What are the Earliest Signs of Increased Intracranial Pressure?

Medically Reviewed on 1/24/2023
Increased Intracranial Pressure
Increased intracranial pressure is a dangerous, life-threatening medical emergency.

A combination of diffuse, sudden, and excruciating headaches (may be associated with an altered mental state), projectile vomiting, and swelling of the optic nerve (papilledema) is considered one of the earliest signs and a clear indication of increased intracranial pressure.

Other symptoms that may follow include:

  • Transient episodes of visual loss (which last a few seconds)
  • Pulsatile tinnitus (a unilateral whooshing sound exacerbated with positional changes)
  • Visual disturbance or blurred vision
  • Pupillary changes (irregular or dilatation seen in one eye)
  • Horizontal diplopia
  • Feeling less alert than usual (lethargy, weakness)
  • Behavioral changes (irritability, slow decision-making, and abnormal social behavior)
  • Problems with moving or talking
  • Lack of energy or sleepiness

Increased intracranial pressure (ICP) is an increase in pressure inside the skull, which compresses the brain (pressure in the cranial vault is usually less than 20 mmHg). It is a dangerous medical emergency and can lead to life-threatening complications, including death, if not treated in time.

Increased ICP is an alarming signal of intracranial hypertension, which can be caused by a head injury, a tumor, a stroke, an infection, or any other condition that causes fluid accumulation in the head.

What is intracranial hypertension?

Intracranial hypertension (ICH) is a clinical condition associated with an elevation of pressure around the brain of more than 20 mmHg.

Based on etiopathogenesis, ICH is classified into four different forms that include:

  1. Parenchymatous ICH
    • Appears in expansive intracranial processes caused by intrinsic cerebral causes such as tumors, hematomas, cerebral abscesses, traumatic brain edema, and general intoxication with neural toxins (exogenous or endogenous).
  2. Vascular ICH 
    • Intracranial pressure is determined by disorders of the cerebral blood volume.
    • Vascular ICH is seen in:
      • Vascular cerebral diseases such as cerebral venous thrombosis, superior sagittal sinus thrombosis, and mastoiditis with transverse, or sigmoid sinus thrombosis.
      • Extra cerebral diseases such as hypertensive encephalopathies, malignant hypertension, glomerulonephritis, eclampsia chronic hypertensive encephalopathy, congestive cardiac failure, and intrathoracic mass lesions.
  3. Meningeal ICH
  4. Idiopathic ICH
    • May occur in endocrine, metabolic, hematological diseases, and hormonal treatments.
    • More often seen in obese women of childbearing age, with some associated conditions such as the use of drugs (tetracycline, cimetidine), oral contraceptives, Cushing’s disease, and hypothyroidism.
    • Although the exact etiology has not been established, researchers have speculated three major theories of the cause of idiopathic ICH, which include:
      • Increased resistance to CSF absorption
      • Increased CSF production
      • Increased venous sinus pressure


The abbreviated term ADHD denotes the condition commonly known as: See Answer

What are the clinical stages of intracranial hypertension?

Three clinical stages (reversible) of intracranial hypertension (ICH) are as follows:

  1. Infraclinic form: Intracranial pressure (ICP) increases over the physiological values (≤15 mmHg).
  2. ICH syndrome: ICP increases up to 20 mmHg along with the presence of clinical symptoms (chronic form).
  3. ICH disease: It is the acute form with ICP over 20 mmHg; the symptoms of the preceding stage increase until decompensation.

What causes increased intracranial pressure?

Increased intracranial pressure (ICP) occurs as a result of the disturbance of the regulatory ICP mechanisms, caused by the changes in the volumes of the intracranial components, which are the brain parenchyma, cerebrospinal fluid (CSF), and cerebral blood volume.

Increased ICP could be a result of the following:

How is increased intracranial pressure diagnosed?

  • Physical examination: The doctor may ask about medical history, any recent injuries, or illnesses, and check for general health status.
  • Neurological examination: To test senses, balance, orientation, and mental status.
  • Spinal tap (lumbar puncture): To measure the pressure of the cerebrospinal fluid.
  • Ocular examination: Papilledema is the hallmark sign of intracranial hypertension, which is graded using the Frisen scale. 
  • Fundoscopic examination: Shows blurring of the disc margins, loss of venous pulsations, disc hyperemia, choroidal compression across the macula, choroidal neovascularisation, and retinal elevation around the optic nerve head.
  • CT scan: To create a series of cross-sectional X-ray images of the head and brain.
  • MRI: Magnetic fields are used to detect subtle changes in brain tissue.

How is increased intracranial pressure treated?

Increased intracranial pressure (ICP) is treated by treating the underlying cause, which could be an infection, high blood pressure, tumor, or stroke.

The treatment of ICP might include:

  • First-line therapy
    • Treatment of pyrexia
    • Management of seizures
    • Drainage of cerebrospinal fluid
    • Head of the bed elevation
    • Analgesia and sedation (intravenous propofol, etomidate, or midazolam for sedation and morphine or alfentanil for analgesia and antitussive effect)
    • Neuromuscular blockade
    • Mannitol (an intravascular osmotic agent)
  • Second-line therapy

What are the complications of increased intracranial pressure?

Some of the serious complications of increased intracranial pressure (ICP) include:

Although ICP cannot be prevented completely, the risk can be reduced by controlling certain underlying conditions such as high blood pressure, stroke, or infection.

Medically Reviewed on 1/24/2023
Image Source: iStock image

Increased Intracranial Pressure (ICP) Headache Johns Hopkins Medicine https://www.hopkinsmedicine.org/health/conditions-and-diseases/headache/increased-intracranial-pressure-icp-headache

Increased Intracranial Pressure NIH https://www.ncbi.nlm.nih.gov/books/NBK482119/

Pseudotumor Cerebri (Idiopathic Intracranial Hypertension) American Academy of Ophthalmology https://eyewiki.aao.org/Pseudotumor_Cerebri_(Idiopathic_Intracranial_Hypertension)

Increased intracranial pressure MedlinePlus https://medlineplus.gov/ency/article/000793.htm