Brain MR imaging is often performed in suspected cases of RCVS, and findings can appear normal or demonstrate evidence of complications of the syndrome, such as watershed infarcts or posterior reversible encephalopathy syndrome.10,12,14,16 For example, T2 FLAIR-weighted imaging can be used to evaluate for subarachnoid hemorrhage and cerebral edema, while diffusion-weighted imaging is helpful in evaluating for watershed infarcts. However, newer imaging techniques, particularly vessel wall imaging, may offer increased specificity for the diagnosis. Although we used the existing diagnostic criteria for RCVS, In these instances, better visualization of the character and distribution of cerebral artery irregularity and the morphology of any cerebral aneurysms present can be helpful. This includes high-resolution MR vessel wall imaging (VWI), a new technique that may help differentiate RCVS from alternative diagnoses by characterizing pathologic changes in the wall of affected cerebral arteries. Koopman K, Uyttenboogaart M, Luijckx GJ, De Keyser J, Vroomen PC. Prognosis. Dual-energy CTA may aid in the diagnosis of cerebral vasoconstriction in suspected cases of RCVS and the evaluation of potential alternative diagnoses such as cerebral aneurysm, by improved bone removal at the skull base.8 However, one important drawback of this technique is the increased radiation exposure to the patient.8 Finally, CT venography can also be performed with CTA with a slightly delayed scan following contrast administration, potentially allowing the diagnosis of cortical vein and/or dural sinus thrombosis. The following sections further explore the various imaging techniques available for evaluation of suspected cases of RCVS, followed by a more detailed discussion of alternative diagnoses. However, the validity of this technique remains uncertain. DWI (A) demonstrates an acute infarct involving the right thalamus and posterior limb of the internal capsule (white arrow). The headache associated with PACNS is often slowly progressive with an insidious onset, differing markedly from the typical thunderclap headache of RCVS in both time course and peak severity.1,2,7,13,16,18,19,57 Patient demographics in these disease entities also demonstrate significant differences. Unfortunately, none of these diagnostic criteria, either alone or in combination, are entirely specific for RCVS vasoconstriction or arterial vasospasm. NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. RCVS is typically encountered in young-to-middle-aged women, as opposed to PACNS, which is most often seen in older men.14,18,19 Analysis of CSF is also helpful because patients with PACNS, in contradistinction to RCVS, typically demonstrate elevations of CSF protein levels and white blood cell count, with values often >100 mg/dL and 5–10 cells/mm, respectively.1,2,7,10,16,18 Finally, the early clinical course of the patient can help distinguish these 2 entities. Clipboard, Search History, and several other advanced features are temporarily unavailable. In addition, the delay in the appearance of RCVS vasoconstriction may mimic the typical time course of arterial vasospasm. These criteria were independently validated in a study comparing cohorts of 173 patients with RCVS and 110 patients with PACNS . Differentiating RCVS cerebral vasoconstriction from arterial vasospasm associated with aneurysmal subarachnoid hemorrhage can also be difficult. The main purpose was to verify whether CSF leucocyte counts < 10/mm³ serve to discriminate RCVS from PACNS. Advances in primary angiitis of the central nervous system. Special emphasis will be placed on differentiating RCVS from aneurysmal subarachnoid hemorrhage and primary angiitis of the CNS (PACNS). Intra-arterial application of nimodipine in reversible cerebral vasoconstriction syndrome: a diagnostic tool in select cases? Primary angiitis of the central nervous system and reversible cerebral vasoconstriction syndrome. In contradistinction, of the 13 patients diagnosed with RCVS, 10 demonstrated diffuse uniform wall thickening, of which only 4 had associated mild wall enhancement. In most cases of RCVS, findings of CSF analysis will be unremarkable, with red and white blood cell counts and protein levels either within normal limits or only mildly elevated.2,7,9⇓⇓⇓–13 Finally, findings of other laboratory tests, including serum analysis for markers of inflammation such as erythrocyte sedimentation rate and C-reactive protein, are also usually within normal limits in patients with RCVS.2,9,14, The role of neuroimaging in patients with RCVS includes demonstration of cerebral vasoconstriction, evaluation of alternative diagnoses, and monitoring potential complications such as intracranial hemorrhage, vasogenic edema, and ischemic stroke.4,7,9 Although conventional angiography has been the criterion standard for evaluation of cerebral vasoconstriction in suspected cases of RCVS, noninvasive imaging modalities such as transcranial Doppler sonography (TCD), CT angiography, and MR angiography are being used with increasing frequency (Table 1).4,5,9,12,15 When present, cerebral vasoconstriction involves multiple vascular territories and results in a beaded appearance of medium-to-large cerebral arteries with multifocal areas of narrowing interspersed with normal-caliber segments.1,4,7,12,14 The severity and distribution of vasoconstriction can fluctuate among examinations, with some areas improving and others worsening.1,2,9,16,17 Although the above angiographic findings are highly suggestive of RCVS in the appropriate clinical setting, they remain nonspecific and can be encountered with various other types of CNS vasculopathies and vasculitis.2,14,18⇓–20, Role of imaging modalities in the management of RCVS, The initial angiographic evaluation findings in suspected cases of RCVS may be unremarkable in the 4–5 days following patient presentation.1,2,4,5,21 In fact, cerebral vasoconstriction may not be visualized in up to one-third of patients with RCVS during the first week following symptom onset.22 As suggested by Ducros and Bousser,2 this finding may be due to segmental vasoconstriction in RCVS beginning in small, peripheral arterioles before subsequently proceeding centripetally to involve medium and large cerebral arteries, which are more readily visualized.23 If cerebral vasoconstriction is not demonstrated on initial vascular imaging and other diagnoses have been excluded, the patient should be managed as if he or she has possible or probable RCVS.1.