Agraphia of Kanji (Chinese characters): an early symptom of sporadic Creutzfeldt-Jakob disease in a Japanese patient: a case report
Journal of Medical Case Reports
Agraphia of Kanji (Chinese characters): an early symptom of sporadic Creutzfeldt-Jakob disease in a Japanese patient: a case report
Keiko Nakamura 0
Kenji Sakai 0
Miharu Samuraki 0
Ichiro Nozaki
Masako Notoya
Masahito Yamada 0
0 Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Sciences , 13-1 Takara-machi, Kanazawa, Ishikawa 9208640 , Japan
Introduction: Slowly progressive cognitive decline is the most frequent initial manifestation in MM2-cortical-type sporadic Creutzfeldt-Jakob disease. Agraphia has never been noted in patients with this type of sporadic Creutzfeldt-Jakob disease, however, we report the case of a Japanese patient with sporadic Creutzfeldt-Jakob disease in whom agraphia of Kanji was an initial cardinal symptom. Case presentation: A 59-year-old right-handed Japanese woman complained of agraphia of Kanji (Chinese characters) as an initial symptom. A neurological examination revealed mild word-finding difficulty, constructive disturbance, hyperreflexia in her jaw and lower limbs, and bilateral extensor plantar reflexes. An examination of her cerebrospinal fluid revealed increased levels of 14-3-3 and total tau proteins, and abnormal conformation of the proteinase K-resistant prion protein. Diffusion-weighted magnetic resonance imaging showed diffuse hyperintensity in bilateral cerebral cortices. Single-photon emission computed tomography scans revealed hypoperfusion in the left temporal lobe, bilateral parietal and occipital lobes. An analysis of the prion protein gene demonstrated no mutation with homozygous for methionine at the codon 129. We diagnosed our patient with sporadic Creutzfeldt-Jakob disease. Although a histological examination was not performed, it was assumed that our patient could be the MM2-cortical type according to the clinical findings and the elevated levels of 14-3-3 protein in her cerebrospinal fluid. The left posterior inferior temporal area, which was affected in our patient as a hypoperfusion area, is associated with selecting and recalling Kanji characters. Conclusions: Focal signs as an early symptom and hypoperfusion areas in sporadic Creutzfeldt-Jakob disease are critical to recognize initial brain lesions damaged by the proteinase K-resistant prion protein accumulation.
Agraphia; Creutzfeldt-Jakob disease; Kana (Japanese syllabary); Kanji (Chinese characters); Magnetic resonance imaging
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Introduction
Creutzfeldt-Jakob disease (CJD), a degenerative
neurological disorder caused by prions, is neuropathologically
characterized by the accumulation of the proteinase
Kresistant prion protein (PrPres), which leads to spongiform
changes in tissues of the central nervous system. CJD is
classified according to its causes: sporadic CJD (sCJD), the
idiopathic form; familial CJD, caused by inherited
mutations in the prion protein (PrP) gene; and acquired CJD,
related to previous infectious episodes [1]. Sporadic
CJD is classified into six types based on the genotype at
polymorphic codon 129 of the PrP gene and the
physicochemical properties of the pathologic PrPres: MM1,
MM2, MV1, MV2, VV1, and VV2 [2]. MM2-type sCJD
comprises of two pathological phenotypes: cortical and
thalamic forms. MM2-cortical-type sCJD is the most
common subtype as an atypical sCJD form in Japan [3].
Although slowly progressive cognitive decline is the
most frequent initial manifestation in this subtype,
aphasia, ataxia, psychiatric symptoms, and visual
disturbance are also described [1,4,5]. However, agraphia
has never been noted in patients with
MM2-corticaltype sCJD.
The Japanese language has two writing systems, that
is, Kanji (Chinese characters) and Kana (Japanese
syllabary), which are different from those of Western
languages. Kanji are the structurally complex morphograms
introduced from China, often having several phonetic
readings, while Kana are the relatively simple syllabograms
having unambiguous phonetic readings [6]. Japanese
sentences consist of various combinations of Kanji and Kana.
The major lexical morphemes of Japanese words are
written in Kanji, and conjugated endings of verbs, adjectives,
and functional words are written in Kana. Both these
systems are associated with distinct regions of the brain [7].
We report a Japanese patient with sCJD in whom
agraphia of Kanji was an initial cardinal symptom. This
patient was presumed to be MM2-cortical-type sCJD
according to the clinical presentation.
Case presentation
A 59-year-old right-handed Japanese woman had difficulty
in writing Kanji. She could neither recognize forms of the
Kanji characters clearly nor write them. One month later,
she developed progressive cognitive impairment; however,
her social behavior remained appropriate.
A neurological examination performed two months
after the disease onset revealed mild word-finding
difficulty and constructive disturbance such as copying
simple diagrams. Hyperreflexia was present in her jaw and
l (...truncated)