Presentation on theme: " Intracranial masses rapidly elevate the intracranial pressure because the skull is a closed compartment. Intracranial hypertension is most commonly."— Presentation transcript:
Intracranial masses rapidly elevate the intracranial pressure because the skull is a closed compartment. Intracranial hypertension is most commonly caused by tumor, hemorrhage, extensive stroke, trauma (and the edema accompanying these conditions), and hydrocephalus.
elevation of the head of the patient to 30°; hyperventilation (if the patient is intubated); osmotic diuretics, such as mannitol, given intravenously, in fractionated daily doses; rapid infusion is important for the generation of an effective osmotic gradient; saluretics, too, can transiently lower the intracranial pressure (caution: excessive use of diuretics can lead to dehydration and impairment of cerebral perfusion);
corticosteroids (e. g., dexamethasone, given intravenously) are used to counteract cerebral edema, particularly of the vasogenic type; they are mainly effective against peritumoral and inflammatory brain edema, less so against ischemic and traumatic brain edema, which are predominantly of the cytotoxic type.
The prevalence of brain tumors is roughly one per 10 000 to 20 000 individuals. Brain tumors are one of the more common causes of intracranial hypertension.
epileptic seizures (focal or generalized); mental changes (irritability, fatigability, impairment of memory and concentration); focal neurological and/or neuropsychological deficits depending on the location and type of the tumor; less commonly, headache (diffuse, at night as well as in the daytime) and occasionally nausea and vomiting; in some patients, further signs of intracranial hypertension
Progress more or less rapidly depending on the type and growth rate of the tumor. Malignant tumors typically present with a “crescendo” course, in which overt signs and symptoms arise soon after the onset of the illness, then progress steadily and rapidly. The manifestations of benign tumors, on the other hand, often progress slowly and insidiously, perhaps over many years.
Neuroimaging studies are essential but cannot always unequivocally identify the type of tumor. A definitive determination is often not possible until the tumor has been at least partly removed and the tumor tissue can be histopathologically examined.
Complete resection of the tumor is indicated whenever it is possible. The operability of brain tumors, however, depends largely on their size, location, histological grade, and relation to the surrounding brain tissue (infiltration vs. displacement). Not every tumor is neurosurgically accessible or fully resectable. Depending on the type of tumor, radiotherapy and/or chemotherapy may have to be used, either as the primary form of treatment, or as adjuvant therapy after a complete or incomplete surgical removal.
Astrocytoma Glioblastoma multiforme is themost malignant grade of astrocytoma (grade IV astrocytoma). This most common and most malignant tumor of the cerebral hemispheres usually arises between the ages of 40 and 60.
is a benign tumor usually seen in children and adolescents. On pathological examination, these tumors are often cystic and partly calcified. Ependymomas usually arise in the posterior fossa, most commonly near the fourth ventricle, and in the conusmedullaris of the spinal cord
focal (often cerebellar) neurological deficits intracranial hypertension secondary to compression of the CSF pathways and occlusive hydrocephalus
undifferentiated, highly malignant tumor characterized by rapid growth and rapidly progressive clinical manifestations Medulloblastomas usually arise from the roof of the fourth ventricle, sometimes filling the entire ventricle, and grow into the inferior portion of the vermis. They grow by infiltration and often metastasize via the CSF into the spinal canal ( drop metastases). gressive clinical manifestations.
usually found in the cerebral hemispheres, particularly the frontal lobes. It tends to arise between the ages of 40 and 50 and is usually a relatively well-differentiated tumor that grows slowly over the years and often becomes calcified
It usually presents with epileptic seizures; recurrent seizures affect 70% of patients with this type of tumor. Oligodendroglioma is mostly radioresistant and is best treated by radical resection. If this can be achieved, radiotherapy is usually not given. Nonetheless, apparently radical resection can be followed by tumor recurrence, which may not take place until years after surgery.
arise from the dura mater and are nearly always benign, well-demarcated lesions that displace rather than invade the adjacent neural tissue as they grow. These mesodermal tumors most often become clinically evident between the ages of 40 and 50.
Meningioma of the left cerebral convexity as seen by MRI after the intravenous administration of gadolinium.
account for about 15% of malignant brain tumors. The most common source of a brain metastasis is bronchial carcinoma in men and carcinoma of the breast in women, followed in both sexes by melanoma and renal cell carcinoma. Brain metastases usually produce extensive peritumoral edema and often cause epileptic seizures; thus, corticosteroids and antiepileptic drugs can be given for palliation. This usually brings a substantial, if only temporary, clinical improvement.
1. An introductions to clinical neurology: path physiology, diagnosis and treatment 1998 2. Parkinsons diseas and Movement Disorders. 1998 3. Neuroscience: Exploring the Brain. 1996 4. Anatomical Science. Gross Anatomy. Embryology. Histology. Neuroanatomy. 1999 5. Headache. Diagnosis and Treatment. 1993 6. Color Atlas of Human Anatomy Sensory organs And Nervous System (Werner Kahle) – 1986 7. Color Atlas of Neurology (Thieme 2004) http://medic.stup.ac.ru/institute/Anatomy/Lection10.htm http://www.erudition.ru/referat/ref/id.52081_1.html http://www.medicreferat.com.ru/pageid-58-1.html