Basal ganglia hemorrhage
Epidemiology
Basal ganglia hemorrhage is a relatively common type of stroke, accounting for approximately 10-15% of all strokes. The incidence of BGH increases with age, and the majority of cases occur in people over the age of 60. Men are more likely than women to experience BGH. Certain medical conditions, such as hypertension (high blood pressure) and diabetes, increase the risk of BGH. Lifestyle factors such as smoking and excessive alcohol consumption have also been associated with an increased risk of BGH. There may be some differences in the incidence of BGH between different ethnic and racial groups, but the data on this is somewhat limited. It's worth noting that these epidemiological factors can vary somewhat depending on the specific population being studied and the methodology used to collect and analyze the data.
Classification
There are two main classification systems for BGH:
Anatomical Classification: Based on the location of the hemorrhage within the basal ganglia, it can be classified into the following types:
Caudate Hemorrhage: This type of BGH occurs in the caudate nucleus, which is located in the center of the basal ganglia. Caudate hemorrhage can cause a range of symptoms, depending on the location and size of the hemorrhage, but commonly causes contralateral hemiplegia and cognitive impairment.
Globus Pallidus Hemorrhage: This type of BGH occurs in the globus pallidus, which is located below the putamen. Globus pallidus hemorrhage can cause a range of symptoms, including hemiparesis, hemisensory loss, and abnormal eye movements.
Clinical Classification: Based on the severity and extent of bleeding, BGH can be classified into the following types: Small BGH: In this type of BGH, bleeding is limited to a small area of the basal ganglia and typically causes mild symptoms.
Moderate BGH: In this type of BGH, bleeding is more extensive and may involve multiple areas of the basal ganglia. Symptoms are usually more severe than in small BGH.
Large BGH: In this type of BGH, bleeding is extensive and involves a significant portion of the basal ganglia. Large BGH typically causes severe symptoms and can be life-threatening.
Hypertensive basal ganglia hemorrhage
Spontaneous basal ganglia hemorrhage.
Traumatic basal ganglia hematomas (TBGHs) are uncommon events in patients with closed head injuries.
Mechanism
Rzepliński et al. injected 40 anatomic specimens of the basal ganglia with a contrast medium, scanned them with a micro-computed tomography scanner, and analyzed the results of radiological studies, and direct and histological examinations.
In 9 cases, micro-computed tomography and histological examinations revealed contrast medium extravasations mimicking intracerebral hematomas. The artificial hematomas spread both proximally and distally along the ruptured perforator and its branches in the perivascular spaces and detached the branches from the adjacent neural tissue leading to the destruction of the tissue and secondary extravasations. Moreover, some contrast extravasations skipped to the perivascular spaces of unruptured perforators, created further extravasation sites, and aggravated the expansion of the artificial hematoma. There was no subarachnoid extension of any artificial hematoma.
They postulate that forming basal ganglia intracerebral hematoma spread initially in the perivascular space, detaches the branches from the neural tissue, and causes secondary bleeding. It can also skip to the perivascular space of a nearby perforator. The proposed mechanism of hematoma initiation and formation explains the extent of damage to the neural tissue, variability of growth in time and space, creation of secondary bleeding sites, and limited usefulness of surgical interventions. The model is reproducible, the extent of the artificial hematoma can be easily controlled, the rupture sites of the perforating arteries can be determined, and the preparation of the model does not require specialized, expensive equipment apart from the micro-computed tomography scanner 1).