Biomedical subjects

H Guesmi

Publications and source records attributed to H Guesmi.

5 recordsLinked to original sources

PubMed2006

[Cerebral hydatid disease: imaging features].

Cerebral hytatid cysts (HC) are extremely rare, forming 2% of all intra cranial space occupying lesions even in counties where the disease is endemic. HC diagnosis is usually based on a pathognomonic computed tomography (CT) pattern. In order to assess the value of MR we reviewed the CT (n=25) and magnetic resonance (MR, n=4 including diffusion and proton magnetic resonance spectroscopy in 1) imaging of 25 patients with pathologically confirmed cerebral hydatid disease. 19 HC were seen in children under 16 years. All were supra tentorial with 22 in the middle cerebral artery territory. HC was solitary in 18 cases, unilocular in 23 and multi-vesicular in 2 with heavily calcified pericyst in 1. 2 cysts were intra ventricular and 1 intra aqueducal. The most typical features were well defined, smooth thin walled spherical or oval cystic lesions of CSF density and/or signal with considerable mass effect (20/25). Surrounding oedema with complete or incomplete rim enhancement was seen in 3 cases which were labelled as complicated and/or infected cysts. Although CT is diagnostic of hydatid disease in almost all cases (22/25), MRI including diffusion and spectroscopy precisely demonstrate location, number, cyst capsule, type of signal and enhancement and allows diagnosis of atypical or complicated HC and appears more helpful in surgical planning.

Adolescent↗

PubMed2005

Sb/Si(111) adsorption: hidden phase transitions behind Langmuir-like isotherms.

The experimental study of the thermodynamic and kinetic properties of the Sb/Si(111) interface reveals a surprising behavior: a 2D phase condensates when the Sb coverage increases, indicating strong attractive Sb-Sb interactions, whereas the isotherms present a quasi-Langmuir shape, suggesting that these interactions should be negligible. Ab initio calculations raise this contradiction: while the adsorption site evolves from ternary towards the on-top position with increasing coverage, the character of the Sb-Sb effective interactions changes from repulsive towards attractive, resulting in an almost constant average adsorption energy. A simple (Langmuir) thermodynamic behavior can then be the consequence of a surface phase transition.

Journal Article↗

PubMed2005

[Calcification of the cervical ligamentum flavum. Case report and review of the literature].

Calcification of the cervical ligamentum flavum is a rare entity observed exclusively in Japanese people. We report a new case in a 65-year-old man from Tunisia who presented with symptoms of cervical myelopathy with mild tetra paresis, sensory abnormalities and dysuria. Magnetic resonance imaging (MRI) showed a posterior compression of the spinal cord at C3-C4. CT-scan showed a calcification of the ligamentum flavum at level C3-C4, compressing the left postero-lateral aspect of the spinal cord. C3-C4 laminectomy was performed with removal of abnormal ligamentum flavum tissue. The postoperative course was uneventful and all symptoms resolved. Calcification of the cervical ligamentum flavum is a rare entity; the diagnosis is easy but the pathogenesis remains unclear. Literature regarding this pathology is reviewed.

Aged↗

PubMed2004

[Intradural and cervical primary malignant melanoma. Case report and review of the literature].

Primary malignant melanoma of the central nervous system is an uncommon localization, first reported by Hirsberg in 1906. Since then, to our knowledge, only 39 cases have been reported in the literature. We present a case of primary intradural extra-medullary melanoma which developed in a 51-Year-old man who complained of pain in the lower cervical spine, difficulties in micturition and sexual impotence. The diagnosis was suspected at the MRI which showed a lesion with a paramagnetic signal and was confirmed by the histological examination. The resection was complete and the course has been satisfactory after 19 months follow-up.

Cervical Vertebrae↗

PubMed1999

[Dysembryoplastic neuroepithelial tumors. Report of 8 cases including two with unusual localization].

OBJECTIVES: Dysembryoplastic neuroepithelial tumors (DNTs) are usually located within the supratentorial cortex. We present a series of eight cases of DNTs including two cases with an extracortical location, one in the caudate nucleus, the other one expanded in the lateral ventricule, septum and fornix. An origin from secondary germinal layers, as previously suggested, can explain these extracortical locations. MATERIAL AND METHODS: Of the eight patients, seven had partial epileptic seizures and one intracranial hypertension. All patients underwent clinical examination, a computed tomographic (CT) scan, a magnetic resonance imaging (MRI) and a surgical removal of the lesion with histological examination. RESULTS: Clinical examination was normal except in the case with intracranial hypertension where a bilateral papillary oedema was found. In seven cases the CT scan showed a hypodense lesion of pseudocystic appearance. All lesions were hypointense on T1-weighted and hyperintense on T2-weighted MRI. Contrast enhancement was observed in two cases. The lesion was intracortical in six cases and extracortical in the remaining two: one in the head of the caudate nucleus and one in the trigonoseptal region. Histological examination identified an appearance of DNT with a specific glioneuronal element in six cases. CONCLUSION: The diagnosis of DNT can be suspected before histological examination on radiological features, chiefly because the tumor is located in the supratentorial cortex. However, extracortical locations do exist, even if unusual. As DNTs are always benign, knowledge and accurate diagnosis of these atypical cases are mandatory in order to avoid useless and even deleterious additional treatments, such as radiotherapy.

Adolescent↗