Radiation damage to the nervous system
Introduction
Introduction to radiation damage in the nervous system Refers to the tissue adverse reactions produced by ionizing radiation through various parts of the nervous system. Adverse reactions may be related to the total dose of radiation, the size of each irradiation component, the total time of irradiation, and the volume and location of the irradiated nerve tissue. The safe exposure dose for each patient can be extrapolated based on the nature of the patient's primary nervous system disease, previous surgery, accompanying chemotherapeutic drugs, and individual sensitivity. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: radioactive myelopathy meningioma
Cause
Causes of radiation damage in the nervous system
Acute radiation encephalopathy is mainly caused by radiation-induced tissue inflammatory reaction leading to changes in blood-brain barrier and cerebral edema and increased intracranial pressure. The nerve tissue is relatively resistant to radiation damage, and the radiation or necrosis of the brain or spinal cord is mostly due to radioactive vascular disease. , thickening of blood vessel wall and thrombosis, secondary ischemic or hemorrhagic necrosis, early delayed radiation-induced myelopathy is demyelinating and less glial cell proliferation, late delayed cranial nerve and peripheral nerve radiation sickness is nerve Fibrosis and plexus ischemia.
Prevention
Radiation injury prevention of the nervous system
Try to avoid reflex damage, and stop radiotherapy immediately when radioactive nerve damage occurs in radiotherapy.
Complication
Neurological radioactive injury complications Complications, radiation, myeloma, meningioma
Early delayed radiation-induced myelopathy is demyelinating and less glial cell proliferation, and late delayed cranial nerve and peripheral neuroradiopathy are neurofibrosis and plexus ischemia. Rarely, radiation therapy can be performed many years after the end of treatment. Cause glioma, meningiomas or peripheral nerve sheath tumors.
Symptom
Symptoms of radiation damage in the nervous system Common symptoms Drowsiness, sensory impairment, dementia
There is a history of overdose radiation, after a certain incubation period, the lesions and symptoms are consistent with the radiation source, as follows:
Primary injury
(1) Brain: 1-2 days of onset, manifested as symptoms of acute encephalopathy, 6-16 weeks of onset, manifested as lethargy, focal signs, months to years, manifested as dementia, focal signs.
(2) Spinal cord: 6-16 weeks of onset, manifested as Lhermittes sign (ie, when the head bows, there is a contact inductance from the neck along the back spine to the lower extremities or limbs. When the head is reset, the symptoms disappear; the more rapid the neck flexion The stronger the contact inductance, such as slow neck movement and slight inductance, and several months to several years, it is a transverse myelopathy.
(3) Peripheral nerve: a few months to several years of onset, manifested as paralysis, feeling missing.
2. Secondary injury
(1) Multiple site injuries: manifested as brain, cranial, and or peripheral nerve sheath tumors.
(2) Arterial (atherosclerosis): manifested as cerebral infarction.
(3) Endocrine organs: manifested as metabolic diseases.
Examine
Examination of radioactive damage to the nervous system
Normal value of CT scan of the brain: no intracranial lesions, all intracranial examination data are normal.
MRI is a MRI examination of the brain for observing the presence or absence of lesions in the brain. It can be used to determine whether the patient is caused by changes in brain structure. Intracranial tumors often cause epilepsy. MRI has low-grade astrocytes in the brain. The diagnostic rate of cell tumors, ganglia, glioma, arteriovenous malformation and hematoma is extremely high.
Normal MRI examination of the brain: Normal brain tissue on the mri image, the gray matter boundary is clear, the white matter signal is higher than gray matter on t1wi, and the gray matter signal is higher than white matter on t2wi, each brain lobe, sulci, cerebral sulcus, cerebral pool And the ventricle is natural in shape, without deformation and enlargement or contraction, and the midline structures are in the middle.
Diagnosis
Diagnostic identification of radiation damage in the nervous system
diagnosis
Diagnosis can be based on medical history, clinical symptoms, and laboratory findings.
Differential diagnosis
The disease must be differentiated from tumor recurrence or metastasis, starting with a history, it is not difficult to identify.
