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Biomedical subjects

Hung-Chou Kuo

Publications and source records attributed to Hung-Chou Kuo.

18 recordsLinked to original sources

Short-term thallium intoxication: dermatological findings correlated with thallium concentration.

BACKGROUND: The dermatological features and skin biopsy findings of short-term thallium intoxication have been described. However, the correlation between the dermatological findings and the thallium concentration, the prognosis of peripheral neuropathy, and a cutaneous nerve biopsy study are lacking. OBSERVATIONS: Two patients initially developed perioral numbness, erythematous facial rashes, and polyneuropathy after ingesting thallium-containing water. Severe diffuse alopecia was noted, and a skin biopsy specimen revealed parakeratosis and vacuolar degeneration of the basal layer. Examinations of the hair mount demonstrated a tapered appearance of the anagen root. A serial cutaneous nerve biopsy study showed a loss of epidermal nerves 7 weeks and even 1 year after the thallium intoxication. A toxicology survey disclosed a high concentration of thallium (about 3124 mg/L) in the water. The clinical dermatological features subsided completely, but polyneuropathy with severe painful feet persisted. The blood and daily urinary thallium concentrations decreased slowly in the following 3-month period. CONCLUSIONS: The clinical dermatological features subsided completely, but painful polyneuropathy persisted. The series cutaneous nerve biopsy specimens showed persistent damage to the sensory nerve endings. The disappearance of the dermatological features and the appearance of Mees lines correlated with the decrease of blood and urinary thallium concentrations.

Alopecia↗

Carbon disulfide encephalopathy: cerebral microangiopathy.

To understand cerebral blood circulation after long-term exposure to carbon disulfide (CS2), four patients with encephalopathy and polyneuropathy, who had worked in a viscose rayon plant, were studied. Clinical and laboratory examinations, including brain magnetic resonance images (MRI), computed tomography (CT), CT perfusion, and CT angiography, were carried out. Brain CT and MRI disclosed mild cortical atrophy in all four patients, and multiple lesions in the subcortical white matter, and basal ganglia in three patients. Brain CT angiography and perfusion revealed a statistically significant decrease of cerebral blood flow (CBF) in the total brain parenchyma and basal ganglia, and a decrease of the cerebral blood volume (CBV) in the basal ganglia and a prolonged mean transit time (MTT) in the total brain parenchyma, and the territories of the internal carotid artery (ICA), basal ganglia and occipital lobe. In conclusion, the decrease of CBV and CBF, and the prolonged MTT in the total brain parenchyma, ICA, basal ganglia and occipital lobes, indicated a microangiopathy in patients with CS2 encephalopathy.

Atrophy↗

Heterozygous mutations affecting the epimerase domain of the GNE gene causing distal myopathy with rimmed vacuoles in a Taiwanese family.

OBJECTIVES: Studies of distal myopathy with rimmed vacuoles (DMRV) revealed that most patients had mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene. However, the correlation between GNE mutations and clinical features was not fully understood. PURPOSES: To report the correlation between the clinical features and genetic analysis of DMRV patients. PATIENTS AND METHODS: The clinical presentations, histopathological findings, image studies, and genetic analyses of two patients with DMRV from a Taiwanese family were studied. RESULTS: Two compound heterozygous mutations, Ile 241 Ser and Arg 246 Gln, located in the epimerase domain, were identified in both patients, who were of the same generation. In addition, the elder sister showed a progressive muscular dystrophy course with severe quadriceps and trunk muscle involvement. CONCLUSION: The compound heterozygous mutations in the epimerase domain of the GNE gene are important in the severe phenotype of DMRV. However, the mechanisms leading to this phenotypic heterogeneity still remain to be elucidated.

Adult↗

Axonal polyneuropathy after acute dimethylamine borane intoxication.

OBJECTIVE: To study a patient with axonal polyneuropathy due to acute dimethylamine borane (DMAB) intoxication. PATIENT: Confusion and drowsiness in the acute stage, followed by cognitive impairments and polyneuropathy, are reported in a chemical factory worker after acute exposure to DMAB. RESULTS: Nerve conduction studies indicated axonal polyneuropathy, particularly in the motor nerves. Sural nerve biopsy studies 3 months later revealed an axonal degeneration with a mild decrease of fiber density in the large myelinated fibers. Quantitative sensory testing also disclosed an impairment of pinprick, temperature, and touch sensations. Cutaneous nerve biopsy studies 9 months later demonstrated a moderate loss of epidermal nerves. During the follow-up period of 1.5 years, the clinical features and serial nerve conduction studies showed a steady improvement. CONCLUSIONS: Since DMAB is a new product and has been widely used recently in the manufacturing of semiconductors and electronics, we conclude that DMAB intoxication may produce motor-predominant axonal polyneuropathy and that the establishment of a threshold limit value is warranted.

Acute Disease↗

Congenital myotonic dystrophy: variability in muscle involvement and histopathological process.

In order to understand the involvement of specific muscles in congenital myotonic dystrophy type 1 (DM1), we studied the clinical manifestations, and the genetic effects on various tissues in 2 siblings with congenital DM1. The distal leg muscles were more severely involved than the thigh muscles, as seen in the skeletal muscle magnetic resonance imaging. Molecular genetic analysis of the myotonic dystrophy type 1 protein kinase showed an elongation of the CTG triplet repeats between 850 and 1400 in the leukocytes, skin, fat, tendon, and muscles. Muscle biopsies showed a significant difference in the fiber type distribution between these two congenital DM1 patients. One revealed a prominent involvement of the tibialis anterior muscle with a predominance of type 1 fibers, similar to those muscle fiber distributions in older congenital or classic DM1 patients, suggesting a neurotrophic influence during muscle development. Another revealed a predominance of type 2 fibers in all muscle specimens, and dystrophic changes were observed in the peroneus longus muscle indicating a delayed differentiation or maturation of muscle fibers. We conclude that despite nearly the same number of CTG repeats in the leukocytes, highly individual variability of muscle differentiation may occur at teenagers of congenital DM1 in addition to different pathological findings in various skeletal muscles of patients with congenital DM1.

Adolescent↗

Visual association memory test in differentiating early stage of Alzheimer's disease from vascular dementia.

We studied the results of the Visual Association Memory Test (VAMT) in differentiating Alzheimer's disease (AD) and vascular dementia (VaD). In addition, other basic neuropsychological tests, including the Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating (CDR) were also used. Generally, with the VAMT, AD patients had a worse performance than VaD patients. Particularly among patients with a CDR = 0.5, the AD patients had statistically significantly lower VAMT scores (score less than 3) (p = 0.026) compared to those of VaD patients. However, the VAMT could not predict clinical severity or disease progression. The VAMT, as revealed in this study, is a brief, simply administered, and less biased test, and may offer a diagnostic adjunct to differentiate AD from VaD especially in an early dementia state.

Aged↗

Central nervous system effects in acute thallium poisoning.

We report the central nervous system manifestations, neuropsychological studies and brain magnetic resonance image (MRI) findings of two patients with acute thallium intoxication. Neurologically the patients suffered from confusion, disorientation, and hallucination in the acute stage, followed by anxiety, depression, lack of attention, and memory impairment, in addition to peripheral neuropathy. Neuropsychological tests revealed an impairment of memory function, including reversed digital span, memory registration, memory recall, memory recognition, similarity, proverb reasoning, and verbal fluency. High concentrations of thallium were found in the urine, blood, and drinking water of these two patients. Brain MRI showed lesions in the corpus striatum in one patient. During the follow-up periods, the clinical manifestations and neuropsychological studies showed a slowly progressive improvement, and a follow-up brain MRI 1.5 months later demonstrated a resolution of the lesions. We conclude that thallium intoxication might induce encephalopathy, and brain MRI studies demonstrated the acute-stage brain lesions in a severe intoxicated patient. In addition, neuropsychological tests also confirmed memory deficits, although the brain lesions in the corpus striatum might resolve.

Antidotes↗

Brain magnetic resonance image changes in a family with congenital and classic myotonic dystrophy.

We present the clinical manifestations, brain magnetic resonance images (MRI), and genetic analysis of a family with 2 siblings with congenital myotonic dystrophy type 1 (DM1) and 4 patients with classic DM1. These 2 patients with congenital DM1 had severe mental retardation and a characteristic feature of hyperintensity of white matter at the posterior-superior trigone (HWMPST), in addition to ventricular dilatation in T2-weighted images (T2WI) of brain MRI. In 2 of the 4 classic DM1 patients, brain T2WI MRI showed hyperintensity lesions in the bilateral frontal and/or temporal regions, which were absent in congenital DM1. In conclusion, we suggest that the HWMPST in brain MRI is a characteristic finding in congenital DM1, and that the severe cognitive impairments are not only attributable to the subcortical white matter lesions. In congenital DM1, the cognitive function is a diffuse impairment, which is different from that in classic DM1.

Adolescent↗

Hereditary neuropathy with liability to pressure palsies: a clinical and genetic study of a Taiwanese family.

Hereditary neuropathy with liability to pressure palsies (HNPP), an autosomal dominant disorder, is characterized by recurrent isolated nerve palsies, which are precipitated by trivial compression or trauma. In this report, we present the clinical features, electrophysiological studies, nerve biopsy results, and molecular analyses of a Taiwanese family. Among the 7 members evaluated, one latent and three symptomatic patients were found who showed a heterogeneous presentation from asymptomatic to characteristically recurrent peripheral neuropathy. Electrophysiological studies revealed a general decrease in nerve conduction velocities in all four patients with focal conduction slowing, especially at the compression sites. A sural nerve biopsy with a teased fiber preparation in the index patient demonstrated a typical tomaculous appearance. Molecular genetic studies exhibited a deletion of the PMP22 gene in chromosome 17p11.2-12 in all 4 patients. In conclusion, the diagnosis of HNPP might be overlooked if based on clinical presentation only. Family survey and electrophysiological and genetic tests should be done to investigate this disorder.

Adult↗

Myotonic dystrophies.

Myotonic dystrophies or dystrophia myotonica (DM) is a clinical syndrome that includes myotonic dystrophy type 1 (DM1), myotonic dystrophy type 2 (DM2), myotonic dystrophy type 3 (DM3), and so forth. The terminology was recommended by the new nomenclature for myotonic dystrophies of an International Panel for Consensus. Previous studies have shown that DM1 is caused by the expansion of a cytosine-thymine-guanine (CTG) repeat in the DM protein kinase gene on chromosome 19, and DM2 is caused by an expansion of a cytosine-cytosine-thymine-guanine (CCTG) repeat in the zinc finger protein 9 (ZNF9) gene on chromosome 3. Because DM1 and DM2 have very similar clinical presentations, the diagnosis of these two disorders needs to be confirmed by molecular genetic analysis. Recently, DM3 was reported to include a multisystem myotonic disorder with frontotemporal dementia, and a linkage to chromosome 15q21-24. Although the age at onset, disease severity, and cerebral abnormality on a brain magnetic resonance spectrometry may correlate with the number of triplet repeats in the blood cells of DM1, it is too early to reach a conclusion. In Taiwan, the prevalence of DM1 is much lower than in Western countries. Previous studies have shown that the central nervous system symptomatology is correlated mainly with the white matter lesions in the brain MRI, but the CNS manifestations seem unrelated to the numbers of CTG triplet repeats in the blood cells. The inverse correlation between age at onset and CTG repeat length is significant only in patients with small expansions of about 100-250 triplet repeats. Transmission contraction of the repeat size is likely to occur in alleles with large repeats and is associated with paternal transmission. In congenital DM1, individual variability of muscle differentiation does occur, in spite of the same number of CTG repeats in the leukocytes.

Brain↗

Charcot-Marie-Tooth disease type 1A: a clinical, electrophysiological, pathological, and genetic study.

Various clinical manifestations, electrophysiological findings, and sural nerve biopsies are reported in a Taiwanese family with type 1A Charcot-Marie-Tooth disease (CMT-1A). In addition, molecular genetic studies for duplication of the peripheral myelin protein 22 (PMP22) gene were also performed. There were 3 patients (2 men and 1 woman) with ages at onset ranging from 37 to 44 years. The onset of symptoms was insidious, and the neurological manifestations included distal muscle weakness and wasting, mild sensory loss, and hyporeflexia or areflexia. The severity of clinical manifestations varied from mild to severe, although with very prominent demyelinating polyneuropathy in electrophysiological studies. The sural nerve biopsy study revealed demyelination and an onion-bulb appearance. The molecular genetic studies confirmed duplication of the PMP22 gene in chromosome 17p11.2-12. We conclude that the clinical presentations, electrophysiological studies, and pathological studies as well as the molecular genetic analysis remain important in the clinical diagnosis of CMT-1A.

Adult↗

Delayed encephalopathy after carbon monoxide intoxication--long-term prognosis and correlation of clinical manifestations and neuroimages.

In order to understand the correlation between the clinical and neuroimaging manifestations and the long-term prognosis in delayed encephalopathy after carbon monoxide (CO) intoxication, we retrospectively reviewed 12 patients who had delayed encephalopathy from 89 patients with CO intoxication. There were 8 men and 4 women, with a mean age of 54.4 +/- 17.2 years (range: 11-79 years). All patients had prominent consciousness disturbance in the acute stage and received high flow of O2 or hyperbaric oxygen therapy. All of them regained consciousness within 1-7 days, but subsequently developed delayed encephalopathy. The delayed encephalopathy occurred from 14 to 45 days after recovery from the acute stage. The clinical manifestations included cognitive impairment, akinetic mutism, sphincter incontinence, gait ataxia and extrapyramidal syndromes such as chorea, dystonia, and parkinsonism. Brain MRI revealed multiple lesions in the subcortical white matter and basal ganglia, mostly in the globus pallidus, and to a lesser degree in the putamen, and caudate. In the follow-up period, sphincter incontinence first disappeared. The cognitive impairment improved greatly in the following few months, but the involuntary movements were improved only slightly. Some patients had persistent neurological sequelae, such as dystonia. Similary, the follow-up brain MRI showed a steady improvement. In conclusion, the delayed encephalopathy usually developed 2 weeks to 1.5 months after the acute phase of CO intoxication. Globus pallidus and subcortical white matter were commonly involved. The neurological manifestations improved and correlated roughly with the neuroimaging changes.

Adolescent↗

Diffuse white matter lesions in carbon disulfide intoxication: microangiopathy or demyelination.

Long-term exposure to carbon disulfide (CS(2)) may induce diffuse encephalopathy with parkinsonism, pyramidal signs, cerebellar ataxia, and cognitive impairments, as well as axonal polyneuropathy. The pathogenic mechanisms of diffuse encephalopathy are unclear, although vasculopathy and toxic demyelination have been proposed. Recently, we have encountered a patient who developed headache, limb tremors, gait disturbance, dysarthria, memory impairment, and emotional lability after long-term exposure to CS(2). The brain magnetic resonance images (MRI) showed diffuse hyperintensity lesions in T(2)-weighted images in the subcortical white matter, basal ganglia, and brain stem. The brain computed tomography perfusion study revealed a diffusely decreased regional cerebral blood flow and prolonged regional mean transit time in the subcortical white matter and basal ganglion. To our knowledge, there have been few reports demonstrating diffuse white matter lesions in chronic CS(2) encephalopathy using brain MRI. In addition, the (99m)Tc-TRODAT-1 single photon emission computed tomography showed a normal uptake of the dopamine transporter, indicating a normal presynaptic dopaminergic pathway. We conclude that diffuse white matter lesions may develop after chronic exposure to CS(2), possibly through microangiopathy. In addition, CS(2) poisoning can be considered as one of the causes of chronic leukoencephalopathy.

Brain↗

Clinical phenotype, prognosis and mitochondrial DNA mutation load in mitochondrial encephalomyopathies.

We studied 42 individuals, including 8 patients with either complete or partial syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), 8 patients with either complete or partial syndrome of myoclonic epilepsy with ragged-red fibers (MERRF) and 26 maternal family members who carried either the A3243G or A8344G mutation of mitochondrial DNA (mtDNA). Clinical manifestations and prognosis were followed up in the patients harboring the A3243G or A8344G mutation. The relationship between clinical features and proportions of mutant mtDNAs in muscle biopsies, blood cells and/or hair follicles was studied. In the 8 regularly followed patients with the A3243G mutation, 4 died within 1 month to 7 years due to status epilepticus and/or recurrent stroke-like episodes. Two patients developed marked mental deterioration and 2 remained stationary. All of the patients harboring the A8344G mutation were stable or deteriorated slightly, except for 1 patient who died due to brain herniation after putaminal hemorrhage. The A3243G and A8344G mtDNA mutations were heteroplasmic in the muscle biopsies, blood cells and hair follicles of both the probands and their maternal family members. The mean proportion of A3243G mutant mtDNA in the muscle biopsies of the patients with MELAS syndrome (68.5 +/- 21.3%, range 33-92%) was significantly higher than that of the asymptomatic family members (37.1 +/- 12.6%, range 0-51%). The average proportions of A8344G mutant mtDNA in the muscle biopsies (90.1 +/- 3.9%, range 89-95%) and hair follicles (93.9 +/- 6.4%, range 84-99%) of the patients with MERRF syndrome were also significantly higher than those of the asymptomatic family members (muscle: 40.3 +/- 39.5%, range 1-80%; hair follicles: 51.0 +/- 44.5%, range 0.1-82%). We concluded that measurement of the proportion of mutant mtDNA in muscle biopsies may provide useful information in the identification of symptomatic patients with mitochondrial encephalomyopathies. For patients with the A3243G mutation, the prognosis was related to status epilepticus and the number of recurrent stroke-like episodes and was much worse than for patients with the A8344G mutation of mtDNA, who had stable or slowly deteriorating clinical courses.

Adolescent↗

Sensory neuropathy in X-linked recessive bulbospinal neuronopathy.

X-linked recessive bulbospinal neuronopathy (X-BSN) is an adult-onset spinal and bulbar amyotrophy. Neurophysiologic studies demonstrate subclinical involvement of sensory nerves with diminished or absent sensory nerve action potientials and denervation changes, indicating the involvement of sensory neurons. We report the clinical features, findings of electrophysiologic study, and results of morphometric analysis of sural nerve pathology in a patient with X-BSN. Molecular genetic studies were also performed in the patient and his three daughters. Electrophysiologic studies revealed decreased amplitude sensory nerve action potentials and the presence of high amplitude motor unit potentials in all muscles tested. Sural nerve biopsy demonstrated axonal degeneration with a predominant loss of large myelinated fibers. Molecular genetic studies confirmed elongation of the CAG triplet repeats in exon 1 of the androgen receptor gene. Sequence analysis of the androgen receptor gene revealed that the number of CAG triplet repeats was 45 in the patient and was 45 to 48 in the mutant allele but only 19 to 30 in the normal allele in his three daughters. These findings suggest that both motor and sensory neurons are involved in X-BSN. Sural nerve biopsy and molecular genetic analysis are helpful in differentiation between X-BSN and other motor neuron diseases.

Biopsy↗