Occipital nerve stimulation for refractory headache in the Chiari malformation population.

Background: Chronic occipital and suboccipital headache is a common symptom in patients with Chiari I malformation. These headaches may persist despite appropriate surgical treatment of the underlying pathology via suboccipital decompression, duraplasty, and cerebrospinal fluid diversion. Occipital nerve stimulation has been shown to be effective in the treatment of a variety of occipital headache/pain syndromes.

Occipital neuromodulation for refractory headache in the Chiari malformation population.

Chronic occipital and suboccipital headache is a common symptom in patients with Chiari I malformation (CMI). These headaches may persist despite appropriate surgical treatment of the underlying pathology via suboccipital decompression, duraplasty and related procedures. Occipital stimulation has been shown to be effective in the treatment of a variety of occipital headache/pain syndromes.

Mechanisms of cerebellar tonsil herniation in patients with Chiari malformations as guide to clinical management.

Background: The pathogenesis of Chiari malformations is incompletely understood. We tested the hypothesis that different etiologies have different mechanisms of cerebellar tonsil herniation (CTH), as revealed by posterior cranial fossa (PCF) morphology.

Methods: In 741 patients with Chiari malformation type I (CM-I) and 11 patients with Chiari malformation type II (CM-II), the size of the occipital enchondrium and volume of the PCF (PCFV) were measured on reconstructed 2D-CT and MR images of the skull.

Association of Chiari malformation type I and tethered cord syndrome: preliminary results of sectioning filum terminale.

Objective: The pathogenesis of CM-I is incompletely understood. We describe an association of CM-I and TCS that occurs in a subset of patients with normal size of the PCF.

Methods: The prevalence of TCS was determined in a consecutively accrued cohort of 2987 patients with CM-I and 289 patients with low-lying cerebellar tonsils (LLCT).

Syndrome of occipitoatlantoaxial hypermobility, cranial settling, and chiari malformation type I in patients with hereditary disorders of connective tissue.

Object: Chiari malformation Type I (CM-I) is generally regarded as a disorder of the paraxial mesoderm. The authors report an association between CM-I and hereditary disorders of connective tissue (HDCT) that can present with lower brainstem symptoms attributable to occipitoatlantoaxial hypermobility and cranial settling.

Methods: The prevalence of HDCT was determined in a prospectively accrued cohort of 2813 patients with CM-I.

Foramen magnum decompression with cranioplasty for treatment of caudal occipital malformation syndrome in dogs.

Objectives: To describe a cranioplasty procedure used in conjunction with foramen magnum decompression (FMD) for the treatment of canine caudal occipital malformation syndrome (COMS), and to evaluate the clinical outcome.

Study Design: Prospective clinical study.

Animals: Dogs (n=21) with COMS diagnosed by magnetic resonance imaging (MRI).

Phenotypic definition of Chiari type I malformation coupled with high-density SNP genome screen shows significant evidence for linkage to regions on chromosomes 9 and 15.

Chiari type I malformation (CMI; OMIM 118420) is narrowly defined when the tonsils of the cerebellum extend below the foramen magnum, leading to a variety of neurological symptoms. It is widely thought that a small posterior fossa (PF) volume, relative to the total cranial volume leads to a cramped cerebellum and herniation of the tonsils into the top of the spinal column. In a collection of magnetic resonance imagings (MRIs) from affected individuals and their family members, we measured correlations between ten cranial morphologies and estimated their heritability in these families.

Acute syringomyelia: case report.

Objective And Importance: Syringomyelia is generally regarded as a chronic, slowly progressive disorder. We describe a case of acute dilation of the central canal of the spinal cord that presented with rapidly progressive segmental signs.

Clinical Presentation: A 29-year-old female patient who had previously undergone surgical treatment for a Chiari I malformation, syringomyelia, and hydrocephalus presented with an 8-day history of headaches, progressive paraparesis, and urinary retention.

Tailored operative technique for Chiari type I malformation using intraoperative color Doppler ultrasonography.

Objective: We describe an operative technique for Chiari Type I malformation that uses color Doppler ultrasonography as a guide for performing patient-specific posterior fossa decompressions. The technique has been used since 1999 in more than 300 operations.

Methods: On the basis of real-time anatomic and physiological measurements, the following goals of surgery were monitored: 1) adequate decompression of the cervicomedullary junction; 2) creation of a retrocerebellar space of 8 to 10 cm(3) volume; and 3) establishment of optimal cerebrospinal fluid flow between the cranial and spinal compartments.

Review Article: Chiari Type I Malformation with or Without Syringomyelia: Prevalence and Genetics.

Chiari type I malformation has traditionally been defined as a downward herniation of the cerebellar tonsils of ≥5 mm through the foramen magnum and it is likely associated with a volumetrically reduced posterior fossa. Syringomyelia is commonly associated with Chiari type I malformation. We estimate the prevalence of these two conditions and determine that they are more common than previously expected.

The tentorial notch: anatomical variation, morphometric analysis, and classification in 100 human autopsy cases.

Object: Variations in the structure of the tentorial notch may influence the degree of brainstem distortion in transtentorial herniation, concussion, and acceleration-deceleration injuries. The authors examined the anatomical relationships of the mesencephalon, cerebellum, and oculomotor nerves to the dimensions of the tentorial aperture. On the basis of numerical data collected from this study, the authors have developed the first classification system of the tentorial notch and present new neuroanatomical observations pertaining to the subarachnoid third cranial nerve and the brainstem.