Postpartum patient with SIH suffering RCVS is rarely reported. Here, we described a young postpartum patient initially developed SIH after painless labor. Subsequently, she suffered thunderclap headache with cortical blindness and generalized seizure. MRI FLAIR sequence found predominantly bilateral regions of subcortical lesions and MRA showed diffuse segmental constriction of cerebral arteries which were consistent with RCVS. With an aggressive treatment, the patient recovered completely and abnormal MRI signals disappeared markedly in ten days.
RCVS is a rare but still poorly understood syndrome which may occur spontaneously or be provoked by postpartum and exposure to adrenergic or serotonergic drugs. Late pregnancy and early puerperium with a high probability of vasoconstriction are common conditions linked to RCVS. Patients who expose to licit or illicit drugs, ergot alkaloid derivatives, immunosuppressant or immunomodulator drugs and blood products are associated with RCVS; other clinical conditions such as acute head and neck conditions, cerebral vascular associations, catecholamine secreting tumors, and headache disorders may also encountered[6,7,8]. However, the certain precipitants of RCVS are still not well established and the pathological process is unknown. SIH occurred in postpartum setting is a relatively rare and easily overlooked condition associated with RCVS, but RCVS may lead to functional disability and death due to postpartum angiopathy[11,12]. In patients with SIH, cerebrospinal fluid (CSF) leakage may lead to traction on intracranial meningeal vessels and a loss of venous blood pooling.Cerebral vasospasm is probably triggered by the anatomical displacement of the brain caused by the decrease in CSF volume. Emotional or pain stimuli due to SIH may trigger an activation of the adrenergic system and vasospasm of the cerebral vessels can occur. Meanwhile, the loss of intracranial volume due to CSF leakage with compensatory dilatation of intracranial venous system could result in adrenergic overstimulation which is also associated with cerebral vasospasm and the occurrence of RCVS.
In our case, the new-onset thunderclap headache (TCH) must be assessed urgently and underlying fatal causes must be considered. SAH, ischaemic stroke, cerebral venous sinus thrombosis, cervical artery dissection, intracranial infection, PRES and RCVS may be potential causes of TCH. It often reaches maximal intensity in under one minute, with or without seizures and focal neurological deficits in patients with RCVS. TCH initially requires a non-contrast brain CT to exclude aneurysmal SAH; if negative, a lumbar puncture should be performed to exclude intracranial infection and untypical SAH[7,8,14]. Non-invasive imaging of MRI, MRA, and CTA of the brain may help exclude other important differentials and reveal the features of RCVS which may find segmental vasoconstriction involving arteries of the circle of Willis that resolves spontaneously within 3 months; while digital subtraction angiography is gold standard diagnostic investigation which can clearly display small distal arteries[16,17]. Except for TCH and seizures, other neurological symptoms, including altered cognition, visual disturbances, motor and sensory deficits, or ataxia, can occur secondary to ischemic or hemorrhagic stroke in brain regions that are perfused by sustained cerebral vasoconstriction[7,15,18]. Transient hypertension can also occur just like in our case, and more than one third of patients have blood pressure surges during headache attacks[16,19].Brain imaging with either CT or MRI of RCVS may be normal, but cortical surface subarachnoid hemorrhage (cSAH), PRES, intracranial hemorrhage, and ischemic stroke might encounter in some patients. As in our case, elevated arterial blood pressure and vasoconstrictions in major cerebral arterial segments of M1 and P2 were important determinants for PRES in patients with RCVS[16,20].
RCVS is a rare neurological disorder which has become increasingly recognized owing to improved imaging techniques and clinical awareness. However, accurate diagnosis can be a challenge in clinical practice. SAH from a ruptured cerebral aneurysm is a well-recognized and life-threatening differential diagnosis which may be confused with cortical SAH. Cortical SAH has received limited attention, and in younger patients the commonest cause is RCVS. Younger age, recurrent TCH, chronic headache disorder, prior depression, and the presence of bilateral arterial narrowing are predictors for RCVS-SAH[7,22]. PACNS and RCVS are invariably considered in the differential diagnosis of new cerebral. PACNS requires long-term immunosuppression therapy while steroids may be deleterious in RCVS, further underscoring the need for proper early distinction between RCVS and PACNS. Patients with RCVS are often female, with migraines, and postpartum. TCH, cortical SAH, border zone infarcts and vasogenic edema have the highest positive predictive value for diagnosing RCVS; but multiple small deep infarcts, extensive deep white matter lesions, tumor-like lesions, or multiple gadolinium-enhanced lesions are observed only in PACNS[23,24]. Meanwhile, cerebral arteriopathies such as intracranial atherosclerosis, infectious arteritis and fibromuscular dysplasia should be considered and excluded. Just like in our case, PRES-like reversible cerebral edema is not uncommon in RCVS which may often occur in the first week and a rapid increase in blood pressure is supposed to be key factor for the development of PRES. However, PRES and RCVS may share some common clinical and radiologic features and occasionally occur in the same patient which is difficult to make differential diagnosis.
In conclusion, RCVS can occur in postpartum patient when one suffered thunderclap headache with or without other acute neurological symptoms. A heightened awareness accompanied by typical clinical features and reversible diffuse segmental constriction of cerebral arteries are associated with an early diagnosis and a better prognosis.