What are the diagnostic criteria for glioma

Generally, the diagnosis of glioma is based on the patient's age, gender, location of occurrence, etc., and the pathological type must be estimated. In addition, it is based on medical history and neurological examination. In addition, it is most necessary to do some auxiliary examinations to confirm the diagnosis. So what are the diagnostic criteria for glioma?

(1) Cerebrospinal fluid examination: The pressure of lumbar puncture is usually increased. For some tumors, such as those located on the brain surface or in the ventricles, the amount of cerebrospinal fluid protein may increase, the number of white blood cells may also increase, and some tumor cells may be found. However, for those with significantly increased intracranial pressure, lumbar puncture has the risk of promoting brain herniation. Therefore, it is generally only performed when necessary, such as when it is necessary to distinguish from inflammation or bleeding. For those with obvious pressure increase, the operation should be cautious and do not release too much cerebrospinal fluid. Mannitol drip is given after surgery and careful observation is required.

(2) Ultrasound examination: It can help determine the side and observe whether there is hydrocephalus. For infants, B-type ultrasound scans can be performed through the anterior fontanelle to show tumor images and other pathological changes.

(3) Electroencephalogram (EEG) examination: On the one hand, the EEG changes of gliomas are limited to changes in brain waves at the tumor site. On the other hand, there are general and widely distributed changes in frequency and amplitude. These are affected by the size of the tumor, infiltration, degree of brain edema, and increased intracranial pressure. Shallow tumors are prone to localized abnormalities, while deep tumors have fewer localized changes. In more benign astrocytomas, oligodendrogliomas, etc., localized delta waves are mainly manifested, and some epileptic waveforms such as spikes or sharp waves can be seen. Large glioblastoma multiforme can show widespread delta waves, which can sometimes only be determined on one side.

(4) Radioisotope scanning (Y-ray brain map): Tumors that grow quickly and have abundant blood supply have high blood-brain barrier permeability and high isotope absorption rate. For example, glioblastoma multiforme shows isotope concentration images, and there may be low-density areas in the middle due to necrosis and cysts. It is necessary to distinguish it from metastatic tumors based on its shape and multiplicity. More benign gliomas such as astrocytomas have lower concentrations, which are often slightly higher than the surrounding brain tissues. The images are not clear, and some may be negative findings.

(5) Radiological examination: including skull plain film, ventriculography, and CT scan. Skull plain film can show signs of increased intracranial pressure, tumor calcification, and displacement of pineal calcification. Ventriculography can show cerebral vascular displacement and tumor vascular conditions. These abnormal changes vary in different types of tumors in different locations, and can help locate and sometimes even determine the diagnosis. In particular, CT scans have the greatest diagnostic value. With intravenous contrast agent enhanced scanning, the positioning accuracy is almost 100%, and the qualitative diagnosis accuracy can reach more than 90%. It can show the location, range, shape, brain tissue reaction, and ventricle compression and displacement of the tumor. However, it still needs to be combined with comprehensive clinical considerations to make a clear diagnosis.

(6) Magnetic resonance imaging: It is more accurate than CT in diagnosing brain tumors, and the images are clearer. It can detect tiny tumors that CT cannot show. Positron emission tomography can produce images similar to CT, and can observe the growth and metabolism of tumors and distinguish benign from malignant tumors.