Callosal atrophy parallels decreased cortical oxygen metabolism and neuropsychological impairment in Alzheimer's disease.

OBJECTIVE: To evaluate the relationship of corpus callosum atrophy to cerebral cortical oxygen metabolism and cognitive function in patients with Alzheimer's disease. DESIGN: Prospective clinicoradiologic correlation with magnetic resonance imaging and positron emission tomography. SETTING: A university hospital. PATIENTS, PARTICIPANTS: Ten right-handed male patients with Alzheimer's disease, aged 46 to 70 years (mean +/- SD 57 +/- 6 years), and 14 age- and sex-matched right-handed control subjects. MAIN OUTCOME MEASURES: The midsagittal corpus callosum areas (on T1-weighted magnetic resonance images), cerebral metabolic rate of oxygen (measured with positron emission tomography using the oxygen-15 steady-state technique), and the IQs of the Wechsler Adult Intelligence Scale. RESULTS: Compared with control subjects, the patients had significantly decreased callosal areas with a posterior predominance of the degree of atrophy. The area of anterior and posterior halves of the corpus callosum had a significant correlation with the value of oxygen metabolism in the frontal and parietotemporo-occipital association cortices, respectively. The total area of the corpus callosum was significantly related to the total and verbal IQs of the Wechsler Adult Intelligence Scale. CONCLUSION: Atrophy of corpus callosum reflects the severity and pattern of cortical damage associated with hypometabolism and cognitive impairment in Alzheimer's disease.

Significance of increased oxygen extraction fraction in five-year prognosis of major cerebral arterial occlusive diseases.

UNLABELLED: In major cerebral arterial occlusive diseases, patients with increased oxygen extraction fraction (OEF), which is measured with PET, may be at increased risk for cerebral ischemia. However, the clinical significance of increased OEF remains unclear. This study investigated whether increased OEF is an independent predictor of 5-y risk of subsequent stroke. METHODS: We prospectively evaluated the relationship between the regional hemodynamic status of cerebral circulation and the subsequent risk of stroke in 40 patients with symptomatic internal carotid or middle cerebral arterial occlusive diseases who underwent PET. Patients were divided into two hemodynamic categories according to the mean hemispheric value of OEF-in the hemisphere supplied by the artery with symptomatic disease: one group with increased OEF and one with normal OEF. All patients were followed for 5 y with medical treatment until the recurrence of stroke or death. RESULTS: During 5 y, 11 total and 9 ipsilateral ischemic strokes occurred. The incidences of all ischemic strokes in patients with increased OEF and in those with normal OEF were 5 of 7 and 6 of 33 patients, respectively. There were 4 ipsilateral ischemic strokes in patients with increased OEF and 5 in those with normal OEF. Kaplan-Meier analysis revealed that the risks of all stroke and ipsilateral ischemic stroke in patients with increased OEF were significantly higher than in those with normal OEF (log-rank test; P<0.0002 and P<0.0018, respectively). Multivariate analysis with the Cox proportional hazards model showed that increased OEF significantly increased stroke recurrence: the relative risk was 7.2 (95% confidence interval [CI], 2.0-25.5; P<0.005) for all stroke and 6.4 (95% CI, 1.6-26.1; P<0.01) for ipsilateral stroke. An increase in the absolute OEF value was a better predictor of recurrent ischemic stroke than was OEF asymmetry. CONCLUSION: These findings suggest that an increased OEF is an independent predictor of 5-y risk of subsequent stroke. Identification of patients with increased OEF may have clinical significance in preventing recurrent stroke.

Effects of L-threo-DOPS, an L-noradrenaline precursor, on locus coeruleus-originating neurons in spinal trigeminal nucleus.

Electrophysiological studies using reserpinized cats were performed to examine the effects of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on the noradrenergic pathway from the locus coeruleus (LC) to the spinal trigeminal nucleus (STN). The spike generation of STN relay neurons induced by trigeminal nerve stimulation was not affected by LC conditioning stimulation nor iontophoretic application of L-threo-DOPS. After intraventricular administration of L-threo-DOPS, the inhibition of the spike generation was seen with LC conditioning stimulation and blocked by iontophoretically applied sotalol, suggesting that L-noradrenaline converted from L-threo-DOPS inhibits transmission of STN relay neurons.

Hemichorea in hyperglycemia associated with increased blood flow in the contralateral striatum and thalamus.

We studied a patient with hyperglycemia who developed choreic involuntary movements in the right extremities using single photon emission computed tomography (SPECT) with 123I-N-isopropyl-p-iodoamphetamine. SPECT revealed an increased blood flow in the left striatum and thalamus. Through the control of blood glucose and the administration of haloperidol, the hemichorea was resolved, and the increased blood flow in the striatum and thalamus disappeared. These findings suggest that the increased blood flow, which probably indicates increased neuron activity in the striatum and thalamus, is an underlying pathophysiological state in hemichorea.

[Left antero-medial thalamic infarction and symptoms of amnesia, aphasia, and dementia].

Three cases of left antero-medial thalamic infarction who showed amnesia, aphasia and dementia were studied comparatively in terms of clinical features and the MRI findings. Case 1 and Case 2, who showed transient amnesia and aphasia respectively, had a single lesion in the left antero-medial thalamus. Case 1 had a lesion in a more ventral part than Case 2, suggesting that Case 1 had a lesion of the bundles into the anterior and dorsomedial thalamic nuclei while Case 2 had a lesion of the ventrolateral thalamic nucleus. On the other hand, Case 3 who showed persistent dementia had multiple lesions in addition to the left antero-medial thalamic infarction. A review of the previous reports and investigations of the present cases suggest that a single ischemic lesion in the left antero-medial thalamus will cause amnesia and/or aphasic symptom while in cases with other multiple lesions it may cause persistent dementia.

[Visual agnosia evolving to optic aphasia--a case study].

The underlying mechanism of visual agnosia and optic aphasia has not been fully elucidated, although a number of hypotheses have been proposed. Besides, the difference between these two conditions has been a matter of debate. We report here the result of neuropsychological evaluation in a case of associative visual agnosia evolving to optic aphasia. A 64-year-old right-handed patient was found to be disoriented and confused after undergoing the operation of gastrectomy. CT scan revealed a large infarction in the territory of left posterior cerebral artery. Since 3 weeks after onset, neuropsychological investigations were carried out during 5 months. He was alert and co-operative. Right homonymous hemianopia with macular sparing was noted, but his visual acuity was normal. There was neither a global deterioration of intellectual capacities nor aphasia. Most striking finding was his difficulty in identifying common objects and colours along with a profound alexia. Prosopagnosia was absent. Visual naming both for objects and line drawings was severely impaired. He was unable to describe or demonstrate the use of the objects which could not be named. Pointing to objects named by the examiner was also severely impaired. Although tactile naming was also impaired, both of auditory naming for environmental sounds and naming objects in response to verbal descriptions were preserved. While he was not able to copy the objects skillfully, matching of identical objects and matching objects to line drawings were normal. Clumsiness of coping was thought to be due to his constructional apraxia and visuomotor ataxia. Therefore, his deficit in visual domain was considered to be associative visual agnosia.(ABSTRACT TRUNCATED AT 250 WORDS)

[Spinal epidural abscess as the cause of torticollis--diagnosis by magnetic resonance imaging].

Spinal epidural abscesses are rare, accounting for only 0.2-1.2 of every 10,000 hospital admissions. Because they often present with non-specific symptoms, they are frequently misdiagnosed. We present a case in which superconduction MRI was used to make the diagnosis and to follow the clinical course of a spinal epidural abscess. In December 1988, a 33-year-old male developed spiking fever and the sudden onset of torticollis. He had had a cerebral palsy from birth, with chronic tetraparesis and mental retardation. Isolation of staphylococcus aureus in urine and blood cultures confirmed the diagnosis of pyelonephritis and septicemia. A high fever persisted despite antibiotic therapy commenced immediately. A technetium 99 m scan showed a localized uptake of isotope in the cervical spine. An MRI examination performed in the following day under sedation showed a mass with the same signal intensity as muscle on T1-weighted images. It was located behind the vertebral bodies C1-Th1 compressing the spinal cord. In addition, a lesion with a decreased signal was also evident in the C5-C6 vertebral bodies. Because of torticollis, the patient was unable to keep his head still for a sufficient period of time, to obtain T2-weighted imaging. The MRI findings indicated the presence of a spinal epidural abscess and osteomyelitis. A second MRI done one month after admission showed a reduction in the size of the epidural mass, but further diminishing of the signal intensity of the vertebral lesion. One month later, the patient underwent the surgical removal of the pus and inflammatory soft tissue, and anterior fusion. The torticollis resolved following the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

[The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction].

We performed MRI and measured cerebral blood flow (CBF) using 123I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p < 0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p < 0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction.

[Cerebral hemodynamics and risk for recurrent stroke in symptomatic internal carotid artery occlusion].

PURPOSE: In internal carotid artery occlusion, patients with inadequate blood supply relative to metabolic demand (misery perfusion) may be at increased risk for cerebral ischemia. This study investigated whether patients demonstrating misery perfusion on positron emission tomography (PET) have a high risk of subsequent stroke in symptomatic internal carotid artery occlusion. METHODS: We prospectively evaluated the relationship between the regional hemodynamic status of cerebral circulation and the subsequent risk of stroke in 40 patients with symptomatic internal carotid artery occlusion who underwent PET. Patients were divided into two hemodynamic categories according to the mean hemispheric value of oxygen extraction fraction (OEF) in the hemisphere supplied by the artery with symptomatic disease: patients with increased OEF and those with normal OEF. All patients were followed with medical treatment until the recurrence of stroke or death for 3 years. RESULTS: The three-year incidence of ipsilateral ischemic strokes for patients with normal OEF and those with increased OEF were 1 of 34 and 3 of 6 patients, respectively. A significantly higher incidence of ipsilateral strokes was found in patients with increased OEF (Kaplan-Meier analysis and log-rank test; p < 0.001). Multivariate analysis with the Cox proportional hazards model demonstrated that increased OEF significantly increased stroke recurrence: the relative risk was 19.5 (95% CI, 2.0-188.6) for ipsilateral stroke. An increase in the absolute OEF value was a better predictor of recurrent ischemic stroke than an OEF asymmetry. CONCLUSION: These findings suggest that patients with symptomatic internal carotid artery occlusion and misery perfusion have a high risk for subsequent stroke. Thus, identification and optimal treatment of patients with misery perfusion may be essential in preventing stroke.

[Clock drawing in dementia: its reliability and relation to the neuropsychological measures].

To examine the reliability and validity of clock drawing (CD) for evaluating dementia patients in Japan, we investigated the CD performance and its relation to several neuropsychological tests in 150 demented patients including 105 patients with Alzheimer disease and 30 age- and education-matched non-demented subjects (16 patients with mild cognitive impairment and 14 normals). Patients were also evaluated using the Mini-mental State Exam (MMSE), Wechsler Memory Scale (WMS), Kohs Block Design, and word fluency. CD was scored using the Shulman method. CD scores showed a high interrater reliability (r = 0.97). CD by non-demented subjects was essentially normal. As a screening test for Alzheimer disease (AD, mean MMSE = 18.0), CD had a sensitivity of 57.1% and a specificity of 96.7%. However, four of eight AD patients who showed normal MMSE score (> or = 24) drew abnormal clocks. CD scores in dementia were significantly correlated with performance on the Block Design (r = 0.68), MMSE (r = 0.56), and the Mental Control subtest in the WMS (r = 0.58). Stepwise regression analysis revealed that performance on the MMSE and the Block Design explain 53.8% of the variance in the CD scores. These findings indicate that low CD score by the Shulman method may be reflective of a constructional disability and general severity of dementia. CD is not so sensitive as the result of the original report when the patient group includes milder cases of AD. CD is, however, an efficient screening test for detecting and following the patients with dementia, especially combined with the MMSE.

[Respiratory management after closure of a bronchial-fistula with an omental pedicled gastric flap].

A 56-year-old female, after closure of a bronchial-fistula with an omental pedicle gastric flap, underwent controlled ventilation for two weeks in order to stabilize the flap. We suspended the administration of vecuronium once a day and examined the plasma concentration of vecuronium when a twitch response appeared. During the two weeks of ventilation, plasma concentration of vecuronium was maintained at low doses by adjusting the daily dose of vecuronium infusion. However, the suspended period of vecuronium infusion was prolonged gradually and the patient care such as tracheal suction and position changing became restricted. In addition, we have to care for the infection and a mental injury.

The cerebral correlates of different types of perseveration in the Wisconsin Card Sorting Test.

OBJECTIVES: To explore the neural substrates corresponding to the perseverative errors in the Wisconsin Card Sorting Test (WCST). METHODS: The study examined the correlations between the WCST performances and the SPECT measurements of regional cerebral blood flow (rCBF) in subjects with neurodegenerative dementia. Negative non-linear correlations between the rCBF and the two different types of the perseverative errors ("stuck-in-set" and "recurrent" perseverative errors) were calculated on a voxel basis and volume-of-interest basis in the mixed groups of 72 elderly and dementia patients. RESULTS: The stuck-in-set perseverative error was associated with the reduced rCBF in the rostrodorsal prefrontal cortex, whereas the recurrent perseverative error was related to the left parietal activity but not to the prefrontal activity. CONCLUSIONS: These findings augment evidence that the rostrodorsal prefrontal cortex crucially mediates attentional set shifting, and suggest that the stuck-in-set perseverative errors would be a true pathognomonic sign of frontal dysfunction. Moreover, this study shows that the recurrent perseverative errors may not be associated closely with the prefrontal function, suggesting that this error and the stuck-in-set error should be differentially estimated in the WCST.

Muscarinic receptor-mediated inhibition of dopaminergic excitatory input to caudate neurons from the substantia nigra.

Microiontophoretic studies using rats anesthetized with chloral hydrate were performed to elucidate the relationship between the striatal cholinergic system and nigrostriatal dopaminergic system. Iontophoretic application of carbachol inhibited the spikes elicited by substantia nigra (SN) stimulation in 21 of 24 caudate neurons in which the spikes induced by SN stimulation were inhibited by microiontophoretically applied domperidone, a dopamine D-2 receptor antagonist. This inhibitory effect was completely blocked by atropine, although the spike generation induced by SN stimulation remained unaffected by the drug. However, carbachol did not affect the glutamate-induced firing of the caudate neurons of which the spikes induced by SN stimulation were inhibited by application of both domperidone and carbachol. Furthermore, carbachol had inhibitory effects on the spikes induced by SN stimulation even after the systemic application of bicuculline. In contrast, in 17 of 24 caudate neurons in which the spikes induced by SN stimulation were not affected by domperidone, carbachol did not inhibit the spikes induced by SN stimulation. These results suggest that the muscarinic receptors located on the SN-derived dopaminergic nerve terminals mainly play a role in inhibiting inputs from the SN to the caudate neurons, probably by reducing the release of dopamine from the nerve terminals.

Pontine ataxic hemiparesis studied by a high-resolution magnetic resonance imaging system.

Using a high-resolution magnetic resonance imaging system, we studied 3 patients who had exhibited pontine ataxic hemiparesis. In each patient, the ischemic lesions responsible for the contralateral ataxia were located in the dorsomedial basis pontis. The isointensity bands in the ischemic area on T2-weighted images showed the spared transverse fibers originating from the contralateral pontine nuclei, and this may explain the cause of the unilateral ataxia.

Acute-onset amnestic syndrome with localized infarct on the dominant side--comparison between anteromedial thalamic lesion and posterior cerebral artery territory lesion.

Among 39 cases with acute-onset amnestic syndrome having unilateral localized infarct, 8 cases with anteromedial thalamic infarct ("thalamic" amnesia), and 18 cases with medial temporal lobe infarct including hippocampus in the posterior cerebral artery territory ("PCA" amnesia) were studied in terms of X-CT and MRI findings and neuropsychological examinations. Results were as follows: 7 out of 8 cases with thalamic amnesia (88%), and 15 of 19 cases with PCA amnesia (78%) showed left side lesions on CT scan. All groups showed a prolonged recent memory loss with little loss of immediate recall and remote memory, and disorientation and dyscalculia. In both types of amnesia, patients having a left sided lesion showed recent memory loss with new learning disabilities of verbal materials. Patients having a right sided lesion showed recent memory loss with new learning disabilities of both verbal and visuospatial materials. Judging from the X-CT and MRI findings, the lesions most probably causing amnesia in these cases seemed to be the anterior and dorsomedial nuclei of the thalamus in thalamic amnesia and hippocampus in PCA amnesia. Differential diagnosis in amnestic syndrome with localized infarct is also discussed.

Magnetic resonance images of neuro-Behçet syndrome show precise brain stem lesions. Report of a case.

Neuro-Behçet syndrome was investigated with magnetic resonance imaging (MRI) showing precise images of brain stem lesions, and therefore suggesting the clinical usefulness of MRI in diagnosis of neuro-Behçet syndrome.

Spinocerebellar degeneration: qualitative and quantitative MR analysis of atrophy.

Magnetic resonance imaging at 1.5 T was performed in 27 patients with either the cerebellar or spinocerebellar form of spinocerebellar degeneration and in 10 control subjects. Neither T1- nor T2-weighted images (T1WIs and T2WIs) of the patients showed any abnormal intensity areas within the cerebellum or in any other structures of the brain. The T2WIs delineated normal configurations of symmetrical dentate and red nuclei. On T1WIs two patterns of atrophy were detected: (a) moderate to severe shrinkage of the basis pontis and the middle cerebellar peduncles associated with atrophy of the cerebellum, and (b) moderate atrophy of the cerebellum with a preserved basis pontis. The former morphological changes are consistent with the pathology of pontocerebellar atrophy (PCA) and the latter with those of cerebellar cortical degeneration (CCD). In 11 patients, only after a quantitative analysis of the images were we able to classify them in one of the two morphological categories (PCA or CCD). There was a significant correlation between atrophy of the cerebellum and atrophy of the basis pontis. Furthermore, in the PCA group the anterior portion of the body of the corpus callosum was significantly smaller in comparison with the control subjects.