Subacute combined degeneration of the spinal cord

　　Subacute combined degeneration of the spinal cord is related to a deficiency of vitamin B12. Myelin is the structure around the nerve that promotes the conduction of nerve impulses, and vitamin B12 is an essential coenzyme for the formation of myelin and nuclear proteins. Deficiency of vitamin B12 can lead to disorders in myelin synthesis, resulting in nerve and psychiatric damage.

　Subacute combined degeneration of the spinal cord often presents as a subacute or chronic course, gradually progressing. Due to long-term bed rest, it can lead to bedsores, urinary tract infections, and formation of lower limb venous thrombosis.

　　Subacute combined degeneration of the spinal cord often manifests secretly in middle-aged and older adults, with no significant difference between males and females. The disease usually presents as a subacute or chronic course, gradually progressing. Before the onset of neurological symptoms, most patients exhibit anemia. Some patients with hypochlorhydria may have mild or severe anemia, presenting with fatigue, weakness, palpitations, dizziness, diarrhea, slight glossitis, and edema. In the presence of gastrointestinal diseases, patients may have decreased appetite, constipation or diarrhea, pale lips, etc.
　　Neurological symptoms often manifest as symmetrical sensory abnormalities in the fingers and toes, such as tingling, numbness, and burning sensation, which are persistent and more severe in the lower limbs. Sensory abnormalities can extend upwards to the trunk, and objective physical examination of the extremities usually shows normal sensation. A few patients may have symmetrical glove or sock-like sensory loss. The posterior column of the spinal cord is damaged, leading to gradual appearance of clumsy limb movements, easy falls, a sensation of walking on cotton, difficulty walking with eyes closed or in the dark. Motor disorders usually appear later than sensory disorders, and the lower limbs may present with incomplete spastic paraplegia. Physical examination may show weakness in the lower limbs, increased muscle tone, hyperreflexia, and positive pathological signs.
　　About 5% of patients experience optic atrophy and bilateral central scotoma, decreased visual field, decreased vision, or blindness. A few patients may exhibit symptoms such as apathy, drowsiness, irritability, suspicion, depression, and emotional instability. In severe cases, there may be confusion, delusion, hallucinations, paranoid tendencies, cognitive function decline, memory loss, and even dementia.

　　The prevention of spinal subacute combined degeneration mainly focuses on the prevention of etiology, such as improving dietary structure, correcting malnutrition, eating more foods rich in Vitamin B group, and should quit drinking; treat gastrointestinal diseases that can cause absorption disorders as soon as possible.

　　The diagnosis of spinal subacute combined degeneration relies not only on clinical manifestations but also on auxiliary examinations, which are indispensable for diagnosis. The main examinations are as follows:
　　1. Cerebrospinal fluid is usually normal, and a few may have slight increase in protein.
　　2. Peripheral blood and bone marrow smear examination show macrocytic hypochromic anemia; injection of Vitamin B12 100 micrograms/day, after 10 days, the increase in reticulocytes is helpful for diagnosis.
　　3. The level of serum Vitamin B12 is reduced.
　　4. Magnetic Resonance Imaging (MRI) can show lesions in the posterior column of the spinal cord.

　　In addition to conventional treatment, dietary attention is needed for spinal subacute combined degeneration: patients should eat more foods rich in Vitamin B12, such as pork liver, milk, fish, eggs, etc.

　　Once spinal subacute combined degeneration is diagnosed, large-dose Vitamin B12 treatment should be started immediately, otherwise irreversible neurological damage may occur. The specific treatment methods are as follows:
　　1. Vitamin B12 2500~1000 micrograms/day, intramuscular injection, for 2~4 weeks continuously, then 2~3 times a week; 1000 micrograms each time, 2~3 times a week after 2~3 months. Some patients may need lifelong medication, and the combination with Vitamin B1 and B6 has a better effect.
　　2. Anemia patients can use iron preparations, such as ferrous sulfate tablets, orally, 3 times a day; or 10% ferrous ammonium citrate solution 100ml orally, 3 times a day.
　　3. Folic acid should not be used alone, otherwise it may worsen symptoms.