Biomedical subjects
Publications and source records attributed to T Rizk.
We report the case of a patient with NF-1 who presented with gross elephantiasis neuromatosa of her right leg. Prior to plastic surgery, Magnetic Resonance Imaging and Angiography (MRI and MRA) were performed to provide a detailed assessment of the extension as well as the vascular and muscular involvement of the neurofibroma.
INTRODUCTION: Megalencephalic leukoencephalopathy with subcortical cysts is a rare disease with autosomal recessive inheritance. MATERIALS AND METHODS: Two brothers born from a consanguineous marriage, presenting with the phenotype of the disease, their parents, brothers and sisters were examined. Magnetic resonance imaging of the brain was performed for the two patients. Sequence analysis of MLC1 (GenBank mRNA accession no. NM_OI5166) was performed for the patients using intronic primers. PCR restriction fragment length polymorphism analysis was done in patients, their parents and in 100 Lebanese controls in order to exclude gene polymorphism. RESULTS: The clinical features were characteristic of the disease, consisting of an early-onset macrocephaly followed by slowly progressive ataxia, pyramidal tract involvement and epileptic seizures. In one patient, the clinical manifestations were aggravated by a trivial brain trauma. In his brother and in one female cousin, a status epilepticus was precipitated by a febrile syndrome. The diffuse cerebral white matter lesions and the subcortical temporo-polar and frontal cysts, best seen on MRI, allowed making the diagnosis. Molecular genetics revealed a new mutation involving the MLC1 gene (263G-->T, exon 3). As a consequence, it affects the second transmembrane domain predict (G88V) of the MLC protein (protein sequence NP_055981). The mutation was confirmed by PCR restriction fragment length polymorphism analysis. CONCLUSION: Megalencephalic leucoencephalopathy with subcortical cysts may be individualized on clinical and radiological basis and confirmed by molecular genetics. In this Lebanese family, a new mutation of the MLC1 gene is reported.
Lipid particles (liposomes and lipid-coated microbubbles) are currently studied as vectors for drug delivery to the central nervous system. The visualization of these particles is usually based on their labeling with a lipophilic fluorescent dye (3,3'-dioctadecycloxacarbocyanine perchlorate) or staining with Oil Red O. The purpose of this article was to highlight the difficulties and pitfalls encountered with the use of these techniques in the detection of lipid particles in neural cell cultures and in brain tissue. In vitro and in vivo studies were conducted on different neural cell cultures (rat and human tumors, microglial cells) and animal models of brain lesion (lipopolysaccharide and quinolinic acid-induced lesion, induced brain tumor). The cells or brain slices were observed with optical microscopy after staining with Oil Red O, fluorescent microscopy, or scanning electron microscopy. Intra and extracytoplasmic lipid particles (stained with Oil Red O or autofluorescent or visualized by scanning electron microscopy) were naturally found in the cells and tissues studied. Intracytoplasmic lipid microparticles were present in tumoral and microglial cells. These lipid microparticles were also observed with some extracytoplasmic lipid droplets in the induced brain lesions. These images could be misinterpreted as lipid vectors if the cells or animals would have been treated with such a vector.
We report four cases of central neurocytoma we operated on at our institution, between 1994 and 2002. This uncommon lesion occurred in young patients, was located in the lateral ventricules and was revealed by signs of intracranial hypertension. The tumor was totally removed in three cases and subtotally in one. Immunohistochemistry provided useful information to distinguish neurocytoma from other nervous system tumors. Prognosis was excellent in two patients. One patient developed tumor recurrence seven years after surgery, without any progression on further follow up evaluation. In the last patient, the tumor showed a more aggressive progression requiring the adjunction of radiosurgery.
A previously non-epileptic 17-year-old patient presented with 2 generalized epileptic seizures, which occurred at 6 months of interval, following the oral intake of 200-250 mg of tramadol. Urine analysis showed only the product and its metabolites. Epileptic seizures induced by tramadol and high risk factors are described and discussed.
BACKGROUND AND PURPOSE: Anterior approach for cervical radiculopathy is a frequently performed operation in neurosurgery. The goal of this study is to evaluate the short and long-term results of anterior cervical discectomy with and without fusion. METHODS: Between 1984 and 1999, we operated on 101 patients presenting with cervical radiculopathy by an anterior approach. The operation consisted of one-level discectomy in 74 cases, two-level discectomy in 25 cases and three-level discectomy in 2 cases. Eighty-four out of 130 levels operated on were fused. Evaluation was done following a consultation with dynamic cervical X-rays and by telephone using a detailed questionnaire. Follow-up was obtained in 91 cases with a mean of 54 months in fused patients, and a mean of 45 months in the non-fused patients. RESULTS: Post-operative results were good in 95% in the 2 groups of patients. We encountered 8 complications, all in patients operated with bone graft placement. Five patients were reoperated on at an adjacent level, 4 being fused previously. CONCLUSIONS: The 2 techniques are comparable in term of goods results at short and long-term follow-up. Anterior discectomy without fusion is associated with less complications, less post-operative pain, and less operative time cost.
We report 4 cases of toxic leucoencephalopathy after heroin inhalation. The clinical features, which usually occur some days or even longer after the last heroin consumption, are dominated by a cerebellar syndrome. The cerebellar hemispheres are almost always affected; the cerebral hemispheres, the cerebellar peduncles and the pyramidal tract may be affected. Vacuolar demyelination is the morphological substract of the lesions, which are symmmetrical, not contrast enhancing, hypodense on CT scan and hyperintense on T2-weighted MRI. The pathophysiology is unknown and seems different from post-anoxic leucoencephalopathy. The disease is usually progressive leading sometimes to death, but some cases show slow recovery.
OBJECTIVE: Establish the risk factors for infection following missile head injuries (MHI). METHODS: Between 1975 and 1990, 500 cases of MHI were admitted, with only 272 responding to inclusion criteria. After initial evaluation including CT scan for 177 patients, all underwent craniectomy with debridement and duroplasty. A retrospective study was undertaken in order to identify the risk factors that increase the infection rate. RESULTS: The global infection rate was 11.39%. Among the studied factors, those increasing the infection rate were: coma on admission (17.6% vs 7.6%), penetrating wounds (12.93% vs 7% for tangential wounds), intracerebral trajectory length over 6 cm (18.42% vs 6.32%), air sinuses effraction (25.8% vs 9.54%), a surgical delay over 72 hours (41.6% vs 10.6%), inadequate duroplasty (28% vs 7.33%), cerebrospinal fluid (CSF) fistulae (58.62% vs 5.76%). The presence of postoperative bone fragments did not increase the infection rate (11.4% vs 11.2%). DISCUSSION AND CONCLUSION: Adequate duroplasty and aggressive treatment of CSF fistulae decrease the infection rate. There is no need to reoperate on residual bone fragments after adequate debridment. A delay of 24 to 48 hours should be considered, to facilitate the procedure without increasing the infection risk.
The authors report a case of intraspinal neurenteric cyst in a 22-month-old child, who presented with acute paraplegia following a vesicourethrogram. Despite 8 days' delay in surgical decompression, he made a complete neurological recovery. Neurenteric cysts are rare congenital lesions of the spinal canal lined with an epithelium of endodermal origin. They are usually located at the cervicothoracic junction and present with progressive mild to moderate signs of myelopathy. This is a unique case in regard both to its clinical presentation and to the excellent outcome after 8 days of complete paraplegia.
Recent studies have suggested that 5-HT may modulate thalamocortical development in somatosensory cortex (S-I) of rats and mice, and that the 5-HT(1B) receptor may play a critical role in this process. Analysis of CO-stained sections through lamina IV of S-I in perinatal and adult 5-HT(1B) knockout mice revealed a normal vibrissae-related pattern, indicating that activation of the 5-HT(1B) receptor is not necessary for the normal development of the vibrissae representation in S-I.
Congenital brain tumors are very rare; their incidence is estimated at 0.34 per million live births. We report a case of congenital gliosarcoma in a neonate conceived by in vitro fertilization (IVF). One other case of brain tumor (medulloblastoma) is reported in a child born after assisted conception. Whether these tumors are causally related to the IVF remains obscure.
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A case of adrenoleukodystrophy in a 9-year old boy revealed by a predominant frontal syndrome is reported. Brain MRI showed an unusual pseudo-tumoral frontal lesion. The diagnosis was confirmed by increased plasma levels of very long chain fatty acids. His young brother had an isolated adrenal insufficiency with normal brain MRI. The frontal predominance of the lesion and the clinical polymorphism of the disease in this family are discussed.
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Temporary arterial occlusion (TAO) is commonly used in the surgery of intracranial giant aneurysms. Its usefulness and safety in the surgical management of all cases of aneurysms remains to be proved. We report a series of 54 patients operated on for an intracranial aneurysm with the use of TAO. Among the 27 patients, admitted before the 4th day following post subarachnoid hemorrhage with I or II on WFNS score clinically, 24 had early aneurysm surgery. The size of the aneurysm was small in 16 cases, medium in 22, large in 13 and giant in 3 cases. The protocol proposed by Batjer in 1988 for large and giant aneurysms (etomidate, normotention and hypervolemia) was used without any electrophysiological monitoring. All patients underwent a post-operative cerebral CT scan to evaluate the incidence of a cerebral ischemia. Serial transcranial doppler was used to evaluate the severity of vasospasm. Clinical results were assessed using the GOS. TAO was elective in 51 patients and done after peroperative aneurysm rupture in 3 patients. The duration of TAO was less than 5 mn in 25 patients, between 5 and 10 min in 12, between 10 and 15 in 11, between 15 and 20 in 5 and more than 20 min in one patient. The last one developed a reversible neurological deficit secondary to ischemia attribuated to TAO. Intracranial aneurysm peroperative rupture was noted in 3 patients, clinical vasospam in 13 patients. These results allow us to recommend the routine use of TAO in the surgery of intracranial aneurysm. When application time is limited and cerebral protection used, TAO is safe. It decreases the risk of intraoperative rupture from a 18% rate in literature to 4.2% in our present experience and the risk of symptomatic vasospasm is not increased.
We report the surgical results in a series of 47 patients with cerebral cavernous malformation who had undergone surgery between 1973 and 1994, with a follow up ranging from 12 months to 24 years (mean: 4 years). They were divided in there groups according to their initial clinical presentation: epilepsy (31 cases), hemorrhage (11 cases) and neurological deficit (5 cases). Surgery consisted of cavernoma resection only (11 cases) or its extension to surrounding gliotic tissue (36 cases). Results are satisfactory: no surgical mortality, low morbidity (4 cases), no recurrent hemorrhage, seizures disappearance with anticonvulsant therapy stop (4 cases) or alleviation (20 cases). Only one patient died far from surgery (6 months) consequently to his initial bleeding, while all the others lead a normal active life. The therapeutic management, compared to the literature, pleads in favour of intentionally surgical attitude and gliotic tissue removal as often as reasonably possible.
We report a case of growing fracture of the orbital roof in a 5-year-old child. The presenting sign was a pulsatile orbital mass. This child had a history of a minor head injury with orbital impact 2 years ago. Cerebral CT scan revealed a diastatic fracture of the right orbital roof. On MRI a leptomeningeal cyst extending in the orbital cavity was shown. Frontal craniotomy with direct repair of the dural and bone defects was performed. The outcome was excellent. In the literature the exact pathophysiology of the growing fractures is still debated but a dural laceration along the fracture line is noted in all the cases. They are mostly located in the cranial convexity, and rarely affect the skull base. Only 5 similar cases were found in the relevant literature. Growing fracture of the orbital roof should be suspected if ocular symptoms appears in childs who have sustained a head injury several months or years ago.
We report a case of giant cephalhaematoma in a 17-year-old boy with Ehlers-Danlos syndrome. This haematoma occurred after a minor head injury. It increased in size, immediately after needle aspiration and was responsible for considerable blood loss. Possible physiopathological mechanisms and treatment modalities are discussed.