2005 Proceedings - ASNR

Regions of interest (ROIs) were drawn bilaterally on the
ADC maps in the caudate heads, putamina, thalami, cerebellar
white matter (WM), frontal WM, frontal-parietal WM,
parietal WM, and the posterior internal capsules. The average
size of the ROIs was 40 mm 2 . The ADCs of the frontal
WM, the frontal-parietal WM, and the parietal WM were
measured at three levels. Statistical analysis was the student
t-test with Bonferroni correction. A p-value of < 0.00625 was
taken to be significant.
RESULTS
The CNS vasculitis patients’ average ADCs versus the controls
were found to be 7.7 x 10 -4 mm 2 /sec versus 7.4 x 10 -4
mm 2 /sec for the caudate heads, 7.3 x 10 -4 mm 2 /sec versus 7.1
x 10 -4 mm 2 /sec for the putamina, 7.4 x 10 -4 mm 2 /sec versus
7.2 x 10 -4 mm 2 /sec for the thalami, 6.7 x 10 -4 mm 2 /sec versus
6.4 x 10 -4 for the cerebellar WM, 8.1 x 10 -4 mm 2 /sec versus
7.3 x 10 -4 mm 2 /sec for the frontal WM, 7.3 x 10 -4 mm 2 /sec
versus 6.7 x 10 -4 mm 2 /sec for the frontal-parietal WM, 7.7 x
10 -4 mm 2 /sec versus 7.1 x 10 -4 mm 2 /sec for the parietal WM,
and 7.3 x 10 -4 mm 2 /sec versus 6.9 x 10 -4 mm 2 /sec for the posterior
internal capsules. The vasculitis patients’ ADCs of the
frontal WM, frontal-parietal WM, parietal WM, and the posterior
internal capsules all were found to be significantly elevated
(p < 0.00625). The vasculitis patients’ ADCs of the
caudate heads, putamina, thalami, and the cerebellar WM
were not elevated significantly (p > 0.00625).
CONCLUSION
Significantly elevated ADCs that could indicate occult damage
were detected in the supratentorial NLB white matter in
patients with CNS vasculitis. This unique information may
provide additional data that in the future could be incorporated
into facilitating the diagnosis and the treatment plan of
CNS vasculitis patients.
KEY WORDS: Central nervous system vasculitis, nonlesional
brain, ADC
Paper 301 Starting at 3:53 PM, Ending at 3:58 PM
MR Imaging Findings and Radiologic-Pathologic
Correlation in a Case of Postvaccination
Meningoencephalitis in Alzheimer’s Disease
Gomez-Anson, B. M. 1,2 · Sanchez-Guerra, M. 3 · Ferrer, I. 4,5,6 ·
Boada, M. 3
1 Hospital Clinic, Barcelona, SPAIN, 2 Institut
d’Investigacions Biomèdiques August Pi i Sunyer,
Barcelona, SPAIN, 3 Fundació ACE, Barcelona, SPAIN,
4 Hospital Bellvitge, Barcelona, SPAIN, 5 University of
Barcelona, Barcelona, SPAIN, 6 Brain Bank Hospital Clinic,
Barcelona, SPAIN
PURPOSE
To describe the MR findings, and their pathologic correlates,
in a case of asymptomatic Aβ-postvaccination meningoencephalitis
(ME) for Alzheimer’s disease (AD).
MATERIALS & METHODS
A 76-year-old mild/moderate AD patient (GDS = 5) enrolled
in a multicentric, international phase II trial with Aβ-42immunization
including 3 repeated MR imagings. Six
months after the second injection, he experienced progres-
159
sive worsening of speech and gait, initially related to progression
of AD. There was no fever, focal neurologic signs,
or acute symptoms. On routine MR imaging (9 months after
the second injection), a diagnosis of ME was suggested.
After treatment with corticosteroids, and improvement, reactivation
occurred 11 months after the second injection. The
patient then suffered from endocarditis and aspiration pneumonia,
the neurologic status worsened, and died 4 months
after the reactivation episode at a nursing home. The brain
was donated to the Brain Bank.
RESULTS
Bihemispheric, large, mass-like lesions were seen mainly
affecting the white matter, and reaching the cortex, in the
frontal and temporal regions. The lesions were hyperintense
on DP/T2-weighted FSE MR-images (Fig. 1a), hypointense
on T1-weighted and 3D-SPGR-MR images, and there was
mass effect and minor midline shift (Fig. 1b). No parenchymal,
but some pachymeningeal and leptomeningeal contrast
enhancement were present (Fig. 1c). On diffusion-weighted
imaging, the lesions were hypointense, having increased
apparent diffusion coefficients (ADCs) within them (Fig.
1d). A diagnosis of postvaccination ME was suggested. After
treatment, repeat MR images showed improvement.
However, clinical worsening and MR imaging reactivation
occurred 3 months after. Post-mortem brain pathology:
Neuropathologic study showed ME, with focal reduction of
diffuse and neuritic plaques and inflammatory changes in the
vicinity of collapsed plaques. These changes were more pronounced
in the frontal and temporal regions, in keeping with
MR findings. There was no reduction of vascular amyloid, or
regression of tau pathology regarding neurofibrillary tangles
and neuropil threads.
Fig.1. MR findings. 1a) T2-weighted FSE axial images show
large, hyperintense, bilateral fronto-temporal mass-like
lesions affecting subcortical white matter, and reaching the
cortex. 1b) The lesions appear hypointense on T1-weighted
3D-SPGR MR images. The right-sided lesion is larger, and
there is associated mass-effect and some midline shift. 1c)
There is no parenchymal, but meningeal contrast enhancement;
1d) There are increased ADCs in the right fronto-temporal
lesion.
Wednesday