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Paper text:
a healthy 33-year - old primipara underwent a cesarean section at 37 weeks of gestation . upon arrival in the operation room
she was then placed in the lateral position and given a dural puncture between the 3rd and 4th lumbar vertebrae , using a 25-gauge quinke needle ( hakko co. ltd . ,
afterwards , a csf leak test was performed , and 8 mg of 0.5% hyperbaric bupivacaine were injected intrathecally .
five minutes later , the height of the sensory block was confirmed to be at t4 , and the operation was initiated . during the operation , the patient 's blood pressure ranged between 90/58 mmhg and 140/70 mmhg , the pulse between 80 and 90 per minute , and the peripheral capillary oxygen saturation between 98 and 100 percent .
the operation ended 1 hour and 15 minutes after its initiation , and the patient was transferred to the recovery room .
after 30 minutes in the recovery room , the patient complained neck stiffness and a mild headache .
the headache continued regardless of a change of position and the patient described that it felt " heavy in her head " .
after 6 hours of observation in the recovery room , the patient was transferred to the ward .
the patient was suspected of pdph and received an epidural blood patch ( ebp ) using an 18-gauge tuohy needle following a dural puncture .
the patient 's autologous blood was injected in a 15 ml dose in the area in which the dural puncture had been performed , but the symptoms persisted and a second ebp was therefore performed the next day .
the patient was discharged 6 days after the operation , with the headache still present although it had eased considerably .
two days after her discharge , the patient came to the emergency room for sudden dyspnea , paresthesia of the lower part of the body , and weakened muscle strength .
the examination in the emergency room revealed that she was experiencing weakened muscle strength and sensory loss below t4 .
an emergency mri scan revealed an anterior spinal subdural hematoma with spinal cord compression from c6 to t5 , and an hematoma was also observed in the subdural space between t6 and t10 ( fig .
there was no finding to presume of a bleeding tendency , as the tests before the anesthesia had reported the following : hemoglobin at 9.5 g / dl ; platelet at 303000 /l ; pt at 12.7 seconds , pt inr at 1.0 ; and ptt at 36.9 seconds .
the vital signs recorded shortly before the operation showed a blood pressure of 140/65 mmhg and a pulse rate of 105 /min .
an arteriography conducted shortly after the operation revealed stasis of the contrast medium in the anterior spinal canal , between c5 and t4 .
this paper reports the case of a patient with presumed pdph following a cesarean section performed under spinal anesthesia , who continued to experience a headache even after ebps and was diagnosed with pseudoaneurysm rupture of the vertebral artery .
differential diagnosis is challenging for this type of headache , as there are a number of possible causes .
primary headaches include migraines and tension headaches , which can be commonly experienced by women of childbearing age .
around 50 to 75 percent of headaches are primary , and migraine is the most common kind . on the other hand , secondary headaches are less frequent than primary headaches , they may bring about critical complications .
secondary headaches can be attributed to cardiovascular diseases such as strokes and high blood pressure , preeclampsia , and pdph .
if a primary headache can be excluded from consideration , when diagnosing a headache that occurred after spinal anesthesia for a cesarean section , most anesthesiologists will suspect pdph as the cause of the secondary headache .
however , there have been case reports in which pdph was wrongly diagnosed as the cause of the secondary headache , when it was in fact caused by other conditions such as cerebral venous thrombosis , cerebral vasoconstriction syndrome , encephalomeningitis , preeclampsia , or stroke . according to the pdph diagnosis guidelines of the international headache society ,
headache is worsened in a sitting or standing position , and is eased in a recumbent position .
it must have one of the following four symptoms : neck stiffness , tinnitus , hypacusia , and photophobia .
most headache develops within 5 days after dural puncture and resolves spontaneously within 1 week , or within 48 hours after ebp . in the present case ,
primary headache could easily be excluded from consideration as a basic analgesic did not ease the symptoms , and no nausea , vomiting , or photophobia was observed .
ebp is generally known to be successful in more than 90 percent of cases , although some studies have reported a success rate of 60 to 70 percent .
therefore , some possibility of pdph can always be present , even in the case of unsuccessful ebps . in this case , however , the patient 's headache was not eased despite the change of position , and there was no sign  such as tinnitus , hypacusia , and photophobia  indicating pdph .
therefore , it is recommended that secondary headache be considered if the characteristics of the headache are different from those of typical pdph , and if the headache continues after the ebp .
common causes of ssh include coagulation disorder , anticoagulant therapy , spinal trauma , tumor , vascular malformation such as avm , and aneurysm .
ssh is often observed in the thoracic spine , and is characterized by sudden localized back pain , sensorimotor deficit , and sphincter disturbance .
mri is the diagnostic method of choice for ssh . according to ruppen et al .
, the incidence of spinal epidural hematoma , spinal subdural hematoma , and intrathecal hematoma after central neuraxial blockade in the obstetric population has been estimated at 1 out of 168000 . during pregnancy , fibrinogens and coagulation factors including factors
vii , viii , ix , x and xii are increased as a defense mechanism against blood loss . over the full pregnancy term
however , most cases have been reported in mothers with coagulation disorders or who had received anticoagulant therapy .
excessive or repeated ebp may bring about ssh or an epidural hematoma . according to beards et al .
, the injection of 20 ml of blood during an ebp can induce a mass effect for 30 minutes to 3 hours , as it spreads 3 to 5 spinal segments within the epidural space the from the injected site .
in contrast , there has been a case of ssh occurring 8 segments away from the ebp area as a result of the mass effect .
it is suspected that the patient in this case experienced ssh due to the rupture of a pseudoaneurysm in the vertebral artery .
the patient did not present an abnormal medical history , experience of anticoagulant therapy , or a finding indicating a bleeding tendency .
moreover , the ebp was performed 10 segments away from the suspected location of the pseudoaneurysm rupture .
therefore , the possibility that the rupture was caused by a mass effect is low .
consequently , it is suspected that the pseudoaneurysm was formed in the vertebral artery due to an injury or other causes unrecognized by the patient .
the headache and neck stiffness experienced by the patient seem to have arisen as the pseudoaneurysm was developing .
the rupture can be attributed to the lack of adequate testing and timely intervention while the patient showed a systolic blood pressure as high as 170 mmhg , headache , and neck stiffness . in light of the prevalence
, the headaches experienced by mothers who deliver under spinal anesthesia are often presumed to be pdphs or migraines .
however , this method of diagnosis paradoxically increases the risk of misdiagnosis , as it excludes other possible causes .
therefore , if the headache continues without demonstrating typical characteristics of the aforementioned causes , secondary causes must be considered . in certain cases , a thorough neurologic examination and an early radiologic examination
should be performed along with other meticulous examinations in order to allow for prompt diagnosis and intervention .
we report a healthy patient with postpartum headache and neck stiffness which were diagnosed as symptoms of pseudoaneurysm of vertebral artery . she had received a cesarean section under the spinal anesthesia , and complaint of headache and neck stiffness . 
 epidural blood patches were done twice , but symptoms persisted . 
 eight days later , she experienced sensory disturbance and emergent laminectomy was done . 
 when persistent postpartum headache occurs after epidural blood patch , more precise differential diagnosis should be made and considering other possible pathologies .