Lecture of increased intracranial pressure syndrome

2021-02-05 12:00 AM

Extracellular oedema is oedema seen around brain tumours, intracerebral hematoma, traumatic brain injury, ischemia, encephalitis, encephalitis - meningitis, brain abscesses.

Outline

Intracranial pressure is the result of individual pressure of each area, namely, there are 3 areas: brain parenchyma 88%, cerebrospinal fluid accounts for 9% volume and blood vessels 3%.

Average intracranial pressure was 10 - 12cmH20.

In practice, accept intracranial pressure through normal CSF pressure 7 - 20 cm H2O while lying down, lumbar puncture. When cerebrospinal fluid pressure (25 cm H2O or when intracranial pressure is over 15 mmHg, there is an increase in intracranial pressure.

Mechanism of pathogenesis

There are 3 basic mechanisms that cause increased intracranial pressure, which are cerebral oedema, hydrocephalus and circulatory stasis; These mechanisms can be either alone or in combination.

Cerebral oedema

Cerebral oedema is the result of fluid retention in the brain parenchyma, the most common mechanism divided into 2 types of intracellular and extracellular oedema.

Cellular oedema (oedème cytotoxique) is divided into two types that damage the cell membranes causing water to enter the cells found in ischemia of the brain (brain tissue), poisoning. CO, tin salts, hexachlorophene, traumatic brain injury. The second type is due to the low osmotic pressure of the plasma that causes water to enter the cell (in this case there is no damage to the membrane) called osmotic oedema, which occurs in hyponatremia (dialysis, water poisoning ....).

Extracellular oedema (oedema of vascular origin - due to damage to the blood-brain barrier) is oedema around the brain tumour, intracerebral hematoma, traumatic brain injury, ischemia, encephalitis, encephalitis - meningitis, abscesses Brain.

Hydrocephalus 

Increased cerebrospinal fluid secretion: Tumours of the choroid plexus, meningeal tumour adjacent to the choroid plexus.

Cerebrospinal fluid absorption disorder in thickened meningitis is often accompanied by a blockage of cerebrospinal fluid.

Stasis of cerebrospinal fluid circulation is found in brain tumours, brain abscesses, hematomas in the brain ...

Circulatory stagnation

Venous origin: Thrombophlebitis of the skull, compression of the tumour, hematoma, increased pressure in the chest, patient character struggles.

Capillary origin: Usually due to damage to brain organization causing local accumulation of metabolic acids, lack of O2, increase CO2, thereby producing vasodilation (mainly capillaries) causing fluid drainage out of the wall of vessels encountered in hyperaemia Malignant pressure, eclampsia.

Symptom

clinical

Headache:

In 80% of people with increasing headache characteristic, especially at midnight in the morning, infrequent pain at first then becomes constant throughout the day.

The location is very variable depending on the location of the lesion, depending on the cause, but usually the whole head can be in the forehead, temples, occipital, eye, ...

The pain pierced, the head exploded, it felt like a beating, increased in waves.

Pain increases with exercise, exertion, coughing and sneezing due to increased venous pressure; Reduce when standing, sitting.

Use only temporary pain relievers, while anti-oedema, the reduction lasts longer.

The patient's reaction and posture, such as the head to the side of the patient, reduces pain, but on the healing side, the pain increases (a stem tumour in the 4 ventricle), or bow down (ventricle 4).

You can look for special signs by typing on the skull, painful facial bones (tumour near the skull, hematoma, ...).

Vomiting: (68%)

There may be nausea due to X-wire stimulation, vomiting usually goes after headache, vomiting easily (called vomiting) usually in the morning, after vomiting can relieve headache, less effective nausea and vomiting. If vomiting a lot, it causes exhaustion.

Dizziness:

This can be caused by frequent compression of the vestibular region or by damage to the vestibular centre in the brain stem or in the temporal or forehead. Note the first postural dizziness of the posterior fossa IV region.

Visual disturbances:

Loss of vision due to changes in the fundus (blurred vision)

In addition, double vision or difficulty seeing due to VI. At first, the faintest glimpse into the morning then decreases to noon.

Papillary oedema is the most objective symptom, usually bilateral oedema. The posterior fossa injury is faster.

In addition, there are several other symptoms such as:

Tinnitus.

The pulse is slow, the blood pressure changes tend to increase.

Respiratory rate: Normal, to the stage after tachycardia, Cheyne - Stokes (especially tumour or posterior fossa abs).

Botanical Disorders: Sweating, cold head limbs sometimes severe abdominal pain like acute abdominal pain, constipation, sometimes increased temperature, black substance vomiting (terminal stage).

Psychiatric disorders are often sluggish, insensitive, lethargic, memory disturbed, often more reversely forgetful, word consciousness is murky, confused, drowsy or lethargic. Sometimes you lose your orientation in space or time. Sometimes the most schizophrenic is the temporal tumour.

There may be neurological signs at the time of residence: Depending on the cause, but can paralyze the cranial nerves, have transverse syndrome, hemiplegia, cerebellar syndrome, meningitis, general or local epilepsy. .

Note that in children under 5 years of age increased intracranial pressure causes cranial joint dilatation manifested by an increase in head circumference. Young skull has varicose scalp vein phenomenon, eyes big, protruding, knocking can hear "broken bottle" is a sign of Macewen. Blow on the skull or eyes may be heard in cases of angioma or angioplasty.

Subclinical

Fundoscopy:

Macular oedema is the most objective and valuable symptom of increased intracranial pressure syndrome, but not all cases are present and often appears late when other symptoms are apparent. Depending on the degree of increased intracranial pressure, papillae progression in different stages from mild to severe.

The first stage: The stasis stage displays the papillae fuller than the surface of the retina and pink than normal. The bristles fade from the nose to the temples, losing the central light of the converging blood vessels.

Stage of spiny oedema: The shoulder blade is completely erased, the disc is swollen on the surface of the retina, like a mushroom, this convexity is measured by diaphones (1mm = 3diop).. The erectile blood vessels zigzag.

Haemorrhagic stage: In addition to the above image, there are also haemorrhagic patches in the papillae and retina.

Stage of atrophy: The final stage, the decompensated stage. The thorns become silvery white, lose their shine, the edges are rusty. Sparse blood vessels pale in colour, accompanied by clinically reduced patient vision.

In children under 5 years old because the skull is still slightly dilated, often do not have all the above stages, rarely see papillary haemorrhage but often gradually atrophy of the papillae.

Papillary oedema in intracranial hypertension often appears both sides with varying degrees. Unilateral single-sided spinal oedema is rare. In the prefrontal spinal papilloma, there may be atrophy of the lateral papillae with the tumour and oedema on the opposite side (Foster Kennedy syndrome).

Pan-tilt imaging:

The simplest cranial joint can be seen, especially in the crown of the crown in children.                       

EEG:

Nonspecific, but suggestive of localization (early stage) and assessment of severity of increased intracranial pressure, more or less slow waves, possibly both hemispheres, especially late.

Angiography when a focal sign is suspected (displacement), in severe cranial hypertension, the artery loses its softness (loss of flexion).

Gravimetric tomography is a basic test that shows site and morphology such as ventricular dilatation in hydrocephalus, or, conversely, ventricular flattening due to cerebral edema; displacement (tumour / hematoma) and the squeezing effect of the brain organization clears the wrinkles of the cortex. For increased density in the hematoma, edema (decreased density).

Transcranial Doppler:

A blood flow rate above 150 mm / sec is vasoconstriction.

Cerebrospinal fluid test is contraindicated in increased intracranial pressure, when on two diodes only unless meningitis is suspected at this time, it is necessary to probe the lying position, small needles, save the barrel, take a little fluid for testing.

Progression and complications

The vast majority of advanced intracranial hypertension progressively worsens (except for benign increases), with the end result:

Atrophy of thorns

Gradually diminished vision fading.

Reduce blood flow to brain organization

The perfusion of the brain is dependent on mean arterial blood pressure and intracranial pressure or venous pressure. The difference between pressure between mean arterial pressure and intracranial pressure, normally above 80 mmHg. When the difference falls below 50 mmHg, cerebral perfusion decreases and this time self-regulation is lost in the cerebral vessels.

Engagement

 This is a serious complication, causing rapid death.

The signs of intimidation:

Consciousness: Slow, sombre consciousness comes into a coma.

Dystonia: Increased muscle tone is usually localized in the neck area, so the neck becomes stiff, the head is tilted to the side, the fossa behind the head is protruding back, the limbs are in a strongly stretched position and too prone on the upper extremities.

Nervous vegetative disorders: Circulation from bradycardia to central tachycardia or arrhythmia, increased or unstable blood pressure, flushing, sweating; increased breathing rate, uneven breathing rate or wheezing due to increased bronchial or alveolar fluid; the temperature rises or falls or the heat rises and the mess is reduced; hiccup.

Mild peel:

Neck scoliosis combined with headache spread down the same neck on one side and more or less stiff neck.

Heavy drop:

Symptoms are much more pronounced such as generalized hypertonia, impaired consciousness, and severe vegetative neurological disorders.

Depending on the location of the leak, there are different symptoms:

Temporal puncture: Squeezing the brain stem by leaking the temples 5 (T5) through Pacchionüi hole (Bichat slit) causes III cord paralysis (drooping eyelids, dilated pupils, squinting, double vision); cerebral loss (arms stretched inward, legs stretched); vegetative disturbances (tachycardia, increased blood pressure, tachypnoea with increased bronchial secretions); panic disorder caused by pressing on the grid system. Death in 1-2 hours.

Cerebellar almonds: Usually in children with posterior fossa, after a slight change of position, the time is usually midnight in the morning, pain in the nape of the neck, panic, struggles, the posterior fossa stretching occurs. Jackson (head outstretched and back, limbs stretched) but the patient is still awake, slow pulse. The attack lasts 1-2 minutes, then cardiac arrest

Reason

Swap injuries are common

Primary brain tumour, brain metastasis, brain abscess.

Traumatic brain injury

Acute epidural or epidural hematoma, brain crushing, chronic subdural hematoma.

Stroke

 Subarachnoid haemorrhage, cerebral haemorrhage (hemisphere, cerebellum), cerebral infarction, cerebral thrombophlebitis, encephalopathy caused by hypertension.

Inflammation

Meningitis, acute encephalitis (Japanese B encephalitis, herpes, Reye's syndrome ...)

Metabolic causes

Acute cerebral O2 deficiency, hypoglycaemia, decreased osmotic pressure, encephalopathy caused by increased CO2, endocrine disorders (acute adrenal insufficiency, hypothyroidism, prolonged steroid therapy).

Hydrocephalus

Due to obstruction, due to decreased absorption of cerebrospinal fluid usually after meningitis, after meningeal bleeding.

Other causes

Due to allergies, brain toxicity (lead, tin, tetracycline, nalidixic acid; CO; Ars; excessive intake of Vitamin A, corticosteroids (causing brain tumour or benign intracranial hypertension), closing too early in some children.

Treatment

Treat the cause

Surgery:

Especially in brain tumours, traumatic hematoma, hematoma and extensive cerebral stasis in the cerebellum, some cerebral abscesses.

Medical:

It is necessary to treat respiratory or metabolic disorders, hypertensive attacks maintain cerebral perfusion pressure (60 - 80 mm Hg. Antibiotics in meningitis, acute abscess, antiviral as in inflammation brain caused by herpes simplex (acidovir = zovirax, see article encephalitis).

Avoid sudden position changes.

Symptomatic treatment

Removal of extracranial factors:

Reduce venous pressure: Lie on your back and raise your head about 10-30 0 to avoid squeezing the carotid veins, avoid strenuous stimulation with sedation (seduxen) and muscle relaxation (myolastan), early control of epilepsy (valium , ...)

Treatment of respiratory disorders to prevent O2 deficiency and increase CO2 (causing vasodilation), if mechanical ventilation should be paid attention because mechanical breathing in the expiratory period increases venous pressure, reducing cardiac output.

Low osmotic pressure should limit water and avoid use of hypotonic solution.

Anti-oedema:

Corticosteroids: Its effects are evident in vasogénique edema, such as in brain tumors, cerebral abscesses, trauma to the skull. Dexamethasone (Sol Decadron 4 mg ampoule) is often used at first bolus 10 mg, after 4 mg every 6 hours. Usually use 16-24 mg / day or Synacthène (Tetracosaclide) 1- 2 mg / 24 hours.

Treatment of fluid reduction in the brain:

Diuretics: Decreased extracellular volume and venous pressure, decreased secretion of cerebrospinal fluid (little), Furosemide at a dose of 1mg / kg intravenously lowers intracranial pressure rapidly. Also using the usual dose of 1-2 tubes with moderate results.

Hypertonic solution: Mannitol 20% dose 0.25- 0.5-1.5g / kg but not more than 5g / kg / 24 hours. The effect of mannitol is short (3-5 hours) should normally pass 100ml 20% in 1 hour (XXX -XXXX drops / min) reattach every 6 hours. Should not last longer than 3-5 days to avoid dehydration, toxic to the liver-kidney.

Intravenous glycerol 30% 20-40ml 3-4 times a day or drink 2g / kg / day for 10-15 days, with little reaction.

Increased ventilation:

Effects through vasoconstriction due to CO2 reduction.

Intravenous barbituric with aesthetic dose reduces perfusion and metabolism in the brain. The mechanism of reducing edema of barbituric is very complicated (vasoconstriction, sedation, or stabilization of cell membranes ...). In severe increase in intracranial pressure, the combination of respiratory support with thiopental 3-5 mg / kg intravenously 50 - 100mg repeated to 2-4g / day gives quite good results.