Alzheimer's disease with cerebrovascular disease: current status in the Asia-Pacific region.

BACKGROUND: There is growing awareness of the coexistence of Alzheimer's disease and cerebrovascular disease (AD+CVD), however, due to lack of well-defined criteria and treatment guidelines AD+CVD may be underdiagnosed in Asia. METHODS: Sixteen dementia specialists from nine Asia Pacific countries completed a survey in September 2014 and met in November 2014 to review the epidemiology, diagnosis and treatment of AD+CVD in Asia. A consensus was reached by discussion, with evidence provided by published studies when available. RESULTS: AD accounts for up to 60% and AD+CVD accounts for 10-20% of all dementia cases in Asia. The reasons for underdiagnosis of AD+CVD include lack of awareness as a result of a lack of diagnostic criteria, misdiagnosis as vascular dementia or AD, lack of diagnostic facilities, resource constraints and cost of investigations. There is variability in the tools used to diagnose AD+CVD in clinical practice. Diagnosis of AD+CVD should be performed in a stepwise manner of clinical evaluation followed by neuroimaging. Dementia patients should be assessed for cognition, behavioural and psychological symptoms, functional staging and instrumental activities of daily living. Neuroimaging should be performed using computed tomography or magnetic resonance imaging. The treatment goals are to stabilize or slow progression as well as to reduce behavioural and psychological symptoms, improve quality of life and reduce disease burden. First-line therapy is usually an acetylcholinesterase inhibitor such as donepezil. CONCLUSION: AD+CVD is likely to be under-recognised in Asia. Further research is needed to establish the true prevalence of this treatable and potentially preventable disease.

Gastrointestinal stromal tumours: a clinico-radiologic review from a single centre in South India.

Gastrointestinal stromal tumours (GISTs) are rare tumours but are the commonest mesenchymal neoplasms in the gastrointestinal tract. To our knowledge, there is no large case series in Asian countries in which a clinico-radiological descriptive analysis of these tumours has been carried out. In this retrospective study, we analysed our experience of 70 patients with histopathologically proven GISTs, who were presurgically investigated by using CT, and describe the demography, anatomical distribution, imaging features and clinical course of the GIST. We found an unusually large predominance of males in our study, stomach and small bowel appeared to have been involved similarly and small bowel tumours had a higher rate of metastases. We also highlight some unusual CT features of these tumours that we encountered during the study, such as the presence of metastatic lymphadenopathy and satellite nodules, relapse in appendices epiploicae of the bowel, metachronous liposarcoma, adrenal and lung metastases, multiplicity of lesions and aneurysmal dilatation of the bowel. Two of our patients also had multiple neurofibromas, whose association with GIST has been seen in earlier reports. To the best of our knowledge, this article presents one of the largest series of articles on GISTs, to date, in Asian countries. We conclude with a differential diagnosis of GIST, with salient features distinguishing each entity.

Primary mediastinal synovial sarcoma with transdiaphragmatic extension presenting as a pericardial effusion.

Synovial sarcoma is a distinctive soft tissue neoplasm, most commonly seen in the extremities of young adults. Mediastinal synovial sarcoma is a well-documented entity; however, in many cases, the differentiation between this and other spindle cell tumours may be difficult, especially in monophasic tumours. Unlike most pleuropulmonary synovial sarcomas which are well circumscribed, mediastinal tumours are often infiltrative and resection may not be adequate, leading to a high rate of recurrence. We present a 49-year-old man with a primary pericardial synovial sarcoma, with transdiaphragmatic intra-abdominal extension, which clinically, radiologically and grossly mimicked a tuberculous pericarditis.

Cognitive performance in cryptogenic epilepsy.

Cognitive impairment in epilepsy has begun to gain more attention in clinical practice. There is now a considerable amount of research relating to memory functioning in epilepsy, however, few studies specifically focused on cryptogenic epilepsy. We investigated the cognitive performance in cryptogenic epilepsy patients with the aid of cognitive ability screening instrument (CASI), based on cross-sectional and longitudinal aspects. A total of 100 patients who met the diagnostic criteria of cryptogenic epilepsy were recruited from a national university hospital. The patients with normal CASI scores were compared with those with abnormal ones. We also compared the follow-up CASI score after 3 years with the previous score in all cryptogenic epilepsy patients. Thirty-six per cent of cryptogenic epilepsy patients showed cognitive impairment. The variables correlated with higher risks of cognitive impairment were lower educational status, number of seizure types, duration of seizure and polytherapy, especially in the lower educational status. The correlation between CASI and the Mini-Mental State Examination was excellent. In the follow-up study, the abnormal group showed significant improvement in total CASI score. The normal group showed no significant change. We suggest that in cryptogenic epilepsy, lower educational status remains the most important factor in determining cognitive performance. Adequate treatment with antiepileptic drugs can improve cognitive performance in previously cognitively impaired patients.

Central neurological abnormalities and multiple chemical sensitivity caused by chronic toluene exposure.

Multiple chemical sensitivity (MCS) is a syndrome in which multiple symptoms occur with low-level chemical exposure; whether it is an organic disease initiated by environmental exposure or a psychological disorder is still controversial. We report a 38-year-old male worker with chronic toluene exposure who developed symptoms such as palpitation, insomnia, dizziness with headache, memory impairment, euphoria while working, and depression during the weekend. Upon cessation of exposure, follow-up neurobehavioural tests, including the cognitive ability screening instrument and the mini-mental state examination, gradually improved and eventually became normal. Although no further toluene exposure was noted, non-specific symptoms reappeared whenever the subject smelled automotive exhaust fumes or paint, or visited a petrol station, followed by anxiety with sleep disturbance. During hospitalization for a toluene provocation test, there was no difference between pre-challenge and post-challenge PaCO(2), PaO(2), SaO(2) or pulmonary function tests, except some elevation of pulse rate. The clinical manifestations suggested that MCS was more relevant to psychophysiological than pathophysiological factors.

Flow resistance in carotid and middle cerebral arteries in postmenopausal women: a comparative study of tibolone and continuous combined hormone replacement therapy.

OBJECTIVE: The study sought to compare the vascular resistance and serum lipids of postmenopausal women assigned to tibolone therapy or continuous combined hormone replacement therapy. DESIGN: This was a 6-month, prospective, single-blind, single-center, randomized study. A total of 50 healthy postmenopausal women were enrolled. At study end, 40 women had completed a 6-month follow-up. The first group (23 subjects) received conjugated equine estrogens (CEE) 0.625 mg/day and medroxyprogesterone acetate (MPA) 5 mg/day. The second group (17 subjects) received tibolone 2.5 mg/day. The pulsatility and resistance indexes of the carotid and middle cerebral arteries, and serum lipid profiles were monitored. RESULTS: Comparisons demonstrated that there were no significant differences between the groups in terms of changes in the pulsatility index (PI) and the resistance index (RI) of the common carotid artery (CCA), internal carotid artery (ICA), and middle cerebral artery (MCA) within the study period. Both treatments effectively reduced the total cholesterol level and with no significant differences found between the two regimens. However, in comparing the two groups, we found that high-density lipoprotein (HDL) cholesterol levels were significantly lower in the tibolone group at either 3 months or 6 months after treatment, whereas a significantly higher triglycerides level was observed in the CEE + MPA group after 3 months of treatment. Low-density lipoprotein (LDL) cholesterol levels indicated no significant differences between the two groups after treatment. CONCLUSIONS: The study demonstrated that major neck and cerebral vascular impedance was not influenced significantly by either regimen. Nonetheless, lipid profiles were affected differently by tibolone and by continuous combined CEE + MPA. However, whether or not these findings might modify cardiovascular risk is still unknown.

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.

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.

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.

Prolonged reversible amnesia: a case report.

A 55-year-old woman sustained an acute amnesia that lasted for 8 days. The results of a cerebral magnetic resonance imaging scan and an electroencephalogram were normal. A Wechsler Memory Scale-Revised (WMS-R) test performed 6 days after the event showed global impairment in every domain, except for attention/concentration. A single photon emission computed tomography (SPECT) scan taken 8 days after the event showed hypoperfusion in the left temporal and frontal areas. The results of a follow-up SPECT scan on the 40th day after the episode were normal. A second WMS-R test showed some improvement on the 40th day after the event and considerable improvement on the 176th day. The clinical feature of the patient meets the criteria of transient global amnesia (TGA), except for her protracted course. It was not amnesic stroke, however, because of its reversibility and because there were no accompanying neurological signs. This case raises some implications of the pathogenesis of TGA and the clinical applicability of research criteria.

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.

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.

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.

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.

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.