negative binomial regression models. RESULTS: Prevalence rates of encephalocele (n = 167), spina bifida (n = 650), and anencephaly (n = 431) were 1.4, 5.5, and 3.7 per 10 000 live births, respectively. Encephalocele was similar to anencephaly in showing an increased prevalence among girls and multiple gestation pregnancies and to spina bifida and anencephaly in an annual prevalence decrease between 1968 and 2002 (-1.2% for encephalocele, -4.2% for spina bifida, and -3.6% for anencephaly). With fortification, prevalence decreased for spina bifida but not significantly for encephalocele or anencephaly. CONCLUSIONS: Encephalocele shows more similarities to spina bifida or anencephaly than it shows differences with respect to characteristics, temporal trend, and impact of fortification. Additional studies should be done to explore the etiologic heterogeneity of encephalocele using better markers of folate status and a wider range of risk factors.

Frontoethmoidal encephalomeningocele: new morphological findings and a new classification.

Given a lack of a comprehensive classification for the frontoethmoidal encephalomeningocele (FEEM), clinical, photographic, and computed tomography (CT) data of 23 nonoperated patients were reviewed. Extracranial pathological findings of interest included herniation masses, facial deformities, and frontonasal bone morphology. Intracranial pathological findings of interest included morphology of the anterior cranial floor and brain malformations. Stereographic software processed data from a new-generation CT scanner into three-dimensional pictures that revealed some interesting morphological findings not often appreciated (eg, herniation mass without underlying external bone defect; mass at location far from external bone defect ["sequestrated cephalocele"]; new type of external bone defect characterized by a combination of nasoethmoidal and naso-orbital defects; correlation between mass, external bone defect, and exit pathway of herniation). Given these observations plus current knowledge available in the medical literature, a new classification system was developed that covers phenotypes and severity of the disease. The "FEEM classification" is an alphanumeric system based on facial deformities, external bone defect, exit pathway of herniation, and malformation of brain. It was tested in 42 patients for usability and validity. When combined with a newly designed "FEEM diagram," relevant pathological findings can be recorded in an objective manner so that diagnosis becomes more precise and uniform and comparison of outcome is possible. It also emphasizes the fact that FEEM has a range of manifestations governed by dynamic interaction between structural defects and herniation. Each clinical entity is a final result of its own disease course (stable, progressive, or regressive FEEM), with a varying degree of communication between the external mass and the central nervous system.

Common craniofacial anomalies: facial clefts and encephaloceles.

The wide variety of craniofacial malformations makes classification difficult. A simple classification system allows an overview of the current understanding of the causes, assessments, and treatments of the most frequently encountered craniofacial anomalies. Facial clefts and encephaloceles are reviewed with respect to their diverse causes, pathogenesis, anatomical features, and treatments. Approaches to the surgical treatment of these conditions are reviewed.

Dermoid cysts, gliomas, and encephaloceles: evaluation and treatment.

The fronto-orbitonasal malformations of encephaloceles, dermoid sinus cysts, and gliomas represent a continuum of neuroectodermal anomalies. The differentiation between them and other similar-appearing lesions is essential for effective management to proceed. Obtaining a reliable history, completing a careful physical examination, and obtaining accurate radiographic documentation represent the first steps. Establishing the timing, staging, and specific surgical techniques for management of a fronto-orbitonasal encephalocele remains as much an art as a science.

Encephalomeningocele cases over 10 years in Thailand: a case series.

BACKGROUND: Encephalomeningocele, especially in the frontoethmoidal region, is a form of neural tube defect which affects patients in Southeast Asia more commonly than in Western countries. Its underlying cause is not known but teratogenic environmental agents are suspected. However, nutritional deficiency, as in spina bifida, cannot be excluded. METHODS: This study reports 21 cases of meningocele (without brain tissue in the lesion) and encephalomeningocele (with brain tissue) that were admitted to our hospital for surgical corrections in the period of ten years, from 1990 to 1999. Clinicopathological findings, as well as occupations of family members and prenatal exposures to infectious agents or chemicals were reviewed and analyzed. RESULTS: The most commonly involved area was the frontoethmoidal region, found in 20 cases. The combined pattern between nasoethmoidal and nasoorbital defects was found most frequently (11 from 21 cases) and had more associated abnormalities. Encephalomeningocele had more related abnormalities than meningocele with proportions of 0.6 and 0.3, respectively. CONCLUSIONS: Here, we confirmed that genetic defects are not likely to be the single primary cause of this malformation. However, we could not draw any conclusions on etiologic agents. We suggest that case control studies and further investigation on the role of nutritional deficiencies, especially folic acid, in the pathogenesis of encephalomeningocele are necessary to clarify the underlying mechanisms.

Can prognostic indicators be identified in a fetus with an encephalocele?

Encephaloceles, like other congenital malformations of the brain diagnosable in utero, can be either complicated (there being an associated chromosomal abnormality, abnormalities in the remainder of the central nervous system (CNS) and/or other organs), or isolated (no abnormalities in the chromosomes, the remainder of the CNS or other organs). Complicated cases invariably have a poor prognosis but amongst those with isolated lesions the outcome is variable with some affected children having poor mental and physical development but others who are only mildly or moderately disabled. To be able to make an informed decision about how to manage their pregnancy parents need to know what the prognosis is likely to be for their fetus with an encephalocele. To see if the necessary information could be reliably gathered by prenatal assessment of affected fetuses, a review was carried out of the medical records and ultrasound scans of 31 fetuses with encephaloceles referred to the Fetal Management Unit at St. Mary's Hospital in Manchester between January 1991 and December 1997. Eighteen of the cohort were classified as having a complicated encephalocele. Thirteen of the pregnancies were terminated; there were three intrauterine deaths, and one neonatal death. There is only one surviving child who is severely disabled. Thirteen fetuses were classified as having isolated encephaloceles, six had a mass of neural tissue in the encephalocele sac and were terminated, one died in utero and six had a cystic lesion or only a nubbin and have survived with few or no abnormalities. This study has shown that it is possible to identify fetuses with an encephalocele with a favourable outcome.

Morphologic study of 120 skull base defects in frontoethmoidal encephalomeningoceles.

Frontoethmoidal encephalomeningocele is a herniation of brain and meninges through a congenital bone defect in the skull at the junction of the frontal and ethmoidal bones. From 1992 to 1996, 120 cases of frontoethmoidal encephalomeningocele were seen in our institutes, and the morphology of the skull defects was studied. The patients underwent thorough physical examinations and radiographic investigations including spiral three-dimensional computed tomography scan. Together with intraoperative findings, we found more types of the defects than previously reported. Our findings were categorized into the following types: type I, a single external opening between frontal, nasal, ethmoidal, and orbital bones; type IA, opening is limited between two bones of the area; type IB, opening is extended transversely or cephalad to involve adjacent structures; type II, multiple external openings in the region; type IIA, all of the openings are limited types; type IIB, one or more of the openings is/are extended type(s) that involve adjacent structures. There are 14 subtypes in these two types: 3 in type IA, 6 in type IB, 3 in type IIA, and 2 in type IIB. This classification is helpful in understanding the herniation pathway and in keeping informative records.

Spinal and cranial neural tube defects.

Developmental lesions of the central nervous system with failure of normal midline fusion are often referred to as being dysraphic and vary from inapparent and insignificant to a massive deformity incompatible with survival. Several different schemata are used to classify this wide variety and often complex set of malformations; however, the nomenclature is confusing and even contradictory. As most of these congenital lesions of clinical significance involve an aberration in the formation of the neural tube, it is suggested that the term neural tube defects (NTD) be used to characterize this entire group of anomalies. From a practical clinical standpoint, NTD can be subdivided into three main groupings: open spinal NTD, closed spinal NTD, and cranial NTD. This article briefly covers the epidemiology, embryology, classification, clinical presentation, and management of this group of congenital lesions.