Early deep vein thrombosis: incidence in Asian stroke patients.

INTRODUCTION: Deep venous thrombosis (DVT) is thought to be less common in Asians than in the Caucasian population. The incidence of asymptomatic DVT in high-risk groups in the Asian population has not been well studied. While DVT incidence among Caucasian stroke patients has been extensively studied and the need for prophylaxis established, the lack of data in Asian patients leaves physicians with no firm basis for adopting prophylactic protocols in the local population. Our aim was to prospectively establish the incidence of early DVT in immobilised stroke patients in a heterogenous Asian population. MATERIALS AND METHODS: We screened 44 patients with significant hemiplegia from acute stroke. Doppler ultrasound, the currently accepted method of investigation for DVT, was used to study patients on admission and at 1 week post-stroke. While there was no standard prophylactic regime in use, none of the patients received heparin and only 2 were given compression stockings. RESULTS: The incidence of DVT at 1 week was 2.4%. Review at 1 month detected another patient with DVT, bringing the overall incidence at 1 month to 4.8%. This is lower than in Caucasian populations, but is similar to another local study on a different group of high-risk patients. CONCLUSION: The low incidence of early DVT in hospitalised stroke patients of Asian ethnicity does not justify routine screening for this population. Further research to validate this should ideally include a comparison test for DVT as ultrasound may have inherently lower sensitivity in an asymptomatic population.

Multivoxel MR spectroscopic imaging--distinguishing intracranial tumours from non-neoplastic disease.

INTRODUCTION: Multi-voxel MR spectroscopic imaging (MRSI) provides chemical metabolite information that can supplement conventional MR imaging in the study of intracranial neoplasia. Our purpose was to use a robust semi-automated spectroscopic analysis to distinguish intracranial tumours from non-neoplastic disease. MATERIALS AND METHODS: Twenty intracranial tumours and 15 patients with non-neoplastic disease confirmed on histological examination or serial neuroimaging were studied with 2-dimensional MRSI using point-resolved spectroscopic (PRESS) imaging localisation. Using semi-automated post-processing software, spectra were analysed for peak heights of choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate (Lac) and lipid (Lip). Normalised Cho (nCho) ratios, computed by dividing maximum Cho in the lesion by the normal-appearing brain, were compared between intracranial tumours and non-neoplastic disease. RESULTS: Meningiomas displayed homogeneously elevated Cho. Malignant tumours, especially large glioblastoma multiforme, displayed inhomogeneity of metabolites within the tumour. All tumours had elevation of nCho >1 (mean 1.91 +/- 0.65), and non-neoplastic diseases had tumour nCho <1 (mean 0.91 +/- 0.46), which was significantly lower (P <0.05). Two patients with non-neoplastic lesions, one with subacute cerebral infarction and the other with cryptococcoma, had elevated Cho compared to normal tissue (false positive rate 13%). CONCLUSION: Using semi-automated MRSI method, a simplified normalised Cho algorithm provides a method to distinguish intracranial tumours from non-neoplastic disease.

Solitary fibrous tumor of the hypoglossal nerve.

SUMMARY: We report a case of solitary fibrous tumor (SFT) causing isolated hypoglossal nerve palsy. The neuroimaging appearance of the tumor was indistinguishable from that of schwannoma or meningioma. Immunohistochemical tests demonstrated strong reactivity for CD34 but an absence of staining for S100 and epithelial membrane antigen; this profile is indicative of an SFT. SFTs are mesenchymal tumors that can affect the dura-covered segments of cranial nerves. They may be considered in the differential diagnosis of an isolated cranial nerve palsy.