Brain trunk tumors
Brain trunk tumors — new growths of the bridge, an average and a medulla. Are shown by many variable symptoms as that: squint, disorder of hearing, , poperkhivaniye, front asymmetry, diskoordination and violation of gait, dizziness, lower or top monoparesis, hemiparesis, likvorno-gipertenzionny syndrome. Brain MRT acts as the only method of diagnostics of new growths of a trunk informative today allowing to define existence of a tumor, its character and prevalence. The possibility of surgical treatment exists only in 20% of cases of stem tumors. At other patients radio - and chemotherapy is applied. The forecast is adverse, the bulk of patients perishes in the first year from a disease demonstration.
Brain trunk tumors
The tumor of a trunk of a brain meets mainly at children's age. Children up to 15 years make about 70% of the patients operated with this diagnosis. The peak of occurrence falls on the 5-6th year of life. Among cerebral tumors stem new growths occupy 10-15% children, the vast majority (90%) of them is presented by brain gliomas. Localization of new growths in structures of a brain trunk is distributed as follows: bridge tumors — 40-60%, midbrain tumors — 15-20%, medulla tumors — 20-25%. Difficulties of early diagnostics and treatment, incidence at children's age, a high lethality — all these factors put stem tumors in a row of the most urgent problems of oncology, neurology, pediatrics and neurosurgery.
Pathogenetic mechanisms and morphology
The trunk of a brain carries out a set of tasks which general result comes down to integration of work of all departments of TsNS with peripheral NANOSECOND for regulation of the main functions of an organism: movements, breath, warm activity, vascular tone, etc. Similar interaction is reached at the expense of the carrying-out ways going from a cerebellum, brain bark and shares of a brain through a trunk to a spinal cord. Besides, in a trunk of a brain kernels of the III-XII pairs of craniocereberal nerves settle down. The vital value of a trunk is caused by existence in it of the cardiovascular and respiratory centers.
The variety both the nuclear, and carrying-out structures of a cerebral trunk causes big variability of symptoms of its defeat. However, unlike cerebellum tumors, the brain trunk tumor seldom is followed by the liquorodynamic frustration leading to hydrocephaly. An exception are only the midbrain new growths which are localized near a silviyevy water supply system.
In the morphological plan approximately in half of cases the tumor of a trunk of a brain represents good-quality, but diffuzno extending, astrotsity. From 15 to 30% of stem new growths make astrotsitoma of malignant character — a glioblastoma and an anaplastichesky astrotsitoma. A gemangioblastoma, an ependimoma, a medulloblastoma, the ganglioglioma, an astroblastoma, melanoma metastasises, etc. are more seldom observed.
Classification of stem new growths
Division of new growths of a trunk by the localization principle is standard. According to it allocate primary and secondary and stem tumor of a trunk of a brain. The first originates directly in stem fabric, it can be intra stem and ekzofitno-stem. The second grows from covers of the IV ventricle and tissues of a cerebellum, then extending in a brain trunk. Allocate also parastem tumors which classify on closely growing together with a trunk and deforming a trunk.
Specialists of institute of neurosurgery of the Russian Academy of Medical Science developed classification of stem new growths depending on type of their growth. In it allocate tumors of nodal type, diffusion and infiltrative. Nodal new growths are expansive growing, delimited from brain fabrics by the capsule from densely intertwining shoots of tumor cells, quite often having a cystous component. The diffusion tumor of a trunk of a brain meets in 80% of cases. Its elements are scattered among brain fabric so that borders of a tumor are not defined even microscopically. At the same time elements of stem fabric appear dezintegrirovana and partially destruktirovanna. The most rare is the infiltrative tumor of a trunk of a brain. Macroscopically it looks as education with well expressed borders, for as received the name "pseudo-nodal tumour". At a microscopic research the infiltrative nature of growth of a new growth with destruction of the nervous tissue adjoining to it is found.
Brain trunk tumor symptoms
Existence in a trunk of a brain of a set of structures (kernels of ChMN, the carrying-out ways, the nervous centers) causes big variety of symptoms of its defeat. It should be noted that at children at the expense of great compensatory opportunities for nervous tissue the tumor of a trunk of a brain can have a long inapparantny current. Disease debut symptoms in many respects depend on an arrangement of a stem new growth, and a further current — on type of tumoral process.
Developing of the central paresis of a facial nerve, the shown asymmetry of the person, a nistagm, squint, a poshatyvaniye is possible during the walking, a diskoordination of movements, dizzinesses, a tremor of hands, relative deafness, difficulties when swallowing and poperkhivaniye. In certain cases there is a muscular weakness (paresis) in a hand, a leg or a half of a body. In process of progressing of tumoral process increase of the specified symptoms and accession of new manifestations is observed. In the majority of clinical cases symptoms of hydrocephaly (a headache, nausea, vomiting) appear in later stages of a disease. Death of patients happens because of violations in work of the cardiovascular and respiratory centers of a brain trunk.
The preliminary diagnosis is established by the neurologist according to the anamnesis and clinical neurologic inspection of the patient. However the leading value in diagnostics belongs to the neurovisualizing researches — brain KT, MCKT and MPT. Among them the most informative is MRT strengthened by introduction of contrast substance. Resolution of MRT allows to reveal the tumors of the small size which are not visualized when carrying out KT. MRT gives the chance to assume histologic type of a tumor, to define presence and prevalence of an ekzofitny tumoral component, previously to estimate the nature of growth of a new growth and extent of infiltration of brain fabric. All these data are extremely necessary for assessment of an opportunity and expediency of surgical treatment.
The analysis of MRT-data is carried out with determination of density of education, a contrast accumulation form (uniform, ring-shaped, uneven), etc. parameters. At diffusion and infiltrative tumors of border of contrasting often do not correspond to the existing new growth sizes. Distribution of changes of a MP signal (mainly in T2 mode) on zones where contrast accumulation is not observed is possible. Similar areas can be a zone of hypostasis of brain fabric, a zone of its infiltration or that and another at once. Identification during MRT of implantation metastasises in walls of ventricular system and in spinal subarakhnoidalny spaces indicates tumor belonging to primitive neyroektodermalny educations.
According to neurovisualization it is possible to differentiate a brain trunk tumor from multiple sclerosis, stem encephalitis, demiyeliniziruyushchy encephalomyelitis, an ischemic stroke, an intracerebral hematoma, a lymphoma and so forth.
Treatment of stem new growths
In the opinion existing earlier any tumor of a trunk of a brain was represented by the infiltrative education diffuzno sprouting stem structures and thereof not subject to surgical removal. Now it became clear that besides diffuzno the extending new growths (which, unfortunately, the majority) in a trunk the delimited nodal tumors which removal is quite possible meet. In such cases consultation of the neurosurgeon is necessary for the patient for the solution of a question of expediency of surgical treatment. The dominating principle of removal of a tumor of a trunk — the maximum rezetsirovaniye of its fabrics at the minimum traumatizing brain structures. In this plan are laid great hopes on development of the microneurosurgical technology of operations.
Unfortunately, about 80% of new growths of a trunk are inoperabelny. Concerning them, and also in quality before - and postoperative therapy chemotherapeutic and beam influence can be applied. The chemotherapy is carried out by a combination of various cytostatic medicines. Radiation therapy allows to achieve symptomatic improvement from 75% of patients. However already in early terms after the carried-out treatment at many of them the lethal outcome is stated. A little the radiotheraphy technique with increase in the general dose of radiation allowed to increase longevity of children with stem tumors. At 30% of children life expectancy after radiotheraphy made 2 years.
The stereotaksichesky radio surgery acts as an innovative method of treatment of stem new growths today. Carrying out 2 types of procedures is possible: gamma knife and cyber-knife. In the first case a helmet is put on the head of the patient, radiation is carried out from a set of sources so that their beams met in one point, the corresponding localization of a tumor. The effect is reached due to total influence of sources of radiation, at the same time radiation of healthy brain fabrics is minimum as each beam bears small gamma energy. The procedure of impact on a tumor by means of a cyber-knife is more automated. The robotic device itself directs radiation to a tumor arrangement zone, considering at the same time its movements in connection with breath or the movements of the patient. However so far these methods are effective generally concerning benign tumors up to 3-3,5 cm in size.
Good-quality new growths of a brain trunk, thanks to the slow growth, can exist up to 10-15 years, having a subclinical current more often. But, unfortunately, the majority of tumors of this area have malignant character and cause a lethal outcome within several years or months from a symptomatology debut. The carried-out treatment in such cases only for a while prolongs life of patients.