Intracranial aneurysm is a kind of aneurysmal protrusion of the arterial wall caused by a limited abnormal enlargement of the internal lumen of the cerebral artery. Intracranial aneurysm is mostly caused by a cystic bulge based on a local congenital defect of the cerebral arterial wall and an increase in intraluminal pressure, and is the first cause of subarachnoid hemorrhage.
Clinical manifestations
1.Aneurysm rupture and bleeding symptoms
Once the aneurysm ruptures and bleeds, the clinical manifestation is severe subarachnoid hemorrhage, with rapid onset and severe headache, which is described as “head exploding”. Frequent vomiting, profuse sweating, elevated body temperature, neck stiffness, and a positive Creutzfeldt-Jakob sign. There may also be impaired consciousness and even coma. Some patients have triggers such as exertion and emotional excitement before bleeding, while some have no obvious triggers or onset during sleep.
2.Focal symptoms
Arteriovenous nerve palsy is commonly seen in internal carotid artery-posterior communicating artery aneurysms and aneurysms of the posterior cerebral artery, manifested as unilateral eyelid ptosis, pupil dilatation, inability to internalize, up and down vision, and loss of direct and indirect light responses. Sometimes focal symptoms appear before subarachnoid hemorrhage and are considered precursors to aneurysm hemorrhage, such as mild migraine and orbital pain followed by arteriovenous nerve palsy, at which time one should be alert to the ensuing subarachnoid hemorrhage. If an aneurysm hemorrhage in the middle cerebral artery forms a hematoma; or an aneurysm hemorrhage in other parts of the brain followed by cerebral vasospasm cerebral infarction, the patient may develop hemiplegia, motor or sensory aphasia. If a giant aneurysm affects the visual pathway, the patient may have visual field impairment.
3.Classification
After aneurysm bleeding, the condition varies in severity. In order to judge the condition, choose the timing of imaging and surgery, and evaluate the efficacy, Hunt’s five-level classification is often used internationally.
(1) Level I is asymptomatic, or has mild headache and neck stiffness.
(2) Grade II has severe headache, cervical tonicity, and no other neurological symptoms except for cerebral nerve palsy such as the motor nerve.
(3) Grade III mild impaired consciousness, agitation and mild cerebral symptoms.
(4)Grade IV semi-comatose narrative, hemiparesis, early denervation tonicity and vegetative disorders.
(5) Grade V deep coma, decerebrate tonicity, and endangered state.
Treatment
1.Non-surgical treatment of intracranial aneurysm
The main purpose is to prevent rebleeding and control arterial spasm, etc. It is applicable to the following cases.
①The patient’s condition is not suitable for surgery or the systemic condition cannot tolerate craniotomy;
②The diagnosis is unclear and further examination is needed;
③The patient refuses to operate or the operation fails;
④As an adjuvant treatment before and after surgery.
2.Surgical treatment of intracranial aneurysm
Patients with subarachnoid hemorrhage should be operated early (clamping of the aneurysm or embolization of the aneurysm), intraoperative measures to protect the brain (mannitol, barbiturates, etc.), and postoperative dilation treatment. For aneurysms of the basilar artery and the first part of the posterior cerebral artery, we wait until their neurological symptoms improve and stabilize before operating.
3.Treatment of special types of aneurysms
(1) Multiple aneurysms have more chances of bleeding than single ones, so some people advocate that it is better to treat one aneurysm than none, and all of them than only one. About 96% of hemorrhagic aneurysms can be distinguished based on a comprehensive analysis of imaging and clinical symptoms, and the management of multiple aneurysms is similar to that of single aneurysms, with similar operative mortality.
(2) About 1/5 patients with giant aneurysms can only be treated conservatively due to various reasons, and 4/5 can be treated surgically.