American Journal of Neuroradiology 24:1492, August 2003
© 2003 American Society of Neuroradiology
Letter
Diagnosis of Pseudosubarachnoid Hemorrhage
a School of Medicine, Monash University, Melbourne, Australia
The recently published description of CT findings in pseudosubarachnoid hemorrhage (1) has, unfortunately, omitted to include neuropathologic correlation, despite the authors noting that subarachnoid hemorrhage was excluded on the basis of autopsy in three of the seven cases described. Despite this, the authors suggested that one possible cause for their findings—increased attenuation in the basal cisterns—was superficial vascular engorgement and dilatation (1). If this were true, enhancement following the administration of intravenous contrast medium could prove to be a useful method for confirming this diagnosis, as occurred in one of their cases. In, to my knowledge, the largest published series with this condition with detailed neuropathologic correlation (2), all five cases demonstrated increased attenuation in the basal cisterns, with (at autopsy) histologic evidence of congested and dilated subarachnoid and pial vessels in each, in addition to cerebral edema. Although Given and colleagues may be excused for omitting the latter article in their comprehensive literature review as the journal in which it was published was not—at that time—indexed by Medline, it indicates that the main cause for the CT appearances is vascular engorgement. Future studies should be directed toward determining whether head CT following the administration of intravenous contrast medium is a means of confirming this diagnosis when it is suspected clinically.
References
- Given CA, Burdette JH, Elster DA, Williams DW. Pseudo-subarachnoid hemorrhage: a potential pitfall associated with diffuse cerebral edema.
AJNR Am J Neuroradiol2003; 24
:254
–256
[Abstract/Free Full Text] - Opeskin K, Silberstein M. False-positive diagnosis of subarachnoid haemorrhage on computed tomography scan. J Clin Neurosci1998; 5 :382 –386[Medline]
b University of Kentucky Chandler Medical Center, Lexington, Kentucky
Reply:
As discussed in our publication (1), one of the contributing causes for the pseudosubarachnoid hemorrhage appearance seen with diffuse cerebral edema in engorgement of the superficial (pial) vasculature. We would like to thank Dr. Silberstein for bringing to our attention the publication by Operskin and Silberstein (2), because it provides further support for vascular engorgement being a contributing factor in pseudosubarachnoid hemorrhage appearance. Contrasted studies may demonstrate enhancement of the subarachnoid space in such cases and prove useful for further evaluation in when the diagnosis is suspected.
References
- Given CA, Burdette JH, Elster DA, Williams DW. Pseudo-subarachnoid hemorrhage: a potential pitfall associated with diffuse cerebral edema.
AJNR Am J Neuroradiol2003; 24
:254
–256
[Abstract/Free Full Text] - Opeskin K, Silberstein M. False-positive diagnosis of subarachnoid haemorrhage on computed tomography scan. J Clin Neurosci1998; 5 :382 –386[Medline]
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