A low pressure headache, or intracranial hypotension, results from abnormally low cerebrospinal fluid (CSF) pressure around the brain and spinal cord. This condition differs from common headaches and can signal a serious underlying issue. Understanding its characteristics and when it requires immediate medical attention is important.
Understanding Low Pressure Headaches
A low pressure headache occurs when insufficient cerebrospinal fluid (CSF) cushions the brain, reducing pressure within the skull. CSF bathes the brain and spinal cord, providing buoyancy and protection. When CSF leaks, the brain can sag downward, causing tension on surrounding structures and pain.
The most distinguishing symptom is its postural nature. The headache worsens when upright (sitting or standing) and often improves within 20 to 30 minutes of lying flat. Other common symptoms include neck pain, stiffness, nausea, vomiting, dizziness, and hearing changes. Some individuals may also experience visual disturbances, impaired concentration, or a metallic taste.
Common Causes of Low Pressure Headaches
Low CSF pressure often results from a leak from the dura, the tough membrane surrounding the brain and spinal cord. A common cause is a post-dural puncture headache, occurring after medical procedures like a spinal tap or epidural injection. If the needle hole in the dura does not seal quickly, CSF can continue to leak.
Spontaneous CSF leaks are another frequent cause, where a tear in the dura occurs without an obvious preceding event. These leaks can sometimes be linked to underlying connective tissue disorders, which may weaken the dura. Trauma, including head injuries or spinal surgery, can also lead to CSF leaks by damaging the dura. Certain medical conditions, such as hydrocephalus, can predispose individuals to CSF leaks.
When Immediate Medical Attention is Needed
While many low pressure headaches resolve with conservative measures, certain signs indicate the need for immediate medical evaluation. A severe or sudden onset headache, particularly if it is the “worst headache of your life,” warrants urgent attention. Any low pressure headache accompanied by neurological symptoms like confusion, weakness, numbness, or difficulty speaking requires an emergency visit.
Additional red flag symptoms include a stiff neck, fever, seizures, or rapid worsening of existing symptoms. If clear fluid drains from the nose or ear, especially after trauma or a medical procedure, this could indicate a CSF leak and requires immediate assessment due to the risk of infection, such as meningitis. Suspected CSF leaks not responding to rest or increasing in severity require urgent medical consultation.
Diagnosis and Management of Low Pressure Headaches
Diagnosing a low pressure headache typically involves a detailed review of symptoms and a physical examination. Imaging studies are often used to confirm the diagnosis and locate the CSF leak. Magnetic Resonance Imaging (MRI) of the brain and spine is a common tool, as it can show characteristic signs such as thickening of the meninges or evidence of the brain sagging. In some cases, specialized MRI or CT myelography, which involves injecting contrast dye into the spinal fluid, can help pinpoint the exact site of the leak. Cerebrospinal fluid pressure measurements, obtained through a lumbar puncture, may also reveal lower than normal pressure, though this procedure can sometimes temporarily worsen symptoms.
Management strategies for low pressure headaches vary based on severity and cause. For milder cases, conservative approaches are often the first step, including bed rest, increased fluid intake, and caffeine consumption, which can help increase CSF production. If conservative measures are not effective, more targeted interventions may be necessary. An epidural blood patch, where a person’s own blood is injected into the epidural space, helps seal the leak and reduce symptoms. This procedure can often provide rapid relief, though sometimes multiple patches are needed. For persistent or severe leaks, surgical repair may be considered, particularly if the leak location is clearly identified.