Anatomy, Physiology, and Pathology

Anatomy, Physiology, and Pathology
The brain is divided into the cerebrum, diencephalon, cerebellum, and brainstem. The brain is the organ responsible for higher nervous activities, consciousness, and thinking in humans, serving as the supreme commander of all bodily systems and playing a crucial role in human life activities, social interactions, and productive labor. Most brain tumors are intracranial tumors, which can be classified as primary or secondary. Primary intracranial tumors arise from brain tissue, meninges, cranial nerves, pituitary gland, intracranial blood vessels, and embryonic tissues; secondary intracranial tumors, on the other hand, are metastases from other malignant tumors.
Based on the origin of the tumor tissue, brain tumors can be categorized as follows: ① tumors originating from neuroepithelial tissue; ② tumors originating from the brain itself and mesenchymal tumors associated with the meninges; ③ tumors originating from Schwann cells of the cranial nerves; ④ tumors originating from vascular components and tumor-like lesions; tumors originating from lymphoid tissue and hematopoietic tissue; tumors derived from germinal cells; tumors derived from anterior pituitary tissue; metastatic tumors; tumors formed due to developmental abnormalities and tumor-like lesions.
There is also a classification based on pathological characteristics combined with clinical manifestations, dividing brain tumors into: ① gliomas, accounting for 45% of all brain tumors and ranking first; ② meningiomas, accounting for about 15% of brain tumors; ③ pituitary adenomas, with a newly reported incidence rate of 15%–20%, mostly located in the anterior pituitary; ④ schwannomas, accounting for about 10% of intracranial tumors; congenital tumors, accounting for about 10% of intracranial tumors; other rare tumors such as lipomas, lymphomas, and melanomas; intracranial metastatic tumors, accounting for about 12% of intracranial tumors, with nasopharyngeal carcinoma being the most common type that invades the skull.
Secondly, Diagnosis and Treatment (---) Clinical Diagnosis
Brain tumors refer to tumors that originate within the skull, with clinical manifestations primarily consisting of neurological symptoms such as headache, vomiting, and visual impairment.
The main clinical symptoms include: ① symptoms of increased intracranial pressure: Common symptoms of elevated intracranial pressure include headache, vomiting, papilledema, visual disturbances, and consciousness disorders; ② epileptic seizures (stimulatory symptoms): Almost any type of epilepsy can occur in patients with brain tumors, with focal seizures, secondary grand mal seizures, and temporal lobe epilepsy being the most common; ③ systemic disorders (destructive symptoms): These can be caused by metabolic disorders or endocrine imbalances, leading to abnormalities in growth, body shape, and sexual function. They can also result from the direct effects of hormones secreted by functional (secretory) pituitary tumors, causing gigantism, acromegaly, galactorrhea, infertility, menstrual irregularities, or from the indirect effects of brain tumors compressing the brain, leading to metabolic decline. Local neurological dysfunction: Patients may experience localized neurological symptoms, such as weakness or clumsiness in one limb, abnormal sensations in one limb, unsteady gait, difficulty speaking, personality changes, visual field defects, or focal epileptic seizures.
Combined with skull X-ray examination showing increased intracranial pressure, typical findings include separation of cranial sutures, increased sulcal markings, decalcification, absorption, or destruction of the posterior clinoid process and sella turcica, and mild enlargement of the sella turcica. CT scans are the most valuable tool for diagnosing brain tumors, with a positive diagnostic rate of 96%. They can clearly show the location, shape, size, and extent of the tumor. CT can visualize brain tumors larger than 1 cm in diameter, often appearing as high-density lesions. After contrast injection, some tumors exhibit enhancement, which aids in diagnosis. MRI has higher soft-tissue resolution than CT, allowing for multi-directional direct imaging and arbitrary multi-layer scanning of any part of the skull, capable of distinguishing lesions smaller than 5 mm. Therefore, MRI is even more valuable than CT in diagnosing intracranial tumors. Cerebral angiography can determine the location of brain tumors, with abnormal pathological blood vessels serving as reference points for qualitative diagnosis. Cerebral angiography is particularly valuable for diagnosing vascular lesions and the blood supply to tumors. PET-CT, by measuring glycolysis levels, can differentiate tumor tissue from normal tissue and display and evaluate blood flow within the tumor lesion, metabolic status, malignancy level, and histological grading. It is also suitable for assessing the effectiveness of surgery, radiotherapy, and chemotherapy, detecting early tumor recurrence, estimating prognosis, and thus aiding in treatment planning and evaluation of treatment outcomes. EEG and auditory brainstem evoked potentials have high localization value for tumors or lesions on the convex surface of the cerebral hemispheres, but are difficult to use for diagnosing midline, deep-hemisphere, and subdural tumors. EEG is more sensitive than routine EEG in localizing intracranial tumors. Auditory brainstem evoked potential recordings can be used to determine the site of brainstem dysfunction.
(2) Western Medical Treatment 1. Surgical Treatment
For primary tumors, surgical resection is performed to remove as many tumor cells as possible, aiming to completely eliminate the tumor and prevent recurrence, which remains the most common treatment approach. For benign tumors, the probability of complete surgical removal is relatively high, and patient survival rates are also higher, such as astrocytomas of the cerebrum or cerebellum, craniopharyngiomas, and choroid plexus tumors of the ventricles, which do not require radiation or chemotherapy and have low recurrence rates, though regular follow-up CT or MRI scans are necessary. For general malignant brain tumors, such as degenerative astrocytomas, medulloblastomas, ventricular meningiomas, and teratomas, those that can be completely or nearly completely removed have better prognoses, but must also undergo radiation therapy or chemotherapy to control tumor growth.
2. Chemotherapy
Currently, commonly used chemotherapeutic drugs mainly include nitrosoureas and temozolomide, either used alone or in combination. The PCV regimen (procarbazine + vincristine + CCNU), which has relatively certain efficacy, is mainly used for oligodendrogliomas; temozolomide is the first-line chemotherapy for gliomas; platinum-based regimens (such as cisplatin, VP-16/VM-26, and bleomycin combinations) are used for intracranial germ cell tumors.
3. Molecular Targeted Therapy
In recent years, with the rapid development of tumor molecular biology technology and increasing understanding of tumors at the molecular level, various targeted drugs have entered the research on gliomas. For example, the U.S. FDA has approved bevacizumab as a single agent or in combination with temozolomide, CPT-11, and other drugs to treat recurrent gliomas and alleviate symptoms, but does not recommend using these drugs for initial treatment of gliomas.

<!-- translated-chunk:2/27 -->

4. Radiation Therapy
   Radiation therapy typically lasts about 4 to 8 weeks, with the radiation field size and dose determined based on the tumor's pathological diagnosis, degree of differentiation, and imaging findings. For many malignant tumors and deep-seated benign tumors that cannot be safely resected, radiation therapy is an effective treatment option. Currently, radiation therapy has advanced to conformal or stereotactic techniques, including linear accelerator radiotherapy, gamma-ray stereotactic radiosurgery, and CyberKnife, among others. However, some malignant brain tumors still require extensive whole-brain radiation or total cranial and spinal irradiation.

5. Interventional Therapy
   Since brain tumors, regardless of their cell type, generally have a rich blood supply with large feeding arteries, embolization therapy is particularly suitable. However, due to the abundant blood supply, perfusion chemotherapy is used less frequently. Embolization is often performed before surgery to significantly reduce the tumor's blood supply, thereby decreasing intraoperative bleeding, facilitating complete tumor resection, and ensuring relatively high safety. Embolization can also shrink the tumor, alleviate certain clinical symptoms, and serve as a good palliative treatment for patients without surgical indications. For gliomas and metastatic brain tumors, perfusion chemotherapy is more appropriate.

III. Professor Pei Zhengxue’s Thinking Method
Professor Pei Zhengxue believes that the head is the convergence point of all yang energies, where the three yang meridians of the hands and feet intersect at the top of the head, hence the name "Baihui acupoint" at the crown. The head belongs to yang while the brain belongs to yin; when yang qi is strong, yin pathogens cannot invade, but when righteous qi is weak, pathogenic factors take advantage of the weakness to enter. When pathogenic factors invade the head, cold energy reaches the marrow, ascends to the brain network, resulting in what is called "excessive yin," which causes headaches, dizziness, vomiting, and even fainting. The crown is located high and belongs to yang, making it most susceptible to wind-pathogen and fire-pathogen-induced disorders of the head. The brain is the sea of marrow; under normal circumstances, clear qi rises while turbid qi descends. When righteous qi is weak, clear qi cannot rise and turbid qi cannot descend, leading to stagnation in the extraordinary fu organs, causing yin-turbidity to accumulate in the brain and form tumors. Dysfunction of the zang-fu organs is mainly due to liver-spleen dysfunction. Therefore, the internal causes of brain tumors include spleen-kidney yang deficiency or liver-kidney yin deficiency, while external factors such as cold qi and pathogenic toxins invading the body lead to phlegm-dampness and blood stasis. Consequently, he believes that blood stasis, spleen-kidney yang deficiency, liver-kidney yin deficiency, phlegm-dampness obstruction, and liver wind stirring are all related to the occurrence and development of brain tumors. The overall principle of TCM treatment for brain tumors should be to treat the root cause when conditions are stable and address the symptoms when they are acute. During attacks, the focus is on resolving phlegm, opening orifices, detoxifying and removing blood stasis, and calming wind to reverse upward flow; in daily life, the emphasis is on reinforcing righteous qi and consolidating the root, nourishing the kidneys and filling the marrow to treat the root, and employing a combination of tonifying and purging methods. When using herbs to tonify the liver and kidneys, preference is given to mild, non-greasy formulas. Xuefu Zhuyu Tang, Tongqiao Huoxue Tang, Sanjia Erdi Tang, and the Lanzhou Formula are commonly used basic prescriptions in Professor Pei Zhengxue’s clinical practice.

IV. TCM Syndrome Differentiation and Formulas

1. Qi Stagnation and Blood Stasis
   Symptoms: Headache and head distension, dull complexion, dry mouth and shortness of breath, blurred vision, cyanosis of lips, dark purple tongue, and fine, stringy pulse. Treatment: Activating blood circulation and removing blood stasis.
   Formulas: Xuefu Zhuyu Tang and Tongqiao Huoxue Tang with added ingredients: Dang Gui 10g, Sheng Di 12g, Tao Ren 10g, Hong Hua 6g, Zhi Ke 10g, Chi Shao 10g, Chai Hu 12g, Chuan Xiong 10g, Niu Xi 15g, Gan Cao 6g, Jie Geng 12g, Cong Bai 5g, Shi Chang Pu 10g, Yu Jin 10g, Yuan Zhi 10g, and Shui Zhi 5g (to be decocted in two doses). Decoct in water and take one dose per day.

2. Spleen-Kidney Deficiency (Both Deficiencies)
   Symptoms: Dizziness and headache, vertigo and hearing loss, dry eyes, visual impairment, lack of spirit, soreness and weakness in the lower back and knees, shortness of breath and reluctance to speak, fatigue and weakness, pale tongue with white, moist coating, and fine, weak pulse. Treatment: Strengthening the spleen and kidneys while activating blood circulation and removing blood stasis.
   Formulas: Lanzhou Formula with added ingredients: Tai Zi Shen 15g, Dang Shen 15g, Bei Sha Shen 15g, Ren Shen Xu 15g, Sheng Di 12g, Shan Yao 15g, Shan Zhu Yu 20g, Gui Zhi 12g, Bai Shao 15g, Mai Dong 10g, Wu Wei Zi 5g, Go Ji 15g, Lu Jiao Jiao 10g (to be dissolved), Tu Si Zi 15g, Fu Xiao Mai 30g, Ma Qian Zi 1 piece (fried). Decoct in water and take one dose per day.

3. Phlegm-Dampness Accumulating in the Brain
   Symptoms: Headache and head distension, limb numbness, hemiplegia, nausea and vomiting, slurred speech, blurred vision, greasy or thin coating, and fine, stringy or slippery pulse. Treatment: Drying dampness and transforming phlegm, softening hard masses and dispersing knots.
   Formulas: Sanjia Erdi Tang with added ingredients: Bie Jia 15g (decocted first), Long Gu 15g (decocted first), Mu Li 15g (decocted first), Gui Ban 15g (decocted first), Nu Zhen Zi 15g, Han Lian Cao 15g, Sheng Di 15g, Xuan Fu Hua 15g, Bai Shao 15g, Niu Xi 15g, Gu Su Bu 15g, Dan Shen 15g, Hong Hua 15g, Ci Shi 15g (decocted first), Zhu Sha 15g (decocted first), Zhu Sha 2g (dissolved in warm water), Xia Ku Cao 15g, Shan Ci Gu 15g, Hai Zao 15g, Kun Bu 15g, San Leng 15g, E Zhu 15g, Ban Xia 15g, Zhu Ru 15g, Quan Ke 15g, Gan Cao 6g, Fu Ling 15g, Suan Zao Ren 15g, Yuan Zhi 15g, Wu Wei Zi 15g. Decoct in water and take one dose per day.

V. Analysis of Professor Pei Zhengxue’s Prescriptions for Brain Tumors
Basic formula: Sanjia Erdi Tang: Bie Jia 15g (decocted first), Long Gu 15g (decocted first), Mu Li 15g (decocted first), Gui Ban 15g (decocted first), Nu Zhen Zi 15g, Han Lian Cao 15g, Sheng Di 15g, Xuan Fu Hua 15g, Bai Shao 15g, Niu Xi 15g, Gu Su Bu 15g, Dan Shen 15g, Hong Hua 15g, Ci Shi 15g (decocted first), Zhu Sha 15g (decocted first), Zhu Sha 2g (dissolved in warm water), Xia Ku Cao 15g (dissolved in water), Shan Ci Gu 15g, Hai Zao 15g, Kun Bu 15g, San Leng 15g, E Zhu 15g, Ban Xia 15g, Zhu Ru 15g, Quan Ke 15g, Gan Cao 6g, Fu Ling 15g, Suan Zao Ren 15g, Yuan Zhi 15g, Wu Wei Zi 15g. This formula is used by the Hunan Provincial Institute of Traditional Chinese Medicine for treating intracranial tumors. Based on the etiology and pathogenesis of brain tumors, the treatment aims to: resolve phlegm and cleanse turbidity to eliminate accumulation, open up depression and regulate qi to unblock the channels; or nourish the kidneys and fill the marrow to calm wind; or detoxify and remove blood stasis to disperse knots. This formula combines the functions of San Jia, Ci Shi, and Zhu Sha to calm wind, settle the mind, and tranquilize the spirit; Er Zhi, Sheng Di, Niu Xi, Bai Shao, Xuan Fu Hua, and Gu Su Bu to nourish the kidneys and liver and tonify yin; Dan Shen and Hong Hua to activate blood circulation and remove blood stasis; Xia Ku Cao, Shan Ci Gu, Hai Zao, Kun Bu, San Leng, and E Zhu to regulate qi, unblock the channels, and transform phlegm and disperse knots. This formula integrates the effects of dissolving phlegm and dispersing knots, activating blood circulation and removing blood stasis, nourishing the liver and kidneys, and stabilizing yang, making it a comprehensive solution for treating brain tumors. It serves as the basic prescription for treating brain tumors, applicable to all cases of space-occupying lesions in the brain, with adjustments made according to individual conditions.
Tongqiao Huoxue Tang: Originates from “Yilin Gaicuo.” Contains Chi Shao 10g, Chuan Xiong 6g, Tao Ren 10g (ground into paste), Red Dates 7 pieces (pitted), Hong Hua 10g, Old Scallions 3 stalks (chopped), Fresh Ginger 9g (chopped), Musk 0.15g (dissolved in water), and Yellow Wine 250ml. In this formula, Chi Shao and Chuan Xiong activate blood circulation, Tao Ren and Hong Hua unblock the channels, scallions and ginger invigorate yang, musk opens the orifices, and yellow wine unblocks the channels. The addition of red dates moderates the pungent and aromatic nature of the other ingredients. Notably, musk has a pungent, warming nature and is specifically used to open blocked orifices, detoxify and activate blood circulation (modern medicine suggests that musk contains ketones and other components that can stimulate the central nervous system, respiratory system, and cardiovascular system, with certain antibacterial, glandular secretion-promoting, and uterine-stimulating effects). Therefore, it is used as the main ingredient; combined with ginger, scallions, and yellow wine, it further enhances the ability to unblock channels and facilitate the flow of qi and blood, allowing Chi Shao, Chuan Xiong, Tao Ren, and Hong Hua to better exert their effects of activating blood circulation and unblocking the channels.