Clinical research of 4 patients with type II Alexander disease and literature review

Abstract

Objective To analyze the clinical and MRI features of patients with type Ⅱ Alexander disease (AxD) in order to better understand and diagnose it earlier. Methods Four type Ⅱ AxD patients identified by glial fibrillary acidic protein gene mutations from Peking University First Hospital and 128 type Ⅱ AxD cases from published literatures were collected, and the clinical and MRI features were summarized. Results (1)In 4 type II AxD patients, 2 adult patients showed abnormal MRI features without clinical manifestation.The other 2 children patients both manifested motor dysfunction of lower limbs, pyramidal signs, paroxysmal deterioration, and seizures during the course of disease, while 1 of them had bulbar paralysis.The MRI of all the cases was abnormal, but only 1 case MRI corresponded with typical MRI features of type Ⅱ AxD.In the other 3 cases MRI showed the atrophy in the medulla and upper spinal cord, or the brainstem lesions and abnormal signal in the periventricular white matter, and abnormal basal ganglia region.(2) In 128 reported type Ⅱ AxD cases, the age of onset was (32±19) years old.The initial syndromes mainly contained bulbar and/or pseudobulbar paralysis (32.48%, 38/117 cases), motor dysfunction of the lower limbs (31.62%, 37/117 cases) and autonomic nerve dysfunction (13.67%, 16/117 cases). During the course of the disease, the clinical manifestation showed bulbar and/or pseudobulbar paralysis (73.50%, 86/117 cases), pyramidal signs (60.68%, 71/117 cases) and ataxia (51.28%, 60/117 cases). The MRI of all cases was characterized by atrophy or abnormal signals in the brainstem, especially in medulla oblongata, and spinal cord.And abnormal signals in the cerebellar dentate nuclei, white matter, basal ganglia and thalamus were also commonly shown in the MRI. Conclusions The patients with type Ⅱ AxD are late-onset.The clinical manifestation mainly contains bulbar and/or pseudobulbar paralysis, motor dysfunction of the lower limbs and pyramidal signs.The MRI is characterized by atrophy or abnormal signals in the brainstem (especially in medulla oblongata) and spinal cord. Key words: Alexander disease; Glial fibrillary acidic protein gene