BACKGROUND In many songbirds the larger vocal repertoire of males is associated with sexual dimorphism of the vocal control centers and muscles of the vocal organ, the syrinx. However, it is largely unknown how these differences are translated into different acoustic behavior. METHODOLOGY/PRINCIPAL FINDINGS Here we show that the sound generating structures of the syrinx, the labia and the ass...

BACKGROUND Cervical spinal canal tapering may increase CSF velocities and pressures. One report suggests that the cervical spinal canal tapers more steeply in patients with Chiari I than in healthy subjects. The goal of this study was to test the conclusion by measuring spinal canal tapering in another cohort of patients. MATERIALS AND METHODS Consecutive patients with scoliosis and MR imagin...

Various surgical procedures for the treatment of post-traumatic syringomyelia have been introduced recently, but most surgical strategies have been unreliable. We introduce the concept and technique of a new shunting procedure, syringo-subarachnoid-peritoneal shunt. A 54-year-old patient presented to our hospital with a progressive impairment of motion and position sense on the right side. Sixt...

Background: The intramedullary pulse pressure theory would provide an explanation of the pathophysiology of idiopathic syringomyelia i.e. Syringomyelia develops where the systolic CSF passes through a regional narrowing in the subarachnoid space which leads to increase in CSF velocity and, according to the Bernoulli theorem, decrease in CSF pressure that would cause a suction effect (Venturi ef...

BACKGROUND AND PURPOSE Steeper tapering of the cervical spinal canal as documented in recent studies is thought to have a role in the pathophysiology of Chiari malformation-associated syringomyelia. This study aimed to determine whether taper ratio of the cervical spinal canal differs between patients with distended and nondistended syringes. MATERIALS AND METHODS Seventy-seven adolescents (1...

BACKGROUND Although Chiari-like malformation (CM) and syringomyelia (SM) have been described in many small breed dogs, the prevalence and clinical manifestations of this complex have not been documented in a large cohort of American Brussels Griffon (ABG) dogs. OBJECTIVES To characterize the clinical and magnetic resonance imaging (MRI) features of CM and SM in the ABG breed. ANIMALS Eighty...

UNLABELLED Patients with syringomyelia may have diverse etiology and experience a variety of symptoms. This report describes two cases of syringomyelia in patients with different profiles, presentations and pathomechanisms. KEYWORDS Syrigomyelia; Syrinx; Arachnoid cyst; Arnold-Chiari.

The diverse vocal performances of oscine songbirds are produced by the independent but coordinated patterns of activity in muscles controlling separate sound generators on the left and right sides of their duplex vocal organ, the syrinx. Species with different song styles use the two sides of their syrinx in different ways to produce their species-typical songs. Understanding how a vocal mimic ...

Like human infants, songbirds acquire their song by imitation and eventually generate sounds that result from complicated neural networks and intrinsically nonlinear physical processes. Signatures of low-dimensional chaos such as subharmonic bifurcations have been reported in adult and developing zebra finch song. Here, we use methods from nonlinear dynamics to test whether adult male zebra fin...

OBJECT In 1998 the authors identified 5 patients with syringomyelia and no evidence of Chiari malformation Type I (CM-I). Magnetic resonance imaging of the entire neuraxis ruled out other causes of a syrinx. Ultimately, abnormal CSF flow at the foramen magnum was the suspected cause. The label "Chiari 0" was used to categorize these unique cases with no tonsillar ectopia. All of the patients un...