myoclonic cerebellar coordination disorder
Introduction
Introduction to myoclonic cerebellar coordination disorder Myoclonic cerebellar coordination disorder (dyssynergiacerebellarismyoclonica) was first described by RamsayHunt (1921), so it is also known as RamsayHunt syndrome (RHS). However, in many cases reported by RHS in the future, the clinical, pathological and etiology are very inconsistent. The disease is autosomal recessive, classified according to its gene delivery form in the spinal cord-type hereditary ataxia, and its etiology is unknown. The Marseille Collaborative Group (1990) has suggested that this name should not be used, and it is divided into two categories according to the clinical reports of patients reported in the past: 1. Progressive myoclonicepilepsy (PME) manifested as myoclonus with epileptic seizures Progressive aggravation, especially the occurrence of ataxia and dementia. 2. Progressive myoclonic ataxia (PMA) is a group of clinical syndromes with myoclonus, progressive cerebellar ataxia, occasional or no seizures and cognitive impairment, but also pointed out The clinical symptoms between these two types of syndromes still partially overlap. basic knowledge Sickness ratio: 0.0001% Susceptible people: no specific population Mode of transmission: mother-to-child transmission Complications: ataxia nystagmus acne multiple lung infections
Cause
Causes of myoclonic cerebellar coordination disorder
(1) Causes of the disease
Myoclonic cerebellar coordination disorder is autosomal recessive, classified according to its gene delivery form to the spinal cerebellar hereditary ataxia (see hereditary ataxia), whose etiology is unknown.
(two) pathogenesis
If the disease is divided into PME and PMA based on the literature review, the former is more than half of the mitochondrial myopathy, Lafora disease, neuronal waxy lipofuscinosis or sialidase deposition. Equivalent, a small number of patients still belong to Unverricht-Lundborg-type PME. As for PMA patients, the exact cause is not clear (Marseille consensus group, 1990). The occurrence of myoclonus and ataxia is considered to be the cerebellar dentate nucleus and its The efferent system disorder is the pathophysiological basis. Some scholars believe that the cerebellar nucleus regulates the movement through the ventrolateral nucleus of the thalamus and the cortex. When the dentate nucleus is damaged, the time course of the sensory afferent cortex is shortened and induced. Myoclonus (Kunesche et al., 1991).
The pathological changes were mainly atrophy of the cerebellar dentate nucleus, while the cerebellar cortex, the olive cerebellar system and the pons cerebellar system remained intact. It was also reported that the degeneration involved the lower olive nucleus (Kobayashi et al., 1994). In addition, the red nucleus and the spinal cord may be affected. .
Prevention
Myoclonic cerebellar coordination disorder prevention
Neurological genetic diseases are difficult to treat, and the efficacy is not satisfactory. Prevention is more important. Preventive measures include avoiding marriage of close relatives, conducting genetic counseling, genetic testing of carriers, prenatal diagnosis and selective abortion to prevent the birth of children.
Complication
Myoclonic cerebellar coordination disorder complications Complications, ataxia, nystagmus, acne, multiple lung infections
With the development of the disease, in addition to ataxia and myoclonus, there may be different signs and symptoms, such as language barriers, unclear articulation, nystagmus, etc., late attention should be paid to lung infections caused by prolonged bed rest, hemorrhoids and so on.
Symptom
Myoclonic cerebellar coordination disorder symptoms common symptoms cerebellar ataxia ataxia dysphonic nystagmus
1. More onset in children and adults early.
2. In the early stage, action myoclonus occurs, which is short-lived, sudden large muscle twitching, and myoclonus is limited to one or more groups of muscle groups, and is sensitive to sound, light and emotional stimuli, and twitching during exercise.
3. Most of them are not accompanied by disturbance of consciousness. Occasionally, they have strong seizures and seizures, but the frequency is very low.
4. The signs of cerebellar ataxia progress slowly, and the cerebellar language disorder occurs in severe cases. The articulation is unclear, swallowing, coughing, and walking instability.
5. Cognitive function remains intact and there is no dementia.
6. There may be nystagmus, enhanced or weakened tendon reflexes and pyramidal tract signs.
Examine
Examination of myoclonic cerebellar coordination disorder
Detection of genetic material and gene products: including chromosome number and structure, DNA analysis and gene product detection, can diagnose and predict disease at the level of gene expression.
Electrophysiological examination
EEG is mostly bilateral symmetrical multiple spikes, slow-synchronous integrated waves, light and acoustic stimulation can be induced, and somatosensory evoked potentials show prolonged latency.
2. Neuroimaging
Brain CT and MRI are normal or mild cerebral cortex and cerebellar atrophy.
Diagnosis
Diagnosis and differentiation of myoclonic cerebellar coordination disorder
According to the younger age of onset, the course progresses slowly, mainly manifested as action myoclonus and cerebellar ataxia. If seizures are not frequent, there is no significant mental retardation. EEG is a combination of spine and spine. Family If there is a similar patient, the disease should be considered.
Other diseases with known pathogens similar to the clinical manifestations of the disease must be excluded: mitochondrial myopathy should be excluded by skeletal muscle biopsy, and Lafora disease and neuronal waxy lipofacia can be excluded by brain biopsy. If seizures are frequent and there is dementia, although cerebellar ataxia should still be diagnosed as progressive myoclonic epilepsy.
