Right unilateral spatial neglect in aphasic patients.

To investigate spatial responses by aphasic patients during language tasks, 63 aphasics (21 severe, 21 moderate, and 21 mild) were administered two kinds of auditory pointing tasks-word tasks and sentence tasks-in which the spatial conditions of the stimuli were controlled. There were significantly fewer correct responses on the right side of a space than on the left side in both the word and sentence tasks, but the left deviation of correct responses was more prominent in the sentence task than in the word task. Additionally, the severe aphasics exhibited a prominent leftward deviation that may have been the result of deficits in rightward attention controlled by the left hemisphere. This phenomenon also seems to reflect the directional attention that is subserved by the right hemisphere, which attends to the left side of a space and, less predominantly, the right side of a space.

[Corpus callosum and somesthetic transfer].

Here we describe somesthetic disconnection in 3 patients with callosal lesions. The results suggest the importance of the anterior and/or dorsal part of the posterior truncus of the corpus callosum for interhemispheric transfer of discriminative sensations and integrated somesthetic information necessary to tactile naming and somesthetic reading. We provide a hypothesis for the neural mechanisms underlying somesthetic communication.

Pseudobulbar dysarthria in the initial stage of motor neuron disease with dementia: a clinicopathological report of two autopsied cases.

We retrospectively analyzed the clinical features of two cases of neurodegenerative disease, whose initial symptoms were motor speech disorder and dementia, brought to autopsy. We compared the distributions of pathological findings with the clinical features. The main symptom of speech disorder was dysarthria, involving low pitch, slow rate, hypernasality and hoarseness. Other than these findings, effortful speech, sound prolongation and initial difficulty were observed. Moreover, repetition of multisyllables was severely impaired compared to monosyllables. Repetition and comprehension of words and sentences were not impaired. Neither atrophy nor fasciculation of the tongue was observed. Both cases showed rapid progression to mutism within a few years. Neuropathologically, frontal lobe degeneration including the precentral gyrus was observed. The bilateral pyramidal tracts also showed severe degeneration. However, the nucleus of the hypoglossal nerve showed only mild degeneration. These findings suggest upper motor neuron dominant motor neuron disease with dementia. We believe the results indicate a subgroup of motor neuron disease with dementia whose initial symptoms involve pseudobulbar palsy and dementia, and which shows rapid progression to mutism.

An autopsy case of frontotemporal dementia with severe dysarthria and motor neuron disease showing numerous basophilic inclusions.

We report a clinicopathological study of a patient suffering from frontotemporal dementia (FLD) with severe dysarthria and concomitant motor neuron disease (MND). The patient was a 52-year-old woman with almost simultaneous emergence of severe dysarthria and FTD. The severe dysarthria subsequently evolved into anterior opercular syndrome. Motor neuron signs then emerged, and the patient developed akinetic mutism approximately 2 years after the onset of the disease. The patient died of pneumonia after a 7-year clinical illness. Pathologically, severe and widespread degeneration in the frontal and temporal lobes, including the anterior opercular area, limbic system, basal ganglia, spinal cord and cerebellum, and frequent ubiquitin- and tau-negative basophilic inclusions were observed. The pyramidal tracts and anterior horns of the cervical cord also showed marked degeneration. Cases showing basophilic inclusions reported so far have been divided into two groups: early onset FTD and MND with basophilic inclusions. Our case presented clinicopathological features of both FTD and MND, which suggests that cases showing basophilic inclusions may constitute a clinicopathological entity of FTD/MND.

A case of frontotemporal lobar degeneration with progressive dysarthria.

We investigated the evolution of the neurological and neuropsychological characteristics in a right-handed woman who was 53-years-old at the onset and who showed personality changes and behavioral disorders accompanied by progressive dysarthria. She had hypernasality and a slow rate of speech with distorted consonants and vowels, which progressed as motor disturbances affecting her speech apparatus increased; finally, she became mute two years post onset. Her dysarthria due to bilateral voluntary facio-velo-linguo-pharyngeal paralysis accompanied with automatic-voluntary dissociation fit the description of anterior opercular syndrome. She showed personality changes and behavioral abnormalities from the initial stage of the disease, as is generally observed in frontotemporal degeneration (FTD), and her magnetic resonance image showed progressive atrophy in the frontotemporal lobes; thus, she was clinically diagnosed with FTLD. This patient's symptoms suggest that FTLD, including bilateral anterior operculum degeneration, causes progressive pseudobulbar paretic dysarthria accompanied by clinical symptoms of FTD, which raises the possibility of a new clinical subtype in the FTLD spectrum.

Right unilateral jargonagraphia as a symptom of callosal disconnection.

We report the case of a right-handed patient who exhibited right unilateral jargonagraphia after a traumatic callosal hemorrhage. The lesions involved the entire corpus callosum, except for the lower part of the genu and the splenium. The patient's right unilateral jargonagraphia was characterized by neologisms and perseveration in kanji and kana, and was more prominent in kana than kanji. The jargonagraphia was similar to that observed in crossed aphasia, except that agraphia occurred only with the right hand. The patient also showed right unilateral tactile anomia and right tactile alexia, along with right-ear extinction on a dichotic listening test for verbal stimuli, which suggested that language function was lateralized to the right hemisphere. Since this patient had learned to write with his right hand, kinesthetic images of characters were thought to be formed and stored dominantly in the left hemisphere. We suggest that the callosal lesions disturbed the interhemispheric transfer of information for the dual-route procedures for writing in the right hemisphere, allowing the kinesthetic images of characters stored in the left hemisphere to be processed freely, resulting in the right unilateral jargonagraphia. At least two factors seem to explain that kana was more defective than kanji. First, writing in kana, which is assumed to be processed mainly via a sub-word phoneme to grapheme conversion route, might depend more strongly on lateralized linguistic processing than writing in kanji. Second, kanji, which represent meaning as well as phonology, with much more complicated graphic patterns than kana, are assumed to be processed in both hemispheres.

Argyrophilic grain disease presenting with frontotemporal dementia: a neuropsychological and pathological study of an autopsied case with presenile onset.

A right-handed Japanese man with no consanguinity exhibited personality changes, speech disorder and abnormal behaviors, such as stereotypical, running-away, environment-dependent, and going-my-way behaviors, since the age of 49 years. At age 52 years, neuropsychological examination revealed frontal lobe dysfunctions, mild memory impairment, and transcortical sensory aphasia. MRI showed symmetrical severe atrophy of the anterior part of the temporal and frontal lobes. The clinical diagnosis was FTD. He died at age 54 years after a clinical illness of approximately 5 years. Numerous argyrophilic grains were observed throughout the limbic system, temporal lobe, frontal lobe and brainstem. In addition, there were many tau-positive neurons and glial cells. These findings are all compatible with argyrophilic grain disease (AGD). Our case, however, is atypical AGD because of the young age of onset of the disease and sharply circumscribed cortical atrophy exhibiting severe neuronal loss and gliosis. Our case, together with some other similar cases of atypical AGD, gives rise to the possibility that this type of AGD would constitute a part of pathological background of FTD.

Kinesthetic alexia due to left parietal lobe lesions.

To investigate the neuropsychological mechanisms of kinesthetic alexia, we asked 7 patients who showed kinesthetic alexia with preserved visual reading after damage to the left parietal region to perform tasks consisting of kinesthetic written reproduction (writing down the same letter as the kinesthetic stimulus), kinesthetic reading aloud, visual written reproduction (copying letters), and visual reading aloud of hiragana (Japanese phonograms). We compared the performance in these tasks and the lesion sites in each patient. The results suggested that deficits in any one of the following functions might cause kinesthetic alexia: (1) the retrieval of kinesthetic images (motor engrams) of characters from kinesthetic stimuli, (2) kinesthetic images themselves, (3) access to cross-modal association from kinesthetic images, and (4) cross-modal association itself (retrieval of auditory and visual images from kinesthetic images of characters). Each of these factors seemed to be related to different lesion sites in the left parietal lobe.