What are the common vascular malformations that can cause intracranial hemorrhage in young patients, and how do they differ from hypertensive hemorrhages?

Vascular malformations such as arteriovenous malformations (AVMs), cavernous malformations, telangiectasias, and venous malformations can cause intracranial hemorrhage in young patients. AVMs often present with a nidus of tangled vessels and can be identified on MRI or CT angiography. Cavernous malformations appear as 'popcorn-like' lesions with a hemosiderin rim on MRI. A common pitfall is mistaking a small AVM for a developmental venous anomaly, which typically does not bleed. Recognizing these differences is crucial for appropriate management.