Otto Mennicke (1876-) and the first description of skull base anomalies causing cerebellar tonsillar ectopia: one of the first mentions of the Chiari I malformation.

INTRODUCTION: Although Hans Chiari made significant and meaningful contributions to our understanding and classification of hindbrain herniations, others have also contributed to this knowledge. One figure who has been lost to history is Otto Mennicke. Herein, we discuss his role in our understanding of tonsillar ectopia and his life and connection to Hans Chiari. CONCLUSIONS: Our knowledge of what is now known as the Chiari malformations has been shaped by several clinicians including Otto Mennicke.

The Chiari 3.5 malformation: a review of the only reported case.

INTRODUCTION: In 1894, Giuseppe Muscatello described what we believe to be the only case of an occipitocervical encephalocele with a communication to the stomach. This case and its history and context compared to the Chiari 3 malformation as described 3 years earlier by Hans Chiari are presented. CONCLUSIONS: Based on the uniqueness of this case, we propose the term Chiari 3.5 malformation be used to describe its anatomical derailment.

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.

Skull deformations in craniosynostosis and endocrine disorders: morphological and tomographic analysis of the skull from the crypt of the Silesian Piasts in Brzeg (16th-17th century), Poland.

RESULTS: of morphological and tomographic (CT) studies of the skull that was found in the crypt of the Silesian Piasts in the St. Jadwiga church in Brzeg (Silesia, Poland) are presented and discussed here. The established date of burial of probably a 20-30 years old male was 16th-17th century. The analyzed skull showed premature obliteration of the major skull sutures. It resulted in the braincase deformation, similar to the forms found in oxycephaly and microcephaly. Tomographic analysis revealed gross pathology. Signs of increased intracranial pressure, basilar invagination and hypoplasia of the occipital bone were observed. Those results suggested the occurrence of the very rare Arnold-Chiari syndrome. Lesions found in the sella turcica indicated the development of pituitary macroadenoma, which resulted in the occurrence of discreet features of acromegaly in the facial bones. The studied skull was characterized by a significantly smaller size of the neurocranium (horizontal circumference 471 mm, cranial capacity ∼ 1080 ml) and strongly expressed brachycephaly (cranial index=86.3), while its height remained within the range for non-deformed skulls. A narrow face, high eye-sockets and prognathism were also observed. Signs of alveolar process hypertrophy with rotation and displacement of the teeth were noted. The skull showed significant morphological differences compared to both normal and other pathological skulls such as those with pituitary gigantism, scaphocephaly and microcephaly.

History of Chiari type I malformation.

Chiari type I malformation (CIM) was first described in the late 19th Century. However, it still raises a great interest among the scientific Community because of the increasing number of diagnosed cases, the still unclear pathogenesis and natural history and the different options in the surgical management. The present review aims at analyzing the centenary history of CIM, starting from the first description done by Hans Chiari to the more recent classification, in order to introduce such a complex disease and to show the way followed for its assessment over the time.

The first posterior fossa decompression for Chiari malformation: the contributions of Cornelis Joachimus van Houweninge Graftdijk and a review of the infancy of "Chiari decompression".

Over the past several decades, our understanding of the pathophysiology of hindbrain hernias has markedly increased. Additionally, with the advent of MRI, diagnosis of these entities is common. Although the history of the discovery of what are now known as the Chiari malformations is well known, publications regarding the historical surgical treatment of these is, to our knowledge, not extant. Many have attributed the first successful patient series to Gardner in the 1950s. However, and unknown to many, the first description of a hindbrain decompression was in 1930 by the Dutchman Cornelis Joachimus van Houweninge Graftdijk. This neurosurgeon also added to our understanding the pathophysiology of hindbrain herniation and its relationship to raised intracranial pressure. The present paper reviews the contributions of this early pioneer of neurosurgery.

The first description of Chiari I malformation with intuitive correlation between tonsillar ectopia and syringomyelia.

Few are familiar with the neurological contributions of the German pathologist Theodor Langhans. Even fewer are aware of his significant and early contributions to the study of what is now known as the Chiari I malformation. In at least 4 cases, Langhans described the association between tonsillar ectopia and syringomyelia. Moreover, this early pioneer speculated that there was a cause and effect with hindbrain herniation resulting in improper flow at the craniocervical junction and consequent development of syringomyelia. These cases were reported prior to Hans Chiari's descriptions, and Langhans' theory of impeded foramen magnum flow as a cause of syringomyelia was novel and preceded the current understanding of this mechanism by almost a century. The authors discuss the life of Langhans and translate excerpts from his 1881 work regarding tonsillar ectopia and syringomyelia.

Chiari malformation in craniosynostosis.

INTRODUCTION: Chiari malformation (CM) is a frequent finding in multisutural and syndromic craniosynostosis, occurring in 70% of patients with Crouzon's syndrome, 75% with oxycephaly, 50% with Pfeiffer's syndrome and 100% with the Kleeblattschädel deformity. The pathogenesis of this condition and rationale for treatment are still controversial. DISCUSSION: Since its first description in 1972, several factors have been cited to play a role in inducing CM. In the light of recent publications, the roles of premature fusion of cranial vault and cranial base sutures, of congenital anomalies of the cerebellum and brain stem, of raised intracranial pressure, of venous hypertension and of hydrocephalus are reviewed. Evaluation and management of CM are also discussed. CONCLUSION: Chiari malformation appears to be an acquired and progressive condition that develops in the first months of life, because of a disproportion between hindbrain growth and an abnormally small posterior fossa, a consequence of the premature fusion of lambdoid and cranial base sutures. Venous hypertension caused by stenosis of the jugular foramen can also be present in these patients, resulting in intracranial hypertension and/or hydrocephalus. Careful MRI evaluation is recommended for the forms of craniosynostosis at a high risk of developing hindbrain herniation. The selection of posterior cranial vault expansion as the first surgical procedure is advocated. In selected cases, treatment of the posterior cranial deformity by occipital vault remodelling and treatment of the Chiari-like deformity by suboccipital decompression can be carried out using the same surgical procedure.

History, anatomic forms, and pathogenesis of Chiari I malformations.

INTRODUCTION: Chiari I malformations constitute a group of entities of congenital or acquired etiology that have in common descent of the cerebellar tonsils into the cervical spinal canal. In recent years, since the advent of magnetic resonance imaging, an increasing number of asymptomatic, doubtfully symptomatic, and minimally symptomatic patients with Chiari I malformations have been diagnosed. This has resulted in controversy about the multiple therapeutic strategies indicated for these problems. OBJECT: With the intention of updating the knowledge that we currently have on the Chiari I malformation and the related syringomyelia we review the literature and discuss the historical background, pathogenesis, anatomic forms, clinical presentation, and diagnostic procedures of these abnormalities.

Definition of the adult Chiari malformation: a brief historical overview.

With the widespread use of newer neuroimaging techniques and modalities, significant tonsillar herniation is being diagnosed in more than 0.5% of patients, some of whom are asymptomatic. This puts the definition of the adult Chiari malformation to the test. The author provides a historical review of the evolution of the definition of the adult Chiari malformation in the neurosurgery, radiology, and pathology literature.