Tumor

• Pentagon sign showing supracellar cistern like a jewish star
• Sites of saccular Aneurysm
• Pituitary adenoma
• Primary headache is a diagnosis of exclusion (by history and examination, with no red flag signs (SNOOP))
• Trauma is the commonest cause of SAH
• ACOM (anterior communicating artery) is the commonest cause of aneurysmal SAH
• Supratentorial vs. infratentorial tumors
• Steroids are contraindicated in brain TRAUMA
• Steroids are indicated in brain TUMORS
• METASTATIC tumor is the commonest brain tumor

  
• GLIOMAS (fibrillary astrocytoma 80%) are the commonest primary brain tumors

  
• MENINGIOMAS are the commonest benign tumors
• WHO Classification
• Low grade: no edema, no enhancement
• High grade: huge edema, enhancement, midline shift, effaced ventricles
• Oligodendrogliomas: calcification
• Multi cystic lesion on MRI? Metastatic tumors

  
• Meningiomas? Reactive hyperostosis
• In CT? hypodense
• In IV CT? Hyperdense, strong enhancement