What is a filum terminale? The filum terminale (FT) is a fibrous band that extends from the conus medullaris to the periosteum of the coccyx, and its functions are to fixate, stabilize, and buffer the distal spinal cord from normal and abnormal cephalic and caudal traction. How do you distinguish between conus medullaris and cauda equina?
What is the function of the filum terminale?
The filum terminale (FT) is a fibrous band that extends from the conus medullaris to the periosteum of the coccyx, and its functions are to fixate, stabilize, and buffer the distal spinal cord from normal and abnormal cephalic and caudal traction.
What is cauda equina and filum terminale?
The fibrous extension of the cord, the filum terminale, is a nonneural element that extends down to the coccyx. The cauda equina (CE) is a bundle of intradural nerve roots at the end of the spinal cord, in the subarachnoid space distal to the conus medullaris.
What is the function of the cauda equina?
The cauda equina is the continuation of these nerve roots in the lumbar and sacral region. These nerves send and receive messages to and from the lower limbs and pelvic organs.
Is the filum terminale part of the cauda equina?
The cauda equina comprises the lumbosacral, the coccygeal nerve roots, and the filum terminale.
What is the filum terminale in anatomy?
The filum terminale is a small thin filament of connective tissue that extends inferiorly from the apex of the conus medullaris to the sacrum.
Is the filum terminale a nerve?
The filum terminale is the nonfunctional continuation of the end of the spinal cord. It usually consists of fibrous tissue without functional nervous tissue.
What is the significance of the cauda equina quizlet?
It provides longitudinal support to the spinal cord as a component of the coccygeal ligament. - It is made up of extensions of the posterior and anterior roots of spinal segments L2 to S5. It forms as the vertebral column continues to elongate after growth of the spinal cord ceases at about age 4.
What happens during cauda equina?
Cauda equina syndrome is a rare and severe type of spinal stenosis where all of the nerves in the lower back suddenly become severely compressed. Symptoms include: sciatica on both sides. weakness or numbness in both legs that is severe or getting worse.
What is the cauda equina quizlet?
Cauda Equina. "horse tail" = spinal nerves within the vertebral canal. After the spinal cord tapers out, the spinal nerves continue as dangling nerve roots called cauda equina. Cerebrospinal Fluid.
Does the filum terminale anchor the spinal cord?
The spinal cord is anchored distally by the filum terminale, a fibrous extension of the pia mater anchoring the spinal cord to the coccyx. [1] Protecting the spinal cord is the surrounding cerebrospinal fluid (CSF), supportive soft tissue membranes and meninges, and the osseous vertebral column.
What is the filum terminale quizlet?
filum terminale. a strand of fibrous tissue, originating at the conus medullaris and extending through the vertebral canal to the second sacral vertebra, ultimately becoming part of the coccygeal ligament.
Where does cauda equina start and end?
The cauda equina is a group of nerves and nerve roots stemming from the distal end of the spinal cord, typically levels L1-L5 and contains axons of nerves that give both motor and sensory innervation to the legs, bladder, anus, and perineum.
What happens if you have cauda equina?
If patients with cauda equina syndrome do not seek immediate treatment to relieve the pressure, it can result in permanent paralysis, impaired bladder and/or bowel control, loss of sexual sensation, and other problems. Even with immediate treatment, some patients may not recover complete function.
What is the most common cause of cauda equina syndrome?
Cauda equina syndrome is most commonly caused by a massive disc herniation in the lumbar spine (low back). A disc herniation occurs when the jelly-like core of a disc herniates, or shifts out of position, putting pressure on nearby nerves in the spine.
What are the first signs of cauda equina?
Early symptoms of cauda equina syndrome can include: Lower limb weakness and intermittent changes in sensation, such as numbness. “Saddle anesthesia” – loss or diminished sensation in areas where a person would sit on a saddle. Urinary and/or bowel problems, such as retention or incontinence.
What happens during cauda equina?
Cauda equina syndrome is a rare and severe type of spinal stenosis where all of the nerves in the lower back suddenly become severely compressed. Symptoms include: sciatica on both sides. weakness or numbness in both legs that is severe or getting worse.
What is the condition that causes the spinal cord to get abnormally stretched?
This condition is called tethered cord syndrome and causes the spinal cord to get abnormally stretched, especially during actions such as spinal flexion (bending forward). 1 Common signs and symptoms include 3:
What is the strand of tissue that connects the conus medullaris to the coccy?
Filum terminale. The pia mater forms a delicate, fibrous strand of tissue called the filum terminale that extends down from the conus medullaris. This strand stabilizes the spinal cord by connecting the conus medullaris to the coccyx (end of the spine). 1.
What is the terminal portion of the spinal cord called?
Conus medullaris . The terminal portion of the spinal cord in the lumbar region is cone-shaped and is called the conus medullaris. The conus medullaris is made up of several neurons (nerve cells) and has 3 protective layers. Starting from the outermost layer, these are the dura mater, arachnoid mater, and pia mater.
What is the lumbar cistern?
Lumbar cistern. The space inside the arachnoid mater is filled with cerebrospinal fluid (CSF). Below the conus medullaris, this space is enlarged. This enlargement is called the lumbar cistern and contains CSF, the filum terminale, and the cauda equina. 2.
What is the sac of the dura mater?
The dura mater and arachnoid mater are collectively called the dural sac or the thecal sac. This sac covers the conus medullaris, cauda equina, and each individual spinal nerve root as it courses out of the cauda equina and travels into the intervertebral foramen (bony opening through which the nerve exits the spinal canal). 2
What are the symptoms of Cauda Equina syndrome?
Compression of the cauda equina within the lumbar cistern can cause serious symptoms in the lower body. The condition is called cauda equina syndrome and presents with the following signs and symptoms 4: 1 Numbness of the inner thighs (saddle anesthesia) 2 Urinary retention 3 Loss of bowel and/or bladder control 4 Severe lower back pain 5 Sciatica-like shooting and burning pain in the leg (s) 6 A feeling of pins-and-needles in the leg (s)
What causes conus medullaris?
The most common causes of conus medullaris syndrome include spinal fracture, disc herniation, tumors, trauma, and collection of pus in the epidural space due to infection (epidural abscess). 1. Conus medullaris syndrome is a medical emergency and requires immediate treatment to preserve leg function.
What is the filum terminale?
Also extending distally from the apex of the conus medullaris is the filum terminale, a vestigial remnant of the distal part of the spinal cord . This thin, approximately 20 cm long filament of connective tissue is actually an extension of the pia mater that runs distally surrounded by the spinal nerve roots of the cauda equina. At the level of S2 vertebra, it becomes covered by the dura and arachnoid layers and attaches to the coccyx, anchoring the distal end of the spinal cord and spinal meninges .
What is the spinal cord that is distal to the conus medullaris?
Distal to the conus medullaris is a collection of spinal nerve roots called the cauda equina, that emerges from the lumbosacral part of the spinal cord below the L1 vertebra and descends toward the coccyx. The cauda equina is translated from Latin into ‘horse’s tail’, and was so named due to its resemblance to the tail of a horse.
What is the conus medullaris?
The conus medullaris (medullary cone) is the cone-shaped terminal portion of the spinal cord . The tip of the conus medullaris is found between the L1 and L2 vertebra in the average adult. The conus medullaris is tethered to the coccyx by a fibrous cord called the filum terminale, which stabilizes the distal end of the spinal cord.
What nerve exits the intervertebral foramen?
The dorsal and ventral roots from the spinal cord fuse to form the true spinal nerve that exits the intervertebral foramen. Once the spinal nerve passes through this bony opening, it immediately branches into two main portions: the dorsal and ventral rami. Dorsal rami innervate the back while ventral rami innervate the anterolateral aspects of the body wall.
What is the cone-shaped termination of the spinal cord?
Conus medullaris is the cone-shaped termination of the spinal cord; filum terminale is a thin strand of pia mater that comes off the cord and passes down into the coccyx; cauda equina are all the spinal nn. exiting the neural/spinal canal lower than the termination of the spinal cord at L2.
Why are there 3 spinal Nn?
Three spinal nn. Because there is some overlap (collateral branches) from each spinal nerve into the dermatome above and below it.
What nerve is formed at the union of the dorsal and ventral roots?
At the union of the dorsal and ventral roots - the formation of the true spinal nerve.
Which spinal nerves do not form a plexus but rather remain segmental and innervate a specific?
A spinal nerve whose ventral rami do not form a plexus but rather remain separate and innervate a specific body dermatome. The dorsal rami always remain segmental (separate).
Which part of the body innervates the muscles and blood vessels of the anterolateral aspects of the body wall?
Ventral rami innervate the muscles and blood vessels of the anterolateral aspects of the body wall.
Which branch of the ramus innervates the skin?
The lateral and anterior cutaneous branches from the ventral ramus, coupled with the branches of the dorsal rami, innervate a band of skin/muscles and blood vessels of the body wall - a dermatome.
What are the malformations of the lower cord and cauda equina?
OTHER MALFORMATIONS OF THE LOWER CORD AND CAUDA EQUINA. Diplomyelia, diastematomyelia, and tight filum terminale are all malformations of the lower part of the cord and the cauda equina, which are often, though not invariably, connected with spina bifida occulta and a tuft of hair over the lumbosacral region.
What is the most common intraspinal lipoma?
Filum terminale lipomas represent the most common intraspinal lipoma. They occur in 1–6% of the population and are usually an incidental finding (95% of those detected by MRI are asymptomatic) (Cools et al., 2014). On imaging, the entire length or a segment of the filum terminale is thickened and contains fat.
What is the function of the filum terminale?
The filum terminale is an extension of the pia mater that is attached to the coccygeal segments, whose function is to suspend the cord in the CSF (like the denticulate ligaments).
What is the filum of the neural tube?
It usually consists of fibrous tissue without functional nervous tissue. Although its embryologic origin is unclear, it probably represents the termination of the neural tube and its most caudal link to the rest of the embryonic tissues. The filum can be enlarged either with fibrous tissue only or with fat.
Where are myxopapillary ependymomas found?
Myxopapillary ependymomas arise predominantly in the region of the filum terminale and cauda equina and present as elongated, sausage-shaped masses with a smooth, lobulated surface [7, 8, 14, 15]. The tumor is usually well defined and almost appears encapsulated, displacing or compressing the nerve roots of the cauda equina, with only a mild tendency to infiltrate or envelope neural structures. Some tumors can be quite large at presentation (e.g. 10 cm or greater in length) and are known to cause erosion and scalloping of the surrounding vertebral bodies and sacrum. On microscopic histological examination, myxopapillary ependymomas are classified as WHO grade 1. Characteristic features include the presence of numerous small papillary structures, each surrounded by well-defined cuboidal or columnar cells, usually in a single layer (Figure 5.4) [ 15]. These cells have rounded, ependymal type nuclei with distinct margins and a delicate chromatin meshwork, without obvious cytoplasmic processes. The cores of the papillae have a myxoid appearance and consist of a central blood vessel surrounded by a mucinous matrix, or are entirely filled by the mucinous material. In papillae with central blood vessels, extensive thickening and hyalinization of the vessel wall may be seen. Other regions of the tumor show a looser structure, with tumor cell nuclei embedded in a meshwork of fine cytoplasmic processes. The processes are often arranged in a radial fashion around the basement membranes of blood vessels and enclose numerous microcystic spaces. On occasion, more compact gliofibrillar areas resembling typical ependymomas can be noted, with the presence of perivascular pseudorosettes or even true ependymal rosettes. Degenerative features, such as microvascular hyalinization, thrombosis, hemorrhage and hemosiderin, are often present. At the edge of the tumor, there is usually a sharp margin between neoplastic cells and normal tissues, although in some cases nerve roots can be enclosed. Mitotic figures and other features of anaplasia are not usually seen.
Which part of the spinal cord is doubled?
In diplomyelia the lower part of the spinal cord is doubled; in diastematomyelia it is divided into two portions by a bony or fibrocartilaginous spicule that arises from the vertebral body and transfixes the cord; the tight filum terminale attaches the lower end of the cord to skeletal structures.
Where do intradural lipomas occur?
Intradural lipomas occur at the midline along the dorsal surface of the unopposed folds of the placode, although they may result in lateral deviation of the cord when large ( Rossi et al., 2004). They are usually subpial and surrounded by an intact dura (Gupta et al., 2013).
What is the filum terminale?
The filum terminale ("terminal thread") is a delicate strand of fibrous tissue, about 20 cm in length, proceeding downward from the apex of the conus medullaris. It is one of the modifications of pia mater. It gives longitudinal support to the spinal cord and consists of two parts: 1 The upper part, or filum terminale internum, is about 15 cm long and reaches as far as the lower border of the second sacral vertebra. It is continuous above with the pia mater and contained within a tubular sheath of the dura mater. In addition, it is surrounded by the nerves forming the cauda equina, from which it can be easily recognized by its bluish-white color. 2 The lower part, or filum terminale externum, closely adheres to the dura mater. It extends downward from the apex of the tubular sheath and is attached to the back of the first segment of the coccyx in a structure sometimes referred to as the coccygeal ligament.
How long is the filum terminale internum?
The upper part, or filum terminale internum, is about 15 cm long and reaches as far as the lower border of the second sacral vertebra. It is continuous above with the pia mater and contained within a tubular sheath of the dura mater.
Where is the lower part of the coccyx?
The lower part, or filum terminale externum, closely adheres to the dura mater. It extends downward from the apex of the tubular sheath and is attached to the back of the first segment of the coccyx in a structure sometimes referred to as the coccygeal ligament.
Which nerve leaves the spinal cord?
The most inferior of the spinal nerves, the coccygeal nerve leaves the spinal cord at the level of the conus medullaris via respective vertebrae through their intervertebral foramina, superior to the filum terminale.
