Article Text
Abstract
Unintentional dural puncture followed by postdural puncture headache (PDPH) is a well-known complication of neuraxial labor analgesia/anesthesia. The resulting headache is a dull throbbing pain which occurs within five days of a lumbar puncture and is usually orthostatic in nature, since it tends to worsen when the patient assumes the standing or sitting position and improves when the patient lies down. Associated signs and symptoms such as neck pain or stiffness, photophobia, tinnitus, hypoacusis and nausea are present in more than 50% of cases. The headache is usually self-limiting within two weeks of onset, while resolution can occur sooner if autologous epidural blood patch is performed. PDPH is very unpleasant to new mothers since it severely limits the interaction between the mother and the newborn, while it can lead to prolonged hospitalization and emergency department visits or rarely result in significant morbidity. The pathophysiology behind the development of PDPH is firstly cerebrospinal fluid leakage through the dural puncture, which can lead to stimulation and stretching of sensory cranial nerve fibers caused by downward shift of the brain and secondly intracranial hypotension which leads to cerebral vasodilation and a vascular-type headache, as a compensatory mechanism to maintain the intracranial volume according to the Monro-Kellie doctrine. The diagnosis is based on clinical presentation (orthostatic headache after a neuraxial procedure) and can be significantly aided by MRI, which reveals signs consistent with intracranial hypotension, such as compression of the ventricles, reduction of the basal cisterns, caudal displacement of the brain, brainstem and optic chiasm, occasional subdural effusions and cerebellar ectopia. The characteristic MRI sign is the diffuse meningeal thickening and enhancement. The differential diagnosis of PDPH ranges from benign conditions, such as tension-type headache and migraine to serious disorders such as preeclampsia, subarachnoid hemorrhage and cerebral venous sinus thrombosis. Serious complications of untreated PDPH can occasionally occur. Subdural hematoma is due to traction and compensatory vasodilation of bridging veins due to loss of cerebrospinal fluid. Cerebral venous sinus thrombosis is caused by cerebral venous dilation and blood stasis due to the leak and damage to the cerebral venous endothelium caused by the negative spinal-cranial pressure gradient in combination with the puerperium hypercoagulability. Both complications can have a deleterious outcome if unsuspected and untreated and difficulties in differential diagnosis arise from the fact that both subdural hematoma and cerebral venous sinus thrombosis present with headache as the commonest symptom, which can lead to considerable delays in diagnosis if accidental dural puncture has simultaneously occurred or is suspected. Therefore, there is a need for urgent neurological consultation as well as urgent neuroimaging in the puerperium in case of new or recurrent neurological symptoms. Both disorders should be considered in the differential diagnosis, especially in case of atypical clinical presentation or in case of loss of the postural component of the headache during follow-up. Furthermore, it is crucial to investigate persistent or recurrent headaches in the puerperium even after the performance of an epidural blood patch in case of focal neurological signs or in case of severe non-positional headache.
References
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Wittmann M, et al. Sinus venous thrombosis: a differential diagnosis of postpartum headache. Arch Gynecol Obstet 2012; 285:93–9