Ching Chen

Validating the Chinese version of the Verbal Learning Test for screening Alzheimer’s disease

Episodic memory tasks are one of the most sensitive tools to discriminate Alzheimers disease (AD). This study aimed to validate a shorter version verbal memory test that will efficiently assess Chinese elderly with memory complaints. One hundred and eighty-five elderly with normal cognition (NC) and 217 AD patients were evaluated. Each participant received the Chinese Version Verbal Learning Test (CVVLT) consisting of 9 two-character nouns with 4 learning trials, 2 delayed recalls in 30 seconds and 10 minutes, and a word recognition test. In the NC elderly, age and sex had significant effects on recall scores in CVVLT, while education level showed an inverse correlation with 3 different patterns of errors made during the learning, recall, and recognition trials. AD patients had lower scores across all recall tests. In those with lower educational level, NC elderly had higher perseveration errors than AD patients. The cutoff value between the AD and NC groups in the 10-minute recall was 4/5 for those aged >75 years and 5/6 for those aged <75 years. This study has good validity in discriminating AD participants and the data here can help in diagnosing AD and mild cognitive impairment using the CVVLT.

Outcome of living donor liver transplantation for glycogen storage disease.

GLYCOGEN storage diseases (GSD) are inherited disorders in which the amount and/or structure of glycogen in body tissues are abnormal. GSD I (von Gierke disease) is caused by a deficiency of glucose 6-phosphatase activity in the liver, kidney, and intestinal mucosa with glycogen overloading in these organs. The clinical manifestations are seizures, systemic acidosis, hyperlipidemia, hyperuricemia, and growth retardation. Without effective treatment, long-term complications occur, including gout, osteoporosis, short stature, and hepatic adenomas. GSD III (Cori disease) is caused by a deficiency of glycogen debranching enzyme activity and characterized with limit dextrin-like glycogen accumulated in both liver and muscle in most patients. Hepatomegaly, hypoglycemia, hyperlipidemia, and growth retardation are the main manifestations in children; while liver cirrhosis and /or hepatocellular carcinoma may occur later. Great progress in the management of GSD I and III has been made recently. For patients affected with GSD I, nocturnal nasogastric feeding of glucose or orally administered uncooked cornstarch is effective. With early diagnosis and initiation of treatment, normal growth and development may be expected. Some patients are free of long-term complications. Treatment of GSD III consists of highprotein diet, and frequent high carbohydrate meals for patients with hypoglycemia. Nocturnal gastric feeding or cornstarch supplements comprise effective therapy. However, some patients with GSD do not respond to diet therapy and may need frequent intravenous glucose infusions and even parenteral nutrition to maintain metabolic homeostasis. Liver transplantation (LT) is considered to correct the metabolic defects and the deleterious complications of GSD. LT for GSD I and III was first reported, respectively, by Malatack et al in 198 and by Superina et al in 1989. We present five cases of GSD (four GSD Ia; one GSD III), which were treated by living donor liver transplantation (LDLT) in our institution. These patients were unresponsive to medical therapy or developed serious complications of GSD. In this study we investigate the outcome of these children after LDLT for GSD. PATIENTS AND METHODS

Clinical significance of the pallidoreticular pathway in patients with carbon monoxide intoxication

Whereas globus pallidus lesions resulting from carbon monoxide intoxication have been extensively described in the literature, the clinical significance of pallidoreticular lesions has rarely been mentioned. This study incorporated information from functional and structural imaging to explore the correlations of pallidoreticular lesions with parkinsonian features and neurobehavioural performance. Twenty-five patients (11 males) with globus pallidus lesions after carbon monoxide intoxication and 25 age- and sex-matched controls were enrolled for detailed neurological examinations, cognitive testing, susceptibility weighted imaging, diffusion tensor imaging and 99mTc-TRODAT-1 single photon emission computed tomography. The post-processing analysis of the neuroimaging included voxel-based morphometry to assess the regional atrophy, tract-based spatial statistics related to white matter involvement, tractography to investigate the rostral and caudal projections from the midbrain level and specific uptake ratios of 99mTc-TRODAT-1 for presynaptic dopaminergic transporter activity. In susceptibility weighted imaging, low-intensity pallidoreticular lesions were detected from the minimal-intensity projections, which were visible in only 7.7% of the T(1)-weighted images and 15.4% of the T(2)-weighted images, whereas inhomogeneous intensities were detected in the globus pallidus. The patients were further divided into two subgroups based on the presence (n = 13) or absence (n = 12) of pallidoreticular lesions. The patients with pallidoreticular lesions showed increased parkinsonian features, poorer performances on the neuropsychiatric tests, lower 99mTc-TRODAT-1 availability in both the caudate and the putamen and greater atrophy of the thalamus, posterior corpus callosum, cerebral peduncle and white matter surrounding the globus pallidus compared to those without pallidoreticular lesions. The tractography results obtained with seed regions of interest in the substantia nigra showed rostral projections to the supplementary motor cortex and anterior cingulate cortex via the globus pallidus; the two pathways were distinct but ran in parallel, caudal to the level of the globus pallidus. In conclusion, the presence of pallidoreticular lesions after carbon monoxide intoxication indicates a poorer cognitive state, which is associated with extensive grey and white matter damage in addition to the damage to the nigra-striatal neuronal networks. The presence of parkinsonian features may be related to pallidal and presynaptic dopaminergic dysfunction. The sensitivity for detecting pallidoreticular lesions can be greatly improved by using susceptibility weighted imaging compared with conventional imaging.

Hyperhomocysteinemia in Alzheimer dementia patients and cognitive decline after 6 months follow-up period.

PURPOSE White matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) are commonly found in Alzheimers disease (AD) and may contribute to cognitive impairment. Plasma total homocysteine (tHcy) had also been linked with cognitive decline in AD. We examined the relationship among change of cognition, tHcy level, and WMHs on MRI in AD patients with a follow-up periods of 6 months. METHODS AD patients with normal creatinine level and initial clinical dementia rating (CDR) of 1 to 2 were enrolled. tHcy and biochemistry tests related to cerebral vascular risk factors were collected. WMHs were measured on MRI fluid attenuated inverse recovery sequence and classified into deep white matter hyperintensities (DWMHs) and periventricular white matter hyperintensities (PWMHs) by visual rating scale. Neuropsychological tests including cognitive ability screening instrument (CASI), mini-mental state examination (MMSE) converted from CASI scores and CDR were collected twice during the follow- up period of 6 months. RESULTS Ninety-two AD patients, 30 men and 62 women completed the study while the tHcy level was not significantly different between AD and age matched controls. tHcy level showed no correlation with CASI or MMSE score, at either the first or second examination. tHcy showed positive correlation with decline of CASI total score and abstract thinking (both p<0.01) but not in MMSE decline. There was no significant correlation between neuropsychiatric assessment and WMHs, but the decline of abstract thinking score was related to frontal PWMHs (R square=0.237, p=0.007). CONCLUSION tHcy might be associated with rapid cognitive decline in AD after a 6-month follow-up period and the effect might not be directly through WMHs. tHcy level correlated with greater WMHs in the trigone area although greater lesion load by MRI was in the occipital lobe.

Multi-parametric neuroimaging evaluation of cerebrotendinous xanthomatosis and its correlation with neuropsychological presentations

BackgroundCerebrotendinous xanthomatosis (CTX) is a rare genetic disorder. Recent studies show that brain damage in CTX patients extends beyond the abnormalities observed on conventional magnetic resonance imaging (MRI). We studied the MRI and 99 mTc-ethyl cysteinate dimer single photon emission computed tomography (SPECT) findings of CTX patients and made a correlation with the neuropsychological presentations.MethodsDiffusion tensor imaging (DTI) and 3D T1-weighted images of five CTX patients were compared with 15 age-matched controls. Voxel-based morphometry (VBM) was use to delineate gray matter (GM) and white matter (WM) volume loss. Fractional anisotropy (FA), mean diffusivity (MD), and eigenvalues derived from DTI were used to detect WM changes and correlate with neuropsychological results. SPECT functional studies were used to correlate with GM changes.ResultsCognitive results showed that aside from moderate mental retardation, the patient group performed worse in all cognitive domains. Despite the extensive GM atrophy pattern, the cerebellum, peri-Sylvian regions and parietal-occipital regions were correlated with SPECT results. WM atrophy located in the peri-dentate and left cerebral peduncle areas corresponded with changes in diffusion measures, while axial and radial diffusivity suggested both demyelinating and axonal changes. Changes in FA and MD were preceded by VBM in the corpus callosum and corona radiata. Cognitive results correlated with FA changes.ConclusionIn CTX, GM atrophy affected the perfusion patterns. Changes in WM included atrophy, and axonal changes with demyelination. Disconnection of major fiber tracts among different cortical regions may contribute to cognitive impairment.

Patterns of executive dysfunction in amnestic mild cognitive impairment.

BACKGROUND Executive dysfunction is not uncommon in patients with amnestic mild cognitive impairment (aMCI). This study aimed to investigate the applicability of executive function tests (EFTs) in aMCI as an aid in establishing the diagnosis of multi-domain MCI. METHODS One hundred and twenty (120) aMCI patients, 126 Alzheimers disease (AD) patients, and 100 normal controls were enrolled. The EFTs evaluated included the trail making test, digit backward span, Stroop color-word test, and design fluency and category fluency tests. RESULTS Of the aMCI participants, 66% exhibited impairment in at least one EFT. Among the five selected EFTs, the category fluency test was the most discriminative in detecting executive dysfunction between patients with aMCI (standardized β = 0.264) or AD (standardized β = 0.361) with the controls, followed by the Stroop test. The performance of aMCI patients with two or more impaired EFTs was significantly different from those of controls but not from those of AD patients. CONCLUSION In the clinical setting, aMCI patients who fail in two or more EFTs may represent a unique population with multi-domain MCI that require close follow-up.

Liver and spleen change in the living related liver donation

DUE TO the difficulty of obtaining organs from cadavers, living-related liver transplantation (LRLT) has been utilized for compatible children and adults with endstage liver disease. The operation involves removal of left lateral segments (S2, S3), extend left lateral segment (S2, S3, and medial part of S4), left lobe (S2, S3, and S4), or right lobe of the liver without endangering the function of the remaining liver. After partial hepatectomy, liver regeneration leads to restoration of liver function. On follow-up computed abdominal tomography (CT), we noted spleen volume changes in the donors after operation, a finding which has not been mentioned in the previous literature. The purpose of this study was to evaluate liver regeneration and spleen volume changes in donors after LRLT using CT volumetry.

Subclinical central pontine myelinolysis after liver transplantation.

A 17-year-old boy was diagnosed with Wilson’s disease, with end-stage liver cirrhosis for 5 years. The major indication for LRLT was repeated esophageal variceal bleeding, which needed sclerotherapy and/or banding (eight times between February 1996 and December 1998). A brain magnetic resonance imaging (MRI) was done (one of the workup tests in transplant candidates with Wilson’s disease) which showed a symmetric hyperintensity signal in the bilateral globus pallidus on T1-weighted image. The globus pallidus MRI result may have been due to portosystemic shunting or the paramagnetic effect of copper or iron deposition. The brainstem at this time was unremarkable (Fig 1A). LRLT was performed on January 14, 1999. The operation was without complications and the patient recovered uneventfully. However, ascites developed and hypoalbuminemia persisted in the postoperative period despite

Vascular anomalies associated with biliary atresia in pretransplant survey

BILIARY atresia is the most common indication for liver transplants in children, and this disorder is associated with some congenital vascular anomalies. Complex vascular anomalies increase the technical difficulties of the operation and previously resulted in high mortality in these patients. The role of the radiologist is to define the conditions in which transplantation is high risk or contraindicated and to identify any anatomic variations that may alter the surgical approach. The purpose of this study is to define the congenital vascular abnormal conditions in biliary atresia patients that would alter the surgical procedure during transplantation.

Learning and Error Patterns in the Chinese Verbal Learning Test in Subjects with Mild Cognitive Impairment and Normal Elderly

PURPOSE The discrimination between normal elderly (NC) and those with mild cognitive impairment (MCI) is of clinical relevance since the conversion from MCI to Alzheimer dementia (AD) is high. METHODS This study enrolled 216 amnestic MCI patients and 103 NC from our memory clinics and assessed whether the learning curve, recall and cued scores, as well as error patterns from the Chinese Version Verbal Learning Test (CVVLT) helped to distinguish between these two groups. RESULTS Our results revealed that subjects with MCI had a lower rate of acquisition and deceleration of learning in the learning curve. The MCI group also showed a lower retention rate and recall scores as compared with the NC group. Further, the error patterns offered discrimination values between the two groups in total number of perseverations, intrusion in the cued recall, as well as prototypic and unrelated errors in recognition. An inverse correlation was seen between memory scores and error patterns. CONCLUSION This study suggests that by combining the learning and error patterns from the verbal memory test, patients with MCI can be better differentiated from normal elderly.