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Biomedical subjects

L M Tang

Publications and source records attributed to L M Tang.

At least 37 records · Page 2Linked to original sources

Nasopharyngeal carcinoma: MRI and CT assessment.

Precise assessment of the extent of nasopharyngeal carcinoma (NPC) represents the basic step towards optimal treatment. We compared the capacity of CT and MRI in assessing the extent of NPC in 67 patients. MRI was superior to CT in demonstrating lesions in the retropharyngeal node, skull base, intracranial area, carotid space, longus colli muscle and levator palatini muscle. Of 25 cases in which retropharyngeal adenopathy was recognised only on MRI, seven had been reported as showing oropharyngeal involvement and 18 as primary extension to the carotid space on CT. MRI showed skull-base involvement in 40 patients compared with 27 on CT and intracranial involvement in 38 patients versus 24 on CT. There was not a single case in which skull base invasion was seen on CT but not on MRI. MRI enabled improved recognition of tumour infiltration of longus colli muscles (34 cases compared with 15 on CT). It allowed us to clarify 12 questionable sinonasal opacities on CT. Overall, T-staging was changed in 18 of 67 patients (26.9%), including upstaging in 15 cases and down-staging in 3 cases, after comparing CT with MRI. The nodel status was changed from negative on CT to positive on MRI in 4 of 67 patients (6%). We believe that MRI allows more accurate evaluation of the extent of NPC than CT and should be the primary mode of investigation.

Adolescent↗

Klebsiella meningitis in Taiwan: an overview.

Klebsiella infection has been considered to be an uncommon cause of meningitis. To determine its incidence and clinical features, we reviewed the microbiologic records of cerebrospinal fluid (CSF) and blood cultures and the medical records of patients with bacterial meningitis admitted between 1981 and 1995. Klebsiella meningitis was diagnosed in 79 patients with 83 episodes. All patients had klebsiella isolated from CSF and/or blood and typical symptoms and signs of acute bacterial meningitis. Of these, 74 were over 16 years of age and 2 of the 5 children were infants. There was an increased prevalence rate of klebsiella meningitis after 1986. Of the 83 episodes, only 9 occurred between 1981 and 1986, accounting for 7.8% of 115 cases with CSF and/or blood culture-proven acute bacterial meningitis, whereas in 1987-95, there were 74 episodes accounting for 17.7% of 419 bacteriologically proven cases. K. pneumoniae accounted for 69 episodes, K. oxytoca, 11 episodes and K. ozaenae, 3 episodes. Male gender, diabetes mellitus and liver cirrhosis were commonly associated with K. pneumoniae meningitis. Neurosurgical procedures were frequently associated with K. oxytoca meningitis. All three patients with K. ozaenae meningitis had a primary disease of the nasopharyngeal pathway. The mortality rate due to K. pneumoniae was 48.5%, K. oxytoca, 10% and K. ozaenae, 0%. In patients with K. pneumoniae meningitis, poor prognostic factors included age over 60 years, diabetes mellitus, bacteremia and severe neurological deficits on the first day of treatment.

Adolescent↗

Guillain-Barré syndrome in Taiwan: a clinical study of 167 patients.

OBJECTIVE: To identify clinical characteristics of various forms of Guillain-Barré syndrome in Taiwan. METHODS: The clinical and electrophysiological data of 167 consecutive patients with Guillain-Barré syndrome admitted to Chang Gung Memorial Hospital, a general paediatric and adult hospital in Taiwan, were reviewed. RESULTS: Analysis of age distribution disclosed a high incidence (21%) among patients under the age of 10 years. Seasonal preponderance in Spring (March to May) was found. Utilizing clinical and electrophysiological data, these 167 patients with Guillain-Barré syndrome were subclassified; 82 (49%) had acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 32 (19%) had Fisher syndrome (FS), and six (4%) had axonal forms of Guillain-Barré syndrome. The remaining 47 (28%) patients were unclassified. Patients with AIDP and FS had many common clinical features, including seasonal distribution, history of preceding illness, sensory abnormalities, cranial nerve involvement except for extraocular motor nerves, and albuminocytological dissociation on examination of CSF. Follow up study on 145 patients disclosed that 127 (87%) recovered satisfactorily, 14 (10%) were persistently disabled, and four (3%) died during admission to hospital. Clinical features associated with poor outcome (persistent disability or death) were requirement for mechanical ventilation, a low mean compound muscle action potential amplitude (< or = 10% of the lower limit of normal), and age greater than 40 years. CONCLUSION: Guillain-Barré syndrome in Taiwan showed a peculiar age and seasonal distribution and a high frequency of FS not seen in other series. Given that patients with AIDP and FS had many common clinical features, AIDP and FS may have similar underlying pathological mechanisms.

Adolescent↗

Local application of anti-NGF blocks the collateral sprouting in rats following chronic constriction injury of the sciatic nerve.

Systemic administration of anti-nerve growth factor (NGF) antibodies can block nociceptive fiber sprouting into denervated adult rat skin. However, the effect of local application of anti-NGF on collateral sprouting in rats caused by chronic constriction injury (CCI) has not been well studied. We investigated the influence of local anti-NGF on collateral sprouting caused by CCI of the rat's sciatic nerve. Using a dye-labeled plasma extravasation technique, we can easily evaluate the extent of collateral sprouting by the clearly defined blue coloration area. Our results showed that local application of anti-NGF either in a high or low dose significantly prevented the spread of collateral sprouting from the saphenous nerve into the sciatic innervation territory. In contrast, distilled water did not show a significant block of the saphenous nerve collateral sprouting. Our study suggests that collateral sprouting is dependent on the local availability of NGF by the nearby intact cutaneous nerve fibers.

Animals↗

Tuberculoma en plaque: CT.

A 35-year-old woman presented with a 6-month history of intermittent headaches, vomiting and dizziness. CT showed a plaque-like mass with tiny calcifications along the surface of the left frontal lobe. The mass exhibited heterogeneous enhancement with a few low-density foci. Underlying sulcal obliteration and enhancement and white matter oedema were also noted. Histopathological examination of excised material was consistent with tuberculoma. Recognition of this unusual presentation of intracranial tuberculoma may facilitate appropriate diagnosis and management.

Adult↗

Bacterial meningitis in patients with nasopharyngeal carcinoma.

Bacterial meningitis was found in 12 patients with nasopharyngeal carcinoma, accounting for 0.65% of the 1850 patients with the tumour diagnosed between 1981 and 1994 in our hospital. In 11 patients, the time-lag between diagnosis of cancer and the appearance of infection ranged from 9 months to 11 years (mean 57 months) whereas in one patient it was only 5 days. Three patients developed mixed bacterial meningitis. Cerebrospinal fluid culture for bacteria was positive in six patients. Three patients (25%) were bacteraemic. Gram-negative bacilli, especially Pseudomonas aeruginosa, were the most common pathogens. Age, sex and histopathology were not risk factors for infection. Conditions predisposing to meningitis included intracranial invasion of the tumor, neutropenia, otitis media, and neurosurgical procedures. All but two patients had intracranial tumour invasion and erosion of the base of the skull. Local spread of micro-organism to the meninges was more important than haematogenous spread. The overall mortality in our patients was 66.7%, much higher than in patients without cancer.

Adult↗

A longitudinal study of multimodal evoked potentials in patients following radiotherapy for nasopharyngeal carcinoma.

Radiation rhombencephalopathy and radiation myelopathy may occur in patients months or years after radiotherapy for malignancy of the head and neck. We obtained multimodal evoked potentials longitudinally in 26 patients with proven nasopharyngeal carcinoma. Recordings were made before radiotherapy and at 1 week, 3 months, 9 months, 15 months, and 24 months after radiotherapy. All absolute latencies of evoked response before and after radiation were within normal limits. However, the I-III interpeak latencies of brainstem auditory evoked potentials and the onset latencies of motor evoked potentials in the whole group of patients at 15 months after radiation were significantly longer than those before radiotherapy, whereas the latencies at 24 months were not significantly different. The N20 latencies of somatosensory evoked potentials after radiotherapy were significantly prolonged at 3 months of follow-up; the prolongation then became normal. They indicate that a subclinical reversible radiation-induced dysfunction may occur in the auditory, sensory, and motor systems.

Adult↗

Tuberculous meningitis in patients with nasopharyngeal carcinoma.

Mycobacterial infection has been recognized as a complication in patients with malignancy. Tuberculous (TB) meningitis has not been reported in patients with nasopharyngeal carcinoma (NPC); it may have been overlooked or confused with the underlying malignancy or meningitis caused by other microorganisms. We describe the occurrence of culture-proven TB meningitis in 2 NPC patients. The time lag between the diagnosis of NPC and the occurrence of TB meningitis was 4 years in 1 patient and 6 years in the other. In both patients, the diagnosis of TB meningitis was delayed; they were initially treated for bacterial meningitis. Subsequent antituberculous chemotherapy was successful in 1 patient but failed in the other. Recognition of the infection is important for early diagnosis and proper treatment of this potentially fatal condition in patients with NPC.

Antineoplastic Combined Chemotherapy Protocols↗

Juvenile-onset of Dejerine-Sottas disease in a Taiwanese woman.

Dejerine-Sottas disease is an uncommon hereditary neuropathy which has not been reported in Taiwan. We describe a 57-year-old woman who had slowly progressive weakness in her four limbs since adolescence. None of her close relatives had the disease and no consanguinity was noted. Neurologic examination showed severe weakness and vibratory sensation loss in the four limbs. The tendon reflexes were generally absent. Electrophysiologic studies suggested a systemic myelinopathic process. Light and electron microscopy of the sural nerve biopsy specimens revealed many onion-bulb shapes formed by the Schwann cell processes or basement membranes without any evidence of myelin sheaths around the axons, which are characteristic features of Dejerine-Sottas disease.

Age of Onset↗

Vocal cord paralysis as an initial sign of multiple system atrophy in the central nervous system.

Multiple system atrophy (MSA) of the central nervous system has been recognized as a rare cause of stridor secondary to vocal cord paralysis. This respiratory problem usually occurs in the later stages of the disease. We report the case of a 53-year-old man who presented with bilateral vocal cord paralysis accompanied by stridor and sleep apnea, which were relieved by a tracheostomy. Two years after the onset of stridor, he developed extrapyramidal and cerebellar signs combined with severe autonomic failure. Magnetic resonance imaging of the brain revealed atrophy of the brainstem and cerebellum. This clinical picture is consistent with the diagnosis of MSA. Vocal cord paralysis preceding any other neurologic and autonomic manifestations has been infrequently described. This case should remind clinicians that MSA should be considered in the differential diagnosis of vocal cord palsy of undetermined origin.

Atrophy↗

Recurrent hypertensive intracerebral hemorrhage.

Hypertensive intracerebral hemorrhage has been considered as a one-time event with rare recurrence. This observation is quite different from our experience in Taiwan. We, therefore, conducted a systematic review of our series of consecutive patients with recurrent bleeding. During a 2-year period, we encountered 47 patients with recurrent hypertensive intracerebral hemorrhage from a total of 892 consecutive patients with hypertensive hemorrhage (5.3%). There were 25 men and 22 women with a mean age of 59 +/- 10 (range: 36-78) years at the onset of the first hemorrhage and 62 +/- 9 (range: 39-80) years at the second hemorrhage. The median interval between 2 hemorrhages was 2 years and 4 months (range: 1 month to 8.5 years). All except one recurrent hemorrhages occurred at a site different from the previous one. Of the 38 patients admitted to our hospital for both hemorrhages only 5 were regularly treated with antihypertensive therapy. The outcome for the recurrent bleeding was grave: 26% died and 51% became totally dependent or vegetative. Recurrent hypertensive hemorrhage is not as rare as previously thought; it comprises 5.3% of our patients with hypertensive intracerebral hemorrhage. The recurrent hemorrhage, however, rarely occurs at the same location as the previous one. Uncontrolled hypertension appears to be an important risk factor for the recurrence. Control of blood pressure after the first bleeding should be attempted to prevent recurrent hemorrhage.

Adult↗

POEMS syndrome in Chinese.

POEMS (polyneuropathy, organomegaly, endocrine disturbance, M-protein and skin hyperpigmentation) syndrome occurring in Chinese has been inadequately described. Here we report our experience of 12 Chinese patients with the syndrome. This series is similar to those reported from Japan and from the Western world by the predominance of middle-aged males. Diabetic mellitus, a common feature in POEMS syndrome, was not present in our patients. M-protein of the lambda type was demonstrated in 7 patients by immunoelectrophoresis or by immunofixation electrophoresis. Osteosclerosis in Chinese patients is not as common as in patients reported from Japan or from the Western world; a common radiographic finding in our patients was a compression fracture of the thoraco-lumbar spine with or without sclerotic and lytic lesions. The condition has a grave prognosis; 9 patients die within 4 years after onset of the disease despite various kinds of treatment.

Adult↗

Acute transverse myelopathy and cutaneous vasculopathy in primary Sjögren's syndrome.

Neurologic complications of primary Sjögren's syndrome (SS) may be under-estimated. Here, we report a patient with primary SS, who developed acute transverse myelopathy (ATM) and skin purpuric lesions simultaneously. In the first episode of myelopathy, the patient's neurologic deficits improved after steroid therapy. However, she died of recurrent myelopathy with systemic complications 4 months later. Review of the English-language literature revealed only 3 cases of primary SS associated with ATM, none of the 3 patients had skin lesions. Anti-Ro(SS-A) antibodies, and ATM in our patient suggests that immune-mediated vasculopathy may play a role in the pathogenesis of acute myelopathy in primary SS.

Acute Disease↗

Brain abscess as a complication of stroke.

BACKGROUND: Systemic infection is a common complication of stroke. However, brain abscess as a complication of stroke has never been reported. CASE DESCRIPTIONS: We report two patients, one with a hypertensive intracerebral hemorrhage and the other with nonseptic cerebral infarction. In both patients, brain abscess developed at the stroke lesion site after an infectious complication. After surgical aspiration and antibiotic treatment, one patient recovered and the other died. CONCLUSIONS: These two cases demonstrate that brain abscess may occur in a previous hemorrhage or infarction area as a complication of systemic infection. Recognition of the risk is important for early diagnosis and proper treatment of this potentially fatal complication of stroke.

Aged↗

Concurrent trigeminal, abducens, and facial nerve palsies presenting as false localizing signs: case report.

Multiple cranial nerve dysfunction presenting as false localizing signs is rare. We report a 20-year-old woman who had concurrent trigeminal sensory disturbance, abducens, and peripheral facial nerve palsies in association with a contralateral acoustic neuroma. After surgery, the trigeminal nerve disturbance and the abducens nerve palsy completely recovered, but the peripheral facial nerve palsy persisted. The nature of tumor, the presence of brain stem distortion, the anatomic variation of posterior fossa, and the relationships of cranial nerves and nearby blood vessels, which are factors influencing the occurrence of false localizing, are briefly discussed.

Abducens Nerve↗

Fabry's disease: report of a case.

Fabry's disease is a rare hereditary disorder of glycosphingolipid metabolism. Its clinical features have not been adequately described in Taiwan. This paper reports on a 32-year-old man who had painful acroparesthesia, disseminated skin angiokeratomas, whorled corneal opacity, mitral valve prolapse and renal insufficiency. There was also involvement of the central motor pathways and the autonomic nervous system. A sural nerve biopsy showed loss of small myelinated and unmyelinated fibers. A reduced serum activity of alpha-galactosidase A and a large amount of urinary globotriaosylceramide confirmed the diagnosis of Fabry's disease.

Adult↗

Epilepsy and intracranial meningiomas.

BACKGROUND: Only a few studies have reflected the incidence and causes of preoperative and postoperative seizures in meningiomas. This study concerned the incidence and types of preoperative epilepsy, and the predisposing factors for postoperative epilepsy in meningiomas. METHODS: Epilepsy occurred in 323 surgically treated intracranial meningiomas. The focus here is different types of seizures, tumor locations, onset of seizures and the histopathological features of the meningiomas. RESULTS: From analysis of 323 patients with intracranial meningiomas, aged 10 to 79, 98 (30.3%) were found to have different types of preoperative epilepsy; in 32 (32.7%) of them, the seizures persisted postoperatively. Among 225 patients without preoperative seizures, 39 (17.3%) developed postoperative seizures. Thus, a history of preoperative seizures is a significant index (p < 0.005) for predicting the occurrence of postoperative seizures. In a total of 71 patients with postoperative seizures, the precipitating factors in the first week were cerebral edema and hemorrhage at the surgical sites. In late postoperative seizures (onset beyond one week post-surgery), the main cause was tumor recurrence. Patients with sagittal and convexity meningiomas had a higher incidence of seizures. There is no relationship between the histopathological features of the tumor and the occurrence of epilepsy in meningiomas. CONCLUSIONS: There is a significant incidence of postoperative seizures in meningioma patients with a history of preoperative seizures. Surgical excision of tumor, absence of postoperative hemorrhage or edema and anticonvulsant therapy reduced the occurrence of postoperative seizures.

Adolescent↗