Neuroradiology Case of the Week

Case 40

Francisco Garcia-Morales, MD and P-L Westesson, MD, PhD, DDS

Clinical Presentation: An 88-year-old male patient presents acutely with aphasia, headache and confusion.

Radiological Findings: CT scan (Fig. 1) demonstrates an acute hemorrhage in the left frontal lobe with its epicenter around the gray white matter junction. There is associated atrophy and small vessel disease.
   Diffusion-weighted MR images (Figs. 2 A&B) show the hemorrhagic lesion in the left frontal lobe, but in addition there is another area of abnormal signal intensity in the left parietal lobe. Flair images (Figs. 3 A&B) demonstrate the hemorrhagic lesion with mixed signal intensity. On T2-weighted image (Fig. 4) only the left frontal lobe lesion is identified. Gradient echo image (Fig. 5) demonstrates multiple punctate areas of decreased signal both left and right frontal lobes. This multitude of earlier hemorrhagic lesions in both left and right hemispheres is a strong indication that there is an underlying amyloid angiopathy as a cause of this acute hemorrhage. The lesions are typically located in the cortex or in the deep cortex area.

Figure 1: CT scan demonstrates an area of increased density in the left frontal lobe consistent with an acute hemorrhage (arrow).
Figure 2A&B: Diffusion-weighted MR images (A) shows the hemorrhagic lesion in the left frontal lobe (single arrow) and another area of abnormal signal intensity in the left parietal lobe (B) (arrow).
Figure 3A&B: Flair images demonstrate the hemorrhagic lesion with mixed signal intensity (arrows) as well microvascular disease in the periventricular white matter (arrowheads).
Figure 4: T2-weighted image - notice that only the left frontal lobe lesion identified.	Figure 5: Gradient echo image demonstrates multiple punctate areas of decreased signal both left and right frontal lobes (arrows)

Diagnosis: Intracerebral hemorrhage from amyloid angiopathy

Discussion:
   Non-traumatic intracranial hemorrhage constitutes approximately 20% of acute “strokes” [1]. The causes are primarily hypertension but in older patients amyloid angiopathy is another alternative etiology. The main differential for this condition is hypertensive hemorrhage. The evidence of multiple prior small hemorrhages is strongly suggestive of amyloid angiopathy [2]. Hypertensive hemorrhage is usually in the basal ganglia whereas hemorrhages from amyloid angiopathies are usually in the cortex or subcortical region. Other etiologies are of course, vascular malformation, hemorrhagic neoplasm or in younger patients, drug abuse.

References:

1. Osborn AG, Blaser SI: Brain, Top 100 Diagnoses, WB Saunders Co, 2002, p90.
2. Tsushima Y, Aoki J, Endo K. Brain microhemorrhages detected on T2*-weighted gradient-echo MR images. AJNR Am J Neuroradiol 2003;24:88-96.