Pediatric dystonia

Introduction

Introduction to deformed dystonia in children Deformative dystonia, idiopathic torsion myodystonia, formerly known as deformed dystonia, is a group of more common extrapyramidal diseases characterized by active muscles and active muscles. Antagonistic muscles undergo continuous involuntary contraction at the same time, presenting a special twist posture or posture. The abnormal movement of this disease begins with local dystonia and gradually develops into systemic dystonia. Because the onset of this disease is earlier, recently the disease is called early-onsettorsion myodystonia, and the hereditary pattern is autosomal dominant inheritance. basic knowledge The proportion of illness: 0.002% Susceptible people: children Mode of infection: non-infectious Complications: writing

Cause

Causes of deformed dystonia in children

(1) Causes of the disease

The disease is a hereditary disease, mainly autosomal dominant, and the cause is unknown.

(two) pathogenesis

1. Extrapyramidal physiological anatomical function

The extrapyramidal structure is very complex. In general, except for the cone system, all motion-related central nervous structures can belong to the extrapyramidal system. The extrapyramidal system includes the basal ganglia, the substantia nigra, the red nucleus, the subthalamic nucleus, and the cerebellum Nucleus and brainstem reticular structure, etc., the main structure is the basal ganglia, the basal ganglia includes the caudate nucleus and the lenticular nucleus. The lenticular nucleus is divided into the outer part of the nucleus and the inner part of the globus pallidus. The nucleus and the putamen are collectively called striatum, and the extrapyramidal system is a multi-neuronal structure. The conduction pathway forms a large circulation circle. In the circulation circle, the excitatory medium is acetylcholine, and the inhibitory medium is dopamine, which ensures the pyramidal system. The active movement initiated is more precise, accurate and stable.

2. Pathology and pathogenesis

There are two types of symptoms of extrapyramidal lesions: abnormal muscle tone and involuntary movement, abnormal muscle tension can be enhanced, weakened and migratory and weakened; involuntary movement including tremor, dance, hand and foot, muscle tension Incomplete, myoclonus, torsion and convulsions, the symptoms of extrapyramidal usually disappear during sleep, and are aggravated when nervous or emotional.

It is generally believed that this disease is a basal ganglia lesion, but there is still no anatomical evidence. Neurobiochemical examination shows abnormal distribution of neurotransmitters in the brain. Dominant genotype shows increased activity of dopamine--hydroxylase in plasma. Electrophysiological examination proves active. The muscles and antagonist muscles contracted for a long time, and the REM sleep was reduced in the late stage of the disease. The electroencephalogram spindle voltage was increased during the second stage of sleep. Recently, some cases of black matter striatum have decreased the intake of dopa.

3. Genetic mode

Hereditary dystonia has different genetic patterns, each with its clinical features, autosomal dominant hereditary dystonia, with varying degrees of penetrance. It was previously thought to be only seen in Jewish people, and is now considered to be visible in all ethnic groups. The sexually-deficient defective gene is located on the long arm of chromosome 9 (9q34), with obvious genomic imprinting and anti-aging phenomenon. The autosomal recessive myasthenia is found in all ethnic groups. Later, the disease progresses slowly, X-linked recessive inheritance is seen in the Philippines, and the following focuses on dominant hereditary dystonia.

Prevention

Prevention of deformity dystonia in children

The disease is directly related to genetic factors, so it is more important to have a genetic background. Preventive measures include avoiding the marriage of close relatives, conducting genetic counseling, genetic testing of carriers, prenatal diagnosis and selective abortion to prevent the birth of children. Early diagnosis, early treatment, and intensive clinical care are important for improving the quality of life of patients.

Complication

Pediatric deformed dystonia complications Complications

When walking, it is inwardly turned to the body position, which can cause limb deformation for a long time, seriously hindering spontaneous movement, writing sputum, facial and facial muscle insufficiency can cause speech, difficulty in pronunciation, difficulty in swallowing and chewing.

Symptom

Degenerative dystonia symptoms in children Common symptoms Sensory disorder Spasm of the torticollis gait abnormal torsion action Muscle muscle weakness Muscle tone reduction Segmental dystonia Anxiety convulsions Asynchronous state

Hereditary dystonia is a chronic progressive disease. The severity of symptoms varies greatly between cases. The onset age varies with heredity, and the dominant type starts from 6 to 14 years old (range 1 to 40 years old); recessive The onset age is 10 years old, also seen in other ages; X-linked hereditary type is more common in 25 to 45 years old.

The early symptoms of torsional dystonia often begin with a certain localized dystonia, which is characterized by simultaneous contraction of the agonist and antagonist muscles, causing dyskinesia and fixing the affected site to a particular posture or posture. In the early stage, the abnormal posture of the axial muscles in the body, especially the torticollis, and the distorted posture of the trunk or pelvic muscle are the main features. The recessive hereditary type mostly has the abnormal gait of one lower limb. Or the posture of the hand is abnormal for the first performance. When walking, it is introverted, and it is difficult to write. The early abnormal posture or posture is intermittent or paroxysmal. It is induced by spontaneous movement, and it is aggravated by emotional or anxiety. After the symptoms disappeared, the abnormal posture frequently appeared, and even continued to occur without remission, and did not disappear when falling asleep. The early limited symptoms gradually developed to the other side and became systemic including the trunk and limbs. Muscle insufficiency, severe head tilting and tilting when the head is severely twisted; when the trunk muscle is involved, the neck is back to the back, and the trunk is twisted along the long axis of the spine. Turning, twisting action is caused by the persistent and unbalanced contraction of the active muscle and the antagonistic muscle. It can cause limb deformation for a long time, seriously hindering spontaneous movement, and some diseases are mild, slow progress or stop progress, and may only have gait. Abnormal, or only spasmodic torticollis, or only writing sputum, sometimes visible facial muscle tension is incomplete, causing speech, difficulty in pronunciation, difficulty in swallowing and chewing, mental development is normal in this disease, no seizures, no pyramidal tract sign, No sensory disturbances.

Examine

Examination of deformed dystonia in children

General laboratory tests are not particularly visible.

Neuroimaging, slit lamp examination, etc. are normal, central neurotransmitter examination can provide clues, brain PET scan with fludopa can be found in the nigrostriatal system to reduce dopamine uptake, but clinical application is difficult.

Diagnosis

Diagnosis and differential diagnosis of deformed dystonia in children

diagnosis

Mainly based on clinical features for diagnosis, central neurotransmitter examination can provide clues, brain fluorescence scan with fludopa can be found in the nigrostriatal system to reduce dopamine uptake, the clinical basis for the diagnosis of this disease is: with muscle insufficiency Abnormal movements and postures; perinatal normal; no history of drug poisoning; no mental retardation, no pyramidal tract sign; family history; exclusion of other causes of dystonia.

Differential diagnosis

Dystonia is a group of symptoms, in addition to the disease, but also seen in many diseases.

1. acquired non-progressive dystonia

Found in perinatal asphyxia, hypoxia, cerebral palsy, encephalitis, trauma, poisoning (such as CO poisoning), cerebrovascular disease, etc., can also be seen in multiple sclerosis and tumors.

2. Drug-induced dystonia

Can be seen in the use of carbamazepine (amide), phenytoin, phenothiazines, butyrylbenzene (including haloperidol), chloroquine, antihistamines, tricyclic antidepressants, lithium, etc. After the first dose of haloperidol, muscle tone insufficiency can occur, which is characterized by torticollis, angular angulation, tight teeth, ocular eye crisis, swallowing and dysphonia, and disappear after reduction or deactivation.

3. Congenital metabolic abnormalities with symptoms of dystonia

These diseases also have other progressive neurological symptoms, and have specific biochemical abnormalities, such as Wilson's disease, brain lipid deposition (GML or GM2 gangliosides, juvenile waxy lipid deposition) Disease, Niemann's disease, metachromatic leukodystrophy), organic acidemia, amino aciduria (such as phenylketonuria).

4. Muscular insufficiency caused by mitochondrial genetic disease

Found in Leigh syndrome, Kearn-Sayre syndrome, Leber optic atrophy, etc.

5. Other diseases with dystonia

Such as Rett syndrome, dystonic paraplegia, Parkinson's disease, paroxysmal baby torticollis, globus pallidus degeneration, local (muscle, bone, ligament) disease caused by torticollis.

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