Abnormally modified tau and hypoxic-ischemic brain damage / 中国病理生理杂志

Tau is the most abundant microtubule-associated protein in the brain .If tau protein lost the normal function, the toxic effect should be showed and plays an important role in various central nervous system lesions .Hypoxic-ischemic encephalopathy ( HIE) is an important cause of mortality in the neonatal period and it is mainly characterized by neurological deficits such as cognitive limitations .However , the mechanism still needs further study , and the underlying re-lationship between tau protein and HIE lacks direct evidence .Some recent clinical study reported that tau protein expres-sion elevated in the serum of asphyxia children and had a high correlation with behavior deficient .In this review , we focus on 3 key points to provide new insights to understand the tau protein-related pathogenesis of HIE as followed:(1) tau pro-tein and its phosphorylation change during central nervous system development ;(2) comparison of tau protein expression in developing brain and adult brain under some neurological disorders;(3) potential pathological change of tau in HIE related pathological conditions , such as dysmyelination , inflammation response and glutamate metabolism .

Dysmyelination of the Cerebral White matter with Microdeletion at 6p25.

A 6-year old boy presented with mental retardation, hypotonia, abnormal facies, impaired hearing, protuberant eyes, visual impairment, short stature, Axenfeld- Rieger anomaly, a bicuspid aortic valve, and bilateral sensorineural deafness. CT scan of head suggested dysmyelination of the subcortical and periventricular white matter. FISH revealed a subtelomeric microdeletion encompassing both FOXC1 and FOXF2 loci within 6p25. Dysmyelination of the central nervous system has been infrequently described earlier in patients with 6p25 deletion.

Pelizaeus-Merzbacher Disease: A case report

Pelizaeus-Merzbacher disease (PMD) is an X-linked recessive disorder characterized by dysmyelination of the central nervous system (CNS) caused by mutations in the proteolipid protein (PLP) gene. PLP is located at Xq22 and its mutation result in abnormal expression or production of PLP, the most abundant protein in CNS myelin. We present a case of PMD in the 7-year-old boy with nystagmus, ataxia, spastic quadriplegia and severe psychomotor delay. His brain MRI revealed totally dysmyelinated white matter involving entire supratentorial region, atrophic change, and overaccumulation of the iron in both basal ganglia. He also showed soft-tissue contractures of the hip adductors, associated hip dislocations and equinovarus foot deformities due to severe spasticity of lower extremities. Orthopaedic surgery was performed on both hips. Antispastic medication and physical therapy were maintained for reduction of spasticity. We report this case with the review of literatures.

Two Cases of Pelizaeus-Merzbacher Disease

Pelizaeus-Merzbacher disease (PMD) is a rare sudanophilic leukodystrophy with a reduced number of mature oligodendrocytes as well as diffuse central nervous system hypomyelination (dysmyelination) due to abnormal synthesis of proteolipid protein. PMD is characterized with pendular nystagmus, stridor, delay in psychomotor development, hypotonia, ataxia, athetosis and extrapyramidal signs. Abnormal high signal intensity is shown in the entire white matter of cerebrum and cerebellum at early stage by T2-weighted magnetic resonance imaging (MRI). We report two cases of PMD diagnosed with characteristic clinical manifestations and brain MRI findings.