Expression and significance of sonic hedgehog signaling pathway-related components in brainstem and supratentorial astrocytomas / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Studies have shown that abnormal activation of the sonic hedgehog pathway is closely related to tumorigenesis in central nervous system. This study aimed to investigate the role of the sonic hedgehog signaling pathway in the occurrence of brainstem and supratentorial glioma.</p><p><b>METHODS</b>Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry were used to detect the expression of sonic hedgehog-related components in 5 specimens of normal brain tissue, 10 of grade II brainstem glioma, and 10 of grade II supratentorial glioma. The significance of differences between two groups was determined using the Mann-Whitney U test or the two-sample test according to the results of normality distribution tests.</p><p><b>RESULTS</b>The mRNA expression levels of sonic hedgehog-related genes were higher in brainstem astrocytomas than in supratentorial astrocytomas and normal brain tissue. The level of protein patched homolog 1 (PTCH1) was significantly higher in brainstem astrocytomas than in supratentorial astrocytomas and normal brain tissue (P < 0.01). Immunohistochemistry semi-quantitative analysis was consistent with the qRT-PCR result that PTCH1 expression was increased significantly in brainstem astrocytomas at the protein level (P < 0.05).</p><p><b>CONCLUSIONS</b>Enhanced PTCH1 expression and activation of the sonic hedgehog pathway are involved in brainstem glioma. This may be related to the difference in malignant biological behavior between brainstem and hemispheric glioma, and could be an ideal therapeutic target in brainstem glioma.</p>

Intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation for preservation of facial nerve function in patients with large acoustic neuroma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although various monitoring techniques have been used routinely in the treatment of the lesions in the skull base, iatrogenic facial paresis or paralysis remains a significant clinical problem. The aim of this study was to investigate the effect of intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation on preservation of facial nerve function.</p><p><b>METHOD</b>From January to November 2005, 19 patients with large acoustic neuroma were treated using intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation (TCEMEP) for preservation of facial nerve function. The relationship between the decrease of MEP amplitude after tumor removal and the postoperative function of the facial nerve was analyzed.</p><p><b>RESULTS</b>MEP amplitude decreased more than 75% in 11 patients, of which 6 presented significant facial paralysis (H-B grade 3), and 5 had mild facial paralysis (H-B grade 2). In the other 8 patients, whose MEP amplitude decreased less than 75%, 1 experienced significant facial paralysis, 5 had mild facial paralysis, and 2 were normal.</p><p><b>CONCLUSIONS</b>Intraoperative TCEMEP can be used to predict postoperative function of the facial nerve. The decreased MEP amplitude above 75 % is an alarm point for possible severe facial paralysis.</p>