**3. Clinical spectrum**

In general, hereditary form of CAA has an earlier onset and more severe clinical manifestations than sporadic CAA. Symptomatic CAA has variable clinical presentations, which include sudden neurologic deficit (stroke) related to acute ICH, TIA-like symptoms, cognitive impair‐ ment and dementia. [7]

The most common presentation of CAA is the development of a sudden neurological deficit secondary to an acute ICH. Specific clinical symptoms and signs depend on both the size and location of the ICH. CAA can have similar presentation as acute ICH related to other causes: headache, nausea and vomiting, loss of consciousness, focal neurological deficits and seizures. [8]

Transient-ischemic attack (TIA) like symptoms also termed as "amyloid spells" is the next most commonly described presentation. The spells are typically brief (<30mts) and are characterized by recurrent, stereotyped episodes of 'positive' spreading sensory symptoms (paraesthesias). The spells are related to hemorrhagic components of CAA, for example cortical microbleeds (CMBs), cortical subarachnoid hemorrhage (cSAH), or cortical superficial siderosis. [4,9]

The prevalence of CAA is significantly higher in demented patients (due to Alzheimer disease) compared to non-demented patients. CAA-related dementia is slowly progressive, similar to that seen in patients with Alzheimer disease. [10] CAA is also the direct cause of cognitive impairment that progresses rapidly over the course of a few weeks. These patients may present with confusion and disorientation. [3]
