Tehran University Medical Journal

---

Background: Chronic Subdural Hematoma (CSDH) is one of the most common challenges of neurosurgeons. Most predominant among the elderly, the incidence increases incrementally with age and might lead to permanent severe complications. The aim of this study is to outline the symptoms and signs and to compare the outcomes and complications among two groups of patients who underwent two different surgical procedures.
Methods: In a cross-sectional and descriptive-analytical study performed on 125 patients with CSDH from 2000 to 2005. Computed tomography scan was used for diagnostic imaging in all cases and magnetic resonance imaging was also obtained for six patients. In one center, group 1, which included 82 patients, underwent surgery with a single burr hole and closed drainage, and, at another center, group 2, which included 43 patients, was treated with a method using two burr holes and close drainage.
Results: Of the 125 patients, 102 were male and 23 were female. The mean age of patients was 65.79±16.41 years. The most common symptoms were weakness in extremities (78.4%), headache (72.8%) and decreased level of consciousness (24%), respectively. At presentation, 88 (70.4%) of the patients had several symptoms and 37 (29.6%) had only one symptom. A history of mild head trauma, such as falling, was observed in 83 (68%) of the patients. The interval between head trauma and the onset of symptoms ranged from 10 to 120 days (mean: 46 days). Hematoma recurred in five cases from group 1, whereas two cases from group 2 had recurrence of hematoma. Postoperative epidural hematoma developed in one case from group 2 and tension pneumocephalus also occurred in one group 2 patients.

Conclusion: As a treatment for CSDH, the single burr hole method was significantly better than the two burr hole method.

---

Background: Epidural fibrosis (EF) is a part of normal physiological tissue response to laminectomy and it may be an important cause of failed back surgery syndrome (FBSS). The objective of this study was to evaluate the effect of using gel foam after laminectomy on reduction of epidural fibrosis.

Methods: In this prospective study forty five rabbits were recruited. The cases undergone bilateral laminectomy at the L4 and L5 lumbar levels under an approved surgical protocol. After eight weeks the rabbits were sacrificed and the spinal segments from L3 to L6 were removed en bloc. The amount of scar tissue at the laminectomy defect was scored. The fibroblast and inflammatory cell counts were also compared between two groups.

Results: In this study 55% of group A rabbits were placed in grade 0 or I, grade II fibrosis could be detected in the remaining 45%. In group B these amounts were 73.7% and 26.3% respectively, which no significant statistical difference could be detected between two arms (p=0.189). Comparing the quantity of fibroblasts 40% of group A rabbits were recognized as grade I and the other 60% as grade II and grade I fibrosis was discovered in 42.1% of group B rabbits, while other 57.9% suffered from grade II fibrosis, again no significant statistical difference could be attributed between two arms (p=0.576). Also comparing inflammatory cell counts detected in the specimens no significant statistical difference could be detected either (p=0.465).

Conclusion: According to this study using gel foam during the laminectomy surgery in rabbits has no obvious effect in reducing post laminectomy epidural fibrosis after eight weeks of follow-up.

---

Background: Pedicular screws are currently the gold standard of internal fixation of spinal column. Pedicular screws have their own complications, however the surgeon should be aware of morphometery of pedicles, as well as the anatomy of surrounding neural structures to minimize these risks. No national study has ever examined the physical characteristics of lumbar pedicles and this study is unique for this purpose.Methods: This study covers the patients undergoing lumbar spinal CT-scanning due to variable causes. 25 vertebrae were selected in either gender, 18 years or older and EFilm computer software was employed to measure different diameters of pedicle and the results were analyzed with p≤0.05 regarded as significant.Results: L5 pedicle was the widest (16.8 mm), while L1 was the narrowest (8.25 mm).this figure was 8.82, 10.48 and 12.86 mm for L2, L3, L4 respectively. Longitudinal depth of pedicle was 47.98, 48.68, 50.42, 48.32 and 47.8 mm for L1, L2, L3, L4, L5 respectively.Statistically significant differences were found between some dimensions detected in our study and similar studies. Conclusions: The advantages of pedicular screws and rods to stabilize spinal column are well known. To avoid neurological complications, an understanding of anatomy and pedicle orientation is mandatory. The shape and diameters of pedicles are different base on races. Some differences were found in our study regarding pedicle dimensions.

---

Background: Osteochondroma is a common tumor of the skeletal bone and is a common benign tumor of the bone constitutes 10-15% of all and 20-50% of the benign bone tumors. The lesion is an exophytic bony protrusion covered by a cartilaginous cap. It is most commonly found in long bones, and especially at the epiphysis. Nearly 40% of cases are seen around the knee joint. Osteochondroma rarely affect skull bones, occurrence of an intracranial osteochondroma is a rarity in the neurosurgical literature and only anecdotal reports are available in the literature. To our knowledge no case arising from foramen magnum has been reported.
Case presentation: We present a 73 years old male with gait problem and limb paresis. Imaging investigation showed a bony mass in the foramen magnum, that compresses neural elements. The patient also complained of persistent headache in his occipitocervical region. There was no history of previous trauma. The patient underwent surgery and histopathological examination confirmed the lesion to be osteochondroma.
Conclusion: Many types of lesion may be seen in foramen magnum area, and in differential diagnosis of such lesion rare, osseous tumors such as osteochondroma should be considered.