Writing errors as a result of frontal dysfunction in Japanese patients with amyotrophic lateral sclerosis

Abstract

Loss of communication is a critical problem for advanced amyotrophic lateral sclerosis (ALS) patients. This loss of communication is mainly caused by severe dysarthria and disability of the dominant hand. However, reports show that about 50% of ALS patients have mild cognitive dysfunction, and there are a considerable number of case reports on Japanese ALS patients with agraphia. To clarify writing disabilities in non-demented ALS patients, eighteen non-demented ALS patients and 16 controls without neurological disorders were examined for frontal cognitive function and writing ability. To assess writing errors statistically, we scored them on their composition ability with the original writing error index (WEI). The ALS and control groups did not differ significantly with regard to age, years of education, or general cognitive level. Two patients could not write a letter because of disability of the dominant hand. The WEI and results of picture arrangement tests indicated significant impairment in the ALS patients. Auditory comprehension (Western Aphasia Battery; WAB IIC) and kanji dictation also showed mild impairment. Patients' writing errors consisted of both syntactic and letter-writing mistakes. Omission, substitution, displacement, and inappropriate placement of the phonic marks of kana were observed; these features have often been reported in Japanese patients with agraphia resulted from a frontal lobe lesion. The most frequent type of error was an omission of kana, the next most common was a missing subject. Writing errors might be a specific deficit for some non-demented ALS patients.

Writing errors in ALS related to loss of neuronal integrity in the anterior cingulate gyrus

“…As reported in a previous study, patients with ALS performed poorly at picture arrangements and writing (the average WEI of the patients was 6.0 while that of 16 normal controls was 2.9) [15].…”

“…To quantify the writing errors, we used the original writing error index (WEI), which we had developed in our previous study [15]. Briefly, the patients were shown a picture of people at a picnic and were requested to give a written description of the photograph.…”

“…These could occur in a patient with both attention deficit and pure agraphia. In our previous study, other cognitive examinations were administered to patients with ALS [15]. Although digit span, which was considered to reflect attention, was preserved in patients who had writing errors, a problem with attention may be a strong candidate for the pathology of writing errors in patients with ALS, but further studies are necessary to reach a conclusion.…”

“…(family-wise error corrected P-value < 0.01 extent threshold = 20voxels). ** The WEI was calculated as described previously [15].…”

“…As a result of intensive explorations of frontal lobe function, impairment of verbal fluency and executive function have been identified as specific deficits in ALS [4,[7][8][9][10][11]. Some Japanese investigators described that ALS patients frequently had agraphia without aphasia regardless of whether they had dementia [12][13][14][15]. Omission of a Japanese kana letter was the most frequent error, and substitution, displacement, and incorrect letters were also often observed.…”