Introduction
Post-dural puncture headache (PDPH) is a common but major complication of neuraxial anesthetic procedure occurring secondary to spinal anesthesia or due to dural puncture during epidural anesthesia. This leads to traction on the pain-sensitive structures due to low CSF (cerebrospinal fluid) pressure (intracranial hypertension) secondary to CSF leakage at the site of injection or lumbar puncture.
Who Is Susceptible to Post Dural Puncture Headache?
PDPH is mostly seen in women of younger ages, between 20 to 40 years, especially ones with a history of headaches and low BMI (body mass index). Pertaining to age-related brain atrophy, PDPH is rarely seen in the elderly population. This is seen in about 10 to 40 percent of conventional lumbar punctures, but the incidence falls below two percent upon recruiting small gauge non-cutting needles. The onset is variable, typically between 28 to 72 hours, or may even be delayed for several months.
What Is the Cause of Post Dural Puncture Headache?
Post-dural puncture headaches can be caused due to following:
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Dural puncture during a lumbar puncture.
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Diagnostic myelography.
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Subarachnoid block.
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Unintentional dural puncture from epidural anesthesia.
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Ventricular shunt placement.
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Brain or spinal cord trauma.
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Spinal surgery.
What Are the Risk Factors of Developing Post Dural Puncture Headache?
The risk factors for developing post-dural puncture headaches can be categorized into:
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Patient factors.
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Needle factors.
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Procedural factors.
Patient Factors
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Young age.
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Female sex.
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Pregnancy.
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Vaginal delivery.
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Obesity (studies are contrasting with the obesity factor).
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Systemic illness.
The age factor produces evidence of a 14 percent incidence in younger individuals compared to seven percent in the elderly, which can be attributed to the decreased elasticity of the dura in the older population, making the dura less likely to gape. Females, especially pregnant ones, are more susceptible to PDPH, most likely due to estrogen levels which greatly influence the tone of cerebral vessels, thereby increasing vascular distension in cases of CSF hypotension. Additionally, pushing motion during vaginal delivery can increase the size of the dural puncture and increase the amount of CSF leak. Contrasting results have been reported by studies regarding the relationship between BMI (body mass index) and PDPH.
Needle Factors
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Sharp cutting tip needles (Quincke needles).
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Needle orientation.
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Size of the needle.
A longitudinal bevel orientation with the bevel parallel to the long axis of the spine separates the dural fibers rather than cutting through them. Additionally, there was a reported decrease in PDPH incidences when the bevel was pierced through the epidural space along the long axis of the spine and then rotated by 90 degrees before introducing the catheter. It is recommended to use Sprotte and Whitacre needles (blunt or pencil point needles) or Atraucan needles (cutting point and double bevel modification of the Quincke needle) to prevent PDPH incidences.
Procedural Factors
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Inexperienced proceduralist.
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The number of punctures.
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Removal of large amounts of CSF.
The CSF may or may not affect PDPH incidences but rather affects the degree of CSF hypotension. Additionally, positioning of the patient during and after the procedure has little to no effect on PDPH incidences.
What Is the Pathophysiology of Post Dural Puncture Headache?
PDPH occurs secondary to cranial hypotension (low pressure of cerebrospinal fluid) caused mainly due to removal (for lumbar puncture diagnosis) or leakage (accidental or procedural) from the site of dural puncture (following epidural or spinal anesthesia). These changes precipitate symptomatic pain over the pian-sensitive structures like meninges, vessels, cranial nerves, etc. Sagging of the brain downward in the upright position contributes to orthostatic symptoms like dizziness, blurry vision, weakness, etc. Diagnostic imaging has also revealed events like vascular dilation of venous sinuses, meningeal layers, and the pituitary gland. Interjugular compression, secondary to physical maneuvers like coughing, laughing, etc., can worsen the pain, which is evidentiary to the PDPH association with compensatory central venous dilation.
What Are the Clinical Features of Post Dural Puncture Headache?
PDPH presents with bilateral frontal or occipital headaches that worsen while sitting or standing and improve in supine positions. Headaches are accompanied by nausea, dizziness, neck pain, visual disturbances, tinnitus, loss of hearing, or radicular symptoms in the arms. The symptoms might worsen with coughing and other Valsalva maneuvers (forced expiration with the glottis closed), even while laying down. Uncommonly, patients may present with nystagmus, horizontal diplopia, facial numbness, or palsy. Cranial nerve VI palsies are a very rare occurrence and may also cause diplopia (double vision). Firm continuous pressure over the abdomen can temporarily improve the symptoms by indirectly increasing the CSF pressure, and pressures over the jugular can worsen.
How to Diagnose Post Dural Puncture Headache?
The diagnosis of PDPH is primarily done by observation and eliciting a history of lumbar puncture or spinal or epidural anesthesia. The CSF of the patients may reveal the presence of RBC (red blood cells), WBC (white blood cells), elevated protein levels, and xanthochromia (bilirubin in CSF). Long-standing cases can be taken in for MRI (magnetic resonance imaging) with gadolinium enhancements. Some of the MRI findings may also be appreciated in a CT (computed tomography) scan, but the CT is prone to misinterpretation as subarachnoid hemorrhage. CT myelography or MRI of the spine can pinpoint the location and severity of the CSF leak.
MRI reports may show:
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The descent of the cerebellar tonsils.
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Effacement of the basilar cisterns.
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Thickening of the meninges.
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Subdural fluid accumulation.
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Venous sinus engorgement.
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Enlarged pituitary gland.
How to Treat Post Dural Puncture Headache?
Initial symptoms can be managed with intravenous hydration, analgesics, abdominal binders, oral caffeine, and lying down during the first two to three days. Pharmacotherapeutic means include oral caffeine (300 to 500 mg once or twice a day), Aminophylline, Theophylline, adrenocorticotropic hormone (ACTH), desmopressin (DDAVP), Hydrocortisone, Dexamethasone, Methylprednisolone, Triptans, Gabapentin, Methylergonovine, Ondansetron, Mannitol, Neostigmine, and Atropine.
Other invasive procedures include;
Therapeutic Epidural Blood Patch (TEBP): TEBP involves an injection of blood in the epidural space, which increases the subarachnoid pressure. The blood clot may also seal the dural puncture. A success rate of 93 percent with a first patch and 97 percent with a second patch has been observed.
Prophylactic Epidural Blood Patch (PEBP): PEBP requires a prophylactic injection of blood (up to 20 milliliters) into the epidural space before the catheter removal.
Intrathecal Catheter Placement: A catheter is placed intrathecally following an unintended dural puncture for 24 hours with an infusion of intrathecal saline.
Although lacking sufficient studies and proof of efficacy, saline, epidural dextran infusion, epidural hydroxyethyl starch infusion, epidural gelatin, or fibrin glue epidural patches have been proposed.
What Is the Differential Diagnosis of Post Dural Puncture Headache?
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Caffeine withdrawal.
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Intracranial pathology.
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Migraines.
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Pneumocephalus.
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Sinus-related preeclampsia.
What Are the Complications of Post Dural Puncture Headache?
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Cerebral venous thrombosis (clot within the cranial vessels).
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Subdural hematoma (bleeding within the subdural space).
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Seizures (epilepsy).
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Hypopituitarism (under-functioning pituitary gland).
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Syringomyelia (cyst within the spinal cord).
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Herniation (intravertebral disc is pushed out).
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Coma.
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Death.
Conclusion
PDPH can be considered an avoidable event. By proper history, patient selection, needle selection, and clinical capability, PDPH can be avoided to a good extent. In case of an inadvertent puncture, the symptoms can be managed by a prompt response. One of the most important factors is to enquire about a history of PDPH; in such cases, it is best to avoid lumbar puncture or anesthesia or inculcate preventive and prophylactic means to manifest a better prognosis.