Migraine with aura
Often the earliest symptom — appearing in the 20s or 30s. About 30–40% of CADASIL patients experience migraine with aura. Auras may be visual, sensory, or aphasic, and are sometimes prolonged (hours rather than minutes), atypical, or hemiplegic.
Rarely, a migraine attack can be followed by an encephalopathic episode — hours to days of fever, seizures, altered consciousness, or severe migraine-like symptoms. These are frightening but generally reversible, and always warrant emergency assessment. Learn more →
Onset: 20s–30s · Frequency: 30–40% of patients
Stroke & TIA
Recurrent lacunar (small, deep) ischemic strokes and TIAs are the clinical hallmark — most often beginning between the ages of 40 and 70. They typically occur in patients without classical vascular risk factors, which is part of why diagnosis is delayed.
In plain terms, a CADASIL stroke often looks like sudden one-sided weakness (arm, leg, or face), slurred speech, or a brief episode of numbness or vision change. Individual events are usually mild, and many people recover most or all of their function. But the cumulative effect of repeated strokes over years is what drives the disease's long-term impact — which is why early diagnosis and vascular risk-factor control matter so much.
Onset: 40s–70s · Frequency: 60–85% over a lifetime
Cognitive impairment
Subcortical vascular cognitive impairment — typically affecting attention, processing speed, and executive function first. Memory tends to be relatively spared early on. Decline is often stepwise rather than smooth.
Onset: 50s–70s · Frequency: Eventually in most patients
Mood disturbance & apathy
Depression and apathy affect ~30% of patients and may precede other symptoms. Apathy in CADASIL is a distinct clinical feature, not just "low mood" — it reflects disconnection of frontal–subcortical circuits and often goes unrecognized.
Onset: Any age · Frequency: ~30%
Gait disturbance
Later in the disease course, many patients develop small-stepped, magnetic gait with imbalance, falls, and pseudobulbar features (emotional incontinence, dysphagia). These reflect cumulative deep white-matter and basal-ganglia injury.
Onset: 60s+ · Frequency: Common in advanced disease
A telling family history
The pattern is autosomal dominant — strokes, "early dementia," migraines, or psychiatric illness across multiple generations. Some families have already been told their relatives had MS, a "weak vessel," or unexplained early decline.
Inheritance: 50% per child · Penetrance: Near-complete, variable expressivity
