Intracranial Hemorrhage

=Objectives=

Describe the most common locations for aneurysms

 * 90% of aneurysms occur in the anterior circulation, especially in the anterior communicating artery, the internal carotid artery branching, and the bifurcation of the middle cerebral artery (most common).
 * 10% occur in the posterior circulation, most commonly at the top of the basilar artery

Describe how subarachnoid hemorrhage from ruptured aneurysms appear in a CT scan and an angiogram

 * CT Scan
 * More than 95% of cases have enough blood to be visualized on a high-quality noncontrast CT scan obtained within 72 h.
 * Blood accumulation in the sulci and fissures appears opaque on noncontrast CT.
 * angiogram
 * aneurysm appears as a saccular outpocketing
 * atypical AVMs may show altered venous filling kinetics

Describe what features are commonly seen in a history of a patient with a ruptured aneurysm

 * Thunderclap headache described "worst headache of my life", rapidly evolving symptoms, loss of consciousness
 * +/- focal neurological deficits (especially in cranial nerves)
 * The Hunt and Hess Grading scale is useful in the acute setting, as it describes the range of prognostic symptoms


 * Delayed symptoms are also important (see next objective).

Describe the four common complications from ruptured aneurysms

 * Delayed symptoms are also important, they include:
 * Rerupture of an aneurysm. Many patients initially present with a small "sentinel headache", which is a leak.  Rebleeding occurs in ~30% of patients in the first 3 weeks, so every patient spends 21 days in the ICU.  Rerupture --> 60% mortality.
 * Hydrocephalus: blood clogs the arachnoid granulations. Causes progressive drowsiness, stupor, incontinence, gait problems.  May be acute or appear months later.
 * Hyponatremia: both natriuresis and volume depletion with SAH. patients become hypovolemic & hyponatremic.  Increased BNP --> cerebral salt wasting.
 * Vasospasm: occurs in 30% of patients, 3 - 21 days after SAH, causes infarctions & ischemia.

Describe the six most common causes of intraparenchymal hemorrhages & key demographics, features of presentation, and locations

 * 1) Amyloid angiopathy
 * 2) *lobar bleeds from cortical and leptomeningeal arterioles
 * 3) *present with headaches (70%), nausea, focal lobar deficits (eg aphagia, cortical blindness, etc)
 * 4) Hypertension
 * 5) *common with deep hemorrhages in the putamen (53%) and thalamus (13%
 * 6) *Putamen signs are contralateral motor/sensory deficits, thalamus: sensory deficits, oculomotor signs
 * 7) *Patients: older with HTN
 * 8) Arteriovenous malformation (AVM):
 * 9) *symptomatic ages 10 to 40, lobar most common
 * 10) *small AVMs are most likely to bleed
 * 11) illicit drug use (cocaine, amphetamines)
 * 12) bleeding disorder
 * 13) tumor (renal, lung, melanoma mets most common & most vascular)
 * 14) *may need MRI or CT to diagnose

=Links= =References=