subarachnoid hemorrhage

Subarachnoid haemorrhage: causes

About five percent of all strokes are caused by a spontaneous (non-traumatic) subarachnoid hemorrhage. In Central Europe and the US, about six to nine out of every 100,000 people suffer an SAB every year. Subarachnoid haemorrhage usually occurs between the ages of 30 and 60, but on average at the age of 50 years. Women are slightly more affected than men.

In about 85 percent of cases, a subarachnoid hemorrhage results from the rupture of a so-called aneurysm in the brain: This is a vascular malformation in the form of a sac like extension of the vessel wall. In the area of ​​this protuberance, the vessel wall is less firm than normal and can easily rupture – the result is a subarachnoid hemorrhage.

The rupture of the aneurysm is not linked to a particular disease, but often occurs in full health without previous discomfort, often even in complete rest. In some people, subarachnoid hemorrhaging is preceded by a physical exertion, such as heavy lifting, difficulty in bowel movements (heavy pressing), or sexual intercourse. The cause of the bursting of the aneurysm may also be a sudden increase in blood pressure.

Rarely triggers of subarachnoid hemorrhage are, for example, craniocerebral injury, sinus vein thrombosis (blood clot in a particular cerebral vessel), vascular inflammation, coagulation disorders, tumors, infections and intoxications (such as alcohol, cocaine, amphetamines, drugs). Despite intensive search, no cause for the subarachnoid hemorrhage can be found in some patients.

Subarachnoid haemorrhage: risk factors

The avoidable risk factors for subarachnoid haemorrhage are high blood pressure, smoking, excessive consumption of alcohol and the use of cocaine. Unavoidable risk factors of SAB include, for example, age, an earlier onset of SAB, the occurrence of SAB in the family, and genetic factors. Even craniocerebral traumas, which have resulted in the formation of a vascular wall bulge, can result in subarachnoid hemorrhage.

Subarachnoid haemorrhage: symptoms

Symptoms of subarachnoid haemorrhage are sudden, intense, never experienced headaches, which spread rapidly from the neck or forehead to the whole head and within the following hours to the back. This “annihilation headache” is often accompanied by nausea, vomiting, photophobia and neck stiffness (meningism). Depending on the extent of the subarachnoid hemorrhage, consciousness disturbances can even lead to a deep coma.

In addition, a subarachnoid hemorrhage can also lead to other symptoms such as increase or decrease in blood pressure, fluctuations in body temperature and changes in heart rate and respiratory rate. Depending on the location and extent of the bleeding, paralysis and (more rarely) epileptic seizures may occur.

Five degrees of subarachnoid hemorrhage

Experts in Germany divide the severity of subarachnoid hemorrhage into five degrees (Hunt and Hess classification). These are based on the severity of the complaints and can be related to the score in the so-called Glasgow coma scale (GCS): In this scale, the patient receives at the accident site for certain reactions (such as eye opening, reaction to pain stimuli and verbal utterances) each have a defined score. The points are finally added. The worst value is three, the best 15.

• Hunt and Hess Grade I: no or only slight headache, possibly slight neck stiffness, GCS value 15.
• Hunt and Hess Grade II: Moderate to severe headache, neck stiffness, no neurological deficits other than cranial nerve disorders due to direct pressure of the leaked blood on the cranial nerves, no change in consciousness, GCS value 13-14.
• Hunt and Hess Grad III: Drowsiness or somnolence, confusion and / or mild neurological deficits (paralysis, sensory disturbances), GCS score 13-14.
• Hunt and Hess Grade IV: severe disturbance of consciousness / deep sleep state (Sopor), moderate to severe incomplete hemiparesis, vegetative disorders (such as respiratory or temperature regulation disorders), GCS score 7-12.
• Hunt and Hess Grade V: deep coma, no light reaction of the pupils, indications in the neurological examination for an obstruction of the brain due to the excessive pressure in the skull, GCS value 3-6.

Subarachnoid haemorrhage: diagnosis

A subarachnoid haemorrhage manifests itself by devastating headache and is life threatening. Therefore, anyone with massive, sudden headaches he has never experienced before should go to the hospital emergency department (if no concomitant symptoms otherwise occur) or call the ambulance (with additional symptoms).

At the hospital, the doctor asks patients about the temporal development of the symptoms. An attendant can provide valuable information, especially if the patient is dizzy or unconscious. The physician also asks about family members with strokes and cerebral hemorrhages, because sometimes subarachnoid hemorrhage occurs in families.

Imaging procedures

When examining the skull by means of computed tomography (cranial computed tomography, cCT), the physician usually recognizes the subarachnoid hemorrhage as a flat, white area adjacent to the brain surface. Within the first 24 hours after the bleeding, 95% of subarachnoid haemorrhages can be detected in the cCT, after which the rate drops. Therefore, cCT is considered the first-choice examination method in the acute phase after subarachnoid hemorrhage.

MRI (Magnetic Resonance Imaging, MRI) can also detect subarachnoid haemorrhage in the first few days after the event. If CT or MRI provides an inconspicuous finding, a lumbar puncture helps in the diagnosis. The cerebrospinal fluid removed during lumbar puncture may indicate a subarachnoid haemorrhage due to its altered appearance (eg bloody).

In the course of time, convulsions (vasospasms) may develop in the affected blood vessels as a reaction to the subarachnoid hemorrhage, leading to additional paralysis in some patients. Vasospasm is detected by a special ultrasound scan of the cerebral vessels (transcranial Doppler sonography, TCD).

To identify the source of bleeding (aneurysm), the doctor can perform a radiographic angiography.

Subarachnoid haemorrhage: therapy

People with subarachnoid haemorrhage need immediate intensive care since the bleeding can be life-threatening. The basic measures of treatment include bed rest and the monitoring and, if necessary, adjustment of blood pressure and blood sugar. Any occurring fever is treated.

Surgery to eliminate the aneurysm

If a ruptured aneurysm (morbid vessel eruption) is the cause of subarachnoid hemorrhage, it is separated from the bloodstream as quickly as possible. This is possible in two ways: either surgically by a neurosurgeon (clipping) or through the blood vessels by an experienced neuroradiologist (endovascular coiling).

At the clipping the surgeon clips the aneurysm at its base. This stops the supply of blood to the aneurysm. However, surgery is only possible if there is no spasm of the vessels. Therefore, clipping operations are mainly performed on the first and second day after the first SAB complaints. If there are vasospasms or if the patient is in a poor neurological condition, the doctors are more likely to wait for the operation, as the spasm may increase as a result of the procedure.

At the coiling the doctor introduces a platinum coil (“platinum coil”) into the aneurysm. To do this, he pushes a catheter over the inguinal artery to the vessel opening. The coil fills out the aneurysm and stops the bleeding. This method is less cumbersome and provokes less vessel cramping than clipping. Therefore, it is recommended if surgery can not be operated on with low risk. But the aneursyma can not be eliminated as effectively by clipping as by clipping. Therefore, after a few months all patients who have undergone coiling have to undergo angiography (vascular imaging using an X-ray contrast medium).

Vascular spasms (vasospasm)

Vascular spasm sets in after the fourth day after subarachnoid hemorrhage and persists for about two to three weeks. By affecting cerebral blood flow, they often cause the onset or increase of paralysis or dysregulation. Vascular spasms are treated with medication.

“Hydrocephalus”

Another possible complication of subarachnoid haemorrhage is the “hydrocephalus” – an enlargement of the cerebral cavities due to pent-up cerebral fluid. In some cases, the hydrocephalus spontaneously recovers. Most of the pent-up brain water must be discharged for a few days via a hose to the outside. If drainage is required over a long period of time, patients will receive a shunt – a surgically inserted catheter that will drain excess brainwash into either the abdominal cavity (ventriculoperitoneal shunt) or the right atrium of the heart (ventriculoatrial shunt).

Subarachnoid haemorrhage: prognosis

The prognosis of a subarachnoid hemorrhage depends on many factors, for example the age of the person affected, the severity of the bleeding and the location of the aneurysm. For example, aneurysms in the posterior parts of the brain have a worse prognosis than those in the front areas of the brain.

Generally speaking, subarachnoid hemorrhage is a life-threatening disease. Overall, about 50 percent of those affected die from the SAB. About half of the survivors suffer from severe deficits (paralysis, coordination disorders, mental impairment, etc.), and one third remain dependent on help from others for life. Early intensive care treatment of the subarachnoid hemorrhage improves the prognosis.