Differential activity to shapes under shape-from-motion condition in macaque middle temporal area.

To investigate the neural mechanisms of motion-defined shape processing, we recorded single unit activity in the middle temporal area (MT) while monkeys performed a shape discrimination task under the shape-from-motion (SFM) condition, where a motion cue is critical for shape perception. About 40% of MT neurons responded differentially to shapes under the SFM condition. The differential responses to shapes could not be explained by either the heterogeneous structure of the receptive field or the amount of motion signal. On the other hand, under the shape-from-luminance (SFL) condition, where a luminance cue is critical for shape perception, the proportion of neurons showing differential responses to shapes was smaller than that under the SFM condition and the magnitudes of differential responses themselves were weaker. Thus, the requirement for motion processing for shape perception may facilitate a differential response to shapes under the SFM condition. We compared neuronal activities during the shape discrimination task with those during the direction discrimination task under the SFM condition. Differential responses to shapes were observed more frequently during the shape discrimination task than during the direction discrimination task. Thus, the motion-defined shape processing influenced MT activity.

Event based and time based prospective memory in Parkinson's disease.

BACKGROUND: Patients with Parkinson's disease have been reported to have retrospective memory impairment, while prospective memory, which is memory for actions to be performed in the future, has not yet been investigated. OBJECTIVE: To investigate the prospective memory of patients with Parkinson's disease. METHODS: Twenty Parkinson's disease patients and 20 age matched normal controls were given event based and time based prospective memory tasks. In the event based prospective memory task, the subject was asked to perform an action whenever particular words were presented. In the time based prospective memory task, the subject was asked to perform an action at certain times. RESULTS: The Parkinson's disease patients were impaired on the event based prospective memory task but not on the time based prospective memory task. The impairment of the Parkinson's disease patients on the event based prospective memory task was not the result of their forgetting the content of the prospective memory instructions, but the result of their failure to retrieve it spontaneously when the target words appeared. CONCLUSIONS: These results suggest that event based prospective memory is impaired in patients with Parkinson's disease, presumably relating to frontal lobe dysfunction.

Abnormal activity in the globus pallidus in off-period dystonia.

Pallidotomy was performed in a parkinsonian patient with off-period foot dystonia. Dystonia appeared at the beginning of surgery and disappeared after the first microelectrode penetration of the globus pallidus, perhaps a micropallidotomy effect. Neuronal recording during dystonia revealed that the mean firing rates were low in both the internal and external segments of the globus pallidus, and that firing was irregular in the internal segment of the globus pallidus, compared with firing patterns in offstate parkinsonian patients without dystonia. These firing patterns immediately changed into those of nondystonic, off-state parkinsonism after relief of dystonia These results suggest that off-period dystonia results from the same physiological change in the basal ganglia as that in primary dystonia.

[Acute myocardial infarction in elderly patients: medical and social problems].

The number of elderly patients with acute myocardial infarction has been increasing. However, the choice of treatment remains controversial. Medical records of 310 consecutive patients with acute myocardial infarction were reviewed. Two retrospective analyses were performed. 1) Patients were divided into the elderly group(70 years or more) and the younger group(under 70 years). In-hospital course and outcome were compared. 2) Pre-hospital performance status and living status were reviewed in the elderly group. Acute phase reperfusion therapy was performed in fewer patients in the elderly group(60.8% vs 71.9%, p < 0.01). The difference was most pronounced in cases of direct coronary angioplasty(28.6% vs 54.7%, p < 0.05). As a result, the rate of reperfusion success(74.8% vs 86.8%, p < 0.01) was lower in the elderly group. Moreover, the rates of in-hospital death(23.6% vs 6.8%, p < 0.005), pulmonary edema(20.3% vs 10.8%, p < 0.05), cardiogenic shock(11.9% vs 6.0%, p < 0.005), pneumonia(17.3% vs 3.0%, p < 0.005), and delirium(29.4% vs 12.0%, p < 0.001) were higher in the elderly group. Five patients in the elderly group and 3 patients in the younger group required rehabilitation because of worsened performance status. Six of them were non-reperfused patients. Elderly patients considered likely to become bed-ridden because of pre-existing physical disability at admission accounted for 28.9% of the total. Moreover, many elderly patients had poor support systems (8.4% were living alone, 21.0% were living only with their spouse or a child, 30.1% were widows or widowers). These results show that a lower acute phase reperfusion rate(especially angioplasty) resulted in a poor prognosis and worse performance status in elderly patients. Also 30% of patients were not good candidates for conventional treatment because of delirium, and that self-help in daily life is a fundamental goal for most elderly patients. Rapid and simple acute phase reperfusion, subsequent immediate mobilization, and early discharge are recommended for elderly patients with acute myocardial infarction.

[Everyday memory impairment in Parkinson's disease].

Memory impairment has been frequently reported in patients with Parkinson's disease. The traditional tests used in previous studies, however, failed to sufficiently reflect memory performance in everyday life. To investigate everyday memory in patients with Parkinson's disease, an objective test of everyday memory, the Rivermead Behavioural Memory Test (RBMT), and an everyday memory questionnaire were administered to 26 parkinsonian patients and 26 age-matched normal controls. The parkinsonian patients scored significantly lower on the RBMT than the controls (p < 0.01). Moreover, the parkinsonian patients performed especially poorly on subtests related to prospective memory (p < 0.05). These subtests are thought to be sensitive to frontal lobe function. On the everyday memory questionnaire, the parkinsonian patients estimated their own everyday memory to be significantly worse than did the controls (p < 0.01). Further, the patients estimated their everyday memory to be especially poor in comparison with the controls on the sub-items related to recency memory (p < 0.05), source memory (p < 0.01), action slip (p < 0.01), and tip-of-the-tongue phenomenon (p < 0.05). In the patient group, the RBMT score correlated significantly with the scores on the Wisconsin Card Sorting Test (p < 0.05) and tests of verbal fluency (p < 0.05). These results indicate that everyday memory is impaired in patients with Parkinson's disease, and that this impairment is partly related to frontal lobe dysfunction.

Intravascular ultrasound findings after successful primary angioplasty for acute myocardial infarction: predictors of abrupt occlusion.

OBJECTIVES: This study sought to evaluate the intravascular structure as depicted by intravascular ultrasound after successful primary angioplasty (i.e., without thrombolytic therapy) for acute myocardial infarction and to investigate the related predictors of acute coronary occlusion. BACKGROUND: The usefulness of primary angioplasty for acute myocardial infarction is still limited by early reocclusion. There are few data regarding the intravascular ultrasound findings after primary angioplasty. METHODS: Intravascular ultrasound was performed in 27 patients after successful primary angioplasty. Repeat coronary angiography was performed 15 min later, on the following day and 1 month after angioplasty. RESULTS: Abrupt occlusion occurred in 8 of 27 patients. Angiographic variables in patients with versus those without abrupt occlusion were not significantly different. Intravascular ultrasound disclosed a significantly smaller lumen area ([mean +/- SD] 2.49 +/- 0.72 vs. 5.06 +/- 1.52 mm2, p < 0.001) and a significantly greater percent plaque area (80.5 +/- 9.1% vs. 63.7 +/- 7.8%, p < 0.001) in patients with abrupt occlusion. There was no significant difference in external elastic membrane cross-sectional area. We classified the ultrasound appearance of the intravascular structure as smooth, irregular or filled. Abrupt occlusion occurred in none of 6 patients with a smooth intravascular structure, 24% of 17 patients with an irregular structure and in all 4 with a filled structure (p < 0.05). In the latter group, the lumen was filled with bright speckled or low echogenic material, although angiography revealed excellent coronary dilation in all these arteries. CONCLUSIONS: Intravascular ultrasound revealed a narrow lumen in coronary arteries showing abrupt occlusion after successful primary angioplasty, even though angiography disclosed successful dilation. Arteries with a lumen filled with bright speckled or low echogenic material frequently develop abrupt occlusion.

[A case of corticobasal degeneration presenting with primary progressive aphasia].

We report a 64-year-old right-handed woman whose initial symptom was slowly progressive aphasia without generalized dementia and who was subsequently diagnosed as having corticobasal degeneration (CBD). Neurological examination revealed disturbed vertical gaze, dysarthria, rigidity of the right upper extremity, and bilateral instinctive grasp reaction. Neuropsychological assessment disclosed Broca's aphasia, buccofacial apraxia, and memory disturbance. MRI of the brain showed atrophy of the frontotemporal lobes, which was more severe on the left than on the right, especially the left inferior frontal gyrus. In most reported cases of CBD, the initial symptom is motor dysfunction of the unilateral upper or lower extremity. However, we should be cautious that among cases with CBD, there have been rare cases that begin with progressive aphasia alone. In our case, the atrophied region of the cerebral cortex was most severe around the left inferior frontal gyrus. In a few reported cases with the initial symptom of aphasia, the atrophied region corresponded considerably to the type of the aphasia. On the other hand, in those whose initial symptom was mainly motor dysfunction of the unilateral extremity, the atrophied region was remarkable in the posterior part of the frontal lobe and parietal lobe. Therefore, we suggest that in CBD the distribution of the cerebral cortical lesions differs in accordance with whether the initial symptom is motor disturbance or aphasia, and that the type of aphasia corresponds to the location of the cortical lesion.

Cytoplasmic body myopathy with hypertrophic cardiomyopathy.

A patient with cytoplasmic body myopathy presented muscle hypotonia from birth and developed progressive muscular atrophy and weakness, scoliosis, contracture of joints and cardiorespiratory failure. At the age of 17, he died of heart failure. Post mortem examination revealed severe hypertrophy of cardiac walls and generalized muscular atrophy. Microscopic examination showed many cytoplasmic bodies in skeletal muscle fibers and myofiber disarray in myocardium. No cases of cytoplasmic body myopathy with hypertrophic cardiomyopathy have been reported previously. It is suggested that the Z-line component is related to the formation of the cytoplasmic body in skeletal muscle and disarray in the cardiac muscle.

[A case of cerebral infarction presenting as retrosplenial amnesia].

We report a 73-year-old right-handed female who presented with an acute amnesic syndrome. On November 18, 1991, she was admitted to a local hospital complaining of sudden-onset vertigo and nausea, but immediately after the admission she developed an amnesic syndrome. On November 27, she was transferred to our hospital for further assessment of her memory disturbance. Neurologically she was normal except for mild right hemianopsia and increased deep tendon reflexes in the extremities. Neuropsychological assessments were performed over 3 weeks. She was always alert, attentive, and cooperative. She had no confabulation. On the Wechsler Adult Intelligence Scale revised (WAIS-R), her total IQ was 110. Frontal, verbal, and perceptual functions and motor performance were normal. She had no signs of a callosal disconnection. Despite these preserved functions, her memory function was obviously disturbed. Several memory betteries showed that her recent memory for both verbal and visual modalities was impaired, while her immediate memory such as digit span was preserved. For remote memory her retrograde episodic memory concerning both personal and public events was almost intact, although she had a profound anterograde amnesia. In particular she recalled her personal information about just-premorbid events in detail. On the other hand, her semantic memory, for example understanding of proverbs, geography, and scientific law, was preserved. Taken together, her procedural memory on learning tasks, such as "Tower of Hanoi" and mirror drawing, was intact. Computed tomography demonstrated a low-density area medial to the trigon of the left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

[Surface anatomy scanning image by MRI in herpes simplex encephalitis].

We present surface anatomy scanning (SAS) image by weighted-summation technique using MRI images in herpes simplex encephalitis. Recently, SAS has been developed as a technique that visualizes brain surface structures. This patient was a 64-year-old male who suffered from aphasia and memory disturbance after herpes simplex encephalitis. He was transferred to our hospital for rehabilitation. Neuropsychological tests showed Wernicke's aphasia and memory impairment. SAS was performed for the purpose of analyzing these neuropsychological deficits, especially the Wernicke's aphasia. In SAS image, sulci were enhanced and gyri were easy to identify clearly. The affected structures disclosed low intensity areas in the entire left temporal lobe, including the superior temporal gyrus. It was clarified that the damage to the left superior temporal gyrus resulted in his Wernicke's aphasia. We think that SAS is very useful for cortical lesion analysis, not only in encephalitis but also in other disorders presenting higher brain dysfunctions.