Clinical analysis of type Ⅱ Alexander disease and literature review / 中华神经科杂志

ABSTRACT

Objective:To analyze the clinical features, imaging findings and gene test of patients with type Ⅱ Alexander disease.Methods:All the clinical data of three cases with type Ⅱ Alexander disease from August 2018 to June 2020 in the Department of Neurology, Qilu Hospital of Shandong University (Qingdao) and Qilu Hospital of Shandong University were collected, and their clinical and imaging findings were analyzed retrospectively.Results:All the three patients were middle aged and old men with a chronic progressive course, beginning with weakness of one or both lower limbs, followed by dizziness, dysarthria, dysphagia, sphincteral disturbances, constipation and orthostatic hypotension. Three patients all experienced misdiagnosis (hydrarthrosis, cerebral vascular disease, alcoholism, respectively) at early stage of the disease. Cranial magnetic resonance imaging (MRI) showed mild supratentorial periventricular leukodystrophy, which was not specific. Sagittal cranial MRI demonstrated medulla oblongata and upper cervical cord atrophy called “tadpole atrophy”, which had high suggestive value. The results of gene analysis showed heterozygous mutation of glial fibrillary acidic protein gene, which had been reported as pathogenic gene; c.1091C>T (p.A364V) in exon 6, c.722C>T (p.R258C) in exon 4 and c.197G>A (p.R66Q) in exon 1, respectively.Conclusions:Type Ⅱ Alexander disease is an autosomal dominant disease, most with point mutations, rarely with deletion mutations. Type Ⅱ Alexander disease should be suspected when a patient had signs of lower brainstem involvement such as dizziness, ataxia, pyramidal sign, autonomic dysfunction, especially when cranial MRI showed mild supratentorial leukodystrophy, and medulla oblongata and upper cervical cord atrophy.