Intracranial Hypotension Headache, although not commonly seen in the community, is a condition that seriously affects the patient’s quality of life when diagnosis is delayed. Headache is often confused with fatigue, stress, or migraine in many people; however, some headaches are harbingers of an important neurological disease that occurs due to the decrease of cerebrospinal fluid (CSF).

When the amount of this fluid that protects the brain and spinal cord decreases, intracranial pressure drops and the brain membranes stretch. As a result, positional headache that increases when standing up and decreases when lying down develops. This picture is called Intracranial Hypotension Headache or by its colloquial name “headache due to CSF leak.”

In this article, we address the causes, symptoms, diagnostic methods, and treatment options of Intracranial Hypotension Headache from a neurology specialist’s perspective, with clarity and scientific accuracy.

What is Intracranial Hypotension Headache?

Intracranial Hypotension Headache, as can be understood from its name, is a severe headache syndrome that occurs as a result of intracranial (intracranial) pressure falling below normal (hypotension). The brain and spinal cord float in a protective fluid called cerebrospinal fluid (CSF). This fluid protects the central nervous system against trauma, carries nutrients, removes waste products, and most importantly acts as a kind of “cushion” for the brain, protecting it from the effects of gravity.

Under normal conditions, the production and absorption of this fluid are in a delicate balance, ensuring that intracranial pressure remains within a certain range. However, when a tear or leak occurs in the membrane surrounding the brain and spinal cord called the dura mater, CSF begins to leak out through this hole. This fluid loss reduces the total fluid volume inside the skull and therefore causes pressure to drop. With the pressure drop in a closed system, the brain loses its protective cushion and sags downward slightly. This sagging stretches the brain’s pain-sensitive structures (vessels, nerves, and brain membranes), leading to severe and unbearable headaches that change with position in Intracranial Hypotension.

What Causes Intracranial Hypotension Headache?

The causes of CSF leak leading to decreased intracranial pressure can vary. These causes are basically examined in two main groups: Spontaneous and Secondary.

1. Spontaneous Intracranial Hypotension:

In this situation, CSF leak develops without obvious trauma or medical intervention. Although the exact cause underlying spontaneous leaks is not always clear, some risk factors and conditions have been identified:

• Connective Tissue Diseases: In people with genetically inherited connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome, the dura mater (spinal membrane) is more fragile and prone to tearing.
• Spinal Pathologies: Bone spurs (osteophytes) formed due to calcification in the spine, disc herniations (lumbar or cervical hernias), or spinal cysts can cause leakage by eroding or piercing the dura mater over time.
• Minor Traumas: Actions normally considered harmless such as sudden movement, sneezing, severe coughing, straining, or a minor fall can lead to tearing on a weak dura mater.
• Idiopathic: In some cases, despite all investigations, the cause of the leak cannot be found. These cases are classified as idiopathic (unknown cause).

2. Secondary Intracranial Hypotension:

This type generally occurs after a medical intervention or trauma and the cause is clearer:

• Lumbar Puncture (Spinal Tap): During this procedure performed to obtain a cerebrospinal fluid sample or measure pressure, the hole where the needle entered may not close completely and can lead to CSF leakage. This is also known as post-dural puncture headache and is the most common secondary cause of Intracranial Hypotension Headache.
• Spinal or Epidural Anesthesia: These types of anesthesia used especially during childbirth or some surgeries can also cause a hole in the dura mater.
• Spinal Surgeries: The dura mater can be accidentally damaged during surgical interventions in the spinal region.
• Head and Spinal Trauma: Serious accidents, falls, or injuries can cause tears in the dura mater leading to CSF leak.

What Are the Symptoms of Intracranial Hypotension Headache?

The most prominent and characteristic feature of Intracranial Hypotension Headache is postural or orthostatic headache. This means the headache changes dramatically according to body position.

1. Headache Increasing with Position

• There is mild or no pain in lying position.
• When the patient stands up, throbbing pain starting from the back of the head occurs within minutes.
• Pain increases with sitting or walking, decreases when lying down.
• This feature is the most typical finding of Intracranial Hypotension Headache.

This positional feature is the most important clue for diagnosis. However, there are other symptoms accompanying the syndrome.

2. Accompanying Symptoms

• Neck Pain and Neck Stiffness: The downward sagging of the brain can affect neck muscles and nerve roots, causing neck pain and neck stiffness.
• Nausea and Vomiting: Severe headache can often be accompanied by nausea and vomiting.
• Hearing and Balance Problems: Tinnitus, sensitivity to sounds (phonophobia), hearing loss, and dizziness (vertigo) can be seen.
• Visual Symptoms: Complaints such as light sensitivity (photophobia), blurred vision, or double vision (diplopia) may occur.
• Other Neurological Symptoms: Rarely, more serious symptoms such as weakness in arms and legs, numbness, taste disorders, and slowing in cognitive functions (difficulty concentrating, memory problems) can also be added to the picture.

International Classification of Headache Disorders (ICHD-3) Diagnostic Criteria – 7.2 Headache attributed to low cerebrospinal fluid (CSF) pressure

Intracranial Hypotension is defined in the International Classification of Headache Disorders (ICHD-3) as “Headache Due to Intracranial Pressure Decrease (7.2.3).”
This classification enables diagnosis based on clinical and imaging findings of the disease.

ICHD-3 Diagnostic Criteria:

1. Headache related to CSF pressure decrease.
   B. At least one of the following findings on brain MRI:

• Contrast enhancement in dural membranes (pachymeningeal thickening)
• Brainstem or cerebellar sagging
• Subdural fluid collection or venous enlargement

1. Headache having the following characteristics:

• Markedly increasing within 15 minutes in sitting or standing position
• Lightening or passing within 15-30 minutes when lying down

1. CSF opening pressure measured during lumbar puncture being ≤6 cmH₂O or detection of CSF leak on imaging.
   E. Headache significantly decreasing or disappearing when pressure returns to normal.

These criteria are the international standard in Intracranial Hypotension Headache diagnosis.
When clinical history (especially positional pain) combines with these findings, diagnosis is strongly supported.

How is Intracranial Hypotension Headache Diagnosed?

Intracranial Hypotension Headache diagnosis begins with detailed inquiry of the patient’s headache history (especially positional headache). However, since history can be confused with other common primary headache diseases such as migraine or tension-type headache, advanced imaging methods are used to confirm diagnosis and determine the underlying cause.

1. Magnetic Resonance Imaging (MRI):

Brain MRI performed with contrast agent (Gadolinium) is the gold standard method in diagnosis. Rather than the CSF leak itself, the indirect effects it creates inside the skull are observed. According to the Monro-Kellie hypothesis, when the volume of one of the components (brain tissue, blood, CSF) inside the skull, which is a closed system, decreases, the others increase to compensate for this. In the case of Intracranial Hypotension Headache, blood volume increases to compensate for the decreased CSF volume. This situation leads to the following typical findings on MRI:

• Pachymeningeal Thickening and Contrast Enhancement: Thickening of brain membranes (especially dura mater) and intense contrast uptake is the most common finding.
• Downward Sagging of Brain (Cerebellar Tonsillar Herniation): Downward sagging of the lower parts of the cerebellum from the opening at the skull base (foramen magnum).
• Enlargement in Venous Structures: Prominence of veins in the brain.
• Enlargement in Pituitary Gland: The pituitary gland appearing larger than normal due to increased blood flow.
• Subdural Fluid Collections or Hematomas: Fluid accumulation between brain and brain membrane.

2. Tests to Detect CSF Leak Location:

Although brain MRI confirms the diagnosis, it may not show the exact location of the leak. To plan treatment correctly, it is important to find at which level of the spine the leak is. The following methods are used for this purpose:

• CT Myelography: After contrast agent is injected into the spinal canal, computed tomography (CT) is taken. Where the contrast agent leaks outside the spinal canal shows the region where the leak is.
• Radionuclide Cisternography: Similarly, a radioactive substance is given to the spinal fluid and the distribution of this substance in the body is monitored with a special camera. The substance accumulating outside the spinal canal indicates the leak.
• MR Myelography: With advanced MR techniques, the location of the leak is attempted to be detected using contrast agent.

Intracranial Hypotension Headache Treatment

Treatment is planned according to the severity of symptoms, the cause of cerebrospinal fluid (CSF) leak, and the patient’s general condition.
The goal is to return intracranial pressure to normal, alleviate headache, and enable spontaneous closure of CSF leakage.

1. Conservative (Non-medication) Treatment

In mild cases and especially in situations of CSF leak developing after lumbar puncture, conservative methods are the first choice.
In this approach, the goal is to enable spontaneous closure of the leak by supporting the body’s natural healing mechanisms.

• Bed Rest:
  The patient remaining in horizontal position for several days helps balance intracranial pressure. This increases the probability of the tear in the dural membrane closing on its own.
• Abundant Fluid Intake (Hydration):
  Daily consumption of 2-2.5 liters of fluid supports CSF production. In addition to water, fresh fruit juice and fluids containing electrolytes can also be recommended.
• Caffeine:
  Caffeine reduces pain by constricting brain vessels and can stimulate CSF production. Coffee or caffeine-containing medications are especially effective in morning hours.
• Analgesics:
  Simple painkillers (paracetamol, ibuprofen, etc.) provide symptomatic relief but are generally short-acting.

These measures generally provide significant improvement within 2-5 days. However, if complaints continue or pain is very severe, advanced treatments such as epidural blood patch come into play.

2. Interventional Treatment: Epidural Blood Patch

In patients who do not respond to conservative treatment or whose complaints are severe, the most effective and frequently applied method is epidural blood patch. This procedure both quickly returns cerebrospinal fluid (CSF) pressure to normal and repairs the dura mater where the leak is.

How is the Application Done?

During epidural blood patch, approximately 20-30 ml of blood is taken from the patient’s own arm. This blood is injected into the epidural space from the spinal level where the leak is thought to be — generally from the lumbar region.

Mechanism of Action

The injected blood creates pressure in the epidural space, instantly raising CSF pressure and alleviating headache within minutes. The blood then clots, forming a “natural patch” in the leak area.
This clot plugs the tear in the dura mater, thus CSF leak stops and intracranial pressure returns to normal.

Success Rate

Epidural blood patch has a high success rate in Intracranial Hypotension treatment.

• Success rate in first application is around 85-90%.
• The procedure can be repeated after 1-2 weeks if necessary.
• After a successful patch, headache generally significantly decreases within 24 hours.

Post-procedure Recommendations

• After the procedure, at least 24 hours bed rest is recommended.
• Within the first 48 hours, heavy lifting, bending forward, and standing for long periods should be avoided.
• Abundant fluid intake and caffeine support accelerate recovery.

3. Surgical Treatment:

In stubborn cases that do not improve despite conservative treatment and repeated epidural blood patches, where the leak location has been clearly identified by imaging methods, surgical intervention is considered. Surgery involves directly reaching the leak area and closing the tear with a stitch, artificial patch, or tissue adhesives. This is generally a method resorted to as a last resort.

In conclusion, Intracranial Hypotension Headache is an important syndrome that is distinguished from other headache types by its typical positional character, but whose diagnosis may be delayed due to its rarity. This condition, which develops due to cerebrospinal fluid leak, has a highly disabling potential that deeply affects patients’ daily life, workforce, and social relationships. With correct diagnosis and effective treatment methods, the vast majority of patients can fully recover. Therefore, it is vitally important for people with headache complaints that start when standing up and pass when lying down to not ignore this situation and definitely consult a neurology specialist.

Frequently Asked Questions About Intracranial Hypotension Headache

1. How can I distinguish this headache from other headaches (e.g., migraine)? What is the most obvious difference?

The most basic and distinguishing feature of this headache is that it is positional. That is, the severity of pain changes dramatically according to your body posture. If you have a headache that starts and gradually intensifies shortly after standing up or sitting, and significantly lightens or completely passes generally within 15-30 minutes when lying down, this is very typical for Intracranial Hypotension Headache. In migraine or tension-type headaches, pain generally does not show such a clear relationship with position.

2. Is Intracranial Hypotension Headache a dangerous condition? Does it cause permanent damage?

Although it is generally not a life-threatening condition, it is a disease that seriously reduces quality of life when not diagnosed and treated, and can rarely lead to serious complications. If the downward sagging of the brain continues, small veins on the brain surface can tear by stretching, causing bleeding (subdural hematoma) between the brain and brain membrane. With early diagnosis and correct treatment, these risks are minimized and the vast majority of patients fully recover without permanent damage.

3. Is there a definitive treatment for this disease? How effective is the “Epidural Blood Patch” procedure?

Yes, there are quite effective treatment methods for this disease. Conservative treatments (bed rest, abundant fluids, caffeine) may be sufficient in some mild cases. However, the most effective and standard treatment method is Epidural Blood Patch. In this procedure, the patient’s own blood is injected into the space around the spinal membrane to close the leak. The success rate is quite high and 85-90% of patients get rid of their symptoms to a large extent even in the first application. In stubborn cases, options such as repeating the procedure or surgical repair are also available.

4. I have a headache that started after lumbar puncture (spinal tap). Could this be Intracranial Hypotension? What should I do?

Yes, this is very likely. The most common cause of headaches developing after lumbar puncture or spinal anesthesia is leakage of cerebrospinal fluid from where the needle entered. This condition is a secondary type of Intracranial Hypotension Headache. If you have a headache after the procedure, especially one that intensifies when standing up, it is first recommended that you rest in bed while consuming abundant fluids and caffeine. If your complaints do not pass within a few days or are very severe, you should definitely consult the physician who performed the procedure or a neurology specialist.

5. How is this disease diagnosed? Is it enough for me to just describe the complaints?

The typical positional headache history described by the patient is the most important clue for the doctor and allows suspicion of diagnosis. However, imaging methods are definitely used to confirm diagnosis. Contrast (medicated) Brain Magnetic Resonance (MR) imaging is the gold standard in confirming diagnosis by showing the indirect findings that decreased intracranial pressure creates in the brain (thickening in brain membranes, brain sagging, etc.). In necessary cases, more advanced tests such as CT Myelography may be requested to find the exact location of the leak.