PMC4681801_01
(a) Symmetric blood volume demonstrated on CT perfusion scan, in a 79-year-old woman presenting with a classic left MCA syndrome. (b) The absence of a proximal vessel cut-off in a CT angiogram reconstruction of the circle of Willis. (c) The absence of restricted diffusion in an MRI brain. (d) The absence of FLAIR hyperintensities indicative of an acute ischemic stroke or herpes simplex encephalitis. (e) Left anterior and midtemporal periodic lateralized discharges seen on hospital day 2, with a notable background which is diffusely slow, and an absence of a posterior dominant rhythm (PDR). (f) Return of the PDR of 8-9 Hz and the absence of PLEDs after the institution of intravenous valproic acid and acyclovir therapy.
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fig1
A stat CT perfusion and CT angiogram were obtained (Figures 1(a) and 1(b)). An MRI brain was obtained on hospital day 2, which demonstrated no evidence of restricted diffusion suggestive of a stroke (Figure 1(c)). Additionally, FLAIR imaging, although slightly motion degraded, showed only nonspecific white matter hyperintensities in the periventricular white matter, suggestive only of microangiopathy (Figure 1(d)). EEG on hospital day 2 demonstrated focal slow waves and focal sharps, which were periodic at times in the left frontotemporal and midtemporal regions, and slowing of the alpha rhythm (Figure 1(e)). These abnormalities normalized by hospital day 3, with a reemergence of a posterior dominant rhythm of 8-9 Hz (Figure 1(e)).