Spinal Headache - A Common Complication

Introduction

Spinal headache is the most commonly arising complication following procedures such as lumbar punctures (spinal tap) or spinal anesthesia. Both interventions involve puncturing the protective membrane enveloping the spinal cord and, in the lower spine, the sacral and lumbar nerve roots. In a spinal tap, a sample of CSF (cerebrospinal fluid) is extracted from the spinal canal, while spinal anesthesia entails injecting medication into the spinal canal to numb the nerves in the lower body.

If there is a leakage of spinal fluid through the small puncture site, it can lead to the development of a spinal headache. The majority of spinal headaches, also referred to as post-dural puncture headaches, typically resolve spontaneously without the need for intervention. However, when severe spinal headaches persist for 24 hours or more, medical treatment may be necessary.

What Are the Characteristics of Spinal Headache?

The characteristic features of spinal headache include:

• Headache typically begins 24 to 48 hours after lumbar puncture.

• In some cases, the onset might be delayed by up to 12 days, suggesting randomness in the defined time points.

• Immediate headache after lumbar puncture is rare.

• Such cases may raise concerns about potential causes like increased intracranial pressure leading to the displacement of intracranial structures.

• The postural nature is distinctive of spinal headaches.

• Symptoms are usually self-limited but can be severe enough to immobilize the patient.

• A dull or throbbing headache typically begins in the occipital or frontal region and may later become generalized.

• Pain may radiate to the shoulder and neck area.

• Neck stiffness may be present.

• Head movements worsen the pain.

• Maneuvers, including intracerebral pressure, coughing, straining, sneezing, and ocular compression, can exacerbate symptoms.

• Lower back pain, vomiting, nausea, vertigo (dizziness), and tinnitus (ringing in the ear) can occur.

• Rarely, diplopia (seeing two images) due to cranial nerve palsy and cortical blindness (loss of vision due to damage to the brain’s occipital cortex) may occur.

• Headache usually resolves within a few days.

• The longest reported duration of headache after lumbar puncture was 19 months.

What Is the Pathogenesis of Spinal Headache?

The precise pathophysiology of post-lumbar puncture headaches remains uncertain. However, it is likely associated with the formation of a hole in the dura mater (thick outer membrane of skull and vertebra) upon needle withdrawal, leading to an ongoing cerebrospinal fluid leak from the subarachnoid space. This continuous leakage results in a reduction of intracranial CSF volume and pressure. While there is agreement existing on the loss of CSF and the subsequent decrease in CSF pressure, the specific mechanism triggering post-lumbar puncture headaches is not well-defined. Two potential explanations are considered:

• Firstly, the diminished CSF volume may deplete the fluid cushion, supporting the brain and its sensitive meningeal vascular coverings. This, in turn, causes gravitational traction on the pain-sensitive intracranial structures, resulting in a classical headache that worsens in an upright position and is alleviated when lying down.

• Secondly, the reduction in CSF volume might directly activate adenosine receptors, leading to cerebral vasodilation (widening of blood vessels) and stretching of pain-sensitive cerebral structures, ultimately causing headaches after lumbar puncture.

How Is a Spinal Headache Diagnosed?

Diagnosing spinal headaches is primarily clinical, relying on the patient’s history of dural puncture and the distinctive postural nature of the headache, often accompanied by related symptoms. If a diagnostic lumbar puncture is conducted, findings may include a low opening pressure in the CSF, a slightly elevated CSF protein level, and an increase in CSF lymphocyte count. Additionally, MRI (magnetic resonance imaging) of the brain may reveal diffuse dural enhancement, indications of sagging, the descent of the brain and brainstem, enlargement of the pituitary gland, and obliteration of the basilar cisterns (expansion of subarachnoid space).

How to Manage Spinal Headaches?

For patients experiencing a headache following a lumbar puncture with identifiable features, it is advisable to promote a comfortable position, typically lying supine, due to the characteristic postural nature of the symptoms. Supportive measures, including rehydration and the administration of simple analgesics, antiemetics, and opioids, may effectively manage symptoms in milder cases. The majority of headaches after lumbar puncture, exceeding 85 %, tend to resolve without the need for specific treatment. However, treatment may be necessary for severe spinal headaches persisting for 24 hours or more.

Therapeutic Approaches for Spinal Headache:

• Blood Patch: To perform this procedure, 0.67 to 1 fluid ounce of blood is drawn from a large vein, which is usually taken from the patient’s arm. The blood is then slowly injected into the epidural space through an epidural needle, forming a clot that seals the perforation and prevents further cerebrospinal fluid (CSF) leakage. After the procedure, the patient is instructed to lie still for one to two hours in a supine position before being allowed to move.

• Epidural Saline: Following the blood patch treatment, the quick relief of symptoms could not be solely caused by the sealing effect at the puncture site. This led to the idea that the resolution might involve compressing the thecal sac using saline, which is relatively inert and sterile, causing an assumed increase in subarachnoid pressure due to the introduced blood volume.

• Epidural Dextran 40: It is not currently in use, but patients experienced relief within 24 hours after receiving a 20 mL epidural injection of Dextran 40. This substance is believed to elevate epidural pressure, reducing cerebrospinal fluid leakage.

• Hydration: Initially, it was suggested that boosting hydration could replace fluids and stimulate more cerebrospinal fluid production.

• Caffeine: Several studies and case reports have suggested both intravenous and oral caffeine as therapeutic options.

• Surgical Closure: When other treatments prove ineffective, surgical closure of the dural gap is considered a final option for treatment.

Can Spinal Headaches Be Prevented?

Given that headache after lumbar puncture is a relatively common occurrence and a notable contributor to morbidity, it is crucial to explicitly address this potential outcome during the informed consent process for lumbar puncture. This emphasis becomes particularly important for individuals with high-risk categories, such as young women with a low body mass index and those who are pregnant. Clear communication about the possibility of post-lumbar puncture headaches ensures that patients are well-informed and can actively participate in decision-making.

Conclusion

Spinal headaches frequently occur as a complication in individuals undergoing a spinal tap or spinal anesthesia. The majority of spinal headaches, also termed post-dural puncture headaches, typically resolve spontaneously without the need for intervention. Management of spinal headaches may include conservative approaches such as resting in bed, elevating fluid intake, and incorporating caffeine. In instances of heightened severity, a blood patch procedure may be implemented.