Subarachnoid hemorrhage (SAH) is an acute hemorrhagic cerebrovascular disease in which blood flows directly into the subarachnoid space due to rupture of blood vessels at the base of the brain or on the surface of the brain and spinal cord from a variety of etiologies. The common causes are cerebral artery malformations, aneurysms, and blood disorders.
Disease Description
Subarachnoid hemorrhage is an acute hemorrhagic cerebrovascular disease caused by rupture of blood vessels at the base of the brain or on the surface of the brain and spinal cord due to a variety of etiologies, with blood flowing directly into the subarachnoid space, also known as primary subarachnoid hemorrhage. In addition, critical clinical cases may also be seen due to intracerebral parenchymal, ventricular hemorrhage, epidural or subdural vascular rupture and other blood penetrating the brain tissue and flowing into the subarachnoid space, which is called secondary subarachnoid hemorrhage and traumatic subarachnoid hemorrhage. Subarachnoid hemorrhage accounts for about 10% of acute strokes and 20% of hemorrhagic strokes.
Etiology and pathology
Any cause that can cause cerebral hemorrhage can also cause the disease, but intracranial aneurysm, arteriovenous malformation, hypertensive arteriosclerosis, anomalous vascular network at the base of the brain (moya-moya disease) and hematologic disease are the most common. The onset of aneurysm is usually due to emotional stress or excessive exertion. Arteriovenous aneurysms occur in the branches of the large arteries of the cerebral base arterial ring, and are more common in the anterior half of the ring. Arteriovenous malformations are mostly located in the middle cerebral artery distribution area of the cerebral hemisphere. When blood flows into the cerebral subarachnoid space from a ruptured vessel, the contents of the cranial cavity increase, pressure increases, and cerebral vasospasm ensues. The latter is due to the traction of the blood clot and the fibrous cords surrounding the vessel wall after bleeding (mechanical factors), and the formation of extensive ischemic damage and edema at the neuromuscular junction between the smooth muscle cells of the vessel wall. In addition, a large amount of blood or clots deposited at the base of the skull, some of the agglutinated red blood cells can also block the small sulcus between the arachnoid villi, so that the back absorption of cerebrospinal fluid is blocked, and thus acute traffic hydrocephalus can occur, causing a rapid increase in intracranial pressure, further reducing cerebral blood flow, aggravating cerebral edema, and even leading to the formation of cerebral herniation. All of the above can cause patients to reappear with impaired consciousness or limited neurological symptoms after their condition has stabilized and improved.
After blood enters the subarachnoid space, blood-stained cerebrospinal fluid can provoke a sterile meningitis reaction against blood vessels, meninges and nerve roots and other brain tissues. The brain surface is often covered by a thin layer of clots, in which ruptured aneurysms or vessels can sometimes be found. Over time, a large number of erythrocytes begin to lyse, releasing iron-containing heme and giving the soft meninges a rusty color with varying degrees of adhesion. If the erythrocytes in the cerebral sulcus lyse and the small sulcus between the arachnoid chromaffin cells reopens, the reabsorption of cerebrospinal fluid can be restored.
Clinical manifestations
It can occur at all ages, but is more common in young adults. Most of them occur acutely during emotional excitement or under exertion, and some patients may have a history of recurrent headache attacks.
1. Headache and vomiting: sudden onset of severe headache, vomiting, pale face and cold sweat. If the headache is limited to a certain place, it has localization significance, such as anterior headache suggesting supratentorial and cerebral hemispheres (unilateral pain), and posterior headache indicating posterior cranial recess lesion.
2. Disorders of consciousness and psychiatric symptoms: Most patients do not have disorders of consciousness, but may have irritability. In critical cases, there may be delirium, varying degrees of unconsciousness and coma, and a few may have seizures and psychiatric symptoms.
3. Meningeal irritation sign: It is common and obvious in young and middle-aged patients, accompanied by neck and back pain. Elderly patients, early hemorrhage or those in deep coma may not have meningeal irritation signs.
4. Other clinical symptoms: such as low fever, low back and leg pain, etc. Light hemiparesis, visual impairment, cranial nerve paralysis of III, V, VI and VII, retinal lamellar hemorrhage and optic papillar edema may also be seen. In addition, upper gastrointestinal bleeding and respiratory tract infection may also be seen.
5, laboratory tests: lumbar puncture intracranial pressure is mostly increased, cerebrospinal fluid is bloody in the early stage, and begins to yellow after 3-4 days. The leukocytes in peripheral blood may be increased in some patients at the early stage of the disease and are mostly accompanied by leftward nuclear shift. The electrocardiogram may be arrhythmic, and tachycardia and conduction block are more common. 75-85% of positive cranial CT scans within 4 days show increased density in the pools at the base of the skull, the longitudinal fissure of the brain and the cerebral sulcus, and thicker blood accumulation suggests that the ruptured artery may be located at or near the site.
Complications
1. Acute obstructive hydrocephalus: It is an important and serious complication of subarachnoid hemorrhage and refers to hydrocephalus caused by acute or subacute ventricular enlargement within a few hours to 7 days after subarachnoid hemorrhage. Filling of the ventricular system with blood is a prerequisite for acute ventricular dilatation, which causes an acute increase in intracranial pressure due to obstruction of cerebrospinal fluid circulation pathways and is one of the main causes of death after subarachnoid hemorrhage. Acute obstructive hydrocephalus occurs. It suggests a poor prognosis. If bilateral ventricular dilatation and lumbar puncture pressure can be found at an early stage, suggesting acute obstructive hydrocephalus, ventricular drainage should be performed immediately, which can sometimes turn the situation into a safe one.
In addition to severe headache, frequent vomiting and meningeal irritation signs, acute hydrocephalus often has intracranial hypertension manifestations such as increased impairment of consciousness. Especially in subarachnoid hemorrhage, coma, pupil narrowing, weakening or disappearance of light reflex and other deterioration gradually appear within 3 days.
2.Normal pressure hydroencephalus (NPH): It is a clinical syndrome caused by a variety of reasons, also known as occult hydrocephalus, low pressure hydrocephalus, traffic hydrocephalus or hydrocephalic dementia, which occurs weeks or years after subarachnoid hemorrhage.
The pathogenesis of normal cranial pressure hydrocephalus is caused by any obstruction of the normal flow of cerebrospinal fluid to the superior sagittal sinus outside the ventricular system, i.e., in the basal pools of the brain or the convex surface of the brain. The three main signs of normal cranial pressure hydrocephalus are mental disturbance, gait abnormalities, and urinary incontinence. Personality changes, epilepsy, extrapyramidal symptoms, strong grip reflex, and sucking reflex may also occur. Central paralysis of both lower limbs occurs in late stages.
Diagnosis and Differentiation
Diagnostic basis
The disease is easily diagnosed by sudden onset of severe headache and vomiting, pallor, cold sweats, positive meningeal irritation signs and blood in the cerebrospinal fluid or blood in the pools of the skull base, longitudinal fissure of the brain and cerebral sulcus as seen on cranial CT. In a few patients, especially in the elderly, clinical symptoms such as headache are not obvious, so attention should be paid to avoid missing the diagnosis, and timely lumbar puncture or cranial CT examination can clarify the diagnosis.
Medical history, neurological examination, cerebral angiography and cranial CT examination can assist in etiological diagnosis and differential diagnosis. In addition to other cerebrovascular diseases, it should be differentiated from the following diseases: ① Meningitis: there are symptoms of systemic toxicity, the onset of the disease has a certain process, and the cerebrospinal fluid shows inflammatory changes. ② Cerebral venous sinus thrombosis: most of them have postpartum onset or have a history of infection before the disease, with dilated veins on the face and scalp, negative meningeal irritation signs, and no blood changes in the cerebrospinal fluid in general.
Symptom characteristics
The clinical manifestations of subarachnoid hemorrhage mainly depend on the amount of hemorrhage, the site of blood accumulation, and the degree of impaired cerebrospinal fluid circulation.
1.Onset of the disease: Most of them have an acute onset under the condition of emotional excitement or exertion.
2.Main symptoms: sudden onset of severe headache, persistent unrelieved or progressive aggravation; mostly accompanied by nausea and vomiting; may have transient disorders of consciousness and mental symptoms such as irritability and delirium, a few appear seizures.
3.Main signs: meningeal irritation signs are obvious, subfoveal hemorrhage can be seen in the fundus, and a few may have signs of focal neurological deficits, such as mild hemiparesis, aphasia, and actinic nerve palsy.
Auxiliary examinations
1, cranial CT: is the preferred method to diagnose SAH, CT shows high-density shadow in the subarachnoid space can confirm the diagnosis of SAH, according to the CT results can initially determine or suggest the location of intracranial aneurysm: if located in the internal carotid artery segment is often asymmetric blood accumulation in the suprasellar pool; middle cerebral artery segment is mostly seen in the lateral fissure blood accumulation; anterior communicating artery segment is the base of the anterior interfracture blood accumulation; and bleeding in the interpeduncular pool and circumferential pool, generally no aneurysm. Dynamic CT examination also helps to understand the absorption of hemorrhage, the presence of rebleeding, secondary cerebral infarction, hydrocephalus and its extent, etc.
2. Cerebrospinal fluid (CSF) examination: Usually, lumbar puncture is not used as a routine clinical examination if the diagnosis has been confirmed by CT examination. If the amount of bleeding is small or the time from the onset of the disease is long, CT examination may not have positive findings, but clinical suspicion of subarachnoid hemorrhage requires lumbar puncture to examine CSF. uniform blood cerebrospinal fluid is a characteristic manifestation of subarachnoid hemorrhage and indicates fresh bleeding, such as yellowing of CSF or finding phagocytes that have engulfed red blood cells, iron-containing heme or bilirubin crystals, etc., it suggests that SAH has existed for different times.
3.Cerebral vascular imaging: It helps to detect abnormal blood vessels in the skull.
(1) Cerebral angiography (DSA): It is the most valuable method to diagnose intracranial aneurysm, with a positive rate of 95%, and can clearly show the location, size, relationship with the aneurysm-carrying artery and the presence of vasospasm. When conditions are available and the condition permits, whole brain DSA should be performed as soon as possible to determine the cause of bleeding, decide the treatment method and judge the prognosis. However, since angiography can aggravate neurological damage, such as cerebral ischemia, aneurysm rupture and bleeding, the timing of angiography should avoid the peak period of cerebral vasospasm and rebleeding, i.e. within 3 days or 3 weeks after bleeding.
(2) CT angiography (CTA) and MR angiography (MRA): they are non-invasive methods of cerebral vascular imaging, mainly used for screening of those with family history of aneurysm or aura of rupture, follow-up of patients with aneurysm and patients who cannot tolerate DSA examination in the acute stage.
4.Other: transcranial ultrasound Doppler (TCD) dynamic detection of major intracranial artery flow velocity is the most sensitive method for timely detection of cerebral vasospasm (CVS) tendency and the degree of spasm; local cerebral blood flow measurement is used to detect changes in local cerebral tissue blood flow, which can be used for the detection of secondary cerebral ischemia.
Disease Treatment
Treatment principles
The principles of treatment for subarachnoid hemorrhage are: stopping further bleeding, preventing secondary cerebral vasospasm, lowering intracranial pressure, reducing cerebral edema, removing the cause of the disease and preventing rebleeding and the occurrence of various serious complications.
Symptomatic treatment
1. Absolute bed rest: Patients should be hospitalized and absolutely rest in bed for 4-6 weeks (avoid all possible causes of increased blood pressure or intracranial pressure, such as forceful defecation, coughing, sneezing, emotional excitement, exertion, etc.).
2, sedation and pain relief: appropriate sedative and analgesic drugs can be given to those with headache, irritability, and psychiatric symptoms, and avoid using drugs that affect breathing and consciousness observation.
3, regulation of blood pressure: appropriate adjustment of blood pressure. Patients with normal blood pressure in the past and elevated blood pressure after SAH should have their blood pressure controlled to a level close to normal; those with high blood pressure in the past should have their blood pressure controlled to a level close to their usual blood pressure. General systolic blood pressure should not be higher than 150-180 mmHg.
4.Anti-convulsion: patients with epileptic seizures can be given anti-epileptic drugs such as phenytoin sodium, carbamazepine, sodium valproate, valium, etc.
5.Correct hyponatremia: give isotonic fluids when there is hyponatremia, correct blood volume deficiency with timely rehydration, and avoid hypotonic fluids.
Reduce intracranial pressure
The increase of intracranial pressure in SAH is due to acute hydrocephalus caused by the occupying effect of hematoma and obstruction of cerebrospinal fluid circulation pathway as well as cerebral ischemia and cerebral edema caused by cerebrovascular spasm, so the increase of intracranial pressure in SAH is heavier and more acute than other cerebrovascular diseases. Mannitol, tachyphylaxis, glycerol fructose, compound glycerol, albumin, dexamethasone, etc. can be given.
Hemostasis and prevention of rebleeding
Anti-fibrinolytic drugs are used to inhibit the formation of fibrinolytic zymogens, delay the dissolution of clots, and prevent the occurrence of rebleeding.
6-Aminohexanoic acid: 4-6g dissolved in NS or 5%-10% GS as an IV, 24g/day for 7-10 days, gradually reduce the dose to 8g/day and maintain for 2-3 weeks.
Hemostatic aromatic acid (PAMBA): 0.2~0.4g slowly intravenous, 2 times/day.
To avoid the occurrence of secondary cerebral ischemia, a combination of calcium antagonists is required.
Prevention and treatment of cerebral vasospasm
Calcium channel antagonists: can reduce vasospasm. Commonly used nimodipine 10mg～20mg/d slowly IV, 1mg/h, for 5~14 days, pay attention to monitor blood pressure. Or nimodipine orally, 20~40mg/d, 3 times/day.
Volume expansion and pressure boosting: If blood volume is insufficient or blood pressure is low, give volume expansion and pressure boosting treatment.
Cerebrospinal fluid replacement therapy: CSF replacement therapy is available for non-aneurysmal SAH or aneurysm surgery. The cerebrospinal fluid can be replaced by lumbar puncture, 10-30 ml/time, 2 times/week; 5-10 ml of cerebrospinal fluid can be released each time according to the cranial pressure; lateral ventricular drainage is done if there is ventricular hemorrhage.
To determine the site of aneurysm
1.Hemorrhage in the interpeduncular pool and circumferential pool, usually without aneurysm.
2, Asymmetric hemorrhage in the suprasellar pool suggests aneurysm of the internal carotid artery system.
3, Bleeding in the lateral fissure suggests middle cerebral artery aneurysm.
4, Bleeding from the base of the frontal interhemispheric fissure suggests an aneurysm of the anterior communicating artery.
If aneurysm is suspected, consult neurosurgery, and if non-aneurysm is treated with general internal medicine.
Re-bleeding: Reduce the factors that may cause re-bleeding. Patient needs to be bedridden to reduce stimulation. Make Subarachnoid hemorrhage
Control pain with analgesics. Use sedation. Regular use of stool softeners and laxatives. The aim of these measures is to avoid an increase in blood pressure that could cause rebleeding due to increased intracranial pressure. If possible, surgery is the best way to prevent rebleeding.
Hyponatremia: Hyponatremia after SAH usually occurs several days after bleeding and often parallels the timing of vasospasm. Hyponatremia is more commonly seen in patients with clinically symptomatic hydrocephalus and is an independent risk factor for poor prognosis. Hyponatremia is usually mild enough to produce symptoms. Management.
(1) Monitor central venous pressure, pulmonary capillary wedge pressure, fluid balance, and body weight in patients with recent SAH to assess volume status. A trend toward decreased volume should be corrected with fluid replacement.
(2) Treatment of hyponatremia after SAH should include intravascular infusion of isotonic fluids. Avoid hypotonic fluids as they can lead to hyponatremia; do not treat hyponatremia by fluid restriction.
Emergency management of morbidity
Subarachnoid hemorrhage is one of the common cerebrovascular diseases, and the common causes are ruptured intracranial aneurysms and vascular malformations. Once a subarachnoid hemorrhage occurs, it should be treated promptly at a local hospital in a condition or transferred to a hospital for resuscitation treatment, and the following points should be noted when transferring patients.
1. Sudden severe headache and vomiting should be suspected as a possible subarachnoid hemorrhage and should be sent to the hospital promptly;
2, try to keep the patient in a high lateral position, to avoid the back of the tongue root obstructing ventilation, and timely clean up the vomit in the mouth to avoid inadvertent aspiration of the airway;
3, try to avoid long-distance transfer, choose the nearest medical unit with conditions for treatment;
4, when transferring patients should be escorted by medical personnel and observe changes in condition at any time, and take the necessary measures at any time.
5, before transfer should be given dehydration, hypotension and other treatment, . Give sedative, painkillers, and absolute bed rest;
6.Avoid vibration as much as possible during transportation;
7.Ventricular puncture and drainage or lumbar puncture to release hemorrhagic cerebrospinal fluid is feasible in case of heavy bleeding; cranial CT or lumbar puncture can confirm;
8, actively look for the cause, for intracranial artery and intracranial vein malformation, after confirming the surgical radical treatment;
9, always pay attention to blood pressure changes;
10.Keep patients happy and avoid emotional stress.
Patients with subarachnoid hemorrhage are often unable to tolerate “such a blow” due to poor function of the heart, lungs and kidneys, which can lead to respiratory, pulmonary and urinary tract infections, etc. Anti-infection treatment and cooling therapy are very important. If there is no contraindication, cerebral angiography should be performed as soon as possible to detect the aneurysm, and if the patient can tolerate the operation, it is best to perform it within one week after the disease, which can greatly reduce the mortality rate and the risk of recurrence of bleeding. Internal therapy is used for patients who are preoperative, postoperative, or unfit for surgery and should include four weeks of bed rest, minimal activity and mental disturbance, avoidance of straining to defecate, nutritional supplements, maintenance of water, salt, and acid-base balance, and the medications listed above. Regardless of whether the treatment is surgical or medical, it is important to prevent the occurrence of rebleeding. In addition, other high-risk factors that can cause bleeding, such as diabetes, heart disease, obesity, hyperlipidemia, smoking, excessive alcohol consumption and other diseases and bad habits, should be treated in a timely manner, to develop good lifestyle habits, to adjust and control the diet appropriately, and to maintain a positive and optimistic attitude towards life, all have a certain value in preventing the occurrence of subarachnoid hemorrhage. This is a good way to prevent subarachnoid hemorrhage.
Chinese medicine treatment
Liver wind and hyperactivity of liver yang
(1) Treatment: Calming the liver and quenching the wind, pacifying the liver and submerging the yang.
(2) Formula: Suppressing the liver and quenching the wind with addition and subtraction.
(3) Composition: 15g of Huai Niu Knee, 15g of Dai Ochre (first decoction), 20g of Raw Dragon Bone (first decoction), 20g of Raw Oyster (first decoction), 30g of Raw Tortoise Nail (first decoction), 16g of White Peony, 10g of Xuan Shen, 15g of Tian Men Dong, 10g of Neem, 20g of Raw Wheat Germ, 20g of Yin Chen, 5g of Glycyrrhiza glabra.
(4) Alternative formula: Antelope horn and hooked vine soup, for hyperactivity of liver yang, with wind and fire disturbing the mouth. Goat’s horn 30g (first decoction), hooked vine 6g (later down), white peony 15g, dandruff 10g, chrysanthemum 10g, gardenia 10g, scutellaria 10g, cow’s knee 15g, raw groundnut 15g, stone cassia 30g (first decoction), raw licorice 6g.
(5) Add and subtract: add 12g each of calamus, yujin and guanghuang for confusion and indifferent expression; add 6g of Huanglian, 12g each of bamboo leaf and lotus seed heart for delirium and delusional movement; add 6g of rhubarb and 15g of xuanming powder (decoction) for constipation; add 12g of tianma, 8g each of scorpion and stiff silkworm, 10g of white sophora and 4g of antelope horn powder for very strong convulsions; add 12g of biliary nancellus and 10ml of bamboo lei for thick yellow sputum. 10ml.
(6) Clinical matters: This formula focuses on subduing the liver and quenching the wind, which is effective for this type of subarachnoid hemorrhage. If the headache is very severe, dysthymia, bitter mouth and red face, constipation and urination, yellow fur, stringiness of pulse, and liver fire, it is appropriate to add products to clear liver and drain fire such as gentian grass and yujin for symptomatic treatment.
Liver and kidney deficiency, deficiency of fire on the disturbance
(1) Treatment: Nourishing the liver and kidney, clearing heat and lowering fire.
(2) Formulation: Zhi Bai Di Huang Wan plus or minus.
(3) Composition: Zhi Mu lOg, Huang Bai 10g, Shan Yao 30g, Cornus officinalis 15g, Mudan Pi 10g, Shu Di Huang 20g, Fu Ling 15g, Ze Xie 15g.
(4) Alternative formula: Qi Ju Di Huang Tang, for liver. Kidney Yin deficiency, dry eyes and head empty pain. Radix Rehmanniae 20g, Fructus Lycii 15g, Chrysanthemum 15g, Cornus Officinalis 15g, Rhizoma Yam 30g, Danpi 10g, Zeligia 20g, Phellodendron 10g, Poria 20g, Araliaceae 10g, Fructus Lonicerae 15g.
(5) Add and subtract: dry eyes and astringent eyes, deficiency heat is more, increase the dosage of Zhi Mu, Huang Bai, and add Fructus Lycii 10g, Chrysanthemum 15g, Bai Wei, Yin Chai Hu, Artemisia 15g each; neck tonic, limb convulsions, add Scorpion, Centipede 6g each, stiff silkworm 8g; disturbed insomnia, restless sleep at night, add Phellodendron, fried jujube seeds 15g each, Huang Lian 4g, Agaricus 12g; blood deficiency and blood stasis, dull tongue or stasis points For Blood deficiency with Blood stasis, dull tongue or stasis points, add 12g each of Agaricus, Radix Angelicae Sinensis and Rhizoma Polygonati, and 20g of Chuanxiong.
(6) Clinical matters: This formula focuses on nourishing Yin, clearing heat and lowering fire. If the headache is pale and the face is cold, the extremities are not warm, the tongue is pale, the pulse is sunken and slow, Yin loss and Yang, the treatment is to warm the kidney and strengthen the spleen, return Yang to save the rebellion, nourish Blood and fill essence.
Phlegm and turbidity obstruction, clear orifice obscured
(1) Treatment: Cleansing phlegm and clearing the orifices, resolving turbidity and opening the blockages.
(2) Formulation: Cleansing phlegm and clearing orifices with addition and subtraction.
(3) Composition: Nanxing lOg, Hexia 10g, Hovenia 15g, Poria 20g, Orange Red 10g, Acorus calamus 10g, Ginseng 10g, Zhuru 10g, Licorice 5g.
(4) Alternative formula: Warming Gall Bladder Soup, for those with phlegm-heat internal closure of the clear orifices. Fa Xian Xia 10g, Chen Pi 10g, Bile Nan Xing 10g, Citrus Aurantium 15g, Scutellaria Baicalensis 10g, Sheng Da Huang 6g (later down), Hooked Vine 10g (later down), Poria 20g, Calamus 10g, Sheng Gan Cao 5g.
(5) Add and subtract: add 12g of Scutellaria baicalensis, 6g of raw rhubarb, 12g of geranium; add 10g of fried Atractylodes macrocephala, 4g of chicken naijin, 15g of fried grain and wheat sprouts; add 12g of atractylodes, 12g of thick park; add 6g of scorpion, 6g of centipede, 30g of stone cassia (first decoction), 8g of stiff silkworm.
(6) Clinical matters: phlegm and mucus are accumulated for a long time and turn into heat. The symptoms include bitterness in the mouth, dry stools, greasy moss and slippery pulse. Liver stagnation, blood stasis blocking the ligaments
(1) Treatment: Relieve liver stagnation, move Qi, activate Blood stasis.
(2) Formula: Blood Mansions and Blood Stasis Tang plus or minus.
(3) Composition: Chai Hu lOg, Citrus Aurantium 15g, Radix Platycodon 10g, Radix Achyranthis Bidentata 15g, Radix Angelicae Sinensis 15g, Rhizoma Chuanxiong 10g, Radix Paeoniae Alba 10g, Radix Rehmanniae 15g, Rhizoma Peach Root 10g, Radix Safflower 15g, Radix Glycyrrhiza Uralensis 5g.
(4) Alternative formula: Tongkang and Blood Activation Soup, for those with blood stasis blocking the orifice and headache fixed at the site like a pinprick, with Angelica sinensis 15g, Radix Aconiti 15g, Rhizoma Ligustici Chuanxiong 10g, Radix Paeoniae Alba 1
Prognosis of disease
The course and prognosis after cerebral subarachnoid hemorrhage depend on its etiology, condition, blood pressure status, age and neurological signs. The prognosis of subarachnoid hemorrhage caused by ruptured aneurysm is poor, while subarachnoid hemorrhage caused by cerebrovascular malformation is often easier to recover. Those with unknown causes have a better prognosis and less chance of recurrence. The prognosis is worse in elderly and frail patients with progressive worsening of consciousness, increased blood pressure and intracranial pressure, or hemiplegia, aphasia, or convulsions.