Cerebral hemorrhage is divided into several forms: subarachnoid hemorrhage, epidural hematoma, subdural hematoma, and intracerebral hematoma. The main types of cerebral hemorrhage are briefly described below.
Subarachnoid hemorrhage
As the name of this type of brain hemorrhage implies, it refers to bleeding under the soft meninges, the arachnoid. In most cases, a subarachnoid hemorrhage results from the sudden rupture of an aneurysm of the brain‘s basal arteries. Aneurysms represent bulges of the vessel walls of different localization, which either do not cause any symptoms at all, or can be the trigger for years of seizure-like headaches often in connection with additional neurological deficits. If an aneurysm ruptures at the base of the cerebral arteries, a subarachnoid hemorrhage (SAB) of varying severity results. Less common causes of SAB are brain tumors, leukemias, or clotting disorders. SAB may occur after years of previous headaches described above with eye movement disorders or vision loss. Often, however, it sets in suddenly from full health without any precursors. It does not occur only after physical exertion with increase of blood pressure, but much more often spontaneously, often even from complete rest. The level of arterial blood pressure does not play a role in the occurrence of subarachnoid hemorrhage. The first symptom is a sudden, never-before-experienced headache that spreads rapidly from the neck or forehead to the entire head and, within hours, to the back. Often there are also initial vegetative symptoms: vomiting, sweating, increase or decrease in blood pressure, fluctuations in body temperature, and changes in the frequency of pulse rate and respiration. Some patients immediately fall to the ground unconscious during acute subarachnoid hemorrhage. In other cases, there are initially only mild disturbances of consciousness, which may intensify as the condition progresses. Overall, the spectrum of possible manifestations ranges from pure headache to clouding of consciousness with neurological deficits and neck stiffness to deep coma and brain death. Epileptic seizures may also occur as an expression of irritation of certain brain centers. The suspected diagnosis of SAB can often be made on the basis of the typical symptom picture alone, but usually requires confirmation by computed tomography of the skull. Electroencephalogram (EEG) and electrocardiogram (ECG) may also show nonspecific changes. Overall, after initial SAB, 25 percent of patients die within the first week. Each rebleed, for which the risk is highest within the first two to three weeks after initial bleeding, reduces survival by 30 percent. Without surgery, mortality from subarachnoid hemorrhage is approximately 70 percent in 5 years.
Epidural hematoma
An epidural hematoma is a hemorrhage between the skull bone and the outer leaf of the hard meninges (dura mater) that usually occurs as a result of head trauma. The epidural hemorrhage is usually caused by an arterial vessel rupture. This often, but by no means always, results from a fracture of the temporal and lateral skull bones. The hematoma usually occurs equilateral to the fracture. The precipitating trauma may be minor and need not even result in concussion. In severe trauma, there may be acute onset of neurologic hemiparesis with severe disturbances of consciousness. If, on the other hand, the trauma was mild, the initial symptomatology is followed by a symptomless, so-called free interval of a few minutes to hours. After that, the condition of the patient deteriorates again progressively. Consciousness becomes cloudy and hemiplegia develops on the opposite side due to compression of one side of the brain. On the side of the hemorrhage, the pupil becomes wide and opaque due to paralysis of an important nerve supplying the eye. Analogous to the subarachnoid hemorrhage, computed tomography of the skull is the diagnostic method of choice. In individual cases, vascular imaging of the cerebral vessels with X-ray contrast medium is also required. If the diagnosis is not made in time, a fatal outcome due to compression and paralysis of vital brain centers must be expected.With timely surgical intervention, complete recovery can be achieved. However, neurologic damage often remains.
Subdural hematoma
In contrast to an epidural hematoma, a subdural hematoma corresponds to an accumulation of blood beneath the meninges (dura mater) and often occurs as a result of an accident due to the rupture of venous blood vessels. Subdural hematomas are usually less sharply demarcated against the brain than epidural hematomas and usually have a more extensive spread. The clinical constellation of symptoms and the course of acute subdural hematoma is similar to epidural hematoma. Here, too, the focus is on displacement and compression of brain structures with subsequent clouding of consciousness and neurological deficits. The chronic variant of subdural hematoma is often accompanied by less dramatic symptoms such as slowly progressing changes in consciousness or impulsive disorders, which can complicate the diagnosis to some extent. In any case, the correct diagnosis can be made with a high degree of certainty during computed tomography of the skull, although the prognosis of the disease depends essentially on timely surgical intervention.
Intracerebral hematoma
Intracerebral hematoma within the brain occurs either in the wake of a traumatic brain injury or after rupture hemorrhage of a small cerebral vessel that has been pre-damaged by hypertension for many years. Depending on the localization of the hemorrhage, different brain centers may be affected with different symptom expression. Relatively typical is the acute onset of hemiplegia on the opposite side of the body. Hypertensive intracerebral hematomas account for approximately 20 percent of nontrauma-related strokes. Diagnosis is again best confirmed by computed tomography, and in acute stroke, differentiation between deficiency and hemorrhage is of essential therapeutic importance.
