What Are the Different Types of Brainstem Surgery?

Glioblastomas are more common in brainstem tumors, followed by vascular reticuloma and cavernous hemangioma. Glioma is more common in astrocytoma and glioblastoma multiforme. Glioblastomas mostly grow infiltratingly in the brainstem and develop along the nerve axis in two directions, usually the pontine is the most common site. Astrocytomas mostly occur in adolescents; ependymal tumors are more common in middle-aged people and originate from the ependyme of the base of the four ventricles or the central cervical spinal canal. Angio reticuloma mostly occurs in adults, and usually develops from the dorsal side of the medulla oblongata to the four ventricles. It can also grow completely in the medulla oblongata, and can also occur at the junction of the medulla oblongata or dorsal side of the cervical spinal cord. ; Others can occur in the pith and fundus. Cavernous hemangioma usually occurs in middle age, and is more common in the pontine, followed by the midbrain and the medulla oblongata.

Basic Information

English name: Tumor of brain stem
Visiting department: Neurology

Common locations: Pontine
Common symptoms: Headache, dizziness, restlessness, squinted eyes, double vision, crooked mouth, numbness of the face, etc.

Clinical manifestations of brain stem tumors

The clinical manifestations of tumors growing in the brainstem are closely related to the location, type and malignancy of the tumor. The most common symptoms and signs are multiple neurological damage, pyramidal tract signs, and cerebellar signs. Patients with advanced disease may show increased intracranial pressure.

Tumor in the midbrain

Rarely, patients may have symptoms of oculomotor nerve palsy such as drooping eyelids. Because the tumor develops to the dorsal side, causing narrowing or atresia of the fourth ventricle or midbrain aqueduct, early symptoms of increased intracranial pressure can occur. Patients often have headaches, dizziness, restlessness, and nausea and vomiting. With tumor compression and place-occupying effects, typical clinical syndromes of midbrain damage can be shown.

Pontine tumor

Symptoms such as esotropia, diplopia, crooked mouth, facial numbness, etc. are often present in the abductor nerves, facial nerves, or trigeminal nerves; motor, sensory, and cerebellar symptoms are also present. The increased intracranial pressure of the tumor at this site appeared later. Because the tumor mostly showed invasive growth, the symptoms and signs were more complicated.

3. bulbar tumor

There are many obvious symptoms and signs, such as bilateral medullary damage, which can be manifested as bilateral posterior cerebral nerve palsy. Patients have swallowing, coughing, hoarseness, tongue muscle paralysis and atrophy. With the development of the tumor, when the pyramidal tract of the ventral side of the brainstem is involved, cross paralysis occurs, which is manifested as cerebral palsy on the same side and decreased muscle strength of the opposite limb, increased muscle tone, hypertenoid reflex, and pathological signs. Positive. Paralysis of the limb usually begins with one lower limb and then progresses to the upper limb of that side. However, the early manifestations of some slow-growing tumors are often not obvious. In the early stage of medullary tumors, there is generally no symptoms of increased intracranial pressure. However, intracranial pressure can occur when bleeding or cystic changes in the tumor affect the circulation of the cerebrospinal fluid. Therefore, for patients with multiple cerebellar nerve damage or progressive cross paralysis, accompanied by pyramidal tract signs, the possibility of tumors at this site should be considered. In addition, cerebellar signs are not uncommon, manifested as gait instability, positive signs with closed eyes, nystagmus and ataxia. In the later stage, bilateral cerebral nerve involvement and pyramidal tract signs may occur. Some patients may also have a forced head position due to tumor invasion and the medulla oblongata and upper cervical spinal cord.

4. Malignant diffuse tumor

Generally, the disease course is short, the condition develops rapidly, and there are signs of severe brainstem damage, including manifestations of cerebral palsy. However, early signs of increased intracranial pressure are rare, and most often occur in the late stage of the disease.

5. Expansion tumor

Neurological impairment usually progresses slowly, and in some cases the signs of focal lesions of the brainstem are minimal. Midbrain tumors can have a variety of different limb spasms.

Brain stem tumor examination

Brainstem auditory evoked potential

Brainstem auditory evoked potentials combined with other auditory function tests are helpful for accurate diagnosis of tumor sites.

2.CT scan

Generally, brain stem glioblastomas are more common with low-density focus and swelling of the brain stem. A few have equal density or slightly higher density shadows, and the cysts are rarely changed. It can invade the optic mound upwards and can develop backward to the pontine and cerebellum. hemisphere. Enhanced scans can have uneven or circular enhancement. Cavernous hemangioma is uniformly high density in the acute phase of bleeding; low density in the subacute and chronic phases. Ependymal tumors are high-density and can be enhanced. Angio reticuloma is high density and significantly enhanced. The nodules are high-density in the shape of a ring, with a low density in the center, which can be significantly strengthened. To distinguish between brainstem tumors and brainstem tumors, CT scans of the cerebellar angiography can be performed if necessary. CT scan can classify brain stem tumors into three types: type is an intensive lesion with low density lesions; type is diffuse enhancement; type is ring enhancement. Among them, type is more common, and types and are less common.

3.MRI examination

Brain stem glioblastomas often show long T ₁ and long T ₂ signal changes, mostly without cystic changes or bleeding, generally with unclear boundaries and irregular morphology. Most tumors are enhanced by Gd-DTPA. Compared with CT scan, because of its multi-view imaging and no skull base artifact interference, it can more clearly show the lesion location and extent. Cavernous hemangiomas are uniformly high-density on the T ₁ WI and T ₂ WI in the acute phase of bleeding, with clear outlines and often round shapes. They are also high in the subacute and chronic T ₁ Wl and T ₂ W1. density. Ependymal tumors are long T ₁ and long T ₂ , which develop outside the brainstem to the fourth ventricle or cerebellar pontine angle. Angio reticuloma is long T ₁ and long T ₂ with a spherical shape located behind the medullary medulla. The nodules are high-density rings, which are more pronounced after strengthening, and low-density in the middle.

Brain stem tumor diagnosis

Most patients with brainstem tumors have a slow onset, headaches are not obvious, and cerebral nerve palsy gradually appears, and abductor nerve palsy is more common. Later, facial paralysis, difficulty swallowing, pronunciation disorders, pyramidal tract damage, gait instability and Ataxia, etc. Typical cases often show cross paralysis. CT scans and MRI examinations can help physicians determine the type of tumor growth.

Brain stem tumor treatment

General treatment

Strengthen support and symptomatic treatment to control infection and maintain nutrition and water-electrolyte balance. For those with medullary bulbar palsy, dysphagia and respiratory failure, nasal feeding, tracheotomy, artificial assisted breathing, etc. should be used. Patients with increased intracranial pressure should be given dehydrating agents and corticosteroids to improve neurological symptoms.

2. Surgical treatment

Brainstem tumors were previously considered to be the "forbidden area" of surgery, because the brainstem has many nerve nucleus clusters, conductive bundles, and reticular structures in a small area. Brain stem tumors are mostly gliomas that grow invasively. Therefore, the operation is difficult, and it is easy to cause important structural damage in the brain stem. The disability and the mortality are high, and the prognosis is poor. In recent years, with the rapid development of microneurosurgical technology, the surgical effect of brain stem tumors has improved significantly. Although there is still a greater risk for brainstem tumor surgery, for more localized, nodular or cystic, well-differentiated tumors, surgical resection should be actively used, and the prognosis is better. For benign brainstem tumors, radical resection can be used to obtain the curative effect.

The purpose of surgery for this type of tumor is to: clarify the nature of the tumor; restore cerebrospinal fluid circulation; benign tumors should strive for total or subtotal resection, such as astrocytoma grade , vascular reticuloma or tuberculosis It is expected that the total resection will have a curative effect; Malignant tumors should also strive for total resection, or complete partial resection and partial resection to achieve a sufficient internal decompression effect; Glioblastoma is supplemented with radiotherapy and chemotherapy after surgery Can extend the survival of patients.

3. Radiotherapy

For a long time, radiation therapy has been considered as the main method for treating brain stem tumors. Brain stem tumors that can be diagnosed based on clinical and imaging examinations can be treated with radiation. 70% to 90% of patients have improved symptoms and signs after receiving the first course of radiation treatment. Generally, the total radiation is 50 ~ 55Gy (5000 ~ 5500rad), and the course of treatment is 5 ~ 6 weeks. Those who are higher than 6Gy are likely to cause brain radiation damage. Radiotherapy can be performed alone or in conjunction with post-operative treatment.

4. Chemotherapy

Commonly used drugs are nimustine (ACNU), carmustine (BCNU), cyclohexyl nitrosourea (CCNU), etc., which are rationally used according to the patient's condition, age and weight.

Brain stem tumor prognosis

The prognosis of brain stem tumors is related to many factors: tumor location, pathological properties, treatment options, and so on. Tumors in the midbrain region are relatively better than pontine tumors; grade - astrocytomas have a better prognosis than glioblastoma multiforme. The CT scan showed a better prognosis for type I and a worse prognosis for type III. Tumor size is also related to prognosis. The larger the tumor, the worse the prognosis.