Siringomielia

Siringomielia Name siringomielie (syrinx = cane = lamb bone) is granted a disease characterized by a hollow expansion of the spinal cord which can cause a progressive myelopathy. These cavities grow mainly in the region periependimara and spinal horns. Siringomielia frequently localize in the upper thoracic or lower cervical region and less frequently in the lumbar region. If it locates in the high cervical region, the cavity can extend the bulb in the deck.
The disease usually occurs in adulthood, between 20 and 40 years. Men are affected to a greater extent than women, probably because injuries occur with greater frequency in males.
Intramedullary cavities occur as a result of conditions such as mielitele, arahnoiditele or from glial tumors. Siringomielia and can result in developmental disorders of the posterior fossa or foramen magnum. Other diseases associated with development are siringomielia atresia of Magendie hole or posterior fossa cyst (also known as Dandy-Walker syndrome). More than 50% of cases of disease associated with Chiari type 1 malformation. These defects involve protrusion of cerebellar tonsils in the foramen magnum and cervical spinal canal. When there is protrusion of the meninges or spinal meninges and a spinal canal that is not fully closed, the anomaly called Arnold-Chiari malformation (or type 2).
The pathogenesis of the disease there are several theories: - Medullary disrafiei Theory - This theory puts siringomieliei development due to defects in the embryological development of the spinal cord. In this case there is a defect in the posterior margin of the neural tube coalescence primitive. This may cause cifoscolioza, spina bifida, sindactilie, enuresis, discrete motility and sensitivity disorders. In the back of the channel islands remain ependimar spongioblastic potential embryonic tissue, which can develop a tissue infiltrating the gliosis. - Infectious Theory - This theory considers the condition as the result of an infection of viral etiology. Some animal experiments have confirmed the hypothesis nerve virus. - Theory tumor - in this case is considered in a gliomatoza neoplastic disease process occurs slowly, over time Dig. - Theory of Traumatic - Injuries, especially in the cervical spinal can cause vascular changes that will contribute to the development of intramedullary cavities.
From anatomical point of view, the cavity appears in a tissue gliosis. Disease occurring mainly in the cervical spinal cord, gliosis tissue may spread to the bulbar region, rarely in the thoracic and lumbar region. The process of gliosis in the gray matter nerve tissue destroys bone marrow. In the bulb is damaged nerve tissue in the side, and the pontine region of oliva bundles Posterolateral portion of the pyramid and the fourth ventricle. Tissue inside the marrow cavity is surrounded by glial cells or glial cells ependimare. The cavity is delimited by a fibrous wall, rough, consisting of a network of axons fibrillary astrocytes or destroyed there on the periphery of the tissue. This process destroys neurons surrounding axons. Blood vessels around the cavity shows a hyaline thickening of the walls. It is found also in the nerve cells of the horn side above the posterior horn, and lateral cord in bundles.
Clinical Symptoms begins insidiously, during adolescence or early youth. Performing in spurts and can regress spontaneously for a while. Onset of symptoms may be the result of trauma, an extension of the neck or episodes of coughing. The lesion produces a central medullary syndrome with dissociated loss of sensation and paresis of the upper limb areflexia. Thermal sensitivity is affected by painful, whose horses are injured at their place of crossing. Tactile and vibration sensitivity is not affected, because the rear is transmitted through the cords, fiber tactile sensitivity that is going to beam spinotalamic and crosses the upper levels, bypassing the limits of this cavity. By extending the process of gliosis in the vegetative to the lateral horn and periependimar, vegetative disturbances occur, and by extension to the earlier horn resulting paralysis and muscle atrophy. In most cases, the onset of disease is asymmetric, unilateral loss of sensitivity. Sensitivity-type disorders have separated the floors above the neck, shoulders and upper limbs, the lesion ranged swelling is more common in cervical region. The development is also affected lateral cord, was injured and spinotalamic beam. This presents sensitivity problems in the lower half of the trunk. Muscular atrophies are found especially in the lower neck, the shoulders, arms and hands. Neurological examination revealed diminished or abolished tendon reflexes. Paravertebral muscles is interested in a lesser degree and tend to emphasize cifoscolioza. As with the pyramid and trapping fascicles advancing disease signs of spastic paraparesis, exaggerated tendon reflexes, paresis of legs, bladder and bowel disorders, Horner syndrome. In some patients noted numbness and loss of sensation to the face resulting from damage to the trigeminal nerve tracts descending C2 level or above. If siringomielia is caused by Chiari malformations is seen in the neck and arm pain, headache triggered by coughing. It may also meet, paralysis of palate and vocal cords, dysarthria, horizontal or vertical nystagmus or paresis of the tongue. Due to injuries from the previous horns trophic and autonomic disturbances occur. Finger skin is dry, rough, scoamoasa with flictene. Some patients have panaritii the fingers. Sometimes the skin may be shiny and stretched that sclerodactilie. Fingers are infiltrated, swollen, edematiate. As a consequence of trophic disorders occurring areas of osteoporosis and painful sensitivity due to loss of patients can easily fractured limbs. Healing fracture callus is deficient because the weight is formed. Siringomielie arthropathy of the rule meets the joint and elbow joint, scapulohumeral periarthritis. Arthropathy can reach large sizes in the short term by increasing the amount of intra-articular fluid. Arthropathy is also painless. Articular surface deformation and signs of resorption of bone ends and limestone areas of precipitation. Articular changes and sometimes meet in the spine, this becoming cifoscoliotica. Over time, the thorax is subject to change, the upper is stiff and the shoulders are designed previously.
Clinical Forms - Shape Neck - is the most frequent siringomielie. Its elements have been described above. - Form sacrolombara - spinal disease process in the region of interest sacrolombara. This form has a familial character, being known as "mutilating acropatia family. - Siringobulbia - represents the bulbar form of the disease. They are often caught and cranial nerves in the region, occurring vestibular signs, nystagmus, dizziness. Capturing the trigeminal nerve leads to painful thermal sensitivity problems in its territory. Impaired hypoglossal nerve nucleus ambiguous and lead vocal tract disorders, swallowing disorders and partial atrophy of the tongue. Catching nucleus is seen in the vagus nerve disorders breathing and heart rate changes.
Diagnostic Laboratory Siringomielie cavities are best identified by MRI (magnetic resonance imaging). Should be made compulsory and an MRI examination of the brain to detect a possible spinal and bulb fixture to evaluate the posterior fossa structures. MRI examination with contrast material is suspected if an intramedullary tumor. Differential Diagnosis is retroolivar syndrome, hematomielia, amyotrophic lateral sclerosis, chronic anterior poliomyelitis, leprosy, disease Morvan, intramedullary tumors.
Treatment Siringomieliei treatment is surgical. If the condition is caused by tonsillar herniation, posterior fossa decompression is done by craniectomie suboccipitala, upper cervical laminectomy and dural graft placement. If there is an obstruction in the fourth ventricle, widening the entry is made. If the disease is caused by a Chiari malformation, is first shunting the cerebrospinal fluid circulation, and then corrects the intramedullary cavity. If trauma or infection is the main determinant of disease, decompression and drainage of the cavity is performed (it is between places a bone marrow cavity and subarachnoid space). In case of an intramedullary tumor tumor resection is performed.