Collagenase-1 and stromelysin distribution in fresh human herniated intervertebral disc: a possible link to the in vivo inflammatory reactions.

Chondrocytes may play an important role in the inflammatory reactions involving intervertebral discs: the role of metalloproteases (MMP) and the imbalance between proteases and their inhibitors seems to play a crucial role in the disc degenerative process. In the present study we have analysed the production of collagenase-1 and stromelysin in different parts of herniated intervertebral discs. Ten samples of herniated lumbar discs were obtained from adult patients operated on for primary microdiscectomy because of persistent radicular symptoms and subdivided into three samples: 1. The nearest to the nerve root in close contact with it, 2. the sample obtained from the intervertebral space, and 3. the sample obtained from the vertebral plates. The DNA content of each specimen was measured in order to obtain the best estimate of the cell content as well as to normalise the content of collagenase-1 and stromelysin found in the same tissues with respect to the number of cells. In 9 out of the 10 cases the DNA content was significantly higher in samples obtained from the intervertebral plates than in samples obtained near the nerve root or the intervertebral space. DNA content did not show any significant difference considering disc samples contiguous to the nerve root and samples obtained from the intervertebral space. The production of collagenase-1 did not show a specific pattern, being produced in similar quantities in the three disc compartments. The production of stromelysin was significantly lower in disc samples obtained from the intervertebral plates. In conclusion the results of the present study suggest firstly that in the herniated lumbar disc the reactivity and the production of pro-inflammatory agents is independent of DNA content, i.e. the cellularity of the sample, and secondly that activated cells in the intervertebral space and in the part of the disc in contact with the nerve root, even if scarce in number, are able to synthesise a proportionally higher quantity of MMP than the high-cellular disc fragments from the intervertebral plates, potentially playing a specific role in the inflammatory reactions.

Metalloproteases and intracranial vascular lesions.

Recent studies have suggested that metalloproteinases (MMP) might be involved in the pathogenesis of cerebral aneurysm formation and rupture and that elevated serum levels of MMP may effectively be considered as possible markers of cerebrovascular malformations. The present study was planned in order to verify if serum levels of MMPs may be the mirror of the MMP activity in the wall of intracranial aneurysms, reflecting the predisposition to aneurysm development and/or rupture. A series of 84 patients operated for intracranial cerebrovascular lesions (63 aneurysms and 21 arterovenous malformations (AVM)) and 20 controls entered the study. Among the 63 cases of intracranial aneurysms, nine were discovered before rupture, while 54 patients were included after subarachnoid hemorrhage (SAH). Using radioimmunoassay, plasma elastase levels were measured in all cases, while in 25 cases, when aneurysmectomy was possible, the activity of elastase and collagenase were measured in aneurysm samples. Mean plasma elastase level in patients bearing both an intracranial aneurysm or an intracranial AVM was significantly higher than in controls, while there was no significant difference between plasmatic level of elastase in patients with aneurysms when compared with patients bearing an intracranial AVM; there was no significant difference between mean elastase level in patients who suffered SAH and patients bearing an intracranial unruptured aneurysm. The activity of elastase and collagenase measured in the aneurysm wall were significantly higher in cases of ruptured than in unruptured aneurysms. The present results show that plasmatic level of elastase does not reflect the activity of MMP as measured in the aneurysm wall and that the patterns of MMP activities measured in the aneurysm wall differ considerably at different stages of SAH. This suggests that local rather than systemic changes in metalloproteases activity might be involved in cerebral aneurysm formation and rupture.

Effects of high-dose methylprednisolone on Na(+)-K+ ATPase and lipid peroxidation after experimental subarachnoid hemorrhage.

The production of oxygen-free radicals and their subsequent peroxidative action on membrane unsaturated fatty acids could be enhanced after subarachnoid hemorrhage. High-dose methylprednisolone (30 mg/Kg i.v.) treatment can antagonize acute SAH-induced brain hypoperfusion and protect the ultrastructural integrity of endothelial cell membranes. Experimental subarachnoid hemorrhage (SAH) was induced in anesthesized rats by slow injection of 0.3 ml of autologous arterial blood into cisterna magna. Tissue lipid peroxidation, quantified as thiobarbituric acid reactive material (TBAR) and Na(+)-K+ ATPase activity were assayed in three different rat brain areas (cerebral cortex, hippocampus and brain stem) of controls (without any surgical manipulation), sham-operated (0.3 ml. of mock CSF into cisterna magna) and after SAH induction, at 1 h, 6 h and 48 h. Na(+)-K+ ATPase activity decreased in the cerebral cortex at 1 h and 6 h and in brain stem at 1 h after SAH, while the same enzymatic activity was unchanged in the hippocampus. High-dose methyl-prednisolone treatment (started immediately after SAH induction) enhanced the Na(+)-K+ ATPase activity until control levels. There was no significant difference in lipid peroxide content between sham-operated and hemorrhagic animals; however, the injection itself induces a transient increase of TBAR (1 h after injection) and methylprednisolone treatment decreases the products of lipid peroxidation in all brain areas.

Growing fractures: an unusual complication of head injuries in pediatric patients.

Authors analyze three cases of growing fractures they observed in infants under the age of one year. It is noticeable that in two cases, even if the lesion was already present when babies underwent the first procedure, no specific treatment was adopted, thus resulting in a progressive enlargement of the extracranial mass. Surgical treatment must be performed quickly after the diagnosis of growing fracture is done due to the necessity of an early repair of the bone defect to avoid the eventual onset of neurological deficits since they are not reversible.

Postoperative scars and recurrent disk herniation: clinical, neuroradiological, and surgical findings.

Authors present 36 patients with recurrent sciatica or low-back pain after lumbar disk operation. All patients were submitted to clinical and instrumental devices. CT-scan was performed in 36 patients, 12 underwent myelography and 4 EMG. Authors verified reliability of clinical and instrumental devices on the basis of surgical results. We believe that myelo-CT is actually the first choice investigation in the neuroradiological ones. In the near future MRI will take its place in investigating spinal pathology.

Spontaneous cerebellar hemorrhage.

Spontaneous cerebellar hemorrhage was rarely diagnosed in the past and therefore thought to be infrequent but after the introduction of CT scanning has been more commonly diagnosed. A series of 28 cases of spontaneous cerebellar hemorrhage is analyzed concluding that the radiological and clinical aspects should be considered, instead of adopting the diameter as surgical indicator. An accurate monitoring of the patient's clinical status is very important since its worsening is an absolute indication for surgery independently of the size of hematoma.

Lumbar canal stenosis: results in 40 patients surgically treated.

Authors present the clinical and neuroradiological characteristics of 40 patients treated for lumbar canal stenosis during a 10 years experience. The usefulness of computed tomography in comparison with myelography and plain X-rays of the spine is stressed. The surgical treatment was wide laminectomy involving one or more levels (two to four) plus an eventual foraminotomy but without discectomy. All patients were followed up and in 85% of cases a reduction of clinical symptoms was observed. Residual symptoms were also present in some of the improved patients, they generally accepted them without great dismay.

Spinal epidural hematoma without vertebral fracture or dislocation. Report of two cases and review of the literature.

Authors present 2 cases of spinal epidural hematoma without vertebral fracture or dislocation and review the literature. 169 fully described cases were found in literature and have been analyzed. Data confirm our opinion that the results of an early diagnosis is a better prognosis. The severity of preoperative neurological status is another important factor for the post-operative recovery, any way the absence of neurological function before the operation is not necessarily leading to a poor prognosis. Prognosis is usually poor when after the removal of the hematoma the dural pulsation is absent.

Complications following surgery for severe head injury.

The number of patients who survive, after severe head injuries, is becoming more and more consistent due to the remarkable progress made in intensive care and rehabilitation units. The aim of this study is to identify, in addition to direct structural damage, medical and neurological problems and describe their frequency within a group of patients with severe head injuries. Neurologic, metabolic, gastrointestinal, genitourinary, respiratory, cardiovascular, cutaneous and endocrinologic problems were more frequently found. All these problems, which were identified during the first month after head injury, are discussed regarding their clinical significance, therapeutic approach, and morbidity.

[Post-traumatic hydrocephalus]. / L'idrocefalo postraumatico.

Post-traumatic hydrocephalus is a complication of cranio-cerebral injuries and can manifest itself through different clinical syndromes. These include obtunding, a tetrad composed of psychomotory delay, memory loss, motility disturbances and sphincter incompetence, and unusual symptoms which comprehend emotional disturbances. Intracranial pressure monitoring, lombo-ventricular infusion test, in addition to neuroradiologic exams, are necessary in order to decide wether or not to derivate a post-traumatic hydrocephalus; neuropsychologic tests complete these investigational methods. The post-traumatic hydrocephalus bearer patient's recovery is always problematic when an important parenchimal damage exists. When a NPH (normal pressure hydrocephalus) is found the shunting operation is always indicated. However it is difficult to take a decision when the patient has a normal liquoral pressure but is too wounded to show a NPH or when he has an atypical clinical feature.