PubMed Health⌕ Search

Biomedical subjects

M C Pai

Publications and source records attributed to M C Pai.

9 recordsLinked to original sources
PubMed2001

Education and cognitive decline in Parkinson's disease: a study of 102 patients.

OBJECTIVE: To understand the correlation between low education level (EL) and the cognitive impairment in Parkinson's disease (PD). PATIENTS AND METHODS: This is a cross-sectional study of cognitive function in 102 non-demented PD patients, from a special clinic (behavioral neurology) in a referral medical center. PD patients were divided into low, middle and high EL groups. We used the Chinese version of the Cognitive Ability Screening Instrument as a neuropsychological test, which covers nine domains of cognitive function. A full score is 100. When determining the abnormality rate of each item of CASI, we used age/education stratified normal control groups as reference to obliterate the influence of education and age on cognitive decline. RESULTS: Recent memory, language and attention are the three items in which there were differences between the groups, in terms of abnormal performance rates. The high EL group is at less risk of recent memory impairment, but at more risk of impairment in language and attention. The other six items and total score showed no differences among the groups. Thirty-eight percent of the patients had a total score below 1.5 SD of the means of the general population. CONCLUSION: This study shows that high EL exerts no protective effect on the cognitive decline in PD patients in general, except in recent memory. The rate of cognitive dysfunction in PD patients is high. This deserves more attention.

Aged↗
PubMed2001

Alzheimer's disease: scintigraphic appearance of Tc-99m HMPAO brain spect.

UNLABELLED: To investigate the value of Tc-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) single photon emission computed tomography (SPECT) as a diagnostic test for Alzheimer's disease. METHODS AND PATIENTS: Tc-99m HMPAO SPECT was performed on 140 patients and 20 controls. A final diagnosis was established for 115 patients, 58 of whom had Alzheimer's disease. The probability of AD was determined for seven scintigraphic patterns. The probability of Alzheimer's disease was 14% for patients with memory loss and normal perfusion. For patients with abnormal perfusion patterns, the probability of Alzheimer's disease was 87% with bilateral temporoparietal defects, 73% with bilateral temporoparietal defects plus additional defects, 62% with a unilateral temporoparietal defect, 33% with a frontal defect only, 0% with other large defects, and 0% with multiple small cortical defects. In 115 patients with the complaint of memory loss or cognitive abnormalities, bilateral temporoparietal hypoperfusion with or without additional hypoperfusion was more frequent than other scintigraphic patterns in patients with Alzheimer's disease. Tc-99m HMPAO SPECT offers the clinician the possibility of differentiating dementias on the basis of differences in perfusion patterns.

Aged↗
PubMed2000

Transient topographical disorientation as a manifestation of cerebral ischemic attack.

Topographical disorientation (TD) is rare, especially as a manifestation of transient ischemic attack. Here, we report a case of transient TD as a manifestation of cerebral ischemic attack. A 55-year-old male bus driver suffered from sudden inability to recognize familiar surroundings. He completely recovered from this within 12 hours, but suffered a second episode of TD 3 weeks later, in combination with visual agnosia and prosopagnosia. Cerebral magnetic resonance imaging and single-photon emission computed tomography showed a lesion that had recently developed in the right posterior cerebral artery, in addition to a previous lesion in the left occipital pole. His TD symptoms persisted after the second episode.

Agnosia↗
PubMed1999

Supplementary motor area aphasia: a case report.

A 72-year-old right-handed woman developed aphasia after a left supplementary motor area (SMA) infarct. She had a right hemiparesis, more paretic on the leg, a tendency to look to her left, and loss of spontaneity. Neuropsychological deficits were mainly in the initiation of language production. She did not speak spontaneously, but responded and articulated well to questions. She named objects correctly when presented, and could repeat words, phrases, and sentences well. She had a difficulty in reading aloud, writing spontaneously and writing to dictation, but preserved the ability to copy written material. This is another rare case of SMA aphasia.

Aged↗
PubMed1999

Transient global amnesia: a retrospective study of 25 patients.

BACKGROUND: Transient global amnesia (TGA) is a syndrome characterized by an abrupt onset of severe anterograde amnesia and variable retrograde amnesia, usually accompanied by repetitive query during the attack. Its etiology is unknown. METHODS: We retrospectively studied patients who were admitted to National Cheng Kung University Hospital during, or just after, their first transient amnesic episode between July, 1988, and December, 1997. We examined the details of the attacks, including time of onset, duration, activities upon onset, potential precipitating factors, behavior during attack, and accompanying neurologic signs or symptoms. We also inquired about past medical history, current status and recurrence. RESULTS: Twenty-five patients, 11 men and 14 women met the criteria for TGA. Their ages ranged from 27 to 77 years (mean, 60 years). The length of an attack ranged from one to 11.5 hours (mean, 6.3 hours). Nineteen attacks occurred in the morning and 10 had precipitating factors. The significant past history included hypertension, cardiovascular disease, migraine headache and thyroid disorders. None of the patients had a family history of TGA. Investigation revealed abnormal cerebral computerized tomographic (CT) scans or magnetic resonance images in three patients (12%), abnormal cerebral single photon emission CT (SPECT) in six (86%) of seven performed within the first eight days, and abnormal electroencephalography (EEG) in five patients (24%). The left temporal region was the most common site of dysfunction shown by EEG and cerebral SPECT. Three (12%) patients experienced a recurrent attack. CONCLUSIONS: Our patients had a higher rate of thyroid disorders, and most had their amnesia attacks in the morning. As compared with previously published studies, the results showed no differences with respect to age, duration of behaviour during attack, EEG, CT, family history and recurrence rate. The exact duration of an attack is sometimes difficult to estimate. Moreover, the increasing case numbers over the years indicates the importance of the need for better education of medical residents regarding TGA.

Adult↗
PubMed1998

Cerebral blood flow velocity and vasomotor reactivity before and after shunting surgery in patients with normal pressure hydrocephalus.

The purpose of this study was to evaluate pre- and post-shunting haemodynamic changes and their correlation with the clinical results in normal pressure hydrocephalus (NPH). Accordingly, eleven demented patients with clinical signs suggestive of NPH received examinations of cerebral blood flow velocity (BFV) and vasomotor reactivity (VMR) by transcranial Doppler sonography with carbogen testing before and after shunt treatment. Computerized tomography (CT), clinical assessment and neuropsychological grading were performed prior to and at 3 months following surgery. A control group consisting of 10 patients was included to establish baseline data. The pre-operative CBF studies in the anterior cerebral artery (ACA) and the middle cerebral artery (MCA) revealed the NPH patients did not have significant decreases of BFVs, but had significant decreases of carbogen VMR (P < 0.05). After shunting, there were no significant changes of the BFVs as compared with the pre-shunting data. The post-shunting VMR of the ACA was significantly higher than the pre-shunting one (p < 0.05), but there was no variation in that of the MCA. Both the values of post-shunting VMR in ACA and the post-shunting increase in VMR in MCA of the 7 shunt-responsive patients who improved mentally and in other symptoms were significantly higher than those of patients without improvement (p < 0.05). In addition, the five patients with gait improvement showed significantly higher values of post-shunting VMR of ACA and the post-shunting increase of VMR for both ACA and MCA when compared with those patients without gait improvement (p < 0.05, respectively). Our study supports the view that patients with NPH had various degrees of impaired VMR in both the ACA and the MCA, but showed insignificant reduction in BFVs, indicating a compensatory mechanism of CBF over time to accommodate the subnormal state of cerebral perfusion pressure. Shunt placement would improve the VMR in responsive patients. Postoperatively, an increase of VMR tends to accompany improvement of the functional state: that in the MCA alone is associated with symptomatic improvement in mental function and that increase in VMR in both the ACA and the MCA with improvement in gait, respectively.

Adult↗
PubMed1998

A specific shifting deficit in Parkinson's disease: a reversal shift of consistent stimulus-response mappings.

Two experiments were designed to investigate effects of cueing upon aptitude for shifting by patients with Parkinson's disease. Subjects executed in alternation two different components of a task set over successive items in a list. We compared the costs of shifting when the stimulus ensemble remained constant from trial to trial ("uniform" lists), with the case in which a change of stimulus ensemble cued each shift of task ("mixed" lists). Shift costs with mixed lists were significantly smaller than those with uniform lists (Exp. 1, ns = 12). This suggests that patients with Parkinson's disease can benefit from cues about the stimulus ensemble in performing tasks. Patients' shifting performance was different from that of controls only in a reversal-shift condition of the previously consistent stimulus-response mappings (Exp. 2, ns = 12). This result suggests that patients with Parkinson's disease suffer from a specific but not a general deficit in ability to shift.

Basal Ganglia↗
PubMed1997

Topographic disorientation: two cases.

Topographic disorientation is very rare, and usually occurs as a result of a right occipitotemporal lesion. The substrates accounting for these symptoms are thought to be the right parahippocampal and lingual gyri. I report two cases of topographic disorientation. Patient 1, a 58-year-old male taxi driver, suddenly lost his way while driving home. At presentation he could neither describe nor draw a route from one place to another. This patient gradually regained his topographic orientation over the course of 3 months. Patient 2, a 58-year-old male farmer, suffered a headache and visual hallucinations, and subsequently lost his bearings. He could describe and draw a map of a route in detail, although the streets that he traveled daily appeared strange to him. The topographic disorientation of patient 2 had changed little 3 years after the onset. Both patients had left homonymous hemianopia, but no prosopagnosia, constructional apraxia, unilateral spatial neglect, or other cortical dysfunction. Brain computed tomography revealed an infarct of the right posterior cerebral artery, involving the cuneus and lingual gyri, in both patients. The lesion was located more dorsally in patient 1, involving part of the right parietal lobe, and more ventrally in patient 2, involving the right parahippocampal gyrus, which might account for the discrepancy between their topographic orientation and the clinical course.

Cerebral Infarction↗