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Biomedical subjects

N S Chu

Publications and source records attributed to N S Chu.

At least 73 records · Page 4Linked to original sources
PubMed1993

Geographic variations in Wilson's disease.

Certain features of Wilson's disease (WD) in Asia have been found to be different from those in other continents. The higher prevalence rate in Japan is presumably due to a higher consanguinity rate. In Chinese there is a tight linkage between WD and two gene loci for esterase D and retinoblastoma in the long arm of chromosome 13. The high proportion of patients with hepatic presentation accounts for early onset of WD in the Japanese and Chinese series. Skeletal involvement, leg hyperpigmentation, dark complexion, amenorrhea, epileptic seizures, and cerebral white matter degeneration are relatively more common among WD patients in Asia. Excessive copper in the liver appears to have a protective effect against hepatocellular carcinoma and type B hepatitis. Electrophysiological studies suggest widespread functional disturbances of the CNS in WD. Side-effects from penicillamine are rather frequent and often lead to interruption of the therapy. Trien is found to be effective without adverse reactions. Oral zinc therapy may be a suitable alternative for long-term management of WD patients in developing Asian countries.

Adolescent↗
PubMed1993

Sudden bilateral hearing impairment in vertebrobasilar occlusive disease.

BACKGROUND: Bilateral hearing impairment is rare in vertebrobasilar occlusive disease. SUMMARY OF COMMENT: Between 1986 and 1991, we encountered seven patients (four men, three women; median age, 61 years; range, 46-71 years) who had sudden bilateral hearing impairment among 503 patients with vertebrobasilar occlusive disease. The main initial neurological symptoms were sudden bilateral hearing impairment, tinnitus, and vertigo. Acute labyrinthitis or Ménière's disease was the initial diagnosis until subsequent brain stem or cerebellar signs appeared. Brain stem auditory evoked potentials were abnormal bilaterally in six patients but had unilateral attenuation of the IV-V complex in the remaining one patient. Computed tomographic scans in all six patients showed multiple hypodense lesions in the brain stem and the cerebellum. Cerebral angiography showed complete occlusion on both vertebral arteries in one patient, occlusion on the left with small caliber on the right in another, and severe stenosis on both sides in a third. There was no opacification of internal auditory arteries in these three patients. The remaining patient had arteriosclerotic changes with faint opacification of the bilateral internal auditory arteries. Five patients had a poor prognosis, with locked-in state in four and severe truncal ataxia in one. CONCLUSIONS: We conclude that sudden bilateral hearing impairment in vertebrobasilar occlusive disease is more common than previously recognized and that it may indicate a grave prognosis.

Aged↗
PubMed1993

Progression after chronic manganese exposure.

We report a longitudinal follow-up study on six patients with chronic manganese-induced parkinsonism following cessation of manganese exposure. Compared with the 1987 study, their parkinsonian symptoms showed a slow progression, particularly in gait disturbances such as freezing during turning and walking backward with retropulsion. The mean disability scores on the King's College Hospital Rating Scale were 15.0 +/- 4.2 in 1987 and 28.3 +/- 6.7 in 1991 (p = 0.003, paired t test). Review of the video records also confirmed a worsening of parkinsonism, especially in difficulty turning. Three of six patients receiving levodopa treatment had an initial improvement. The response decreased after 2 to 3 years. During the therapy, they did not develop on-off fluctuation or dyskinesia. We conclude that patients with manganese-induced parkinsonism may develop increasing neurologic dysfunction long after cessation of exposure and that their responses to levodopa are different from those of patients with Parkinson's disease.

Adult↗
PubMed1993

Early and late CT manifestations in the persistent vegetative state due to cerebral anoxia-ischemia.

Although there are reports on early CT findings in the persistent vegetative state (PVS) from cerebral anoxia-ischemia, later CT changes have received little attention. CT scans were obtained from six patients who were in PVS from four months to three years. Initial CT scans showed non-specific changes of diffuse cerebral edema. Later CT findings often showed infarction in the superficial or deep border zones (five patients), low density in the basal ganglia (four patients), and infarction in the posterior cerebral artery (PGA) territory (three patients). When the survival time extended beyond eight months, there was an enormous enlargement of the hemispheric ventricles that was disproportionate to the cortical atrophy. The data indicate that border zone and PCA territory infarctions are common in PVS. A progressive, and eventually significant loss of the cerebral mass seems to occur in long-term survivors.

Adolescent↗
PubMed1993

Cardiovascular responses to betel chewing.

The cardiovascular effects of betel nut were studied in 47 healthy male subjects who were divided into three groups: chronic, occasional and new chewers. Cardiovascular responses measured included heart rate and blood pressure changes following betel chewing. All three groups showed a significant increase in heart rate lasting an average of 16.8 minutes. On the other hand, only the new chewer group showed an increase in systolic blood pressure. Present data indicate that betel chewing can affect cardiovascular function, and that tolerance to the pressor response may occur in habitual users.

Adult↗
PubMed1993

Disappearance of N20 and P25 components of somatosensory evoked potential: an ominous sign in severe acute hepatitis.

The scalp-recorded somatosensory evoked potentials (SSEPs) of 14 patients who died of hepatic encephalopathy (HE) caused by severe acute hepatitis and 22 normal volunteers were studied. The present data showed that progressive deterioration of HE resulted in sequential prolongation and eventual disappearance of SSEP components beginning from the late P90 component towards the early P25 and N20 components. Four patients with systemic hypotension, supposedly due to brain edema and increased intracranial pressure, showed disappearance of the N20 and P25 components and died within 24 hours. The N20 and P25 components were preserved in the other 10 patients without systemic hypotension. The disappearance of the N20 and P25 components as well as later components suggests an almost total loss of cortical function. The present study suggests that the disappearance of the N20 and P25 components during the course of HE is an ominous sign in severe acute hepatitis.

Acute Disease↗
PubMed1992

Late CT manifestations in spontaneous putaminal haemorrhage.

Serial CT studies were performed on 61 patients with putaminal haemorrhage, to determine outcome. The average duration of the follow-up was 2 years and 5 months. Several types of late CT change were identified, including disappearance of the haematoma without a trace of haemorrhage, a residual cavity, deformity of the lateral ventricle, atrophy of the head of the caudate, white matter degeneration and linear pseudocalcification around the cavity. Small haematomas, comma-shaped and less than 2 cm wide might disappear without leaving any trace. A slit or small rounded residual cavity was a frequent result of elliptical or irregular haematomas with little mass effect. With prominent ventricular compression, there were distortion and dilatation of the lateral ventricle and atrophy of the head of the caudate nucleus, which might be accompanied by white matter degeneration and pseudocalcification around the cavity. Five cases (8%) were left with no trace of previous haemorrhage, 32 (52%) with a slit cavity, 10 (16%) with a small round cavity, 8 (13%) with a large cavity, 5 (8%) with no residual cavity but with ventricular deformity, and 1 (3%) with only pseudocalcification at the site of the haemorrhage.

Adult↗
PubMed1992

A simultaneous comparison of acupuncture needle and insulated needle sphenoidal electrodes for detection of anterior temporal spikes.

Uninsulated acupuncture needles have been used as sphenoidal electrodes, but the issue of insulation has not been adequately addressed. In this report, acupuncture needles and insulated needle sphenoidal electrodes were simultaneously used to compare the rate of spike detection, spike amplitude and distribution of maximal spikes from eight spike foci in seven patients with temporal lobe epilepsy. When compared to the insulated needle electrode, the acupuncture needle electrode was equally effective in spike detection, but spike amplitudes tended to be smaller and maximal spikes were less frequently encountered. Thus, insulation has an influence on the spikes recorded by the acupuncture needle sphenoidal electrode. However, the overall effect appears to be not sufficiently different from the insulated needle electrode for the purpose of detecting anterior temporal spikes in outpatient EEG recordings for the diagnosis of temporal lobe epilepsy.

Acupuncture Therapy↗
PubMed1992

Surface sphenoidal electrode for recording anterior temporal spikes.

Spike analysis was performed to determine if surface sphenoidal electrodes were suitable substitutes for depth sphenoidal or anterior temporal electrodes in outpatient EEG recordings for the diagnosis of complex partial seizures of anterior temporal origin. Spike measurements consisted of spike detection rate, spike amplitude, and location of maximal amplitude spikes. Depth sphenoidal electrodes had the highest yield in these three measurements. Surface sphenoidal electrodes did not differ from anterior temporal electrodes in spike detection rate and spike amplitude, but the former recorded almost no maximal amplitude spikes, while the latter had approximately 30% of the maximal spikes. It is concluded that surface sphenoidal electrodes are slightly inferior to anterior temporal electrodes, but the differences between them are minimal for practical purposes in outpatient EEG recordings.

Adolescent↗
PubMed1992

Wilson's disease: clinical analysis of 71 cases and comparison with previous Chinese series.

We analyzed 71 patients (45 males and 26 females) with Wilson's disease (WD) who were seen at our hospital from 1979 through 1990. The mean age at onset was 18.1 +/- 6.5 years, with 17.0 +/- 6.6 years for males and 20.2 +/- 5.7 years for females. The mean age at the time of diagnosis was 21.0 +/- 6.3 years. Hepatic WD was the most frequent mode of presentation in childhood with a mean age of 15.5 +/- 6.0 years, while neurologic WD tended to occur in adolescence with a mean age of 21.0 +/- 8.9 years. The ages of onset were 12.5 +/- 0.5 years for renal WD and 25.3 +/- 2.4 years for psychiatric WD. The common initial symptoms were neurologic and hepatobiliary. In addition, hematologic and renal disorders were also common during evaluation. The neurologic findings at the time of diagnosis were tremors (66.2%), dysarthria (56.3%), gait disturbances (46.5%), dystonia (42.3%) and decreased facial expressions (40.8%). Less frequent but notable neurologic presentations were psychosis (11.3%), epileptic seizures (5.6%) and hypokalemic periodic paralysis (1.4%). When compared with two previous large Chinese series, the present data show a male preponderance, an earlier age of onset for males and higher incidences of hepatic, hematologic and renal involvement. The possible reasons for the discrepancies between the present study and previous Chinese series are discussed.

Adolescent↗
PubMed1992

Resolution of cerebral white matter lesions following long-term penicillamine therapy for Wilson's disease: report of a case.

Although lenticular gray matter lesions in Wilson's disease (WD) may resolve following long-term decoppering therapy, response of cerebral white matter lesions to such a treatment has not been reported. A patient with WD developed dystonia of the left hand and focal seizures involving the left upper limb with occasional generalization. CT disclosed a low density area in the right frontal white matter. Initiation of penicillamine therapy resulted in worsening of clinical manifestations, further extension of the right frontal lesion, and development of a new left parietal lesion. However, after five years of continued penicillamine therapy, clinical improvements were noted, including disappearance of the left parietal lesion and almost complete resolution of the right frontal lesion. The present case suggests that cerebral white matter lesions in WD may also respond to long-term chelating therapy.

Adult↗
PubMed1991

Sphenoidal EEG recording using acupuncture needle electrode in complex partial seizure.

Sphenoidal EEG recording using an uninsulated acupuncture needle electrode were performed in 41 patients with or suspected of complex partial seizures of temporal lobe origin. The anterior temporal spikes were detected by the routine EEG in 17 patients (41%) and by the acupuncture sphenoidal needle in 29 patients (70%). The anterior temporal spikes recorded by the acupuncture needle were almost identical in configuration, amplitude and distribution to those recorded by conventional wire or insulated needle sphenoidal electrodes. The sequence in the frequency of spike detection by these 3 types of sphenoidal electrode were SP1-2, T1-2, F7-8 and A1-2 locations. The spikes of maximal amplitude were most frequently recorded by the SP electrode followed by the T1-2 electrode. The placement of the disposable acupuncture needle was simple and safe. Patients experienced minimal discomfort or pain that lasted at most 0.5 h. No complications occurred. The records were generally free of artifacts. It is concluded that the acupuncture needle can be used as sphenoidal electrode in outpatient EEG recording for the diagnosis of complex partial seizures of anterior temporal-origin.

Action Potentials↗
PubMed1991

EEG spectral analysis and topographic mapping in Wilson's disease.

Computerized EEG spectral analysis and topographic mapping were performed on 14 patients with Wilson's disease (WD) and 10 normal subjects of comparable ages. The predominant EEG changes in WD were diffuse but uneven topographic abnormalities with a decrease in alpha activity, an increase in theta and delta activities, and a low voltage background mainly in the alpha frequency band. Eleven patients (80%) had at least one of the above EEG changes. Furthermore, topographic mapping provided more clearly defined foci of slowing and epileptiform activity. Patients with cerebral white matter involvement, akinetic-rigid syndrome, dystonia, or psychiatric symptoms tended to have more abnormal EEGs. It is concluded that EEG changes in WD are common and the quantitative EEG analysis can increase the likelihood of detecting mild or even subtle EEG abnormalities in individual patients as well as in the patient group.

Adolescent↗
PubMed1991

CT, somatosensory and brainstem auditory evoked potentials in the early prediction of functional outcome in putaminal hemorrhage.

The CT and median somatosensory and brainstem auditory evoked potentials (SEP and BAEP) were studied in 80 patients with spontaneous putaminal hemorrhage for their values in the early prediction of functional outcome. The CT scan was performed within 2 days and EPs within a week after the onset of symptoms. The activities of daily living was assessed at 6 months. Patients with good functional recovery had the following findings: 1) the hemorrhage had not involved the thalamus or the posterior limb of the internal capsule; 2) the SEPs were normal or had prolonged central conduction time; and 3) the BAEP was normal. When the cortical SEPs were absent, the majority of patients were moderately or severely disabled. Attenuation or absence of BAEP wave V always forecast a grave prognosis. It is concluded that the combined use of CT, SEP and BAEP is an objective and reliable method for the early prediction of functional outcome in patients with putaminal hemorrhage.

Activities of Daily Living↗
PubMed1991

Effects of alcohol on myoclonus and somatosensory evoked potentials in dyssynergia cerebellaris myoclonica.

Three brothers with dyssynergia cerebellaris myoclonica received alcohol to study the correlation between improvement of myoclonus and alteration in somatosensory evoked potentials (SEPs). Alcohol considerably improved myoclonus for about six hours in two patients (cases 1 and 2) but had only a mild effect in one (case 3). All three patients had giant cortical SEPs. The amplitudes of median N20-P25 and P25-N35 components and tibial N30-P40 and P40-N50 components were considerably decreased after alcohol ingestion in two patients (cases 1 and 2) but unchanged or slightly decreased in one (case 3). The peak latencies of those components were not affected by alcohol. There was thus a good correlation between the suppression of myoclonus and the decrease in giant SEP amplitude.

Adult↗
PubMed1991

A case of cerebral nocardiosis successfully treated with trimethoprim-sulfamethoxazole.

Nocardiosis is an opportunistic infection that often occurs in patients who are in an immunosuppressive state. It is often difficult to treat and the mortality is high. We report on an immunocompromised patient who suffered from cerebral nocardiosis with multiple brain abscesses which was successfully treated with trimethoprim-sulfamethoxazole (TMP-SMX) for a period of 6 months. The resolution of the brain abscesses with this treatment was documented by serial CT scans. Our experience indicates that a short course of TMP-SMX in a low dose may not be effective in preventing the spread of nocardiosis to the central nervous system (CNS). We recommend a prolonged course of a high dose of TMP-SMX in the treatment of CNS nocardiosis.

Adult↗
PubMed1991

Successful pregnancy after D-penicillamine therapy in a patient with Wilson's disease.

Infertility and amenorrhea are reported in most cases of Wilson's disease. In this report, we describe a case of Wilson's disease with pancytopenia and liver cirrhosis for over 4 years, without any specific treatment. After 2 years of D-penicillamine therapy, the patient became pregnant and delivered a liver mature female baby with a body weight of 2,800 g. Both before the pregnancy and after delivery, brainstem auditory evoked potential studies showed similar bilaterally abnormal prolongation in the III-V and I-V intervals. In visual evoked potentials, the P 100 latency was delayed bilaterally. Although serial evoked potential studies failed to show any improvement, a successful pregnancy was proven to be possible in a patient with Wilson's disease who had received regular D-penicillamine treatment.

Adult↗