Presentation of Intracranial Aneurysms in Children

• Most present with subarachnoid hemorrhage: In the pediatric age group, 60% to 70% of patients with intracranial aneurysms present with subarachnoid hemorrhage (49).
• Hemorrhage is more likely in children younger than age 5: The rate of hemorrhage is higher in children younger than 5 years (80%) and lower in children older than 5 years (45%) or in those bearing a giant aneurysm (49).
• Most patients with giant aneurysm present with focal neurological deficits: This specific form of aneurysm presents with rupture in only 35% of cases, whereas the prevailing mode of presentation is focal neurological signs and symptoms (e.g., cranial nerve deficits) due to mass effect and location (frequently in the posterior fossa) (49).
• Most children with ruptured aneurysms present with normal mental status and no motor deficits: Most children with ruptured aneurysms present in a good clinical status (i.e., Hunt and Hess grades I and II) (9).

Symptoms and Signs

Common signs and symptoms encountered in children with intracranial aneurysms include the following (75,81–83):

• Headache: Acute headache is often due to rupture, classically described as thunderclap headache. A subacute onset of headache is common with mycotic aneurysms.
• Focal neurological deficits: This form of presentation may occur in children with dissecting aneurysms, which can lead to ischemic stroke, or with giant aneurysms, which exert local mass effect.
• Hydrocephalus: Hydrocephalus can be a result of hemorrhage or mass effect of the aneurysm itself.
• Impaired consciousness, irritability, vomiting: These symptoms suggest elevated ICP.
• Seizures: Seizures may be due to subarachnoid hemorrhage, ischemia, hydrocephalus, or mass effect. They may present with aura.
• Other symptoms related to mass effect: Brainstem compression and cranial nerve dysfunction may be observed due to local mass effect.

Patterns of evolution

• Ruptured aneurysms: Acute onset of thunderclap headache is often observed in patients with ruptured aneurysms. Seizures and symptoms of elevated ICP may present later, although there is not a stereotypic pattern of acquisition of these signs and symptoms.
• Unruptured aneurysms: The type, location, and size of unruptured intracranial aneurysms are highly variable. Accordingly, there is not a stereotypic pattern of acquisition of signs and symptoms related to these lesions.

Time of evolution

• Subarachnoid hemorrhage: Patients with hemorrhage usually present with an acute onset of symptoms, although a “sentinel” or “warning” bleed is possible (84).
• Dissecting aneurysm: Patients with dissecting aneurysm may present with subacute ischemic symptoms (49).
• Giant aneurysm: Patients with giant aneurysm may present with progressive neurological deficits (e.g., cranial nerve compression) (43,81).
• Traumatic aneurysm: Patients with traumatic aneurysm may present with an interval of several weeks to a few months between trauma and presentation (74).
• Infectious aneurysm: Aneurysm formation and hemorrhage may occur within 24 and 48 hours of septic embolization, respectively (85).

Evaluation at Presentation

Pediatric aneurysms pose a diagnostic challenge for several reasons, such as:

• Low incidence: The low incidence and thus often scarce knowledge of this condition among physicians might delay diagnosis.
• Poor history: In children, depending on age, it might be difficult to obtain a conclusive history. The very young are unable even to express their complaints (e.g., sudden onset of severe headache).
• Delayed presentation: In cases of traumatic aneurysms, a longer interval between trauma and presentation might obscure the diagnosis.

History and Physical Examination

The diagnostic algorithm upon presentation should be as follows:

• Physical examination: Physical examination should include a basic assessment of level of consciousness (e.g., by means of the GCS) and a focused neurological examination to detect focal deficits.
• Past medical history: Risk factors, such as predisposing conditions or previous head trauma, are of particular interest.
• Diagnostic imaging: As a next step, imaging should be obtained (86). A nonenhanced CT scan is the initial modality to diagnose intracranial hemorrhage. CTA can detect intracranial aneurysms, although DSA remains the gold standard. MRI and MRA can provide additional information in selected patients (87). Color flow Doppler ultrasound may be useful in the initial evaluation of cerebral blood flow patterns in neonates (88), but is of limited utility in older children due to their increased skull thickness and lack of fontanelle patency.
• Lumbar tap: In certain cases, namely those with diagnostic uncertainty, a lumbar tap can be performed to rule out subarachnoid hemorrhage (89). Prior to lumbar puncture, an intracranial space-occupying lesion should be radiologically excluded.
• Blood cultures for infectious aneurysms: Blood cultures are important in children with suspected bacterial endocarditis or other etiologies of infectious aneurysms. Note that blood culture may be negative in a small proportion of patients (86).

Intervention at Presentation

Depending on the severity and evolution of symptoms, the following steps are recommended:

Stabilization

• Vascular access: Large bore IVs, arterial line, and central venous catheter should be discussed.
• Airway intubation: Although it should not be used as the sole criterion for intubation, a GCS ≤8 reflects significantly impaired consciousness, and intubation should be discussed.
• Blood pressure control: In the acute phase, especially in subarachnoid hemorrhage, aim for normotension for the child’s age.
• Treatment of hydrocephalus and elevated ICP: An EVD may be indicated if hydrocephalus is present.
• Treatment of seizures: Antiepileptic medication should be administered in symptomatic epilepsy.
• Antibiotics for infectious aneurysms: Broad-spectrum antibiotic therapy should be initiated for patients with suspected infectious aneurysms (86).

Preparation for definitive intervention, nonemergent

• Diagnostic imaging: In a nonemergent setting, DSA is commonly performed in addition to CT/MRI imaging.
• Preoperative blood tests: These should comprise all basic tests, including a coagulation screen, as well as blood typing and crossmatching.

Preparation for definitive intervention, emergent

• Diagnostic imaging: CTA is a faster alternative to DSA in an emergency.
• Preoperative blood tests: These should comprise all basic tests, including a coagulation screen, as well as blood typing and crossmatching.

Admission Orders

• Vital signs: Blood pressure (aim is normotension for age in the acute phase), heart rate, volume status, and oxygenation should be monitored.
• Activity: Prior to definitive treatment of the aneurysm, bed rest with the HOB elevated at 30 degrees is recommended.
• CSF drainage parameters (in case an EVD was inserted prior to admission to ICU): The aim should be physiological ICP for age. The authors’ preference is to never drain more than 3 to 5 mL CSF at a time to avoid provocation of rebleeding.
• Medication: While oral or IV nimodipine is standard treatment for adults with ruptured aneurysms, great care should be taken when administering this drug to children. There are no controlled trials in children, and data from small series suggest a substantial risk of induced arterial hypotension (90). Deep sedation should be avoided whenever possible to allow for neurological assessment.