Makindo Medical Notes

Related Subjects:Migraine |Basilar Migraine |Cluster Headaches |Sumatriptan |Tension Headache |Analgesic Overuse Headache |Headaches in General

Headaches caused by low cerebrospinal fluid (CSF) pressure, also known as low-pressure headaches or CSF leak headaches, are a distinct type of headache that occurs when the pressure of the CSF, which cushions the brain and spinal cord, drops below normal levels. This type of headache is often associated with a spinal CSF leak, which can be spontaneous or result from medical procedures.

About

• Low CSF pressure headache occurs due to presumed leakage of cerebrospinal fluid (CSF).
• This leakage leads to reduced pressure in the CSF, resulting in headache and other symptoms.

Aetiology

• Spontaneous CSF Leak: Often occurs due to a small tear or hole in the dura mater, the protective membrane around the brain and spinal cord.
• Post-Lumbar Puncture: Following a lumbar puncture (spinal tap), the needle puncture may not properly seal, causing CSF leakage.
• Trauma: Head or spinal injuries can tear the dura mater, leading to CSF leaks and low-pressure headaches.
• Surgical Procedures: Surgeries involving the spine or brain can sometimes result in inadvertent CSF leaks.
• Connective Tissue Disorders: Conditions like Marfan syndrome or Ehlers-Danlos syndrome can weaken the dura mater, making it more prone to tears and leaks.

Circulation of cerebrospinal fluid (CSF). CSF is produced by the choroid plexus, which consists of specialized secretory tissue located within the cerebral ventricles. It flows from the lateral and third ventricles through the cerebral aqueduct and fourth ventricle and exits the ventricular system through two laterally situated foramina of Luschka and a single, medially located foramen of Magendie. CSF then enters and circulates through the subarachnoid space surrounding the brain and spinal cord. It is ultimately absorbed through arachnoid granulations into the venous circulation.

Clinical Features

• Diffuse, throbbing headache, usually most severe in the occipital region but can affect the entire head.
• Symptoms typically worsen when the patient stands or sits and improve when lying down.
• Worsening of symptoms on waking, with resolution upon lying flat.
• Associated symptoms may include nausea, vomiting, neck pain, and stiffness.
• Tinnitus (ringing in the ears) or a sensation of fullness in the ears may occur.
• Cranial nerve palsies, such as diplopia, may be present in some cases.

Investigations

• MRI with gadolinium: Used to detect signs of a CSF leak, such as meningeal enhancement, subdural fluid collections, or brain sagging.
• CT Myelography: Involves injecting contrast into the CSF space to locate the source of the leak.
• Intrathecal Contrast-Enhanced MRI: An advanced imaging technique to visualize the leak more accurately.
• Radioisotope Cisternography: Involves injecting a radioactive tracer into the CSF to detect leaks, though it is used less frequently.

Management

• Conservative Management: Bed rest, hydration, and caffeine intake may help alleviate symptoms in mild cases.
• Epidural Blood Patch: The most common treatment, especially for post-lumbar puncture headaches. A small amount of the patient's blood is injected into the epidural space to seal the leak.
• Surgical Repair: In cases where the leak persists or conservative treatments fail, surgical repair of the dura mater may be necessary.
• Hydration and Caffeine: Increased fluid intake and caffeine may temporarily elevate CSF pressure, providing symptom relief.
• Pain Management: Analgesics and antiemetics can help manage headache, nausea, and vomiting associated with low CSF pressure.