What is Alexander Disease?

Alexander disease

Definition of Alexander Medical Terms

Alexander disease Chinese name

Alexander disease

Alexander disease English name

Alexanderdisease

Alexander disease definition

Alexandria disease is a rare nonfamilial white matter encephalopathy, with typical cases of white matter abnormalities and giant brains, mainly in the frontal lobe. The presence of Rosenthal fibers in the brain is a histological prerequisite for the diagnosis of Alexandria.

Alexandrian disease diagnostic criteria

(1) Extensive white matter abnormalities, mainly in the frontal lobe.

(2) The periphery of the ventricle showed a high signal on the T1 weighted image and a low signal on the T2 weighted image.

(3) Basal ganglia and thalamus abnormalities.

(4) Brainstem abnormalities, especially involving the midbrain and medulla.

(5) Contrast enhancement of one or more structures (including peripheral ventricle, frontal white matter, optic cross, dome, basal ganglia, thalamus, dentate nucleus, and brain stem).

4 of the 5 criteria can be confirmed as Alexander's disease).

Etiology and pathogenesis of Alexander's disease

The cause of Alexandria's disease is still not very clear, but there are many studies on RF. In 1990, Bettica et al. Have confirmed in RF microimmunolocalization studies that RF has an immune response to glial fibrillary acidic protein, which is the main component of astrocyte intermediate filaments. RF contains two small stress proteins (aB-crystal protein, heat shock protein 27), of which aB-crystal protein has been isolated and purified from RF, and may be a major component of RF. In 1993, 1waki discovered that hypoxia can cause this aB-crystal protein to increase, and this protein is also increased in broken red fibers, so it is believed that the disease is related to mitochondrial function.

In 1982, Horoupian discovered that implanting nickel wire into the brain of rats could make an experimental model of RF, but he did not understand the mechanism of RF formation. At present, a more in-depth study of this disease has been made. In 1996, the human glial fibrillary acidic protein gene was inserted into a mouse model, which led to the overexpression of glial proteins. The central nervous system of rats has widely distributed RF. The mice died on the 10th day after birth. This transgenic mouse provided the formation of RF and became a model of Alexandria disease. The clear etiology and pathogenesis of this disease need further research.

Clinical characteristics of Alexandria disease

Alexander disease infant type

Currently the most common type. Symptoms usually develop within one to two years after birth, and the course of disease is mostly two to three years. Rare cases can survive to their teens. Typical symptoms are stunting, megacephaly, and epilepsy, followed by psychomotor retardation, cramps, and quadriplegia. Babies usually do not respond, do not learn to laugh, and their head circumference increases gradually. The head circumference usually exceeds 98% of normal 6 to 18 months after birth. The head is out of control. Occasionally, the child has a giant brain abnormality at birth, but also In rare cases, giants do not appear because the cranial suture has been closed. In addition, some children with obstructive hydrocephalus may be caused by the presence of Rosenthal fibers (RF) under the ventricular membrane leading to narrowing and occlusion of the ventricular system and affecting cerebrospinal fluid flow.

Alexander disease juvenile

Rare than baby. The age of onset is 6 to 10 years, and can survive for 10 years or more. The difference is mainly the symptoms of brainstem involvement, such as pseudoball palsy (dysphagia, coughing of drinking water, and unclear articulation), drooping eyelids, nystagmus, and facial paralysis. Generalized spasms, weakness, and no giant Intelligence can be unimpaired or manifested as a slow, progressive decline.

Alexandrian disease adult type

Rarely, the clinical manifestations are similar to multiple sclerosis or juvenile Alexandria, but the age of onset is relatively late, and most patients are young.

Alexander's disease is mostly sporadic, with no family history, but rare. Wohlwill (1959) and Klein (1988) and other siblings with infantile Alexandrian disease were presumed to be caused by autosomal recessive inheritance; Howard et al. (1993) reported a case of family adult Alexandrian disease, possibly It is autosomal dominant.

Alexander disease treatment

There is currently no specific treatment for any type of Alexander disease. Various supportive and symptomatic treatments such as nutrition, anti-infection and anti-epilepsy are effective for patients.