Background Writer＇s cramp is a type of task specific idiopathic focal dystonia and has an incompletely understood pathophysiology. The present study utilized functional magnetic resonance imaging （fMRI） to investig...Background Writer＇s cramp is a type of task specific idiopathic focal dystonia and has an incompletely understood pathophysiology. The present study utilized functional magnetic resonance imaging （fMRI） to investigate what type of brain activity correlates with writer＇s cramp and its physiological mechanism.Methods Ten patients with writer＇s cramp were age and gender matched with ten nealthy control suojects in a block design. Subjectswere scanned by fMRI while performing three consecutive, visually instructive, tasks with MR Vision 2000： （1） suppositional writing, （2） writing with finger and （3） writing with a pencil. Data was analysed using AFNI software for groups of patients and controls.Results The patients with writer＇s cramp showed significant activations of contralateral basal ganglion （especially the putamen）, motor cortex （primary sensorimotor cortex, supplementary motor cortex, premotor cortex） and ipsilateral cerebellar hemisphere in writing with a pencil compared with controls; whereas there was no obvious difference between patients and controls during writing with finger. Furthermore, these differences exist in the stibtractive activated maps for ＂writing with a pencil＂ minus ＂writing with finger＂ of patients, when the activation of subcortical area and insula in controls disappeared.Conclusions Abnormal activations of contralateral basal ganglion, motor cortex and ipsilateral cerebellar hemisphere of the patients with writer＇s cramp suggest dysfunction of basal ganglion and subcortical-cortical loop might play a pathophysiological role in writer＇s cramp.展开更多
Background Histamine H3 receptor antagonists have been considered as potential drugs to treat central nervous system diseases. However, whether these drugs can inhibit epileptogenesis remains unclear. This study aimed...Background Histamine H3 receptor antagonists have been considered as potential drugs to treat central nervous system diseases. However, whether these drugs can inhibit epileptogenesis remains unclear. This study aimed to investigate the effects of thioperamide, a selective and potent histamine H3 receptor antagonist, on the seizure development and memory impairment induced by pentylenetetrazole （PTZ）-kindling epilepsy in rats. Methods Chemical kindling was elicited by repeated intraperitoneal （ip） injections of a subconvulsant dose of PTZ （35 mg/kg） once every 48 hours for 12 times, and seizure activity of kindling was recorded for 30 minutes. Control rats were ip injected with saline instead of PTZ. Morris water maze was used to evaluate the spatial memory. Phosphorylated cyclic adenosine monophosphate response element binding protein （p-CREB） was tested by Western blotting in hippocampus. Results Intracerebroventricular （icv） injections with thioperamide （10 μg, 20 μg） 30 minutes before every PTZ injections, significantly prolonged the onset of PTZ-kindling and inhibited the seizure stages. PTZ-kindling seizures led to the impairment of spatial memory in rats, and thioperamide ameliorated the impairment of spatial learning and memory. Compared to non-kindling rats, there was a significant decrease in p-CREB level in hippocampus of the PTZ-kindling rats, which was reversed by thioperamide. Conclusions Thioperamide plays a protective role in seizure development and cognitive impairment of PTZ-induced kindling in rats. The protection of thioperamide in cognitive impairment is possibly associated with the enhancement of CREB-dependent transcription.展开更多
Background An early identification of the composition of arterial thrombus may have diagnostic, therapeutic, and prognostic implications. The variation of magnetic resonance （MR） signal intensity between white and r...Background An early identification of the composition of arterial thrombus may have diagnostic, therapeutic, and prognostic implications. The variation of magnetic resonance （MR） signal intensity between white and red thrombi, especially in the susceptibility sensitive MR sequence, remains unknown. Our research was to evaluate the feasibility of MRI in differentiating of white and red thrombi with a phantom study. Methods A total of 12 red and 12 white thrombi were prepared with the venous blood. Examination of the phantom was completed using a 3.0T MR unit, including fluid attenuated inversion recovery （FLAIR） T1, T2-weighted imaging （T2WI）, FLAIR T2, T2＊ gradient echo （T2＊GRE） imaging, and susceptibility weighted angiography sequences （SWAN）. MR signal intensity patterns of the thrombi were objectively classified as hyperintensity, isointensity and hypointensity, compared with the background agar. The volume of thrombus was calculated and correlated with its signal intensity. Results For white thrombi, 11/12 clots showed hyperintensity and 1/12 showed isointensity in FLAIR T1 images. In T2WI, 6/12 clots showed hyperintensity, 3/12 isointensity, and 3/12 hypointensity. In FLAIR T2, 8/12 clots showed hyperintensity and 4/12 showed isointensity. In T2＊GRE, 3/12 clots showed hyperintensity and the remaining 9/12 clots showed isointensity. In SWAN, 5/12 clots demonstrated hyperintensity and 7/12 isointensity. For the red thrombus, 12/12 clots demonstrated hyperintensity in FLAIR T1, T2WI, and FLAIR T2 sequences. In T2＊GRE and SWAN sequences, 3/12 clots displayed hypointensity and the remaining 9/12 clots showed slight hyperintensity. Thrombi with hypointensity displayed in T2＊GRE and SWAN sequences were significantly larger than those with hyperintensity. Conclusions Differentiation of white and red thrombi with conventional MR sequence is unreliable, because both kinds of thrombi do not possess unique signal intensity features in these sequences. Red thrombus may or may not show hypointensity in the susceptibility sensitive MR sequences, depending on its size and time course.展开更多
Background Some studies indicated that cases of idiopathic oculomotor nerve palsy can be explained by vascular compression of the oculomotor nerve. Vascular contact with or compression to the cisternal segment of the ...Background Some studies indicated that cases of idiopathic oculomotor nerve palsy can be explained by vascular compression of the oculomotor nerve. Vascular contact with or compression to the cisternal segment of the oculomotor nerve has been reported frequently in asymptomatic individuals. In this study, we retrospectively analyzed the relationship between the oculomotor nerve＇s cisternal segment and adjacent arteries in asymptomatic patients and the prevalence of this occurrence via magnetic resonance imaging （MRI）. Method MRI of bilateral oculomotor nerves in 93 asymptomatic patients were reviewed. The oculomotor nerve-artery relationship was evaluated and classified from levels 1 to 3, representing the degrees of contact on oblique transverse and oblique sagittal reconstructed MRI. Prevalence of the nerve-artery relationship at each level was described. The correlation between the nerve-vessel relationship （levels） and the age was analyzed by Spearman＇s rank correlation analysis. Results Cisternal segment of the oculomotor nerve did not have contact with any artery （level 1） in 27.4% （51/186） nerves. One hundred nerves made contact with at least one artery （level 2）, but their shapes or configurations were not changed; 35 nerves （18.8%） were displaced or distorted due to artery compression （level 3）. The posterior cerebral artery had the greatest incidence of making contact with or compressing the cisternal segment of the oculomotor nerve （58.1%）. No significant correlation between nerve-vessel relationship （levels） and the age was found in this study. Conclusions Whether oculomotor nerve contact with or compression by one or more arteries is of high prevalence in asymptomatic individuals as evidenced by MRI examination. There is no correlation with individual age. Discretion should be used when making an etiological diagnosis of vascular compression for patients with oculomotor nerve palsy. Further investigation of other causes is warranted.展开更多
文摘Background Writer＇s cramp is a type of task specific idiopathic focal dystonia and has an incompletely understood pathophysiology. The present study utilized functional magnetic resonance imaging （fMRI） to investigate what type of brain activity correlates with writer＇s cramp and its physiological mechanism.Methods Ten patients with writer＇s cramp were age and gender matched with ten nealthy control suojects in a block design. Subjectswere scanned by fMRI while performing three consecutive, visually instructive, tasks with MR Vision 2000： （1） suppositional writing, （2） writing with finger and （3） writing with a pencil. Data was analysed using AFNI software for groups of patients and controls.Results The patients with writer＇s cramp showed significant activations of contralateral basal ganglion （especially the putamen）, motor cortex （primary sensorimotor cortex, supplementary motor cortex, premotor cortex） and ipsilateral cerebellar hemisphere in writing with a pencil compared with controls; whereas there was no obvious difference between patients and controls during writing with finger. Furthermore, these differences exist in the stibtractive activated maps for ＂writing with a pencil＂ minus ＂writing with finger＂ of patients, when the activation of subcortical area and insula in controls disappeared.Conclusions Abnormal activations of contralateral basal ganglion, motor cortex and ipsilateral cerebellar hemisphere of the patients with writer＇s cramp suggest dysfunction of basal ganglion and subcortical-cortical loop might play a pathophysiological role in writer＇s cramp.
基金This study was supported by grants from the Natural Science Foundation of Zhejiang Province （No. Y2090184） and the Project of Chinese Traditional Medicine of Zhejiang Province （No. 2006Y005）.
文摘Background Histamine H3 receptor antagonists have been considered as potential drugs to treat central nervous system diseases. However, whether these drugs can inhibit epileptogenesis remains unclear. This study aimed to investigate the effects of thioperamide, a selective and potent histamine H3 receptor antagonist, on the seizure development and memory impairment induced by pentylenetetrazole （PTZ）-kindling epilepsy in rats. Methods Chemical kindling was elicited by repeated intraperitoneal （ip） injections of a subconvulsant dose of PTZ （35 mg/kg） once every 48 hours for 12 times, and seizure activity of kindling was recorded for 30 minutes. Control rats were ip injected with saline instead of PTZ. Morris water maze was used to evaluate the spatial memory. Phosphorylated cyclic adenosine monophosphate response element binding protein （p-CREB） was tested by Western blotting in hippocampus. Results Intracerebroventricular （icv） injections with thioperamide （10 μg, 20 μg） 30 minutes before every PTZ injections, significantly prolonged the onset of PTZ-kindling and inhibited the seizure stages. PTZ-kindling seizures led to the impairment of spatial memory in rats, and thioperamide ameliorated the impairment of spatial learning and memory. Compared to non-kindling rats, there was a significant decrease in p-CREB level in hippocampus of the PTZ-kindling rats, which was reversed by thioperamide. Conclusions Thioperamide plays a protective role in seizure development and cognitive impairment of PTZ-induced kindling in rats. The protection of thioperamide in cognitive impairment is possibly associated with the enhancement of CREB-dependent transcription.
文摘Background An early identification of the composition of arterial thrombus may have diagnostic, therapeutic, and prognostic implications. The variation of magnetic resonance （MR） signal intensity between white and red thrombi, especially in the susceptibility sensitive MR sequence, remains unknown. Our research was to evaluate the feasibility of MRI in differentiating of white and red thrombi with a phantom study. Methods A total of 12 red and 12 white thrombi were prepared with the venous blood. Examination of the phantom was completed using a 3.0T MR unit, including fluid attenuated inversion recovery （FLAIR） T1, T2-weighted imaging （T2WI）, FLAIR T2, T2＊ gradient echo （T2＊GRE） imaging, and susceptibility weighted angiography sequences （SWAN）. MR signal intensity patterns of the thrombi were objectively classified as hyperintensity, isointensity and hypointensity, compared with the background agar. The volume of thrombus was calculated and correlated with its signal intensity. Results For white thrombi, 11/12 clots showed hyperintensity and 1/12 showed isointensity in FLAIR T1 images. In T2WI, 6/12 clots showed hyperintensity, 3/12 isointensity, and 3/12 hypointensity. In FLAIR T2, 8/12 clots showed hyperintensity and 4/12 showed isointensity. In T2＊GRE, 3/12 clots showed hyperintensity and the remaining 9/12 clots showed isointensity. In SWAN, 5/12 clots demonstrated hyperintensity and 7/12 isointensity. For the red thrombus, 12/12 clots demonstrated hyperintensity in FLAIR T1, T2WI, and FLAIR T2 sequences. In T2＊GRE and SWAN sequences, 3/12 clots displayed hypointensity and the remaining 9/12 clots showed slight hyperintensity. Thrombi with hypointensity displayed in T2＊GRE and SWAN sequences were significantly larger than those with hyperintensity. Conclusions Differentiation of white and red thrombi with conventional MR sequence is unreliable, because both kinds of thrombi do not possess unique signal intensity features in these sequences. Red thrombus may or may not show hypointensity in the susceptibility sensitive MR sequences, depending on its size and time course.
文摘Background Some studies indicated that cases of idiopathic oculomotor nerve palsy can be explained by vascular compression of the oculomotor nerve. Vascular contact with or compression to the cisternal segment of the oculomotor nerve has been reported frequently in asymptomatic individuals. In this study, we retrospectively analyzed the relationship between the oculomotor nerve＇s cisternal segment and adjacent arteries in asymptomatic patients and the prevalence of this occurrence via magnetic resonance imaging （MRI）. Method MRI of bilateral oculomotor nerves in 93 asymptomatic patients were reviewed. The oculomotor nerve-artery relationship was evaluated and classified from levels 1 to 3, representing the degrees of contact on oblique transverse and oblique sagittal reconstructed MRI. Prevalence of the nerve-artery relationship at each level was described. The correlation between the nerve-vessel relationship （levels） and the age was analyzed by Spearman＇s rank correlation analysis. Results Cisternal segment of the oculomotor nerve did not have contact with any artery （level 1） in 27.4% （51/186） nerves. One hundred nerves made contact with at least one artery （level 2）, but their shapes or configurations were not changed; 35 nerves （18.8%） were displaced or distorted due to artery compression （level 3）. The posterior cerebral artery had the greatest incidence of making contact with or compressing the cisternal segment of the oculomotor nerve （58.1%）. No significant correlation between nerve-vessel relationship （levels） and the age was found in this study. Conclusions Whether oculomotor nerve contact with or compression by one or more arteries is of high prevalence in asymptomatic individuals as evidenced by MRI examination. There is no correlation with individual age. Discretion should be used when making an etiological diagnosis of vascular compression for patients with oculomotor nerve palsy. Further investigation of other causes is warranted.
