Stroke. 1996;27:1417-1419
(Stroke. 1996;27:1417-1419.)
© 1996 American Heart Association, Inc.
Leukoencephalopathy-Related Cerebral Amyloid Angiopathy With Cystatin C Deposition
Koichi Shimode, MD, PhD;
Shotai Kobayashi, MD, PhD;
Kaoru Imaoka, MD;
Nobuyuki Umegae, MD
Atsushi Nagai, MD
the Third Internal Medicine Department, Shimane Medical University (Japan).
Correspondence to Koichi Shimode, MD, PhD, Third Internal Medicine Department, Shimane Medical University, 89-1, Enya, Izumo, Shimane 693, Japan.
 |
Abstract
|
|---|
Background We have described sporadic cases of cerebral amyloid
angiopathy with cerebral hemorrhage showing a low cystatin C
level in the cerebrospinal fluid detected by enzyme-linked immunosorbent
assay. Recently, several cases of leukoencephalopathy in patients
with cerebral amyloid angiopathy have been reported. We describe
a sporadic case of leukoencephalopathy with cystatin C-type
cerebral amyloid angiopathy diagnosed during life by enzyme-linked
immunosorbent assay.
Case Description A 74-year-old man who had suffered from progressive dementia for 3 years was admitted with right hemiparesis, dysarthria, and ataxia. MRI revealed pontine infarction and multiple lacunar state with leukoaraiosis. We suspected cystatin C-type cerebral amyloid angiopathy because of the low level of cystatin C in the cerebrospinal fluid. The patient died of sepsis 3 months later, and the presence of leukoencephalopathy with cerebral amyloid angiopathy was confirmed by autopsy. Immunohistological examination disclosed cystatin C and ß-protein deposition in amyloid structures of the cortical cerebral arteries.
Conclusions Measurement of cystatin C in the cerebrospinal fluid by enzyme-linked immunosorbent assay is a useful method of diagnosing leukoencephalopathy related to sporadic cystatin C-type cerebral amyloid angiopathy.
Key Words: amyloid cerebrospinal fluid cystatins leukoencephalopathy
 |
Introduction
|
|---|
In 1972, Gudmundsson et al
1 first described families with HCHWA-I.
Ghiso et al
2 reported that amyloid protein is a variant of
cystatin C (

-trace), which is a cysteine proteinase inhibitor.
Grubb et al
3 reported in 1984 that the cystatin C concentration
in the CSF of patients with HCHWA-I was abnormally low. We have
reported that the measurement of cystatin C concentrations in
the CSF by a new enzyme-linked immunosorbent assay was a useful
tool for the diagnosis of sporadic cerebral hemorrhage caused
by CAA with deposition of cystatin C.
4 In the present report
we describe a case of leukoencephalopathy with dementia, which
was suspected to be cystatin C-type CAA because of the abnormally
low cystatin C concentration in the CSF. We also confirmed the
leukoencephalopathy related to CAA with deposition of cystatin
C by histopathological examinations.
 |
Case Report
|
|---|
A 74-year-old man with a history of mild hypertension and diabetes
mellitus showed slowly progressive dementia during the last
3 years before his admission. He was admitted to the hospital
because of sudden onset of vomiting, urinary incontinence, dysarthria,
and right hemiparesis. His blood pressure was 180/100 mm Hg
at admission. Neurological examinations revealed an apathetic
and demented mental condition and right-sided ataxic hemiparesis.
MRI demonstrated left pontine infarction with multiple small
infarctions in the corona radiata and basal ganglia and marked
leukoaraiosis with brain atrophy. The cystatin C concentration
of CSF measured by the enzyme-linked immunosorbent assay method
was decreased to 56 ng/mL (control values ranged from 70 to
600 ng/mL),
4 and therefore cystatin C-type CAA was suspected.
The patient's mental condition deteriorated, and he became bedridden.
He died of sepsis 3 months after the admission. We received
permission to perform an autopsy.
Autopsy Findings
The brain weighed 1125 g. We noted brain atrophy and moderate atherosclerosis in the arteries of the circle of Willis. Macroscopic observation of the brain manifested left pontine base infarction and multiple lacunes in the basal ganglia and deep white matter. Microscopic examination of specimens stained with hematoxylin and eosin and Kluver-Barrera revealed diffuse demyelination mainly located in the frontoparietal lobes. However, U fibers were well preserved (Fig 1
). Alkaline Congo red staining disclosed deposition of amyloid in leptomeningeal and cortical small arteries. However, amyloid deposition was not seen in the vessels of the deep white matter and basal ganglia. Hyaline changes and fibrinoid necrosis were seldom seen. Thickening of the wall of arterioles in the deep white matter was rarely observed. Immunohistochemical study by the avidin biotin complex method disclosed the amyloid deposition in the cortical and leptomeningeal small arteries. These arteries were positively stained for both anti-cystatin C antibody, which was kindly provided by Dr Andres Grubb, University of Lund (Fig 2
, left panel), and anti-ß/A4 antibody, which was kindly provided by Dr George Glenner, University of California at San Diego (Fig 2
, right panel). A small number of senile plaques, mainly in the temporal lobe, were positively stained for ß/A4; however, no neurofibrillar tangles were observed. The patient did not fulfill Khachaturian's criteria for senile dementia of the Alzheimer type.5

View larger version (135K):
[in this window]
[in a new window]
|
Figure 1. Microscopic examination of specimen stained with Kluver-Barrera reveals diffuse demyelination in the frontoparietal lobes (magnification x1).
|
|


View larger version (289K):
[in this window]
[in a new window]
|
Figure 2. Closely adjacent sections from the same tissue block. Top, Cortical small arteries with amyloid deposition show positive immunoreactive staining for cystatin C (magnification x200). Bottom, Cortical small arteries with amyloid deposition show positive immunoreactive staining for ß/A4 (magnification x200).
|
|
We believe that this is the first case confirmed as cystatin C-type CAA during life and postmortem examinations.
 |
Discussion
|
|---|
Gray et al
6 have reported several cases of leukoencephalopathy
with sporadic CAA. They explained that amyloid depositions in
the cortical long perforating arterioles caused obstructive
changes and resulted in ischemia in the white matter. It has
been demonstrated that HCHWA-D showed not only lobar hemorrhages
but also marked leukoencephalopathy. Vinters et al
7 8 9 reported
that the amyloid proteins that were deposited in sporadic CAA
and Alzheimer's disease were both ß/A4 protein and cystatin
C by immunohistochemical studies. Hann et al
10 reported colocalization
of ß/A4 and cystatin C in the cortical blood vessels of
patients with HCHWA-D but not in patients with HCHWA-I. We previously
reported a low cystatin C level in the CSF of patients with
cerebral hemorrhage who had CAA, and we noted that it was a
useful diagnostic indicator of cystatin C-type CAA.
4 We also
detected a low concentration of cystatin C in the CSF in the
present patient, and we therefore suspected that leukoencephalopathy
was related to CAA. We confirmed the diagnosis of CAA with cystatin
C deposition by postmortem histopathological examination. We
ruled out a diagnosis of senile dementia of the Alzheimer type
by pathological examination findings. This case indicates that
measurement of cystatin C in the CSF may be a very useful method
of premortem diagnosis of leukoencephalopathy associated with
cystatin C-type CAA. Hypertension is considered one of the critical
causes of leukoencephalopathy, whereas additional findings in
CAA also need to be identified.
The mechanism of amyloid deposition in CAA has not been clearly elucidated. It has been reported that ß/A4 protein (4 kD) was found in the CSF not only in patients with Alzheimer's disease but also in normal subjects.11 It has been established that cystatin C is higher in CSF than in serum. Therefore, we presume that abnormal levels of ß/A4 protein and cystatin C might result in the formation of insoluble amyloid from soluble protein in the CSF. The insoluble amyloid will be deposited in the cerebral vessels to induce CAA, with consequent occurrence of subcortical hemorrhage and leukoencephalopathy. Hann et al10 reported that the possibility of preceding deposition of ß/A4 protein promotes deposition of cystatin C. Since both ß/A4 protein and cystatin C are proteinase inhibitors, we speculate that the abnormal metabolisms of proteinases and proteinase inhibitors are deeply involved in the initiation mechanism of CAA. Amyloid deposition in the meningeal arterioles and the cortical long perforating arterioles could be a cause of recurrent subcortical hemorrhages. We concluded that the present patient had evidence of amyloid depositions in the small arteries of the cerebral cortex and the subcortex, which induced obstruction of the small arteries in combination with advanced (for his age of 74 years) arteriostenosis. This symptom and chronic widespread arteriostenoses may have resulted in leukoencephalopathy associated with a partial cerebral infarction.
 |
Selected Abbreviations and Acronyms
|
|---|
| CAA |
= |
cerebral amyloid angiopathy |
| CSF |
= |
cerebrospinal fluid |
| HCHWA-D |
= |
hereditary cerebral hemorrhage with amyloidosis, Dutch type |
| HCHWA-I |
= |
hereditary cerebral hemorrhage with amyloidosis, Icelandic type |
|
 |
Acknowledgments
|
|---|
We wish to express our gratitude to Dr Andres Grubb (University
of Lund) and Dr George Glenner (University of California at
San Diego) for kindly providing us with antibodies and antigens.
We also express our sincere thanks to Dr Shigeyoshi Fujihara
(Jusei Hospital) for advice.
Received October 26, 1995;
revision received April 30, 1996;
accepted April 30, 1996.
 |
References
|
|---|
-
Gudmundsson G, Hallgrimsson J, Jonasson TA, Bjarnasson O. Hereditary cerebral hemorrhage with amyloidosis. Brain. 1972;95:387-404.[Free Full Text]
-
Ghiso J, Jensson O, Frangione B. Amyloid fibrils in hereditary cerebral hemorrhage with amyloidosis of Icelandic type is a variant of gamma-trace basic protein (cystatin C). Proc Natl Acad Sci U S A. 1986;83:2974-2978.[Abstract/Free Full Text]
-
Grubb A, Jensson O, Gudmundsson G, Arnason A, Lofberg H, Malm J. Abnormal metabolism of gamma-trace alkaline microrotein: the basic defect in hereditary cerebral hemorrhage with amyloidosis. N Engl J Med. 1984;311:1547-1549.[Medline]
[Order article via Infotrieve]
-
Shimode K, Fujihara S, Nakamura M, Kobayashi S, Tsunematsu T. Diagnosis of cerebral amyloid angiopathy by enzyme-linked immunosorbent assay of cystatin C in cerebrospinal fluid. Stroke. 1991;22:860-866.[Abstract/Free Full Text]
-
Khachaturian ZS. Diagnosis of Alzheimer's disease. Arch Neurol. 1985;42:1097-1105.[Medline]
[Order article via Infotrieve]
-
Gray F, Dubas F, Roullet E, Escourolle R. Leukoencephalopathy in diffuse hemorrhagic cerebral amyloid angiopathy. Ann Neurol. 1985;18:54-59.[Medline]
[Order article via Infotrieve]
-
Vinters HV, Secor DL, Pardridge WM, Gray F. Immunohistochemical study of cerebral amyloid angiopathy, III: widespread Alzheimer A4 peptide in cerebral microvessel walls colocalizes with gamma-trace in patients with leukoencephalopathy. Ann Neurol. 1990;28:34-42.[Medline]
[Order article via Infotrieve]
-
Vinters HV, Nishimura GS, Secor DL, Pardridge WM. Immunoreactive A4 and gamma-trace peptide colocalization in amyloidotic arteriolar lesions in brain of patients with Alzheimer's disease. Am J Pathol. 1990;137:233-240.[Abstract]
-
Vinters HV. Cerebral amyloid angiopathy and Alzheimer's disease: two entities or one? J Neurol Sci. 1992;112:1-3.[Medline]
[Order article via Infotrieve]
-
Hann J, Maat-Schieman MLC, van Duinen SG, Jensson O, Thorsteinsson L, Roos RAC. Co-localization of ß/A4 and cystatin C in cortical blood vessels in Dutch, but not in Icelandic hereditary cerebral hemorrhage with amyloidosis. Acta Neurol Scand. 1994;89:367-371.[Medline]
[Order article via Infotrieve]
-
Shoji M, Golde TE, Ghiso J, Cheung TT, Estus S, Shaffer LM, Cai XD, Mckay DM, Tintner R, Frangione B, Younkin SG. Production of Alzheimer amyloid ß protein by normal proteolytic processing. Science. 1992;258:126-129.[Abstract/Free Full Text]
This article has been cited by other articles:

|
 |

|
 |
 
S. Kobayashi, K. Okada, H. Koide, H. Bokura, and S. Yamaguchi
Subcortical Silent Brain Infarction as a Risk Factor for Clinical Stroke
Stroke,
October 1, 1997;
28(10):
1932 - 1939.
[Abstract]
[Full Text]
|
 |
|