Common Symptoms of Symptomatic Intracranial Atherosclerosis
Symptomatic intracranial atherosclerosis most commonly presents with transient ischemic attacks (TIAs) or ischemic strokes in the territory of the stenotic artery. 1
Primary Clinical Presentations
Focal Ischemic Events
The hallmark presentations include:
- Transient ischemic attacks (TIAs) - temporary focal neurological deficits that resolve, occurring in the vascular territory supplied by the stenotic intracranial artery 1
- Ischemic stroke - permanent neurological deficits corresponding to the affected arterial territory 1
- Recurrent stereotyped TIAs - brief, repetitive episodes of similar symptoms suggesting critical stenosis and hemodynamic compromise 1
Territory-Specific Symptoms
The specific symptoms depend on which intracranial artery is affected:
- Middle cerebral artery stenosis (most common location) - contralateral motor weakness, sensory loss, and possible aphasia if the dominant hemisphere is involved 2
- Vertebrobasilar stenosis - vertigo, diplopia, ataxia, bilateral motor or sensory symptoms, and cranial nerve deficits 1
- Anterior circulation involvement - hemispheric symptoms including hemiparesis, hemisensory loss, visual field defects, and language disturbances 3
Stroke Mechanisms and Associated Symptoms
The underlying mechanisms producing symptoms include artery-to-artery embolism, hypoperfusion, branch occlusion, or mixed mechanisms. 3
- Artery-to-artery embolism - sudden onset focal deficits, often cortical symptoms like aphasia or neglect 3
- Hypoperfusion - symptoms triggered by positional changes or blood pressure drops, watershed infarct patterns 3
- Branch occlusion - small deep infarcts causing lacunar syndromes (pure motor hemiparesis, pure sensory stroke) 2
- Mixed mechanism (artery-to-artery embolism plus hypoperfusion) - associated with higher recurrence risk and more severe presentations 3
Critical Presentation Features
High-Risk Symptoms
- Recent symptom onset (within 17 days) indicates highest risk for recurrent stroke 1
- Severe stenosis (≥70%) correlates with higher stroke risk and more frequent symptoms 1
- Progressive or crescendo TIAs suggest unstable plaque or critical hypoperfusion requiring urgent evaluation 1
Atypical Presentations
While less common, some patients present with:
- Memory, speech, and hearing difficulties in cases of critical (>70-90%) stenosis causing chronic hypoperfusion of the dominant hemisphere 1
- Cognitive deficits when stenosis affects multiple territories or causes chronic hypoperfusion 1
Important Clinical Pitfalls
Do not confuse nonfocal symptoms (isolated vertigo, syncope, transient global amnesia, bilateral weakness) with typical symptomatic intracranial atherosclerosis - these have uncertain relationship to intracranial disease and may represent other pathology. 1
Brief, stereotyped, repetitive symptoms require electroencephalography to exclude partial seizures rather than assuming vascular etiology. 1
Risk Stratification Based on Symptoms
The annual stroke risk varies by presentation:
- Carotid territory symptomatic disease - 3.1-11.7% annual stroke rate 1
- Middle cerebral artery symptomatic disease - 2.8-4.7% annual stroke rate 1
- Vertebrobasilar symptomatic disease - 2.4-13.1% annual stroke rate 1
Patients with symptomatic intracranial atherosclerosis face the highest recurrent stroke risk among all stroke subtypes, with risk concentrated in the first few weeks after the initial event. 4, 5