Dictionary of Medical Terms
|
Term
|
Definition
|
| Achilles tendon | The strong fibrous tendon which attaches to the heel of the foot and originates from the calf muscles. Can become shortened and tight due to spinal cord tethering. Surgery is usually indicated to lengthen the tendon, which allows the heel to be placed flat on the ground, thereby facilitating normal gait. |
| Agenesis | A condition in which part of the body does not completely develop or fails to develop at all. |
| Anencephaly | Underdeveloped and incomplete brains in newborn babies. Death is usual within a few hours. |
| Arnold-Chiari Malformation | Congenital malformations of part of the brain. See relevant section of http://www.graylab.ac.uk/ for full details. |
| Atretic | An abnormal closure or absence of a body opening or tubular organ. |
| Cauda equina | A bundle of parallel nerves at the lower end of the spinal cord. May be seen externally in some forms of spina bifida aperta as a rudimentary tail "horse's tail". |
| Caudal | A position at the tail end of the spinal cord. |
| Cellulitis | |
| Cerebrospinal Fluid | The clear colourless fluid which bathes the surface of the brain and spinal cord. |
| Conus medullaris | Conical termination of the spinal cord. |
| Dermal sinus tract | See Sinus. |
| Diastematomyelia | A type of tethered cord. The longitudinal splitting of the spinal cord at one or more levels. The split is caused by the existence of a spur of bone or cartilage through the cord. It can also be associated with a short filum. |
| Diplomyelia | Duplication of the spinal cord. Each part is enclosed within its own dural sac and has its own nerve roots. |
| Dorsal | Pertaining to the back of a structure. |
| Dura | The outermost, toughest and most fibrous of the three membranes covering the brain and spinal cord. |
| Dysraphism | See Spinal Dysraphism. |
| Ectoderm | Outer of the three germ layers of an embryo (others are the mesoderm and endoderm). |
| Encephalocele | A hole in the skull through which brain tissue protrudes. Death is usual in most cases; survivors are severely retarded. |
| Erythromelalgia (EM) | |
| Fatty filum | See Thickened Filum. |
| Filum terminale | A small threadlike piece of connective tissue that connects the lower end of the spinal cord to the sacral end of the spinal cord. See Thickened Filum Terminale. |
| Fistula | An abnormal passage or communication, usually between two internal organs or leading from an internal organ to the surface of the body. |
| Folic Acid |
A B-vitamin, essential for the functioning of the human body. Can reduce
the occurrence of spina bifida by 72% in high risk and first pregnancies.
|
| Haemangioma | A vascular tumour composed of large dilated blood vessels, often containing large amounts of blood, occurring in the skin or subcutaneously or both. Superficial lesions are bright to dark red in colour, and deep lesions are a blue colour. |
| Herniation | The bulging of tissue through an opening in a membrane, muscle or bone. |
| Hydrocephalus | An abnormal accumulation of cerebrospinal fluid in the cavities (ventricles) of the brain, distending them and stretching and thinning the brain tissue covering them. |
| Kyphosis | Posterior curvature of the thoracic spine, usually as a result of a disease or a congenital problem. |
| Laminectomy | The surgical removal of a portion of the bone comprising
a vertebra. It is used to relieve pressure on the spinal cord or a nerve
root due to a slipped disk. It may be used in detethering surgery to gain access to the tethered cord site. |
| Lipoma | A collection of fat cells. |
| Lipomyelomeningocele | A form of tethered cord, whereby the spinal cord and nerve roots are tethered within a benign lipoma. |
| Lumbosacral | The lower part of the back. |
| Magnetic Resonance Imaging | A technique used to create images of both hard and soft tissues in the body. Images are very clear and provide more accurate information than x-rays. It is especially useful for the imaging soft tissues of the brain, spinal cord, joints and abdomen. |
| Meninges | Three layers of membrane covering the brain and spinal cord. Cerebrospinal fluid occupies the space between two of the layers. |
| Meningocele | A form of spina bifida cystica. An opening in the spine through which protrudes a fluid-filled sac, containing the meninges. Usually causes no disability and has a low incidence of associated anomalies and hydrocephalus. |
| Myelocele | A protruding sac containing the spinal cord only. |
| Myelocystomeningocele | A congenital defect whereby the membranes and spinal cord protrude within a sac through a defect in the vertebral column. |
| Myelomeningocele | A congenital defect. The neural arches fail to close in the embryonic stage, therefore exposing the meningeal tissue and nervous tissue of the spinal canal. It mainly occurs in the lumbosacral part of the spine. It usually causes sensory and motor changes below the lesion, as well as various degrees of weakness, anaesthesia, urinary and faecal incontinence. |
| Myeloschisis (an old term was Rachischisis) | A severe form of spina bifida cystica, in which the entire length of the spine may be open. It causes severe neurological disability and death. |
| Neural Arches | Outward facing bony parts of the spine. The skeletal structure arising dorsally from the vertebral column. Two plates rise from the vertebral column and meet above the spinal cord to form the neural arch and spine. |
| Neural Tube | The initiator of the central nervous system. Formed by the fusion of the two upturned neural folds formed by the edges of the neural plate, giving rise to the brain and spinal nerve cord. |
| Pes cavus | Latin term meaning "hollow foot". A foot with too high an arch. |
| Sacral agenesis | Malformations characterised by partial or complete absence
of a number of lumbar or sacral vertebrae, together with the corresponding
areas of the neural tube. May include myelomeningoceles; is associated
with limb and uro-genital abnormalities and scoliosis. Clinical features
are flattened buttocks, a short bottom cleft and motor deficits. If the
cord is tethered, surgery may be required, as well as the treatment of
associated abnormalities. A severe form is sirenomelia, a congenital fusion of both lower limbs. |
| Scoliosis | A congenital abnormal lateral curvature of the spine. |
| Sinus | A notch or cavity on the surface of an organ. In the context of a neural tube defect it is known as a dermal sinus tract. |
| Spina bifida occulta | A covered opening in the vertebrae, but no protruding sac of spinal tissues or nerves is present. |
| Spinal dysraphism | Describes developmental abnormalities in the midline region of the back. Dysraphism signifies incomplete fusion or malformation of a seam, and includes all forms of spina bifida (occulta and cystica). Comes from Dys- meaning faulty, raphic- Greek word for seam- therefore "faulty seaming". |
| Spinal stenosis | Abnormal narrowing of the spinal canal. May be congenital, or acquired through injury. Surgery (including a laminectomy) is usually required to widen the canal and thereby reduce pressure on the spinal cord. |
| Tethered Cord Syndrome | A collection of clinical and physical abnormalities associated with the tethering of the spinal cord to an immovable structure within or around the vertebral column. See thickened filum, lipomyelomeningocele, dermal sinus tract and diastematomyelia. |
| Thickened filum terminale | A fibrous band extending from the bottom of the spinal cord
to the bottom of the spinal canal, associated with cutaneous markers.
The least serious type of tethered cords. The conus ends at L4 instead of the usual L1 termination. The filum is short and thickened and tethers the conus at an abnormally low caudal position . The filum is usually filled with adipose (fatty) tissue. |
| Urodynamics | The mechanical laws of fluid dynamics applied to urine transport. Tested in relation to bladder function. |
| Ventricles | Cavities in the brain. |
| Vertebral column | The bones comprising the spinal column, enclosing the spinal cord and its nerves and tissues. It is also known as the backbone. The spinal cord runs through central openings of each vertebra. |