Basilar Impression - Acquired or innate impression inside the skull portion of the occipital bone in craniovertebral transition. The resulting decrease in the volume Impressions basilar skull and cranial (toward the skull) are offset spine cause of hydrocephalus, cerebellar disorders, disorders of the cranial nerves, radicular symptoms and signs of lesions of the upper cervical spinal cord. Basilar Impression diagnosed by X-ray craniovertebral transition, CT and MRI scans of the skull and cervical spine. Basilar Impression treated only by surgery. However, the presence of non-progressive lung clinical changes such treatment is not required.
Neurology basilar Impression refers to anomalies craniovertebral transition, which also includes platibaziya, assimilation of the atlas, atlantoaxial dislocation and Chiari malformation. Often congenital basilar Impression craniovertebral combined with other anomalies and malformations of the spine. The most common combination vice, in which notes and congenital basilar Impression platibaziya.
chlamydia, rubella, measles, cytomegalovirus infection, and others.), radioactive radiation, exposure to harmful chemicals.
Acquired (secondary) basilar Impression develops as a result of disruption of normal bone structure of the occipital bone. Its cause can be osteoporosis, which in turn is associated with hypoparathyroidism, osteomalacia, severe rickets, Paget's disease. Acquired basilar Impression possible as a result of destructive changes of the occipital bone during germination in her posterior fossa tumors or as a result of the inflammatory process (syphilis, tuberculosis, actinomycosis, osteomyelitis).
hydrocephalus and compression of it located in the anatomical structures: the cerebellum, brain stem, the roots of the cranial nerves. In addition, compression of the exposed segments and upper cervical spinal cord, leading to the appearance of spinal and radicular symptoms.
General neurological symptoms, which is accompanied by basilar imperssiya reduces headaches in the occipital region, often have paroxysmal in nature and dependent on the position of the head. Against headaches are possible vegetative disorders:. Feeling of cold or heat in the body, tachycardia, rash, changes in blood pressure, etc. In some cases, basilar Impressions observed one-sided pain in the occipital region, which gradually may take bilateral. Occasionally the pain of the neck extends anteriorly in one or both eyes. It can be caused by the type of occipital neuralgia, aggravated by turning your head, coughing, laughing and straining.
Cerebellar symptoms that occur basilar Impression, is the appearance of ataxia - violation of the stability of the body position and unsteadiness when walking. The defeat of the brain stem appears nystagmus, choking when eating (dysphagia), hoarseness, hearing loss (deafness), vertigo, the disorder of the skin sensitivity. The most pronounced symptoms stem when basilar Impression combined with the assimilation of the atlas.
Often basilar Impression accompanied by pain in the neck and upper limbs, as well as paresthesias (numbness, "pins and needles") in the field of head and neck. These symptoms are caused by compression of the upper roots of the cervical spine. In the case of the basilar Impressions compressive myelopathy in the upper cervical spine rarely leads to development of spastic tetraparesis. Basically when basilar Impressions observed moderate dissociated disorders of sensitivity, requiring exceptions initial manifestations of syringomyelia.
On examination, patients who have a basilar Impression, often draws attention to themselves short neck and down the boundary of hair growth. There unsteadiness in Romberg, promahivanie when the coordination tests (knee-heel and fore-finger), decreased sensitivity in the area of the cervical dermatomes and face.
a neurologist at the thought of the presence of pathology in the posterior fossa and craniovertebral transition. At the same time to identify basilar Impressions or other anomalies in this area primarily carried out X-ray examination. Better than the X-ray, imaging of bone structures in the area, as well as data on other malformations, which are often combined congenital basilar Impression, can be obtained using CT scans of the skull and spine.
Sighting radiography skull in craniovertebral transition and radiography of the spine in the cervical region are conducted in line (FASD) and lateral (profile) projections. Basilar Impression diagnosed by an increase in the angle between the underlying bone plate and the slope more than 130 °, and also from the shift-up process of the second cervical vertebra. Defining the location manufacture process with respect to the conventional lines: Chamberlain line (between the rear edge of the hard palate and the rear edge of the foramen magnum) and the line de la Petite (between the tops of the right and left mastoid). Normally, the process of the second cervical vertebra located below these lines. Basilar Impression characterized by a shift process to 6-30 mm above the Chamberlain and 10-15 mm above the de la Petite.
When ophthalmoscopy in patients with basilar Impress can be detected stagnation of the optic nerve, during the threshold audiometry - sensorineural type of hearing loss. To identify the state of soft tissue structures of the posterior fossa and spinal cord, assess their degree of compression at the basilar Impressions is necessary to conduct a brain MRI scan and MRI of the spine.
Basilar Impression requires differentiation from other anomalies craniovertebral transition, syringomyelia, Friedreich's ataxia, cerebellar tumors, ataxia, Pierre-Marie, as well as the cortical type of ataxia.
Treatment of basilar Impressions
When basilar Impression radiologic finding is random and does not cause compression of the symptoms of brain structures, the treatment is not required. The indication for surgery when the basilar Impressions can be a steady progression of symptoms; clinical signs of compression of the spinal cord, brainstem or cerebellum; expressed liquor dynamic disorders with progressive occlusive syndrome. For the purpose of decompression during operations produce large expansion of the foramen magnum.