Mitsuru Kawamura

Recognition of emotion from facial, prosodic and written verbal stimuli in Parkinson's disease.

Although the basal ganglia are thought to be important in recognizing emotion, there is contradictory evidence as to whether patients with Parkinsons disease (PD) have deficits in recognizing facial expressions. In addition, few studies have examined their ability to recognize emotion from non-visual stimuli, such as voices. We examined the ability of PD patients and age-matched controls to recognize emotion in three different modalities: facial, prosodic, and written verbal stimuli. Compared to controls, PD patients showed deficits in recognizing fear and disgust in facial expressions. These impairments were not seen in their recognition of prosodic or written verbal stimuli. This modality-specific deficit suggests that the neural substrates for recognizing emotion from different modalities are not fully identical.

Recognition of emotion from moving facial and prosodic stimuli in depressed patients

Background: It has been suggested that depressed patients have a “negative bias” in recognising other people’s emotions; however, the detailed structure of this negative bias is not fully understood. Objectives: To examine the ability of depressed patients to recognise emotion, using moving facial and prosodic expressions of emotion. Methods: 16 depressed patients and 20 matched (non-depressed) controls selected one basic emotion (happiness, sadness, anger, fear, surprise, or disgust) that best described the emotional state represented by moving face and prosody. Results: There was no significant difference between depressed patients and controls in their recognition of facial expressions of emotion. However, the depressed patients were impaired relative to controls in their recognition of surprise from prosodic emotions, judging it to be more negative. Conclusions: We suggest that depressed patients tend to interpret neutral emotions, such as surprise, as negative. Considering that the deficit was seen only for prosodic emotive stimuli, it would appear that stimulus clarity influences the recognition of emotion. These findings provide valuable information on how depressed patients behave in complicated emotional and social situations.

Isolated hand palsy due to cortical infarction: localization of the motor hand area.

The authors investigated the lesions and symptoms of five patients who presented with monoparesis of an upper limb due to cortical infarction. The location of the cortical motor hand area seems to be in the middle to lower portion of the anterior wall of the central sulcus. Severity of finger paralysis associated with impairment of this area varied in different fingers and occurred in two patterns: one variant predominantly affected the radial side, and the other predominantly affected the ulnar side.

Deficits in long-term retention of learned motor skills in patients with cortical or subcortical degeneration.

We investigated the acquisition and long-term retention of new skills in patients with cortical (Alzheimers disease, AD) and subcortical (progressive supranuclear palsy, PSP; Parkinsons disease, PD) degeneration. The motor skill task performance of the PD and PSP patients improved with training, but the improvement disappeared within a few months, whereas AD patients retained learned skills for 3-18 months. The results of our experiments show that subcortical dysfunction induces a retention deficit for newly learned motor skills. Our present study suggests that a normal striatum is necessary for the formation of long-lasting motor skills, and that the striatum plays an important role as a motor skill consolidation system.

Cerebral localization of the center for reading and writing music

The mechanisms that underly the ability to read and write music remain largely unclear compared to those involved in reading and writing language. We had the extremely rare opportunity to study the cerebral localization of the center for reading and writing music in the case of a professional trombonist. During rehearsal immediately before a concert, he suffered a hemorrhage that was localized to the left angular gyrus, the area that has long been known as the center for the ability to read and write. Detailed tests revealed that he showed symptoms of alexia with agraphia for both musical scores and language.

Utilization Behavior as a White Matter Disconnection Syndrome

We report a case of utilization behavior that was examined neuropathologically. A 72-year-old right-handed male patient, who was admitted with a complaint of transient loss of consciousness, displayed utilization behavior several times. He used daily objects that were placed in front of him, such as a teacup and a toothbrush, without instructions to do so. If the examiner asked the patient not to use the objects, the patient did not use them. MRI revealed acute infarction of the left superior frontal gyrus, where decreased blood flow was revealed by SPECT. The patient died of an acute worsening of dilated cardiomyopathy. Neuropathological examination demonstrated an acute phase infarction of the subcortical white matter of the left superior frontal lobe, which correlated well with neuroradiological findings. Utilization behavior has been thought a frontal lobe symptom. However, we propose that utilization behavior might be considered a white matter disconnection syndrome.

Musical Alexia for Rhythm Notation: A Discrepancy Between Pitch and Rhythm

In the process of reading music, the reading of rhythm and pitch might be differentiated, although there is no evidence of this to date. There have been cases of disorders restricted to the reading of pitch, but none in which the disorder has been restricted to the reading of rhythm. We present a case of musical alexia and agraphia with Wernicke’s aphasia. An in-depth assessment of the subject’s musical reading ability showed that her musical alexia was restricted to unfamiliar melodies. When a melody was divided into rhythm elements and pitch elements, pitch reading was preserved, but rhythm reading was severely disturbed. This is the first case reported of a disorder restricted to rhythm reading, and suggests the independence of rhythm reading and pitch reading.

A disconnection syndrome due to agenesis of the corpus callosum: disturbance of unilateral synchronization.

Recently, interhemispheric disconnection syndromes have been noted in patients with agenesis of the corpus callosum (ACC) during the performance of certain tasks. However, few studies have demonstrated an asymmetric disconnection syndrome. In this report, we present just such a syndrome in a patient with ACC, who manifested ambidexterity (but with a left-hand tendency) and had high intelligence, no neurological deficits, and no associated malformations. In a comparison with similar subjects (amateur musician), we studied her asymmetric deficits using four tasks: (1) simple reaction time for visual stimuli, (2) paced finger tapping in synchrony with visual or auditory stimuli, (3) paced finger tapping without an external reference, and (4) rhythmical finger tapping in synchrony with visual or auditory stimuli. While the comparable subjects displayed no significant difference between hands, and the patient showed no significant difference between hands in the auditory paradigm, her tapping performance deteriorated significantly when asked to synchronize the left hand with timed visual stimuli, irrespective of whether finger tapping was paced or rhythmical. We believe that this phenomenon constitutes a novel asymmetrical disconnection syndrome in an ACC subject; these results suggest that synchronization of multimodal temporal information was lateralized in the left hemisphere (in this case), which is something that the ACC patient could not compensate for.

An autopsied case of Sjogren's syndrome with massive necrotic and demyelinating lesions of the cerebellar white matter.

A 69-year-old woman developed subacute cerebellar ataxia and tremors in all four limbs in April 1996. Laboratory examination showed elevated antibodies against Ro and La. Head magnetic resonance imaging showed T(2) high-intensity lesions in the cerebellar white matter bilaterally and later in the pons. In April 2000, she died of multiple organ failure with incidental colon cancer. The autopsy showed atrophic parotid glands with an accumulation of lymphocytes around the ducts, confirming the diagnosis of Sjogrens syndrome histopathologically. The neuropathological examination revealed severe necrotic lesions in the cerebellar white matter bilaterally with several foci of perivenous demyelination in the periphery of the lesions and similar demyelinated areas in the pons. Immunohistochemistry with anti-JC virus antibody demonstrated no positive inclusions. A single focus of granulomatous arteritis was observed in one subarachnoid artery. The combination of Sjogrens syndrome, granulomatous angitis, and foci of perivenous demyelination suggests that an autoimmune mechanism played an important role in causing the necrotic lesions in the cerebellar white matter in this case.

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 patients 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.