We encountered a case of pure alexia that selectively affected kana accompanied by agraphia due to a left occipito-temporal medial hemorrhage that resulted in difficulty reading horizontally written kana words aloud in letter-by-letter and whole-word at the right end. To clarify the factors leading to alexia, we examined (1) the effect of the number of letters, (2) the difference in oral reading performance between vertically and horizontally printed words, (3) whole-word reading of horizontally and vertically printed words under a short presentation time of 100 msec, and (4) nonverbal visual information processing ability. The results showed that (1) there was a word-length effect, and although letter-by-letter reading was generally accurate, there were morphological similarity errors, (2) horizontally printed words had longer reading time than vertically printed words, (3) horizontally printed words had lower performance than vertically printed words, and there were frequent phonological errors at the end of words, and (4) reaction time was longer for discrimination of differentiation on the right side of the stimulus than on the left side. These findings suggest that subcortical lesions in the left occipitotemporal region may result in a specific type of alexia, characterized by difficulty in reading horizontally printed words aloud.

PTSD and dissociative disorders, which are mental illnesses related to trauma and stress, were examined from the perspective of memory impairment. Memory issues range from explicit to implicit memory and have a dynamically fluctuating nature, making them difficult to detect through formal memory tests. In implicit memory, problems arise from classical conditioning and long-distance priming effects, and being aware of these phenomena can be useful in diagnosis and treatment. The essence of dissociative identity disorder is not a split in personality but a fragmentation of memory. Therefore, the goal of treatment is not personality integration but memory sharing, and the principles of cognitive rehabilitation can be applied.

It has long been known that the cerebellum is the center of motor control. However, since the mid-1980s, with rapid developments in anatomy, neuroradiology, and electrophysiology, there has been an increasing number of reports and studies on the cerebellum’s role has reached a major turning point. In clinical practice, cognitive and emotional impairments in patients with cerebellar lesions have long been recognized. However, since the proposal of the concept of Cerebellar Cognitive Affective Syndrome (CCAS), the role of the cerebellum in cognitive function has gained increasing attention in rehabilitation and other clinical setting. To further advance this field, it is essential for more clinicians to focus on the cerebellum’s role in cognition and contribute to accumulating new findings through detailed observation of symptoms.

The effectiveness of thermal stimulation against dementia has been reported in Finnish saunas. In a prospective study of 2,315 healthy men, the risk of dementia was reduced by 22％ by sauna bathing 2-3 times a week and 66％ by sauna bathing 4-7 days a week compared to sauna bathing once a week. It is considered that the heat improves endothelial function, increases angiogenesis, and reduces inflammation, preventing a decrease in cerebral blood flow. It has also been reported that heat reduces the excessive phosphorylation of tau protein, which is associated with dementia. A cohort study of 10,147 healthy people aged 65 years or older in Japan, who had bathing frequency recorded, also reported that the incidence of dementia was lower in those who bathed 7 times or more per week than those who bathed 0-1 times per week. Both hot springs and saunas have a body temperature rise of 38.5℃ or more, and this heat stimulation increases the NK cell activity, which are cell surveillance mechanism, and heat shock proteins, which manage and repair proteins, and defense mechanisms are activated. It is considered that hot springs bathing can suppress the increase and deposition of abnormal proteins associated with dementia by enhancing the heat stimulation defense mechanism due to the increase in body temperature.