Kalpana Devadathan, Parvathy Lalitha, Ahamed Shahanaz M, Iype Mary, Kunju Mohammed P A
Department of Pediatric Neurology, Government Medical College, Thiruvananthapuram, Kerala, India.
Pediatr Neurol. 2009 Apr;40(4):302-5. doi: 10.1016/j.pediatrneurol.2008.11.009.
Pontocerebellar hypoplasia is a heterogeneous group of disorders characterized by abnormally small cerebellum and brainstem. Pontocerebellar hypoplasia type 1 is associated with spinal anterior horn cell degeneration, microcephaly, congenital contractures, polyhydramnios, and respiratory insufficiency leading to death in infancy. Recently, however, the spectrum of this disease has been extended to include less severe variants, some of which are associated with minimal atrophy of the brainstem. In two reported cases of late-onset variant pontocerebellar hypoplasia, the siblings were alive at 9 years and 6 years, respectively, but were severely crippled and anarthric; they had features of anterior horn cell involvement and cerebellar atrophy but the brainstem was spared. The present case is that of a 12-year-old boy with early onset of anterior horn cell involvement and slowly progressive cerebellar ataxia who is still able to walk with support and speak in sentences. He was found to be devoid of the exon 7 and exon 8 deletion of the survival motor neuron gene seen in classical spinal muscular atrophy, and magnetic resonance imaging indicated marked atrophy of the cerebellar vermis and hemispheres, with minimal involvement of the brainstem. This form is apparently the mildest variant of pontocerebellar hypoplasia type 1 described to date.
脑桥小脑发育不全是一组异质性疾病，其特征为小脑和脑干异常小。1型脑桥小脑发育不全与脊髓前角细胞变性、小头畸形、先天性挛缩、羊水过多及呼吸功能不全相关，可导致婴儿期死亡。然而，最近该疾病的范围已扩大，包括症状较轻的变异型，其中一些与脑干轻度萎缩有关。在两例报道的迟发型变异型脑桥小脑发育不全病例中，两兄弟分别在9岁和6岁时存活，但严重残疾且不能言语；他们有前角细胞受累及小脑萎缩的特征，但脑干未受累。本病例为一名12岁男孩，早期出现前角细胞受累及缓慢进展的小脑共济失调，目前仍能在支撑下行走并能说出完整句子。他未发现经典型脊髓性肌萎缩中所见的生存运动神经元基因第7外显子和第8外显子缺失，磁共振成像显示小脑蚓部和半球明显萎缩，脑干受累轻微。这种类型显然是迄今为止所描述的1型脑桥小脑发育不全最轻微的变异型。
