• Recurrent ischemic stroke [ Time Frame: 90 days ]
• modified Rankin scale [ Time Frame: 90 days ]
  The modified Rankin Scale (mRS) is a commonly used scale for measuring the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. The scale runs from 0-6 with "0" being perfect health without symptoms to "6" being death. 0 - No symptoms.

  1. - No significant disability. Able to carry out all usual activities, despite some symptoms.
  2. - Slight disability. Able to look after own affairs without assistance, but unable to carry out all previous activities.
  3. - Moderate disability. Requires some help, but able to walk unassisted.
  4. - Moderately severe disability. Unable to attend to own bodily needs without assistance, and unable to walk unassisted.
  5. - Severe disability. Requires constant nursing care and attention, bedridden, incontinent.
  6. - Dead.

  9 - No data.

• Recurrent ischemic stroke [ Time Frame: 90 days ]
• modified Rankin scale [ Time Frame: 90 days ]
• modified Rankin scale [ Time Frame: 2 years ]

Rationale: Over 20.000 people suffer an ischemic stroke in the Netherlands each year. Large artery occlusions are easy to identify and can be treated with endovascular clot removal. 70% of patient will however suffer from a more distal occlusion resulting in small volume stroke or a transient ischemic attack (TIA). Small ischemic lesions are hard to detect with current acute stroke protocols. TIA and small volume stroke patients, are at an increased risk for recurrent stroke, making immediate diagnosis critical. Because thrombo-embolic sources often cause these strokes, identifying and treating the underlying aetiology has the potential to radically lower the risk of recurrence and improve the outcome of these patients.

Objectives: 1) To identify clinical and imaging predictors of recurrent stroke; 2) To improve early detection of small volume stroke with admission computed tomography perfusion (CTP) in patients with suspected acute ischemic stroke with small volume stroke or no ischemia on admission imaging.

Study design: Prospective, multicenter cohort study.

Study population: All patients who visited the University Medical Center (UMC) Utrecht, the Amsterdam University Medical Centers (Amsterdam UMC), location Academic Medical Center (AMC) or the St. Antonius Hospital and who underwent a CT-scan of the brain within 9 hours after onset of stroke symptoms with an age ≥18 years. Within 36 months, 720 patients will be enrolled in the study. Of these patients, 300 patients will be included for the follow-up magnetic resonance imaging (MRI).

Main study parameters/endpoints: The main study endpoints are: 1) Stroke recurrence rate at 2 years; 2) Presence and volume of acute ischemic lesions on follow-up diffusion weighted imaging MRI.

Inclusion Criteria:

• Age ≥18 years;
• Time from symptom onset until imaging is <9 hours*;
• Clinical diagnosis of acute ischemic stroke or TIA;

• Informed consent from patient or family after the admission scan (unless the patient died).

  • Patients who awaken with stroke symptoms can only be included if they went to sleep without any stroke symptoms and the time from going to sleep until imaging is less than 9 hours.

Exclusion Criteria:

• Patients with another diagnosis such as intracerebral hemorrhage, subarachnoid hemorrhage or tumor;
• Patients with known contrast allergy or renal failure.

• Dutch Heart Foundation
• Netherlands Organisation for Scientific Research