Agraphia is an impairment or loss of the ability to write. In general, injury of the cortical language centers and their associated subcortical structures in the dominant hemisphere leads to agraphia [1]. Agraphia can occur in isolation or concurrently with other neurological deficits including aphasia, alexia, apraxia, and hemispatial neglect [1,2]. However, agraphia caused by the lesion of the right hemisphere is rare. Herein, we report a case of the patient presenting with agraphia due to right parietal lobe infarction.

A 65-year-old man was admitted to the emergency room with left-sided weakness and paresthesia that had persisted for a week. The patient had no previously diagnosed diseases and smoked a pack of cigarettes a day. He was ambidextrous, writing with his right hand and mainly using his left hand when exercising. He had 16 years of education. On examination, the patient was alert, with a blood pressure of 185/101 mmHg, a regular heart rate of 109 beats/min, and a temperature of 37.1 °C. A neurological examination showed mild dysarthria, paralysis of the left arm and leg with the Medical Research Council grade IV, left visuospatial neglect, and left sensory extinction. Sensory and cerebellar tests were normal. A brain magnetic resonance imaging showed acute infarction in the right parietal lobe (Fig. 1A, B). Magnetic resonance angiography (MRA) of the brain showed focal stenosis of bilateral posterior cerebral arteries, and there was no stenosis or occlusion in the bilateral middle cerebral arteries (Fig. 1C). Neck MRA revealed moderate stenosis in the right common carotid artery (Fig. 1D). The patient was admitted to the department of Neurology for treatment of acute cerebral infarction. After hospitalization, the patient complained that he had no problems reading and communicating, but unlike before, he hesitated when writing and was unable to use consonants properly (Fig. 2). The patient expressed that he had no difficulty in speaking, but when he tried to write down letters, he suddenly had difficulty remembering the spelling. In addition, he complained that it was difficult to distinguish between similar Korean consonants such as ‘ㅎ’ and ‘ㅇ’. The patient did not show ideomotor apraxia. Neuropsychological testing using the Seoul Neuropsychological Screening Battery revealed that there were no abnormalities in the language domain, but deteriorations in visuospatial, memory, and frontal/executive function. In particular, the patient had difficulty with the Rey Complex Figure Copy task and appeared to make repeated corrections (14 out of 36 points; Z-score, -9.58). Considering the above findings, the patient’s writing difficulty was assumed to be visuospatial agraphia. Afterward, the signs of neglect syndrome disappeared, but agraphia did not improve. The patient was found to have rectal cancer and was referred to the department of surgery for cancer treatment.

We report a patient with agraphia after an acute infarction in the right parietal lobe. In the neuropsychological test, the patient had no abnormalities in language functions other than writing but showed impairments in visuospatial and constructional abilities, including visual memory. We assumed the patient’s writing disability was visuospatial agraphia due to the right parietal lobe injury.

Agraphia can be divided into central agraphia (linguistic or aphasic agraphia) and peripheral agraphia (nonlinguistic or nonaphasic agraphia) [3]. Several processes are required to perform the act of writing, including language processing, spelling, visual perception, visuospatial orientation for letters, motor planning, and motor control of writing [2]. Lesions that interfere with the process of properly organizing letters and forming sentences can result in central agraphia. In contrast, lesions that cause impairment in motor planning, visuospatial ability to implement on a writing surface, or motor action of writing lead to peripheral agraphia. Visuospatial agraphia belongs to the group of peripheral agraphia and refers to a disability in writing due to errors of orientation to the writing instrument or surface [1]. In a previous study included 21 patients with right hemisphere damage who performed a writing test, motor-associated deficits (iterations of letters and features) predominated in patients with pre-rolandic damage, whereas spatial impairment (inappropriate distribution of written material in the space, splitting of words, and grouping of letters belonging to different words) was evident in patients with damage to the post-rolandic area [4]. Our patient showed writing errors such as overwriting different letters in the same space or confusing consonants with similar shapes. The patient’s cerebral infarction lesion was extensive in the right parietal lobe, encompassing the post-rolandic area.

The bilateral parietal lobes are primarily involved in processing visuospatial and constructional functions [5]. In the case of Alzheimer’s dementia (AD), it has been reported that hypometabolism of the parietal lobe appears more severely in patients with early-onset AD than in patients with late-onset AD [6]. A previous study of agraphia in Korean patients with early-onset AD presented that these patients exhibit visual-constructional manifestations of agraphia as well as linguistic errors, even in the early stage of the disease [7]. Another study in Korean stroke patients found that patients with lesions in the left hemisphere produced linguistic errors, whereas visuospatial/constructive errors predominated in patients with lesions in the right hemisphere [8]. The Korean writing system, Hngul has unique dimensional and spatial rules. Unlike the alphabetic writing system where graphemes are written horizontally and in tandem, each grapheme in Hangul must be arranged from top to bottom or left to right within a square space to form a syllable [9]. Therefore, Korean patients with right hemispheric lesions may exhibit diverse features of visuospatial/constructive errors in writing, which are not commonly observed in the English language [8]. In a previous Korean case report of agraphia after an acute infarction in the right angular gyrus, the patient showed decreased neatness in writing, suggestive of visuospatial dysfunction [10]. However, unlike our case, there were no errors such as overwriting letters or confusing similar consonants. More research is needed on the characteristics of agraphia caused by lesions of the right parietal lobe in patients who use Hangul.

In conclusion, our case highlights that the injury of the right parietal lobe in Koreans can cause agraphia, which is associated with Hangul’s unique visuospatial/constructional features.