Trace minerals in experimental subarachnoid haemorrhage: zinc, copper and manganese levels in rat brain tissue, blood and urine.

BACKGROUND: Zinc (Zn), copper (Cu) and manganese (Mn) are involved in regulatory systems in the cell. Their role in neuromodulator activities and redox reactions has been implicated in the pathogenesis of neurological disorders. The aim of this study was to determine changes of Zn, Cu and Mn levels in brain tissue, blood and urine after experimental subarachnoid haemorrhage (SAH). The possible importance of these trace minerals on the pathogenesis of SAH was also discussed. METHOD: Rats were divided into three groups; namely a SAH group, a control group and a normal group. Blood samples in the SAH group and normal saline in the control group were injected into the cisterna magna. No surgical procedures were performed on the normal group. Brain tissue, blood and urine samples were measured for trace minerals by atomic absorption spectrophotometry. Measurements were taken on days 3, 7 and 10 after the onset in the control and SAH groups, and on the first day in the normal group. FINDINGS: The reduced blood Zn levels and increased Zn urine loss observed in the SAH group were conspicuously significant. Furthermore, significant changes in Mn levels were also seen at different stages of the trial in the SAH group. However, differences found in the Cu levels between the groups were not significant enough to explain the results. INTERPRETATION: These results suggest that the low blood Zn levels seen throughout the stages, the low brain tissue Mn levels seen during the latter part of the trial, and the low blood Mn levels observed during the early stages, may all be related to an increased risk in experimental SAH in rats. These differences may have possible role in the pathogenesis of SAH, and further investigations into the reduced blood Mn levels observed during the study may lead to new insight into the treatment of SAH.

Spinal toxoplasmic arachnoiditis associated with osteoid formation: a rare presentation of toxoplasmosis.

STUDY DESIGN: An extremely rare presentation of an isolated spinal toxoplasmic arachnoiditis is described. OBJECTIVE: To draw attention to the fact that spinal arachnoid membranes may be a potential reservoir for Toxoplasma gondii. SUMMARY OF BACKGROUND DATA: Central nervous system toxoplasmosis is a common manifestation in patients who are immunodeficient. Reports on the spinal toxoplasmosis are rare and focused on spinal cord involvement. METHODS: An adult patient presented with symptoms of spastic paraparesis that had begun 13 years before admission. Thoracic spinal magnetic resonance imaging showed small lesions in posterior subarachnoid space at Th7-Th8. A Th7-Th8 laminectomy was performed. Intradural-extramedullary lesions were excised. RESULTS: Clinical, immunologic, and pathologic examinations showed adhesive spinal arachnoiditis associated with osteoid formation caused by past toxoplasmic infection. There was no impairment of the immunologic defense system. CONCLUSION: Where no causative factor is found in serious spinal adhesive arachnoiditis, the possibility of spinal toxoplasmosis should also be investigated.

Indications of Philadelphia collar in the treatment of upper cervical injuries.

The principles of the management of upper cervical injuries remain controversial. The specific anatomical conditions render upper cervical injuries more problematic than lower cervical injuries. Here we present and discuss our experiences with upper cervical injury, comparing them with other treatment modalities. The 24 patients admitted to our department with upper cervical injury were treated surgically or conservatively according to their neurological and radiological status. Five patients were treated surgically due to neurological abnormality associated with compression to neural structures observed in computerized tomography/magnetic resonance imaging (CT/MRI). Patients with no neural compression were managed conservatively, with the Philadelphia collar. All patients showed stable fracture healing and experienced no additional clinical disability on follow-up after a minimum of 3 months, except one who died due to cardiac and respiratory failure. Regardless of the type of injury, indication for surgery in many cases of upper cervical injury is neurological abnormality associated with radiologically observed neural compression. It is our belief that, in the absence of both neurological abnormality and compression to neural structures observed in CT/MRI, treatment with the Philadelphia collar alone is safe, cost-effective and easily applicable for many cases of upper cervical injury.

Injury caused by deeply penetrating knife blade lodged in infratemporal fossa.

Knife-inflicted, deeply penetrating head and neck trauma is an uncommon life-threatening injury and a challenging problem. An examination of the neurovascular and systemic physical status is a first requirement and the decision as to which approach to adopt for the removal of the blade is of critical importance. Here we report a rare case of a pre-auricular stab wound with the knife blade deeply lodged in the extracranial infratemporal fossa. Radiological investigations showed that the knife blade had entered from the temporomandibular joint and become lodged through the anterior margin of foremen magnum below the petrosal bone. Minimal left vocal cord paresis, left palatal weakness and a slight deviation of the tongue towards the left side were observed. The other neurological and systemic physical evaluations were normal. Simple withdrawal of the blade in the operating room did not cause serious neurovascular injury. Here we discuss and compare the expanded exposure of anatomical structures for blade removal and simple withdrawal in similar injuries.

Cerebral blood flow alterations in progressive communicating hydrocephalus: transcranial Doppler ultrasonography assessment in an experimental model.

OBJECT: In many cases communicating hydrocephalus is the result of impairments in cerebrospinal fluid absorption in the arachnoid villi at the cranial convexity. Reported methods of creating experimental hydrocephalus have not sought to produce an arachnoidal adhesion in the cranial convexity. In this study the authors investigate alterations in cerebral blood flow (CBF) in experimental communicating hydrocephalus induced by the injection of kaolin into the subarachnoid space at the convexity in neonatal rats. METHODS: In neonatal rats, kaolin was injected into the subarachnoid space at the cranial convexity. Assessment of CBF alterations was performed using transcranial Doppler ultrasonography preinjection and at 10 days, 4 weeks, and 8 weeks postinjection. Light microscopy examination was also performed at 4 weeks and 8 weeks postinjection. Conspicuous lateral ventricle enlargements of different dimensions were observed in kaolin-injected rats at 4 to 8 weeks postinjection. The third and fourth ventricles were dilated to a lesser extent. Resistance to CBF and increased mean CBF velocity were apparent 8 weeks after kaolin injection. Further, destruction and even loss of ependymal layers were more prominent at the chronic stage. CONCLUSIONS: The present model may be considered a progressive communicating hydrocephalus because of marked changes in blood flow dynamics and destruction of the ependymal layer at the chronic stage.

Non-hindbrain-related syringomyelia. Obstruction of the subarachnoid space and the central canal in rats. An experimental study.

BACKGROUND: The aim is to determine the mechanism of non-hindbrain-related syringomyelia in experimental models. The effects of obstruction of central canal and subarachnoid space on occurrence of cavities were discussed. METHODS: 31 Sprague-Dawley rats were used with eight (Group D) as a control. In 10 rats (Group A) 1.5 microl kaolin was microinjected into the dorsal columns and central gray matter of the spinal cord at the level of Th6-10. In 10 rats (Group B) 0.1 cc kaolin was injected into the subarachnoid space at the same level. In 3 rats (Group C), 1.5 microl kaolin was administered into both dorsal midline of the spinal cord and the subarachnoid space. RESULTS: In Group A, histological examination revealed cystic cavity and dilatation of the central canal in five rats; denuded ependymal line and multicystic formations in ependymal and periependymal areas in seven rats. In Group B, denuded ependymal line in three rats and microcystic formations in ependymal and periependymal areas in four rats were revealed. In Group C, there were microcystic formations in two rats and syrinx cavity in one rat. CONCLUSIONS: Developments leading to occurrence of cavities are focused on the central canal in all groups. These models indicate that the CSF-flow is from the subarachnoid space to the central canal leading to changes of cavities. In cases of obstruction of the subarachnoid space or the central canal, the occurrence of syrinx cavity initially is due to increased CSF (cerebrospinal fluid) pressure in the central canal. Flow changes in spinal cord is indicated by this study.