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Biomedical subjects

F Ozaki

Publications and source records attributed to F Ozaki.

At least 19 recordsLinked to original sources
PubMed2002

Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe.

We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas.

Aged↗
PubMed2002

Silent cerebral infarction and cognitive function in middle-aged neurologically healthy subjects.

We sought to clarify whether apparently silent cerebral infarcts and periventricular hyperintensities are associated with depressed cognitive function in middle-aged subjects. Subjects were 84 middle-aged neurologically normal adults who wished to undergo a screening examination of the brain. We performed magnetic resonance imaging (MRI) of the brain and neuropsychologic tests in all subjects. Silent cerebral infarcts and periventricular hyperintensities, respectively, were detected in 21 and 14 of 84 subjects. Mini-mental state (MMS) and Raven's colored progressive matrices (RCPM) scores were significantly lower in subjects with than without silent cerebral infarcts. By two-factor analysis of variance, MMS score was affected by silent cerebral infarcts or periventricular hyperintensities, with interactions between the two lesion types (P < 0.05). Silent cerebral infarcts may be an independent factor in the pathogenesis of intellectual dysfunction, but truly independent analysis is difficult because many subjects with silent cerebral infarcts also have periventricular hyperintensities.

Adult↗
PubMed2001

Memory impairment and spatial disorientation following a left retrosplenial lesion.

We treated a patient in whom a left retrosplenial lesion resulted in memory impairment and spatial disorientation. A 31 year old, right handed man was admitted to our hospital after the sudden onset of headache. He was alert, attentive and cooperative, and showed no motor or sensory deficits. Although intelligence was preserved, memory was obviously deficient. The patient proceeded in wrong directions after he left his hospital room and subsequently his home. Neuroimaging revealed a subcortical hematoma in the left cingulate isthmus, while single-photon emission computed tomography demonstrated decreased perfusion in the splenium and left parietal lobe.

Adult↗
PubMed2001

Transient crossed aphasia and persistent amnesia after right thalamic haemorrhage.

A 45-year-old right-handed woman suffered transient aphasia and persistent amnesia after a right thalamic haemorrhage. This patient appeared to have crossed aphasia, although it disappeared within 8 weeks. It is noteworthy that the patient had a unilateral right thalamic lesion but exhibited both verbal and non-verbal memory impairment. Computed tomography and magnetic resonance imaging revealed cerebral haemorrhage in the right thalamus involving the ventral anterior nucleus, medioventral nucleus, mamillothalamic tract, internal medullary lamina, and mediodorsal nucleus. An amytal test was performed and suggested that the right hemisphere was dominant for language functions and the left hemisphere was dominant for visuospatial functions. Single photon emission CT revealed a low perfusion area only in the right thalamus. These findings suggest that the right hemisphere might be dominant for both verbal and non-verbal memory function in this patient, although visuospatial function was lateralized in the left hemisphere.

Amnesia↗
PubMed2000

Haemorrhagic complication following percutaneous transluminal angioplasty for carotid stenosis.

We report 2 cases with haemorrhagic complications following percutaneous transluminal angioplasty (PTA) for carotid stenosis. Computed tomography (CT) scanning of these cases demonstrated diffuse subarachnoid haemorrhage in 1 case, and intracerebral haemorrhage in the other case on the next day after PTA. In the latter case, we measured cerebral blood flow velocity and mean transit time with transcranial doppler (TCD) and dynamic CT scan, which demonstrated remarkable increases in the blood flow velocity and peak height, respectively. From these results, postoperative hyperperfusion was suggested to have caused haemorrhagic complications.

Aged↗
PubMed2000

Interhemispheric neuroepithelial cyst associated with agenesis of the corpus callosum. A case report and review of the literature.

This report describes a neonatal case in whom a large interhemispheric cyst associated with agenesis of the corpus callosum was revealed by fetal ultrasonography and demonstrated by MRI to be multilobulated. Endoscopic fenestration of cysts was initially designed in view of the development of the patient's brain and surgical invasiveness. One year later, when motor paresis of the left arm and progressive enlargement of the cyst on MRI were revealed, open surgery was performed. The histological diagnosis was a neuroepithelial cyst with the feature of choroid plexus epithelia. The clinicopathological features of interhemispheric epithelial cysts associated with agenesis of the corpus callosum are reviewed in the light of differential diagnosis and therapeutic considerations.

Agenesis of Corpus Callosum↗
PubMed1999

Transcortical sensory aphasia due to a left frontal subcortical haemorrhage.

A case of transcortical sensory aphasia caused by a cerebral haemorrhage in the left frontal lobe is presented. A 72-year-old right-handed woman was admitted to the hospital, with a history of acute onset of speech disturbance and headache. On initial assessment, her spontaneous speech was fluent. She had no difficulty initiating speech, articulated normally, and did not exhibit logorrhea. Her ability to repeat phonemes and short sentences (5-6 words) was fully preserved, however she had severe difficulty with visual recognition of words, and with aural comprehension at the word level, although she was able to read words aloud. Computed tomography and magnetic resonance imaging showed cerebral haemorrhage in the left frontal lobe, involving the superior and middle frontal gyrus. Single photon emission CT revealed a wider area of low perfusion over the entire left frontal lobe, including the superior, middle and inferior frontal gyrus. The aphasia symptoms, mainly poor comprehension, disappeared quickly several weeks after the event. This may have been due to a reduction in the size of the haematoma and a resolution of the oedema around the haematoma. Clinically, the transcortical sensory aphasia in this case was indistinguishable from that caused by damage to the posterior language areas. Further case reports of transcortical sensory aphasia associated with frontal lobe lesions would help to confirm whether a relatively rapid recovery is characteristic in cases such as this.

Aged↗
PubMed1999

[Construct validity of a new computer-assisted cognitive assessment battery in normal adults].

A computer-assisted battery for neuropsychological tests (CNT) has been designed to screen adults for cognitive impairment. The aim of this study was to gather evidence for the construct validity of CNT and also investigate the relationship between CNT and conventional neuropsychological tests. Subjects were 45 healthy adults (21 men and 24 women), who ranged in age from 20 to 70 years (mean = 33.5, SD = 1.9) with no history of substance abuse, or of psychotic or neurological disorders. The CNT in our study consists of six subtests designed to assess various components of driving, such as digit span, visual scanning, visual and verbal memory, complex reaction time, and vigilance. Mini-mental state test, Kana-hiroi test, word fluency, the auditory-verbal learning test and Raven's colored progressive matrices were also performed as conventional neuropsychological tests. Results showed there were high correlations between each CNT subtests and conventional neuropsychological tests. A factor analysis (with varimax rotation) identified 4 factors with eigen values greater than 1, which accounted for over 70% of the variance. CNT was able to estimate each factor related to cognitive function such as learning and memory, attention, judgment, and visual scanning selectively. CNT may thus be a useful tool for detection of cognitive impairment, although this test has important limitations. Broader applications of these tests will require extensive population-based validation.

Adult↗
PubMed1999

[Dural arteriovenous fistula at the cranio-cervical junction presenting transient ischemic attack: a case report].

A 58-year-old male was admitted to our hospital because of repeated transient ischemic attack of right hemiparesis and speech disturbance. A CT scan did not demonstrate any remarkable findings. No significant cerebral arterial stenosis or occlusion was found on angiography. However, dural arteriovenous fistula fed by the radiculo-meningeal artery was found at the cranio-cervical junction on left vertebral angiography. The shunt flow from the arteriovenous fistula drained into the superior petrosal sinus and sigmoid sinus in a retrograde fashion. On the angiographic findings when his transient ischemic attack (TIA) had disappeared, the venous drainage had returned to its normal fashion. Venous hypertension around the brain stem was supposed to have caused the transient ischemic attack in this case. We performed coagulation of the draining vein and fistula surgically. After surgery, the patient's TIA completely disappeared. We report the first case of dural arteriovenous fistula at the cranio-cervical junction presenting transient ischemic attack.

Aged↗
PubMed1998

[A case of agraphia due to cerebral infarction in the left parietal lobe].

A case of agraphia due to cerebral infarction in the left parietal lobe was reported. A 63-year-old right-handed man was admitted to our hospital with writing disturbance. His spontaneous speech was fluent, and object naming, word fluency, repetition, verbal comprehension, and reading were fully preserved. However, his writing was slow and required effort. He showed hesitation in spontaneous writing and dictation. His power to copy was better than his power to write spontaneously or to take dictation, but he had some difficulty in copying letters and complex figures. The patient showed abnormal sequences of strokes and completed his strokes by piecing out of several fragments. CT scan and MRI showed a cerebral infarction in the left parietal lobe which included the superior parietal lobule. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. The characteristics of his agraphia much more closely resembled "apractic agraphia", as reported by Alexander et al (1992), than spatial agraphia or pure agraphia. Agraphia in this patient might result partially from the loss or unavailability of the memory of motor patterns necessary for writing letters.

Agraphia↗
PubMed1998

[Thoracic arachnoid cyst presenting incomplete features of Brown-Séquard syndrome: a case report].

Spinal intradural arachnoid cyst presenting incomplete features of Brown-Séquard syndrome is very rare. Only 6 cases have been reported. We report one in a thoracic lesion. A 42-year-old man noticed thermohypesthesia in his right leg, and monoparesis in his left leg. On admission, he presented incomplete features of Brown-Séquard syndrome below the Th7 level. MRI showed the spinal cord to be displaced antero-laterally to the right at Th6-7 level. Myelography and CT myelography failed to show the cyst wall, but an arachnoid cyst was totally removed with T5-8 osteoplastic laminotomy. Sensory disturbance has not changed postoperatively, but motor weakness in his left leg recovered within one month after the operation. No cystic lesion has been detected by MRI during the ten months since the operation. We investigated all seven cases in the literature including our case which showed incomplete features of Brown-Séquard syndrome. As regards to the location of the cyst, all cases were at the mid-thoracic level. And four cases were at the midline. These results suggest that the mechanism of Brown-Séquard syndrome associated with spinal arachnoid cyst may be related not only to the laterality of the lesion but also to the asymmetrical circulation in the watershed area.

Adult↗
PubMed1997

Impairment of short-term memory in left hemispheric traumatic brain injuries.

We report on two patients with traumatic lesions in the temporal and parietal lobes who demonstrated disturbances of short-term memory (STM) following improvement on the aphasia. Patient 1 was a 66-year-old right-handed man who presented to our hospital with a cerebral contusion. One admission we observed a Wernicke's aphasia with paraphasic jargon in this patient that resolved within 8 weeks. Patient 2 was a 35-year-old right-handed woman, with an acute subdural haematoma and a cerebral contusion, who underwent craniotomy and evacuation of the haematoma. In this patient we noted a transient Wernicke's aphasia following the operation that improved within 3 months. Linguistically, the aphasia observed in each of these two patients was not a typical conduction aphasia because of the absence of paraphasia, and impairment of comprehension was unclear despite a decrease in performance on repetition tasks. Both verbal and non-verbal tasks suggested an impairment in STM. These findings suggest that involvement of the left hemisphere may cause disturbances in both verbal and non-verbal STM.

Adult↗
PubMed1997

[Distribution of Candida species and mutans streptococci related to oral conditions in elderly persons].

The purpose of this investigation was to find the relationship between the occurrence of Candida species and mutans streptococci at 7 sites (saliva, tongue, mucosa, teeth, clasp, external, and mucosal denture surfaces) in the mouth of 97 elderly persons (males: 43, age: 76.4 +/- 6.7 years; females: 54, age: 75.0 +/- 6.6 years). Among the subjects, there were complete denture wearers (n = 20), partial denture wearers (n = 45), and non-denture wearers (n = 32). Candida species were more significantly (p < 0.001) predominant in complete and partial denture wearers (80% each) than in non-denture (18.8%) wearers. The presence of Candida was highest on the mucosal denture surfaces followed by clasp, tongue, and remaining teeth in that order. Positive correlation were significantly found between the CFU numbers of Candida species and mutans streptococci present on the external surfaces (p < 0.001), natural teeth (p < 0.001), clasp (p < 0.01), and saliva (p < 0.05). A negative correlation (r = -0.503; p < 0.001) was found between the number of teeth and the CFU numbers of Candida species. Moreover, the CFU numbers of both groups of microorganisms also increased in 80-year-old and over persons. Candida species were most predominantly found in persons with poor oral and denture cleanliness.

Age Factors↗
PubMed1997

[Syringomyelia appearing in a short term after brain abscess].

We describe a rare case of syringomyelia that developed within only 4 months after the cure of the focal cerebritis and abscess. An 18-year-old man who had suffered from meningitis and brain abscess 1.5 years before, presented with pain and sensory disturbance in his left shoulder. Magnetic resonance image (MRI) showed a syrinx formation extending from the upper cervical to the lower thoracic cord. Investigation by MRI during the course of the brain abscess had the appearance of posterior cerebellar arachnoid cyst 3 months after the onset of brain abscess and syrinx developed within 9 months. After posterior fossa decompression and reopening of the Magendie's foramen, his symptom and MRI abnormality improved after one month. In contrast to reported cases of syringomyelia following cerebritis, syrinx formation in our case appeared in relatively a short time. We speculated that basal arachnoiditis and the formation of posterior cerebellar arachnoid cyst caused syrinx formation in a short term after cerebritis.

Adolescent↗
PubMed1995

Unilateral spatial neglect due to a haemorrhagic contusion in the right frontal lobe.

We report two cases of unilateral spatial neglect associated with an isolated right frontal lobe lesion. Case 1 was a 59-year-old, right-handed man, who developed a left hemiplegia, disorientation, and frontal lobe neglect associated with a haemorrhagic contusion following a head injury. Case 2 was a 55-year-old, right-handed man, who also developed disorientation and frontal lobe neglect secondary to a haemorrhagic contusion following a head injury. 99mTc HM-PAO SPECT revealed an isolated reduction in the regional cerebral blood flow (CBF) around the haematoma in the frontal lobe; blood flow to remaining parts of the brain was normal. Damage to the right frontal lobes of these patients was confirmed as being the cause of the unilateral spatial neglect in accordance with the results of CBF studies.

Attention↗