Intracranial Atherosclerotic Disease

You have been diagnosed with intracranial atherosclerosis – what does this mean?

A diagnosis of intracranial atherosclerosis means that one or more arteries inside the brain are significantly narrowed due to plaque buildup (“hardening” of the arterial wall). This reduces blood flow to specific brain regions and increases the risk of ischemic stroke or TIA.

It does not mean that a major stroke is inevitable. With a structured treatment plan that includes optimized medical therapy, aggressive control of risk factors, and—when indicated—targeted interventional treatment, the risk of recurrence can be substantially reduced.

What exactly is intracranial atherosclerosis?

It is the form of atherosclerosis that affects the major arteries within the skull (internal carotid arteries, middle cerebral artery, basilar artery, vertebral arteries, etc.). Cholesterol, inflammatory cells, and calcium accumulate in the vessel wall, forming plaques that narrow the lumen.

This narrowing may lead to:

• Local thrombosis with complete arterial occlusion
• Distal embolization of small clots
• Chronic hypoperfusion (“hemodynamic insufficiency”)

Why does it develop? Risk factors

The risk factors largely mirror those of “classic” atherosclerosis, although in certain populations (e.g., individuals of Asian or African descent) the intracranial form is more prevalent.

• Age > 55 years
• Diabetes mellitus
• Arterial hypertension
• Dyslipidemia (elevated LDL, low HDL)
• Smoking
• Metabolic syndrome & obesity
• Family history of stroke

Large epidemiological studies indicate that intracranial atherosclerosis accounts for approximately 8–10% of ischemic strokes in Western countries and up to 30–50% in Asia.

How does it present? Symptoms & clinical picture

Patients may experience:

• Transient ischemic attacks (TIAs) – brief episodes of weakness, numbness, speech disturbance, or visual loss that resolve within < 24 hours.
• Ischemic stroke – persistent or prolonged neurological deficits.
• “Crescendo” TIAs – recurrent episodes in the same vascular territory, a warning sign for impending occlusion.

Depending on the affected brain region, symptoms may include:

• Weakness or paralysis of an arm or leg
• Speech or language impairment (aphasia)
• Visual loss or hemianopia
• Imbalance, dizziness, diplopia, dysphagia (especially in vertebrobasilar disease)
• Memory, concentration, or personality changes in chronic hypoperfusion

How is it diagnosed and evaluated?

Diagnosis is based on a combination of clinical findings and cerebrovascular imaging:

• CT / MRI of the brain – identifies acute or chronic infarcts.
• CTA (CT angiography) – rapid, reliable visualization of intracranial arteries and stenoses.
• MRA (MR angiography) – non-invasive imaging without ionizing radiation.
• DSA (digital subtraction angiography) – gold standard when maximal detail is required or before intervention.
• Transcranial Doppler (TCD) – ultrasound assessment of flow, useful for screening and follow-up.

In selected patients, hemodynamic evaluation (CT/MR perfusion, SPECT, PET, quantitative MRA) is performed to assess whether the brain receives adequate blood flow or is in a state of “misery perfusion.”

Who requires treatment and how urgent is it?

All patients with intracranial atherosclerosis require intensive medical management, whether they have already experienced a stroke/TIA or the condition was discovered incidentally.

The condition is considered urgent when:

• There has been a recent TIA or stroke in the same vascular territory
• Recurrent or “crescendo” TIAs are present
• Stenosis is severe (> 70%) in a critical artery
• Imaging demonstrates hemodynamic insufficiency

What does medical therapy include?

Intensive medical management is the foundation of treatment and typically includes:

• Dual antiplatelet therapy (e.g., aspirin + clopidogrel) for the first 3 months after a symptomatic event, followed by single antiplatelet therapy depending on risk profile.
• Strict blood pressure control with individualized targets.
• Lipid-lowering therapy (usually high-intensity statins) aiming for low LDL levels.
• Optimal glycemic control in diabetic patients.
• Smoking cessation, weight management, and regular physical activity.

In certain cases, additional treatments may be indicated (e.g., management of arrhythmias, anticoagulation for other conditions). Therapy is always individualized.

What interventional options exist and when are they considered?

Interventional therapies are not first-line treatment, but may be life-saving in a small, carefully selected group of patients.

• Endovascular angioplasty with or without stenting – catheter-based dilation of the stenosis, with stent placement in selected cases.
• Microsurgical bypass (EC–IC bypass) – a rare indication, reserved for severe hemodynamic compromise with persistent symptoms despite maximal medical therapy.

Intervention is considered when all of the following are present:

• Severe stenosis (> 70%) of a major intracranial artery
• Documented hemodynamic compromise or low flow
• Recurrent TIAs or strokes despite optimal medical therapy
• Availability of treatment in a specialized center with low perioperative morbidity

What is the prognosis and risk of recurrence?

Without appropriate treatment, intracranial atherosclerosis carries a relatively high risk of recurrent stroke, particularly within the first year after the initial event.

With aggressive medical therapy, recurrence rates can be significantly reduced. Prognosis depends on:

• Severity and location of stenoses
• Extent of established brain injury
• Control of risk factors (blood pressure, glucose, lipids)
• Adherence to medication and lifestyle modifications

Many patients, with appropriate follow-up, can maintain good functional status and lead active lives.

How does this affect daily life? What can I do to help myself?

Lifestyle modification is as important as medication. Key goals include:

• Consistent blood pressure control
• Smoking cessation (with support if needed)
• Mediterranean-style diet, weight control, and limiting processed foods
• Regular aerobic exercise, following medical guidance
• Good sleep quality and stress management
• Strict adherence to prescribed medications

In most cases, work and travel are possible with minor adjustments and a clear follow-up plan.

When should I seek immediate medical attention?

Call emergency services immediately if you experience:

• Sudden weakness or numbness of the face, arm, or leg
• Acute difficulty speaking or understanding speech
• Sudden loss of vision or double vision
• Severe imbalance, dizziness with coordination problems
• Sudden, intense headache with neurological symptoms