Mercury toxicity tremor

Introduction Mercury poisoning is characterized by psycho-neural abnormalities, gingivitis, and tremor. Acute mercury poisoning occurs when high-dose mercury vapor inhalation or ingestion of mercury compounds occurs. Those who are allergic to mercury may be poisoned even if they are partially coated with a mercury oil base. Mercury mining, amalgam smelting, gold and silver extraction, mercury rectifiers, and vacuum pumps, lamps, gauges, thermometers, amalgams, mercury, pigments, pharmaceuticals, nuclear reactor coolants and anti-atoms Production workers of radiation materials, etc. Organic mercury compounds have been used mainly as agricultural fungicides in the past, but they are highly toxic and are no longer produced and used in China.

Cause

Mercury vapor is more easily transmitted through the lipid-containing cell membrane of the alveolar wall, binds to lipids in the blood, and is rapidly distributed to tissues throughout the body. Mercury is oxidized to Hg2+ in red blood cells and other tissues, and accumulates in combination with proteins, making it difficult to release. Metallic mercury is hardly absorbed in the gastrointestinal tract, only about one ten thousandth of the food intake, and the mercury salt is absorbed in the digestive tract by about 10%. Mercury is mainly excreted in urine and feces, and saliva, milk, and sweat are also excreted in a small amount, and the lungs are exhaled. The half-life of mercury in the body is 60 days, the mercury salt is about 40 days, and the amount of excretion is more in the first 4 days.

Mercury ions are easily combined with sulfhydryl groups to inactivate cytochrome oxidase, pyruvate kinase, succinate dehydrogenase, etc. associated with sulfhydryl groups. Mercury also binds to amino groups, carboxyl groups, and phosphoryl groups to affect the activity of functional groups. Since the activities of these enzymes and functional groups are affected, cell biological activity and normal metabolism are hindered, eventually leading to cell degeneration and necrosis. In recent years, it has been found that mercury damage to the kidneys is mainly caused by renal proximal tubular epithelial cells. Mercury can also cause immune dysfunction, produce autoantibodies, and develop nephrotic syndrome or glomerulonephritis.

an examination

Related inspection

Serum mercury (Hg) urinary mercury

1. Physiological tremor: In some cases, most normal people will have a slight rapid tremor in the hand when the upper limbs are stretched forward. Intensification of physiological tremor can be seen in anxiety, stress, fatigue, metabolic disorders (eg, alcohol withdrawal, thyrotoxicosis), or the use of certain drugs (eg, caffeine and other phosphodiesterase inhibitors, beta- Adrenergic agonist, adrenocortical hormone).

2, primary (benign hereditary) tremor: a subtle to coarse slow tremor, usually affecting the hands, head and vocal cords. There are autosomal dominant genetic factors in 50% of cases. The tremor can be unilateral. The tremor is very slight or does not occur at rest, and can cause tremor when the patient performs delicate movements, and the primary tremor is enhanced under the influence of any of the factors that can enhance the physiological tremor. As the age increases, the incidence of primary tremor increases, and is occasionally mistakenly referred to as senile tremor.

3, Parkinson's disease: Parkinson's disease (Parkinson's disease) also known as "tremor palsy", Parkinson's disease or Parkinson's disease. The disease is a neurodegenerative disease common in middle-aged and elderly people, and it usually develops after the age of 60. Mainly manifested as slow movement of the patient, tremors in the hands and feet or other parts of the body, the body loses its softness and becomes stiff. The earliest systematic description of the disease was the British physician Jane Parkinson, who did not know which type of disease the disease should be classified into, which was called "tremor paralysis." Parkinson's disease is the fourth most common neurodegenerative disease in the elderly, with 1% of people 65 years old and 0.4% of people >40 years old. The disease can also occur in childhood or adolescence.

4. Tremors of cerebellar diseases: Intentional tremors (as seen in multiple sclerosis and other cerebellar efferent disorders) occur when the moving limb approaches the target. Supportive (positional) tremor is a large, rotational tremor at the proximal end of the limb that is most pronounced when the patient attempts to maintain a fixed posture or load. Titubation is a large tremor of the head and body. It is also a kind of supportive tremor. It is obvious when maintaining an upright posture and disappears after lying down. Flap-like tremors are seen in cases of hepatic encephalopathy and other metabolic encephalopathy. When the patient stretches out his hands forward, a large, slow, non-rhythmic movement occurs. Using electromyography records, it can be observed that when the patient tries to maintain a fixed posture, intermittent electromyography is present in the antigravity muscle, causing flapping tremor; therefore, it is not true tremor, but a kind of Myoclonus, a negative myoclonus.

5, Wilson's disease tremor: Intentional tremor and resting tremor can occur in Wilson's disease. The most characteristic is the rhythmic slap at the distal end of the limb or the flapping-like action at the proximal end of the limb.

6. Essential tremor (ET): Also known as primary tremor, it is one of the most common adult tremors. The prevalence is about 0.4-5%, and the incidence increases with age. ET is considered a benign disease that does not reduce the life expectancy of patients. It is the only manifestation of dyskinesia with tremor, mainly manifested by hand or head movement and posture tremor, increased during stress, without muscle stiffness and slow movement. More than 50% of ET patients have a positive family history and are autosomal dominant.

Differential diagnosis

Differential diagnosis of mercury toxic tremor:

First, acute mercury poisoning

Mainly caused by mercury compounds such as oral mercury. Patients with acute corrosive stomatitis and gastroenteritis occur several minutes to tens of minutes after taking the drug. The patient complained of burning in the mouth and throat, and had nausea, vomiting, abdominal pain, followed by diarrhea. Vomiting and feces often have bloody mucus and shed necrotic tissue. Patients can often be accompanied by peripheral circulatory failure and gastrointestinal perforation. Acute renal failure can occur after 3 to 4 days (seriously within 24 hours). There may be liver damage at the same time.

Inhalation of high concentrations of mercury vapor can cause fever, chemical tracheobronchitis and pneumonia, respiratory failure, and acute renal failure.

Skin contact with mercury and its compounds can cause contact dermatitis and is allergic. The rash is a erythematous papule that can be fused into a piece or form a blister, and the pigmentation is followed.

Second, chronic mercury poisoning

Often caused by occupational inhalation of mercury vapor, a small number of patients may also be caused by the application of mercury preparations. Psycho-neuro symptoms can be dizzy, headache, insomnia, and more dreams, followed by emotional or depression, anxiety and timidity, and autonomic dysfunction such as blushing, sweating, and skin scratches. Muscle tremor is first seen in the fingers, eyelids and tongue, and later affects the arms, lower limbs and head, and even the whole body; it is more noticeable when noticed and excited. Oral symptoms are mainly mucosal congestion, ulcers, swelling and bleeding of the gums, loose teeth and shedding.

Those with poor oral hygiene can see blue-black mercury sulfide fine particles arranged in rows of mercury lines, which is a marker of mercury absorption. In the kidney, there is a subclinical tubular dysfunction, low molecular proteinuria, and nephritis and nephrotic syndrome. Kidney damage is expected to recover after exposure to mercury. Chronic poisoning patients may still have weight loss, sexual dysfunction, women's menstrual disorders or miscarriage, and hyperthyroidism, peripheral neuropathy. The brown light reflection in the anterior chamber of the lens is considered to be "mercury lenticular inflammation" caused by mercury deposition. This brown light reflection can persist after the symptoms of poisoning disappear or are separated from mercury. It is another marker of mercury absorption. .

Differential diagnosis of mercury toxic tremor:

1. Physiological tremor: In some cases, most normal people will have slight rapid tremor in the hand when the upper limbs are stretched forward. The strengthening of physiological tremor can be seen in anxiety, tension, fatigue, and metabolic disorders (eg , alcohol withdrawal, thyrotoxicosis), or the use of certain drugs (for example, caffeine and other phosphodiestera inhibitors, beta-adrenergic agonists, adrenocortical hormones).

2, primary (benign hereditary) tremor: a subtle to coarse slow tremor, usually affecting the hands, head and vocal cords. In 50% of cases have autosomal dominant genetic factors. tremor can be unilateral. tremor It is mild or non-occurring at rest. When the patient performs delicate movements, it can cause tremor. Under the influence of any factors that can strengthen the physiological tremor, the primary tremor will also increase. With age, the primary tremor The incidence has also increased, and is occasionally mistakenly referred to as senile tremor.

3, Parkinson's disease: Parkinson's disease (Parkinson's disease) also known as "tremor palsy", Parkinson's disease or Parkinson's disease. The disease is a neurodegenerative disease common in middle-aged and elderly people, and it usually develops after the age of 60. Mainly manifested as slow movement of the patient, tremors in the hands and feet or other parts of the body, the body loses its softness and becomes stiff. The earliest systematic description of the disease was the British physician Jane Parkinson, who did not know which type of disease the disease should be classified into, saying that the disease was "tremor paralysis." Parkinson's disease is the fourth most common neurodegenerative disease in the elderly, with 1% of people 65 years old and 0.4% of people >40 years old. The disease can also be used in children. Onset or puberty.

4. Tremors of cerebellar diseases: Intentional tremor (as seen in multiple sclerosis and other cerebellar efferent disorders) occurs when the moving limb approaches the target. Supportive (positional) tremor is a gross rotation of the proximal extremity. Sexual tremor is most pronounced when the patient tries to maintain a fixed posture or weight. Titubation is a large tremor of the head and body. It is also a supporting tremor. It is obvious when maintaining an upright posture and disappears after lying down. Flapping-like tremors are seen in cases of hepatic encephalopathy and other metabolic encephalopathy. When the patient stretches his or her hands forward, a large, slow, non-rhythmic movement occurs. Application of EMG recording can be observed when the patient tries to maintain a fixed posture. At the time, intermittent electromyography is present in the anti-gravity muscle, causing flapping tremor; therefore, it is not a true tremor, but a myoclonic phenomenon, a negative myoclonus.

5. Wilson's disease tremor: Intentional tremor and resting tremor can occur in Wilson's disease. The most characteristic is the rhythmic slap at the distal end of the limb or the flapping-like action at the proximal end of the limb.

6. Essential tremor (ET): Also known as primary tremor, it is one of the most common adult tremors. The prevalence is about 0.4-5%, and the incidence increases with age. ET is considered a benign disease that does not reduce the life expectancy of patients. It is the only manifestation of dyskinesia with tremor, mainly manifested by hand or head movement and posture tremor, increased during stress, without muscle stiffness and slow movement. More than 50% of ET patients have a positive family history and are autosomal dominant.

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