Fourth ventricle tumor
Introduction
Introduction to the fourth ventricle tumor The fourth ventricle is located in the posterior cranial fossa, and its shape is like a tip-up tent. The apical part is composed of anterior and posterior medullary sails, the dorsal side is cerebellum, and the ventral side is pons and medulla. The fourth ventricle is connected to the midbrain aqueduct, and the lower end is connected to the subarachnoid space by a side hole. The position is equivalent to the cerebral angle of the cerebellar bridge, and the middle hole is connected with the occipital pool. The fourth ventricle receives cerebrospinal fluid from the third ventricle through the midbrain aqueduct, and flows through the mesopores or lateral orifices into the subarachnoid space, and then enters the venous system through the arachnoid granules. The bottom of the fourth ventricle is rhomboid, and the nucleus of the pons and medulla are more adjacent to this, such as the sublingual nucleus of the medulla, the dorsal nucleus of the vagus nerve, the cochlea and the vestibular nucleus; the facial nucleus of the pons, the trigeminal nucleus and Trigeminal sensory nucleus, etc. The fourth ventricle tumor refers to a disease in which the tumor grows in the fourth ventricle located in the posterior cranial fossa, causing clinical symptoms such as intracranial hypertension. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: optic atrophy
Cause
Fourth ventricle tumor cause
The cause of this disease is the same as that of other parts of the body. It is still not fully understood. A large number of studies have shown that there are oncogenes on the chromosomes of the cells and various congenital causes can cause them to occur. Possible factors for inducing this disease are: genetic factors. , physical and chemical factors as well as biological factors.
When a tumor occurs in the fourth ventricle, the cerebrospinal fluid circulation is first blocked. When the tumor spreads to the periphery of the cerebral ventricle or the surrounding tissue is compressed, the corresponding clinical symptoms are generated, that is, the corresponding clinical symptoms are generated, mainly the symptoms of cranial nerve damage. The tumor originating from the fourth ventricle is mostly choroidal papilloma. The tumor originating from the ventricular wall not only invades the fourth ventricle, but also often invades the brain stem or cerebellum, such as ependymoma and hemangioblastoma. The tumor at the top of the ventricle is mostly in the crotch of the cerebellum, and the medulloblastoma is mostly present. The fourth ventricle tumor mostly occurs in children and young people.
Prevention
Fourth ventricle tumor prevention
Primary prevention refers to the promotion of health and the reduction of risk factors. This first line of defense is to promote the healthy lifestyle of the general population and reduce the harmful factors in the contact environment, so as to completely avoid the occurrence of cancer. In addition to preventing air, water, food and workplace carcinogens and suspected carcinogens, lifestyle changes in smoking, drinking and other bad habits are primary prevention.
Complication
Fourth ventricle tumor complications Complications optic atrophy
1. The disease can cause optic nerve atrophy and cause blindness.
2. On the basis of chronic occipital foramen magnum, an acute attack occurs, resulting in a sharp increase in intracranial pressure, a change in vital signs in the medulla oblongata, and death from respiratory and circulatory failure.
Symptom
Symptoms of the fourth ventricle tumor common symptoms coma increased intracranial pressure forced obsessive head hearing loss nausea hiccups sensory disturbances hoarse gait instability cerebral palsy
1. Increased intracranial pressure
The course of the fourth ventricle tumor is generally short, and intracranial hypertension can occur in the early stage. This is because cerebrospinal fluid circulation is caused by obstruction of the tumor. The initial symptoms of almost all patients are caused by increased intracranial pressure. Headache, accompanied by nausea and vomiting, some patients have dizziness at the same time, more headache than the posterior occipital region, headache caused by the fourth ventricle tumor, vomiting and dizziness are more volatile, showing intermittent episodes, can be head and Induced by changes in body position, the patient often maintains a special posture, the so-called compulsive head position, the patient can flex the head forward or backward, or can flex to both sides to reduce the onset, a small number of patients often Changes in head position and position cause the nerve nucleus at the end of the fourth ventricle to be stimulated, resulting in corresponding clinical symptoms such as dizziness, headache, vomiting, diplopia, nystagmus and changes in vital signs, and even coma, intraventricular The tumor has a large degree of activity. When the midbrain aqueduct, mesopores and lateral holes are not blocked, the patient does not have symptoms of increased intracranial pressure such as headache and vomiting; when the head position or body position changes Because the tumor moves in the ventricles and suddenly blocks the cerebrospinal fluid circulation pathway, the patient may have a paroxysmal increase in intracranial pressure. A severe increase in intracranial pressure will lead to the formation of cerebellar crisis and cerebral palsy.
2. Chronic occipital foramen
Due to the compression and continuous growth of the tumor, the extrusion of the brain tissue is aggravated, and the long-term intracranial pressure is increased, which causes the cerebellar tonsils to swell out to the occipital foramen, and the corresponding clinical symptoms appear, but the patient's condition is generally better. The cerebellar tonsils can be congested and edema, compressing the medulla and the upper cervical cord, but the patient's general symptoms are not obvious or only mild clinical symptoms. Because the cerebellar tonsils can block the fourth ventricle, the intracranial pressure is further increased. High, the latter can increase the extent of cerebral palsy, and most of the chronic occipital foramen occlusion occurs and is difficult to reset.
(1) Pillow pain:
Because the sputum causes the meninges, blood vessels, and upper cervical nerve roots of the large part of the occipital bone to be stimulated, causing pain in the occipital region. This pain is caused by radiation pain from the upper neck to the occiput, and the patient's lower part of the pillow often has tenderness.
(2) Neck stiffness and forced head position:
Because the brain tissue that is pulled out oppresses the medulla and the upper cervical spinal cord, the muscles of the neck produce a protective reflex, and the sputum occurs, keeping the head in a fixed position, so as to avoid the head position changes and the symptoms are aggravated. The rigidity of the neck is often on the side of the lesion or on the severe side of the sputum, but the degree of sputum sputum on both sides is almost equal, so most patients have the same degree of cervical muscle spasm.
(3) When the occipital foramen magnum is involved, the patient's cranial nerve is pulled, so the patient has clinical manifestations of damage to the cranial group, such as difficulty swallowing and hearing loss.
(4) Acute exacerbations may occur on the basis of chronic occipital foramen magnum, resulting in a sharp increase in intracranial pressure, a change in vital signs in the medulla oblongata, and death from respiratory and circulatory failure.
3. Cerebellar symptoms
When the tumor grows backward or oppresses or invades the cerebellum or cerebellum, cerebellar symptoms appear. Due to the coordination function between the cerebellar muscles, the patient develops ataxia, which is characterized by walking squats, unstable gait, often toward the disease side and the rear. Dumping, the patient's muscle tension is reduced, the limb posture is abnormal, and the affected limb has a large and irregular tremor, that is, intentional tremor. In addition to the above symptoms, the cerebellar damage is often accompanied by the level of the eyeball, vertical and rotational tremor.
4. Brain stem symptoms
Brainstem symptoms refer to the brain neurological symptoms caused by the tumor invading the fourth ventricle, causing the cerebral nucleus of the medullary bridge brain to be stimulated or destroyed. The fourth ventricle tumor is more common with the brainstem symptoms as the first symptom, and the fourth ventricle is relatively rare. When the upper part is damaged, the patient's intracranial pressure rises earlier, mainly manifested as dizziness, nystagmus, forced head position, and some patients have hearing loss, facial paralysis, facial sensory disturbance, chewing weakness, abductor nerve paralysis, etc. The lower part of the ventricle is damaged, causing IX, X, XI, XII to be involved in the cerebral nucleus. Patients have vomiting, hiccups, difficulty swallowing, hoarseness, cardiovascular and respiratory disorders, and tumors in the lower part of the fourth ventricle. The symptoms of increased intracranial pressure appear earlier, and the long sacral sign appears due to the compression of the brainstem of the occipital foramen. The patient feels and the movement is impaired. The two legs are soft and easy to fall, the tendon reflex is reduced, and sometimes the pathology can be induced. reflection.
5. Optic nerve nipple changes
Because the tumor is easy to block the cerebrospinal fluid circulation pathway, the intracranial pressure is increased, resulting in optic nerve head edema, which shows that the boundary is unclear, the physiological depression disappears, and the optic nerve secondary atrophy occurs for a long time, and the patient's vision is reduced or even blind.
Examine
Fourth ventricle tumor examination
EEG examination
EEG showed a general abnormality, paroxysmal synchronous slow wave appeared in bilateral cerebral hemispheres, diffuse , wave and occipital part, some people with statistical increase of intracranial pressure accompanied by papilledema, 28% The patient has an abnormal EEG.
2. Cerebral angiography
Due to the blocked circulation of cerebrospinal fluid, hydrocephalus is produced, and the ventricle is uniformly enlarged. The carotid angiography shows signs of hydrocephalus, which shows that the anterior cerebral artery moves up and the lateral fissure artery shifts outward. The lateral image shows the periorbital artery. Straightening and disappearance of the knee, the middle artery side lobes move up and up, because the fourth ventricle tumor often has occipital foramen magnum, the vertebral artery shows the posterior inferior cranial artery displacement, can be moved into or under the occipital foramen .
3. Ventricular angiography
Cerebral ventriculography is of great value in the diagnosis of the fourth ventricle tumor. The ventricle is enlarged due to the cerebrospinal fluid circulation. The angiography shows that the ventricle is uniformly enlarged. The fourth ventricle can be seen in the nodules or massive tumor tissue. The tumor invades the cerebellar medulla. When the pool or the vertebral canal grows, the angiography shows irregular shape of the tumor tissue in the cisterna magna.
4. Skull flat film
The flat slice of the skull showed an increase in intracranial pressure, which was manifested by an increase in cerebral gyrus, and absorption or destruction of the posterior bed and saddle background.
5. Other
Isotope scanning is helpful for the diagnosis of the fourth ventricle tumor, and the brain CT examination can show the fourth intraventricular tumor.
Diagnosis
Diagnosis and diagnosis of fourth ventricle tumor
diagnosis
Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.
Differential diagnosis
First, fourth ventricle colitis
Fourth ventricle cysticercosis occurs due to cystic obstruction of the mesopores or the lower mouth of the midbrain aqueduct, resulting in increased intracranial pressure. Cerebral cysticercosis is usually multiple, cysticercosis is not only located in the ventricles, but more in the cortex or subcortical structures. There are often seizures, patients usually eat infected pork, or have been to the epidemic area, multiple nodules are often seen under the skin, subcutaneous nodular resection examination often found cysticercosis, cerebrospinal fluid and blood complement binding test are positive, ventricle The angiography showed a uniform expansion of the ventricles, and there was a soft tissue shadow or filling defect in the fourth ventricle.
Second, posterior cranial arachnoiditis
Patients often have brain adjacent parts, brain tissue or systemic infections. In patients with acute infection, there is an increase in body temperature and mild intracranial pressure. Generally, there is a long period of remission, and the symptoms may worsen due to colds and fatigue. In arachnoiditis, the midbrain aqueduct can be narrowed or occluded, and the fourth ventricle and the occipital pool are simultaneously cohesive, causing cerebrospinal fluid circulation disorder, and intracranial hypertension, clinically manifested as headache, nausea and vomiting. Papillary edema, such as brain stem involvement, often have symptoms of cranial nerve involvement in the posterior group, but generally no brain lesions, most of the disease progresses quickly and severely, the mortality rate is higher, the number of cerebrospinal fluid cells is increased by lumbar puncture, and the intracranial pressure is significantly increased. The flat slice of the skull shows signs of increased intracranial pressure. The subarachnoid space of the cerebral ventricle and the occipital sac can not be filled. The ventricle angiography can show the consistency of the ventricular system above the midbrain.
Third, cerebellar tuberculosis
Tuberculoma can be single or multiple, usually more common in children and young people. In addition to tuberculoma in the posterior cranial fossa, there are active tuberculosis in the body. The patient is generally in poor condition and has symptoms of systemic tuberculosis. It is characterized by low fever, night sweats, flushing and weight loss. Some patients may have tuberculous meningitis symptoms, meningeal irritation, single tuberculosis, obvious cerebellar symptoms, dysfunctional movement, nystagmus, Cerebellar tonicity occurs in severe cases. A small number of patients have symptoms of tuberculosis poisoning. Most patients are generally in good condition. Lumbar puncture examination, cerebrospinal fluid pressure is high and protein is contained, but the number of cells and sugar content are normal.
Fourth, cerebellar abscess
Often due to otitis media or mastoiditis caused by inflammation of the posterior wall of the tympanic cavity, and upward development led to cerebellar abscess, and less blood-borne, cerebellar abscess patients generally have symptoms of primary lesions and systemic infection symptoms, manifested as Fever, chills, increased white blood cells and increased erythrocyte sedimentation rate. At the same time, the patient's intracranial pressure increased, headache, nausea and vomiting, cerebellar signs, manifested as ataxia, gait paralysis, decreased muscle tone and forced head position, sometimes The posterior cranial nerve symptoms may occur, and ventriculography shows that the fourth ventricle deformation and displacement are of great value for diagnosis.
Five, cerebellar hemisphere tumor
Most patients with cerebellar hemisphere tumors have increased intracranial pressure, and often have headache as the first symptom. The pain is often located in the posterior occipital region, accompanied by nausea and vomiting. The headache is more frequent, optic nerve head edema, vision loss, and some may appear double vision. Due to impaired cerebellar hemisphere, ataxia (bomb upper and lower limbs), nystagmus, dizziness, etc., the tumor develops laterally to cause cranial nerve damage. Commonly, trigeminal nerve, facial nerve, auditory nerve and glossopharyngeal nerve are damaged. The clinical symptoms appearing are facial sensory disturbance, hearing loss and cough, etc. The brain stem is invaded by long-term signs, long-term high intracranial pressure and tumor growth continue to produce occipital foramen magnum, and the patient appears to be forced head. Position, ventriculography showed deformation, displacement and filling defects in the fourth ventricle.
Six, cerebellar sac tumor
The cerebellar sacral tumor is easy to block the cerebrospinal fluid circulation pathway and the intracranial pressure is increased. The patient has headache, nausea and vomiting and optic nerve head edema. This is also the main symptom of the cerebellar sac tumor. Because the cerebellar sac is small, the tumor will occur when the tumor occurs. The cerebellar hemisphere pushes to both sides, damages the cranial nerves (IV, VI, VII, VIII to the cranial nerves). The ataxia after cerebellar sacral damage is trunk ataxia, sometimes nystagmus, cerebellar vermis The tumor is prone to occipital foramen magnum. The bilateral cerebellar tonsils are symmetrical into the occipital foramen. The patient has a forced head position. The head is often tilted forward. Some patients often have a knee-thoracic posture. The ventriculography can be determined. diagnosis.
Seven, brain stem tumor
Brain stem tumors occur mostly in children, mostly in gliomas, clinical manifestations of increased intracranial pressure, consciousness and mental disorders, focal lesions, etc., increased intracranial pressure is generally more advanced, but midbrain tumors are particularly located In the cover, due to the compression of the midbrain aqueduct, the intracranial pressure may increase at an early stage. Due to the damage of the brainstem reticular structure, the patient produces drowsiness, apathy, and even coma. The most prominent after the brain stem is damaged. The focal symptoms are cross palsy, followed by cranial nerves, pyramidal tract and cerebellar damage. Patients with hearing loss, dysphagia, paralysis, ataxia and nystagmus, increased pressure on cerebrospinal fluid examination, increased protein content, skull Occasionally, the bone in the inner auditory canal is destroyed. The ventricle angiography shows a consistent enlargement of the ventricle. The posterior part of the third ventricle often has filling defects. The vertebral artery angiography shows the displacement of the posterior cerebral artery and the superior cerebellar artery.
Eight, cerebellopontine angle tumor
Cerebral ganglion tumors are mostly acoustic neuromas, followed by epithelioid cysts and meningiomas. Clinical manifestations are cerebellar cerebral horn syndrome, trigeminal nerve, auditory nerve, facial nerve, abductor nerve, glossopharyngeal nerve, vagus nerve, sublingual Dysfunction after nerve and cerebellar damage, and the occurrence of brain stem compression and elevated intracranial pressure, patients will have persistent tinnitus, progressive deafness, facial numbness, corneal sensation, difficulty swallowing, sound Deaf-mute, etc.; patients may also have facial paralysis, unclear speech, ataxia, and intraocular obliqueness. A small number of patients may have mild hemiplegia and hemiplegia.
Acoustic neuroma
Acoustic neuroma mostly occurs in middle-aged and elderly people, and most of them are female. The first episode is the stimulation and destruction of the auditory nerve. It is characterized by high-pitched tinnitus, followed by hearing loss, dizziness, nausea, vomiting and nystagmus, due to tumor oppression and invasion. Patients V, VII, IX, X have dysfunction of the cranial nerve, which is characterized by corneal sensation, facial numbness, chewing weakness, difficulty in swallowing and hoarseness. A small number of patients have pain in the trigeminal nerve distribution area, and patients with cerebellar damage may appear. Ataxia, X-ray skull plain film showing enlargement of internal auditory canal or bone destruction.
2. Cerebellar cerebellopontine epithelioid cyst
Its incidence rate is second only to acoustic neuroma in the cerebellopontine angle tumor, which is common in young and middle-aged people. It is clinically manifested as symptoms of cranial nerve damage, among which there are more cases of trigeminal neuralgia. The performance is the second branch of the trigeminal nerve. The third branch has a burning or electro-shock-like pain. There is a trigger point. Secondly, the patient may have tinnitus, deafness and walking instability. A small number of patients have dysphagia, hoarseness and other pharyngeal and vagus nerves. Impaired symptoms.
Nine, large occipital tumor
Meningiomas and neurofibromas are more common. The tumor originates from the periphery of the foramen magnum or the upper part of the spinal canal. Most of the patients are adults. After the early stage of the disease, the occipital and upper neck pains and radiate to the top. The pain is aggravated when coughing, so the patient has stiff neck and forced head position, and there may be physical activity disorders. This movement disorder often starts from one limb and develops to other limbs. It also starts from the upper or lower limbs. Spinal hemisection can occur, manifested as different degrees of hemiplegia on the same side, sensory disturbance of the contralateral limb, and shoulder muscle atrophy, increased intracranial pressure and cranial nerve damage in the late stage, common XI, IX, X brain Nerve damage, followed by trigeminal nerve and facial nerve damage, patients may have hiccups, nystagmus, ataxia, dizziness and cervical sympathetic nerve palsy, cerebrospinal fluid examination protein content is helpful for diagnosis, skull X-ray film shows occipital foramen Bone hyperplasia or destruction, the upper cervical lamina, vertebral arch can also be destroyed, brain CT examination is very helpful for diagnosis.
