Stem Cell Dynamics in an Experimental Model of Stroke / 전남의대학술지

We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC). The contrast to noncontrast ratio (CNR) on MRI was greatest at 12 hours in DWI and decreased over time. By contrast, T1-weighted and T2-weighted images showed a constant CNR from the beginning through 8 weeks. MRI of the lesional cortex correlated with histopathologic findings, which could be divided into three stages: acute (edema and necrosis) within 24 hours, subacute (acute and chronic inflammatory cell infiltration) at 2 to 7 days, and chronic (gliofibrosis) at 2 to 4 weeks. The volume of the infarct was significantly reduced by reparative gliofibrosis. The number of nestin+ NSCs in the contralateral SVZ was similar to that of the ipsilateral SVZ in each group. However, the number of nestin+ NSCs in the ipsilateral cortex and CC increased at 12 hours to 3 days compared with the contralateral side (p<0.01) and was reduced significantly by 7 days (p<0.01). Active emigration of internal NSCs from the SVZ toward the infarct lesion may also contribute to decreased volume of the infarct lesion, but the self-repair mechanism by endogenous NSCs is insufficient to treat stroke causing extensive neuronal death. Further studies should be focused on amplification technologies of NSCs to enhance the collection of endogenous or transplanted NSCs for the treatment of stroke.

Stem Cell Dynamics in an Experimental Model of Stroke / 전남의대학술지

We investigated the migration of endogenous neural stem cells (NSCs) toward an infarct lesion in a photo-thrombotic stroke model. The lesions produced by using rose bengal dye (20 mg/kg) with cold light in the motor cortex of Sprague-Dawley rats were also evaluated with sequential magnetic resonance imaging (MRI) from 30 minutes through 8 weeks. Migration of NSCs was identified by immunohistochemistry for nestin monoclonal antibody in the lesion cortex, subventricular zone (SVZ), and corpus callosum (CC). The contrast to noncontrast ratio (CNR) on MRI was greatest at 12 hours in DWI and decreased over time. By contrast, T1-weighted and T2-weighted images showed a constant CNR from the beginning through 8 weeks. MRI of the lesional cortex correlated with histopathologic findings, which could be divided into three stages: acute (edema and necrosis) within 24 hours, subacute (acute and chronic inflammatory cell infiltration) at 2 to 7 days, and chronic (gliofibrosis) at 2 to 4 weeks. The volume of the infarct was significantly reduced by reparative gliofibrosis. The number of nestin+ NSCs in the contralateral SVZ was similar to that of the ipsilateral SVZ in each group. However, the number of nestin+ NSCs in the ipsilateral cortex and CC increased at 12 hours to 3 days compared with the contralateral side (p<0.01) and was reduced significantly by 7 days (p<0.01). Active emigration of internal NSCs from the SVZ toward the infarct lesion may also contribute to decreased volume of the infarct lesion, but the self-repair mechanism by endogenous NSCs is insufficient to treat stroke causing extensive neuronal death. Further studies should be focused on amplification technologies of NSCs to enhance the collection of endogenous or transplanted NSCs for the treatment of stroke.

Neurofilament Protein Subtype Expression in Neuronal Migration Disorders

BACKGROUND: Neuronal migration disorder (NMD) is one of the causes of medically intractable epilepsy. As neurosurgical treatments for medically intractable epilepsy have expanded recently, precise histopathologic diagnosis is required. Histopathologic grading of NMD is important due to its association with neocortical development and expectation of prognosis. Many studies revealed abnormalities of neuronal cytoskeletal protein in abnormal neuronal cells of NMD. METHODS: We performed immunohistochemical staining for neurofilament protein (NF) subtypes, one of the neuronal cytoskeletal proteins, and investigated the staining pattern of specific cells in each grade of NMD. RESULTS: NF-L was more intensely labeled in perikarya, dendrites, and axons of normal or small sized dysplastic neurons, cytomegalic neurons, and balloon cells than of normal-looking neurons. Furthermore, positive reaction was more intense in high-grade lesion. NF-H and NF-M were mainly positive in the axons of gray and white matter and weakly positive in a few cytomegalic neurons and some balloon cells. CONCLUSION: NF-L is a better marker than NF-H and NF-M for the detection of normal or small sized dysplastic neurons, cytomegalic neurons, and balloon cells and for grading of NMD.

Risk Factors of Epilepsy After Stroke in Children / 대한소아신경학회지

PURPOSE: Post-stroke seizures and epilepsy were mainly studied in adults. Selected groups of children with stroke were studied to evaluate the incidence of seizures and epilepsy and the risk factors of epilepsy after stroke. METHODS: Seventy consecutive stroke children younger than 15 years of age were retrospectively reviewed to evaluate the incidence, times, causes of epilepsy and the risk factors epilepsy after stroke. The number and location of the lesion as imaged on the CT scan, and MRI scan were determined. RESULTS: Epilepsy after stroke was diagnosed in 38(54.3%) of 70 stroke patients:16 (45.7%) of 35 with hemorrhagic stroke and 22(62.9%) of 35 with ischemic stroke. Arteriovenous malformation(18), vitamin K deficiency(7), hemophilia(5) were frequent causes in hemorrhagic stroke, and idiopathic(15), moyamoya disease(11), hemiconvulsion-hemiplegia-epilepsy syndrome(6) were frequent in ischemic stroke. No statistically significant differences were noted with relation to sex, type of stroke, number of the lobar lesions, between cortical and subcortical lesions and onset time of initial seizure. Epilepsy developed more often in patients who had lesions located in the left cerebral hemisphere (76.7%) than on the right(42.3%)(P<0.01). CONCLUSION: Epilepsy developed more often in children who had lesion located in left cerebral hemisphere. No statistically significant differences noted in relation to sex, type of stroke, number of the lobar lesions and between cortical and subcortical lesions.

Three Cases of Symptomatic Huge Arachnoid Cysts / 대한소아신경학회지

Congenital arachnoid cysts are commonly located at sylvian cistern or middle cranial fossa which are usually asymptomatic and incidentally found. Posterior fossa cysts, however, are usually large when diagnosed, and symptomatic. Three cases of large posterior fossa cysts were recognized on the diagnostic MRI investigation for infantile spasm, developmental delay, and the precocious puberty. Surgical decompression of the cysts by craniectomy, cyst excision and fenestration were performed successfully in two patients with arachnoid cysts in the cerebellopontine cistern and the suprasellar, right cerebellopontine, and prepontine cisterns, but an additional cystoperitoneal shunt was needed in a case with the cyst in the quadrigemial cistern with obstructive hydrocephalus. Infantile spasm was treated with vigabatrin and pyridoxine, and the true precocious puberty was managed with LHRH analogue(Decapeptyl ).