Cerebellum tumor — the good-quality or malignant new growth which is localized in a cerebellum. Can carry primary and secondary (metastatic) character. The tumor of a cerebellum is shown by variable symptoms which carry to 3 main groups: all-brain, cerebellar and stem. Diagnostics is based on results of a magnetic and resonant tomography of cerebral structures. Final verification of the diagnosis is carried out only according to a histologic research of fabrics of a tumor. Treatment is surgical, consists in as much as possible radical removal of education, restoration of circulation of tserebrospinalny liquid and elimination of a sdavleniye of a brain trunk.
New growths of a cerebellum make about 30% of all cerebral tumors. The modern histologic analysis allowed to allocate more than 100 morphological types of these educations. However the generalized data collected by the practicians specializing in the field of neurology, neurosurgery and oncology say that in 70% of cases the glioma acts as a tumor of a cerebellum.
Tumoral formation of a cerebellum can arise at any age. Some types of new growths (for example, a medulloblastoma) occur mainly at children, others (gemangioblastoma, astrotsitoma) — at middle-aged persons, the third (glioblastoma, metastatic tumors) — at elderly. Belonging to a male and Caucasian race increase risk of developing of an oncopathology of a cerebellum.
Reasons and pathogenesis
For certain the etiologichesky factors provoking growth of tumoral educations are not known. It is noted that approximately at the tenth part of the diseased the tumor of a cerebellum is hereditarily determined and enters into clinic of a neurofibromatosis of Recklinghausen. The important part in initiation of tumoral process is assigned to the radioactive radiation, influence of onkogenny viruses (some types of adenoviruses, herpes viruses, a virus of papilloma of the person, etc.) and to influence on an organism of cancerogenic chemicals. The risk of emergence of new growths increases at immunokomprometirovanny persons (The HIV-positive people receiving immunosupressorny therapy, etc.).
The pathogenetic mechanisms accompanying a cerebellum tumor are implemented in three main directions. First, there is a defeat of tissues of cerebellum connected with their sdavleniye the growing tumoral education and death. Clinically it is shown by focal cerebellar symptomatology. Secondly, the cerebellum tumor in the course of the growth fills a cavity of the IV ventricle and begins to squeeze a brain trunk that is shown by stem symptoms and disorder of function of the craniocereberal nerves (CN). The third mechanism causes development of all-brain symptomatology, it is connected with the accruing hydrocephaly and increase in intra cranial pressure. Sharp increase in pressure in a back cranial pole leads to omission of almonds of a cerebellum and their infringement in a big occipital opening. At the same time the lower part of a medulla is clamped between a cerebellum and a bone of an occipital opening, the sdavleniye of the structures which are localized in it leads to heavy bulbarny violations, disorder of warm activity and breath.
As well as new growths of other localizations, tumoral processes of a cerebellum are divided on good-quality and malignant. From good-quality educations in a cerebellum locally growing gemangioblastoma and astrotsitoma having infiltrative growth are most often observed. Often these tumors give cystous transformation and represent knot of the small sizes with a nearby big cystous cavity. The most frequent malignant tumor of a cerebellum at children is the medulloblastoma differing in especially intensive growth and distribution on subarakhnoidalny spaces. The second place on prevalence belongs to cerebellum sarcoma.
It should be noted that clinically it is possible to classify a cerebellum tumor on good-quality and malignant a little conditionally. The limited space of a back cranial pole causes danger of a sdavleniye of a brain trunk at any type of a new growth.
According to genesis of new growths of a cerebellum they are allocated in 2 big groups — primary and secondary tumors. Primary tumor of a cerebellum originates directly from its cages, being result of their tumoral metaplaziya. The secondary tumor of a cerebellum has a metastatic origin, can be observed at a breast cancer, malignant tumors of lungs, cancer of a thyroid gland, GIT malignancies. Primary tumors can have both good-quality, and malignant character. Secondary tumors always malignant.
Cerebellum tumor symptoms
The clinic of tumoral processes of a cerebellum consists of all-brain and cerebellar symptoms, and also signs of defeat of a trunk of a brain. Often symptoms of these 3 groups arise at the same time. In certain cases the disease demonstrates emergence of symptoms only of one group. For example, the cerebellum tumor which is localized in his worm usually begins to be shown with all-brain symptoms, and defeat of cerebellar fabric can be compensated and not give a long time of any clinical manifestations. Sometimes signs of a sdavleniye of a trunk or damage of any craniocereberal nerve become the first symptoms.
The all-brain symptoms accompanying a cerebellum tumor do not differ from similar symptoms at tumors of hemispheres of a brain. Patients complain of the constant or paroksizmalno the amplifying headache which more often is arising in the morning, having diffusion character (is more rare — localized in a nape). Tsefalgiya is accompanied by the nausea not dependent on food. Vomiting at headache height, dizziness, cortical frustration are possible (drowsiness, devocalization, the raised exhaustion, in some cases — olfactory, acoustical or light hallucinations). If the growing tumor of a cerebellum blocks ways of outflow of tserebrospinalny liquid, then the symptomatology accrues: the patient holds the compelled position — incline the head back or forward, accept a knee and elbow position with the hung head, attacks of nausea and vomiting become frequent. At the sharp blocking often connected with bystry change of position of the head gipertenzionno-gidrotsefalny crisis is observed.
Actually cerebellar (focal) symptoms vary depending on the location of a new growth. The cerebellar ataxy acts as the main clinical syndrome. At defeat of a worm it is shown by disorder of gait and instability. The patient goes, being unsteady and stumbling, widely places legs or balances with hands not to fall, can "bring" him on turns. Existence of a nistagm — involuntary movements of eyeballs is typical. Development of a cerebellar dizartriya — the violation of the speech which is characterized by its interruption, division into syllables ("the chanting speech") is possible. At defeat of a hemisphere of a cerebellum gomolateralno (on the party of defeat) coordination and harmony of movements is broken. The promakhivaniye when performing is noted a finger - nasal and knee and calcaneal tests, a dismetriya, an intentsionny tremor, change of handwriting on large and wide.
In process of growth the tumor of a cerebellum gets from one hemisphere into another, from a worm in hemispheres and vice versa. Clinically it is followed by mixing of signs of defeat of these structures, bilateral disorder of coordination.
Defeat of a brain trunk can be shown both by signs of its sdavleniye, and violations from separate ChMN. Trigeminal neuralgia, squint, the central neuritis of a facial nerve, relative deafness, disorder of flavoring perception, a dysphagy, paresis of a soft palate can be observed. The vomiting which does not have communication with a headache is typical for a stem syndrome. It is caused by irritation of receptors of a back cranial pole and can be provoked by the sharp movements or change of situation. The progressing sdavleniye of a trunk is followed by motive concern, tachycardia or bradycardia, a diplopiya, strengthening of a nistagm and glazodvigatelny violations (look paresis, the dispersing squint, , ); vegetative frustration, arrhythmia, tonic spasms are possible. Breath violations are noted, up to its full stop which can become a cause of death of the patient.
Diagnosis of a tumor of a cerebellum
Not always the inspection of the patient performed by the neurologist allows to assume a cerebellum tumor as specific cerebellar signs can be absent. Existence of the expressed all-brain symptomatology is a reason for the direction of the patient on consultation of the ophthalmologist with carrying out an oftalmoskopiya. Identification on eye day of a picture of "stagnant" disks of optic nerves testifies to hydrocephaly. Further diagnostic search demands connection of methods of neurovisualization: KT or MRT of a brain. They allow not only to reveal new growths, but also to determine its sizes and an arrangement that is necessary for planning of surgical treatment. In some cases, in particular at suspicion on the vascular nature of a tumor, the cerebral magnetic and resonant angiography is in addition carried out.
It is necessary to differentiate a cerebellum tumor from a cyst of a cerebellum, aneurism of vessels of a brain, cerebral abscess, an intracerebral hematoma, an ischemic stroke in the vertebro-bazilyarny pool.
Treatment of a tumor of a cerebellum
The main method of treatment is surgical. The question of expediency and volume of surgery is solved the neurosurgeon. Radical removal of a tumor is optimum. However it is not always possible because of germination of education in difficult anatomical structures, the IV ventricle. In such cases removal becomes the purpose of operation as also restoration of a normal likvorotsirkulyation is possible the bigger volume of tumoral fabric. For elimination of a sdavleniye of a brain trunk can the partial resection of an opening of an occipital bone and the 1st cervical vertebra is carried out. In some cases the shunting operations are applied to reduction of hydrocephaly. At sharp development of hydrocephaly with increase of stem symptomatology the puncture of ventricles of a brain and external ventrikulyarny drainage is shown.
Removal of a tumor is always followed by the histologic analysis of its fabrics. Definition of degree of a zlokachestvennost of a new growth has crucial importance for the subsequent tactics of treatment. Surgical treatment of malignancies is, as a rule, combined with beam and chemotherapy. In parallel with surgical symptomatic treatment — anesthetics, antiemetic, diuretic, sedative medicines, etc. is carried out.
Results of treatment of new growths of a cerebellum depend on their sizes, prevalence and a zlokachestvennost. In cases of good-quality nature of a tumor and its full removal the forecast favorable. Without treatment at the progressing increase in the amount of education the patient perishes from a sdavleniye of the stem structures which are responsible for breath and cardiovascular activity. During incomplete removal benign tumors of a cerebellum recur and in several years repeated operation is required. Malignant tumors predictively are adverse. Survival of patients after the carried-out surgical treatment in combination with adjyuvantny therapy makes from 1 to 5 years.