Articles

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More than 200 results
Article

Poliomyelitis-like syndrome

Poliomyelitis-like syndrome, or polio-like paralysis, is an uncommon form of myelitis that presents similar to polio, due to non-poliovirus pathologies which selectively involve the anterior horn cells of the spinal cord and result in an anterior horn syndrome. Although it usually has an infecti...
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Cervical plexus

The cervical plexus is formed by the ventral (anterior) rami of the C1 to C5 nerve roots and innervates the diaphragm, provides motor supply to some neck muscles and cutaneous sensation to the skin of the head, neck, and chest. Gross anatomy Roots anterior rami of C1 to C5 nerves Course run...
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Thoracic spine protocol (MRI)

The MRI thoracic spine protocol encompasses a set of MRI sequences for the routine assessment of the thoracic spine. Note: This article aims to frame a general concept of an MRI protocol for the assessment of the thoracic spine. An MR thoracic spine protocol might be combined with a cervical sp...
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Powers ratio

The Powers ratio is a measurement of the relationship of the foramen magnum to the atlas, used in the diagnosis of atlanto-occipital dissociation injuries. The ratio, AB/CD, is measured as the ratio of the distance in the median (midsagittal) plane between the: basion (A) and the posterior spi...
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Alar ligament

The alar ligaments join the lateral margins of the sloping upper posterior margin of the dens of C2 to the lateral margins of the foramen magnum (adjacent to the occipital condyles) and lie on either side of the apical ligament. They may be oblique or vertical and are thickest at the occipital a...
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Annulus fibrosus calcification

Annulus fibrosus calcification is a form of intervertebral disc calcification where the peripheral annular portion (annulus fibrosus) can get calcified. This may occur in isolation or in conjunction with other sites of disc calcification. It could involve any portion of the spine. Some suggest t...
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Spinal epidural venous plexus congestion

Spinal epidural venous plexus congestion or dilatation is typically a complication of other pathologies.  Clinical presentation Radiculopathy caused by the dilated epidural veins is not uncommon 1. More severe symptoms such as cauda equina compression syndrome have been reported 6, 7. Patholo...
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Basilar invagination

Basilar invagination, also called basilar impression, is a congenital or acquired craniocervical junction abnormality where the tip of the odontoid process projects above the foramen magnum.  Terminology The following terms are often used interchangeably because they describe upwards migration...
Article

Pneumorrhachis

Pneumorrhachis refers to the presence of gas within the spinal canal (either intra- or extradural). It is rare. Clinical presentation Patients can often be asymptomatic 3. Pathology Etiology Pneumorrhachis can result from a number of causes: trauma (traumatic pneumorrhachis): can occur in ...
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Sinuvertebral nerve

The sinuvertebral nerve, also known as the recurrent meningeal nerve, or the recurrent nerve of Luschka, is a branch of the primary ventral ramus and grey ramus communicans in the intervertebral foramen. It enters the spinal canal and supplies the posterior portion of the annulus of the interver...
Article

Basion-dens interval

The basion-dens interval (BDI) is the distance between the basion and the tip of the dens, used in the diagnosis of atlanto-occipital dissociation injuries. It is the distance from the most inferior portion of the basion to the closest point of the superior aspect of the dens in the median (mid...
Article

Chalk stick fracture

Chalk stick, also known as carrot stick fractures, are fractures of the fused spine, classically seen in ankylosing spondylitis. Terminology Some authors define the chalk stick fracture as a fracture through a Pagetoid long bone (see Paget disease) 3. Pathology They usually occur through the...
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Autonomic nervous system

The autonomic nervous system (ANS) is a subdivision of the peripheral nervous system. The autonomic system provides innervation of the involuntary muscles, i.e. myocardium and smooth muscle, and glands, through which fine control of homeostasis is maintained. The afferent innervation of the aut...
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Diplomyelia

Diplomyelia is a rare spinal cord malformation in which the cord is duplicated. It should be distinguished from diastematomyelia in which a single cord is split. Having said that it has been proposed that the term be abandoned in favor of split cord malformation, which encompasses both diastemat...
Article

Intramedullary spinal tumors

Intramedullary spinal tumors are rare, representing 4-10% of all CNS tumors and <10% of all pediatric CNS neoplasms 5. They account for 20% of all intraspinal tumors in adults and 35% of all intraspinal tumors in children 8. A long duration of symptoms prior to diagnosis is typical. Pathology ...
Article

Cortical bone

The outer shell of compact bone is called cortical bone or cortex. It is formed by compact bone which is one of the two macroscopic forms of bone, the other being cancellous bone.  Gross anatomy Cortical bone contains Haversian systems (osteons) which contain a central Haversian canal surround...
Article

McRae line

McRae line is a radiographic line drawn on a lateral skull radiograph or on a midsagittal section of CT or MRI that connects the anterior and posterior margins of the foramen magnum (basion to opisthion). Significance indicates the presence of basilar invagination (atlantoaxial impaction): the...
Article

Cervical spine (AP oblique view)

The AP oblique cervical spine projections are supplementary views to the standard AP, odontoid and lateral images in the cervical spine series and are always done bilaterally for comparison purposes. However, the PA oblique projection is preferred as it reduces radiation dose to the thyroid 1 co...
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Arterial vasocorona

The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.  Engorgement of arterial v...
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Burst fracture

Burst fractures are a type of compression fracture related to high-energy axial loading spinal trauma that results in disruption of a vertebral body endplate and the posterior vertebral body cortex. Retropulsion of posterior cortex fragments into the spinal canal is frequently included in the de...

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