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M N Pamir

Publications and source records attributed to M N Pamir.

At least 37 records · Page 2Linked to original sources
PubMed2000

Treatment of the subarachnoid-pleural fistula. Case report.

Subarachnoid-pleural fistula is a rare type of cerebrospinal fluid (CSF) fistula, and there are only several cases reported in the literature. The authors describe a 65-year-old male patient in whom a diagnosis of T7-8 disc herniation had been made. He underwent surgery via a right lateral extracavitary approach. Postoperatively he developed progressive respiratory distress and headache. A chest x-ray film revealed a pleural effusion, and computerized tomography (CT) myelography demonstrated a subarachnoidal-pleural fistula at the level at which the herniated disc had been removed. The patient had been managed via a CSF drainage system and a chest tube. He was discharged after relief of symptoms was attained. Subarachnoid-pleural fistulas can be secondary to traumatic injury and surgery, or they can be spontaneous. Patients present with rapidly filling pleural effusion and headache. A diagnosis can be established using CT myelography or myeloscintigraphy. Treatment is conservative, with the placement of a chest tube and insertion of a CSF drainage catheter, and surgical repair should be considered only if the conservative therapy fails.

Aged↗
PubMed2000

Serial MRI and MRS studies with unusual findings in Rasmussen's encephalitis.

Rasmussen's syndrome is characterized by intractable seizures and progressive neuropsychiatric deterioration secondary to unilateral cortical inflammation and tissue destruction. Diagnosis of Rasmussen's syndrome in the early phase depends mainly on the clinical features. Neuroimaging and histopathologic examinations may not be specific during this period. We report a case of Rasmussen's syndrome followed by serial MRI and magnetic resonance spectroscopy (MRS) studies over a 3- to 16-month period. A healthy 6-year-old boy presented with focal motor seizures. An MRI study demonstrated prominent enlargement and T2 hyperintensity of the left mesial temporal lobe and perisylvian region. This early finding evolved to volume loss and later progressive atrophy of the ipsilateral hemisphere when epilepsia partialis continua occurred. Being aware of those early MRI features in a patent with increasing frequency of focal motor seizures should suggest Rasmussen's syndrome. In addition, we found prominently increased myoinositol concentration in atrophic cortex which might reflect increased gliosis in the late period of the disease.

Biopsy↗
PubMed2000

Expression of structural proteins and angiogenic factors in cerebrovascular anomalies.

OBJECTIVE: The goal of this study was to describe the expression of matrix proteins and angiogenic factors in cerebrovascular malformations. METHODS: Forty-six cerebrovascular malformations were immunohistochemically investigated with a battery of staining for five structural proteins (collagen IV, collagen III, smooth muscle actin, fibronectin, and laminin), and three angiogenic factors (vascular endothelial growth factor [VEGF], basic fibroblast growth factor [bFGF], and transforming growth factor alpha [TGFalpha]). The lesions consisted of 34 arteriovenous malformations (AVMs), 10 cavernous malformations (CMs), and 2 venous angiomas. Expression intensity for each histological layer in the abnormal vessel wall was graded and compared. RESULTS: AVM endothelia and subendothelia expressed more laminin and collagen IV than the same layers of CMs. Conversely, CMs expressed more fibronectin than AVMs. CM endothelia exhibited more prominent staining for smooth muscle actin than AVM endothelia. AVMs and CMs expressed VEGF in the endothelium and subendothelium, and TGFalpha in endothelial and perivascular layers. However, unlike AVMs, CMs expressed bFGF in the endothelium as well. The brain tissue intermingled within AVMs also expressed growth factors. Modified glial cells in the brain tissue adjacent to CMs expressed bFGF and TGFalpha, but not VEGF. Venous angiomas did not express the studied growth factors and mainly consisted of structural proteins of angiogenically mature tissue. CONCLUSION: Expression characteristics of structural proteins reveal that AVMs and CMs have different immunohistological properties. This study provides strong confirmation of previous findings of VEGF and bFGF immunoexpression in AVMs and CMs. It adds new information on TGFalpha expression in these malformations and on expression of the angiogenic factors in venous angiomas.

Actins↗
PubMed1999

Findings and outcome of revision lumbar disc surgery.

One hundred fourteen patients (64 men, 50 women) with prior lumbar disc surgery underwent a reexploration for intractable back and/or leg pain. The finding in revision surgery included disc herniation in 89 cases (78%), epidural fibrosis in 14 cases (12.2%), adhesive arachnoiditis in 4 cases (3.5%), isolated lateral spinal stenosis in 3 cases (2.6%), and iatrogenic instability in 4 cases (3.5%). Review of operative reports of patients who underwent a first operation in our institute revealed that seven cases (12.5%) had a second laminotomy without a discectomy in addition to the previous laminotomy and discectomy performed in the same session. Fifty-six of the patients with disc hemiation in revision surgery had a true recurrence. Disc hemiation was protruded in 38 cases (42.8%), extruded in 44 cases (49.4%), and sequestrated in 7 cases (7.8%). The outcome was assessed using Prolo's functional and economic scale. According to Prolo's scale, a good outcome was detected in 79 cases (69.2%), moderate in 22 (19.2%), and a poor outcome was detected in 13 cases (11.4%). The best outcome was achieved in patients with disc hemiation. It is concluded that recurrent disc disease is the most important cause of reexploration. This fact dictates a careful preoperative workup and discectomy in the first intervention. The likelihood of occurrence of disc herniation in the negative laminotomy level (i.e., laminotomy without discectomy procedure) also requires a careful preoperative radiologic workup before lumbar disc surgery.

Adult↗
PubMed1998

Tizanidine is an effective agent in the prevention of focal cerebral ischemia in rats: an experimental study.

BACKGROUND: Focal cerebral ischemia secondary to cerebral vessel occlusion is still an important cause of mortality and morbidity. Excitatory neurotransmitters are gathered in the extracellular space during ischemia and initiate or stimulate a series of pathophysiological biochemical processes and consequently lead to neuronal death. Tizanidine (Sandoz compound DS 103-282, 5-chloro4,2 (2-imidazolin-2-yl-amino)-2,1,3-benzothiazol hydrochloride) is a selective alpha 2 adrenoreceptor agonist which shows its effect by stimulating presynaptic alpha 2 adrenoreceptors in central ASPergic and GLUergic system by inhibiting aspartic acid and glutamic acid release. In this study, the effect of Tizanidine on reversible focal cerebral ischemia was evaluated. METHODS: Cerebral blood flow to the left hemisphere of adult Sprague-Dawley rats (n=48) was temporarily interrupted by middle cerebral artery and bilateral common carotid artery occlusion for 3 hours in eight rats of each group. Tizanidine was given to each group of rats intraperitoneally before the ischemic insult, 2 hours after ischemia, right after the reperfusion, 2 h after reperfusion, and 4 hours after reperfusion; the animals survived for 24 hours after the reperfusion. After killing and triphenyltetrasoliumchloride staining of brain slices, infarction volumes and ratios of the brains were calculated and the results were compared with those of the control group. RESULTS: Infarction volumes and infarction ratios of the Tizanidine group 1/2 hours before ischemia (143.7+/-6.34 mm3 and 10.1+/-0.43%) and the Tizanidine group 2 hours after ischemia (145.6+/-6.32 mm3 and 10.3+/-0.43%) were found to be significantly lower in favor of the Tizanidine groups when compared with those of the control group (173.9+/-6.38 mm3 and 12,4+/-0.41%). Tizanidine is not effective if used just after reperfusion or later. CONCLUSION: This study shows that Tizanidine pretreatment before the ischemic insult and the administration of the drug within the 2 hours after ischemia reduces ischemic damage significantly. Therefore, this drug can be used as a protective and therapeutic agent in ischemic diseases.

Adrenergic alpha-Agonists↗
PubMed1998

Cervical spondylotic myelopathy: surgical results and factors affecting prognosis.

OBJECTIVE: A variety of factors may affect surgical outcome in patients with cervical spondylotic myelopathy. The aim of this study is to determine these factors on the basis of preoperative radiological and clinical data. METHODS: To assess the factors affecting postoperative outcome after surgery for cervical spondylotic myelopathy, the clinical and radiological data of 27 patients with cervical spondylotic myelopathy were reviewed. Functional and neurological statuses were assessed using the Japanese Orthopaedic Association (JOA) scale modified by Benzel. In all patients, the effect of age, symptom duration, cervical curvature, presence or absence of preoperative high signal intensity within the spinal cord as revealed by T2-weighted magnetic resonance imaging, and diameters of the spinal canal and vertebral body on pre- and postoperative neurological statuses were investigated. Plain radiographs were obtained for all patients, magnetic resonance images for 21 patients (77.8%), computed tomographic scans for 13 patients (48.1%), myelograms for 6 patients (22.2%), and computed tomographic myelograms for 4 patients (14.8%). There were five patients with a JOA score of 10, six patients with a JOA score of 11, six patients with a JOA score of 12, four patients with a JOA score of 13, four patients with a JOA score of 14, one patient with a JOA score of 15, and one patient with a JOA score of 16. All patients underwent cervical laminectomies. The mean follow-up period was 54.1 months. The final neurological examinations revealed improvement in the JOA scores of 85.1 % of the patients. RESULTS: Statistical analysis of all patients revealed mean JOA scores of 12.185 +/- 1.618 and 14.370 +/- 2.15 before surgery and at final examination, respectively. The difference between the preoperative JOA score and the final JOA score was determined to be statistically significant (P < 0.0001). Statistical analyses also showed better neurological improvement in patients younger than 60 years and in patients with normal preoperative cervical lordosis. Although patients without preoperative high signal intensity of the spinal cord showed a better improvement rate than did patients with preoperative high signal intensity, the determined difference was statistically insignificant. CONCLUSION: It can be concluded that age and abnormal cervical curvature predict less postoperative neurological improvement. The presence of preoperative high signal intensity within the spinal cord may also reflect less neurological improvement.

Adult↗
PubMed1998

Grading and hemodynamic follow-up study of arteriovenous malformations with transcranial Doppler ultrasonography.

This study presents and tests the clinical validity of a hemodynamic grading system that depends on noninvasive transcranial Doppler ultrasonographic parameters. The suggested transcranial Doppler-based grading system was compared with the Spetzler-Martin anatomic grading for prognosticative validity and clinical dependability. We concluded the following: (1) The pulsatility index was shown to be a more dependable transcranial Doppler parameter in the clinical evaluation of an arteriovenous malformation because of two reasons: preoperative pulsatility index findings inversely correlated with arteriovenous malformation volume, and the pulsatility index returned to normal values before the mean blood flow velocity did. Therefore, hemodynamic arteriovenous malformation grading can be based on the pulsatility index. (2) A transcranial Doppler-based hemodynamic arteriovenous malformation grading system correlated highly with the Spetzler-Martin grading in predicting postoperative neurologic deficits and adverse radiologic findings. (3) The presented grading system may contribute to the standardization and quantification of the hemodynamic changes during multidisciplinary management of arteriovenous malformations.

Adolescent↗
PubMed1996

A new, more dependable methodology for the use of transcranial Doppler ultrasonography in the management of subarachnoid haemorrhage.

The role of transcranial Doppler ultrasound (TCD) in clinical decision making about vasospasm due to subarachnoid haemorrhage (SAH), shows a great variation according to neurosurgical clinics. In this prospective study, a total of 143 patients, admitted to Marmara University Department of Neurosurgery between January 1991 to March 1995 and treated surgically with the diagnosis of aneurysmal SAH, were examined by TCD. Eighty of these patients fulfilled the requirements for inclusion. In order to increase clinical dependability of TCD, a new grading system is proposed and tested in comparison with the one previously used, which takes absolute flow velocities as the main parameter in grading. The new, individually based TCD grading system is proposed to minimize the pitfalls caused by proximal stenosis, wide range of normal Vm values and proximally evolving vasospasm. We concluded that: 1) The new, individually based TCD grading system has a high degree of clinical dependability. 2) Daily TCD examinations supply reliable predictive information about developing delayed ischaemic deficit (DID). If a TCD Gr II patient shows an increase of 35 cm/sec (in 24 hours) in Vm value, his probability of developing DID was found to be 60% (p < 0.05); if a TCD Gr B III patient shows the same rate of increase in Vm, his probability of developing DID was 80% (< 0.05). 3) TCD has an important clinical role in decision making about the management of SAH patients. 4) Surgical manipulation causes a reversible increase of one or two TCD-grades in the early postoperative days.

Adolescent↗
PubMed1995

Microvascular decompression in the surgical management of trigeminal neuralgia.

The pathophysiological mechanisms underlying trigeminal neuralgia are not clearly understood and several therapeutic modalities have been advocated. Microvascular decompression (MVD) is a widely used surgical approach for the decompression of the affected root entry zone (REZ) of the fifth cranial nerve. In this paper, we present our experience based on 32 patients with trigeminal neuralgia who were treated with MVD, and discuss the role of this procedure in the surgical management of trigeminal neuralgia. All patients had typical TN pain and had had previous medical management which was unsuccessful. Fourteen patients (44%) had been previously treated with other surgical procedures and had persisting pain at the time of admission. Preoperatively, computerized tomography was obtained in all patients; twelve patients (37.5%) were evaluated with magnetic resonance imaging. These neuroradiological studies revealed an asymmetrical vascular structure at the involved REZ in nine patients (28%). All patients underwent MVD, and a vascular loop causing compression on the REZ of the fifth cranial nerve was demonstrated in each case. No mortality was observed, and the only permanent morbidity was cerebellar infarction in one patient (3%). Symptoms disappeared in all patients in the early postoperative period, and only three recurrences (12%) were observed within the follow-up period (mean: 26 months).

Adult↗
PubMed1995

Brucellar spondylitis mimicking lumbar disc herniation. Case report.

In this paper, a patient with brucellar spondylitis who was initially diagnosed as having a lumbar disc herniation is presented. As the disc tissue enlarges in the early stages of discitis because of the inflammatory reaction, it may compress the related root(s) mimicking a disc herniation. For this reason infectious discitis, as in our case, should be kept in mind in the differential diagnosis of the radicular symptoms caused by a disc herniation. The crucial role of magnetic resonance imaging in making the differential diagnosis of the case is especially emphasized.

Adult↗
PubMed1994

Muscarinic receptors in rat cortex, hippocampus, hypothalamus and brainstem following transient forebrain ischemia and hemorrhagic shock.

[3H]Quinuclidinyl benzilate binding properties of cerebral cortex, hippocampus, hypothalamus and brainstem of rats subjected to transient forebrain ischemia or severe hemorrhagic shock were investigated. Maximal binding capacities (Bmax) were not significantly different from control animals in either model. On the other hand, significant increases in binding affinities at all four brain regions in the ischemia-reperfusion group and at hypothalamic and brainstem membranes in the hemorrhagic shock group were observed. Kd values obtained in cortex and hippocampus of animals in shock were similar to control values. It was concluded that in brain ischemia models, the number of brain muscarinic receptors do not change at early stages, but binding affinities increase most likely due to systemic hypotension rather than reperfusion. The well-developed circle of Willis seems to protect cortical and hippocampal muscarinic receptors from hypoxia-induced changes.

Animals↗
PubMed1994

Intradural rupture of cervical vertebral disc.

STUDY DESIGN: The authors discuss their experience with a patient who had cervical intradural disc herniation and relate the case to the relevant literature. OBJECTIVES: The patient was evaluated with direct radiographies, myelography, electromyography, and computerized tomography, as well as with neurologic examination. The follow-up period was 10 months post-operative. SUMMARY OF BACKGROUND DATA: Intradural disc herniation is a rare pathology nearly always confined to the lumbar region. In 1989, Katooka et al reviewed the existing literature and discovered 70 cases. Cervical intradural disc herniation, on the other hand, is much rarer, and there are only five cases in the literature. METHODS: The patient's neurologic, neuroradiologic, and operative findings were evaluated and compared with the cases reported in the literature. CONCLUSIONS: The five patients in the literature had signs of cord compression, but the present patient is the first with root compression.

Adult↗
PubMed1993

Pleomorphic xanthoastrocytoma associated with von Recklinghausen neurofibromatosis.

The authors present a case of pleomorphic xanthoastrocytoma that occurred in a 14-year-old boy with von Recklinghausen's neurofibromatosis. The circumscribed tumor with a cystic component was located in the medial right temporal lobe. The designation of pleomorphic xanthoastrocytoma has been suggested for this neoplasm on the basis of its unique histological features. These include positive glial fibrillary acidic protein staining.

Adolescent↗
PubMed1993

Magnetic resonance imaging in the diagnosis of idiopathic giant-cell granulomatous hypophysitis: a rare cause of hyperprolactinaemia.

Idiopathic giant cell granulomatous hypophysitis is a rare disorder of pituitary gland characterised by a chronic inflammatory process. It can also be an extremely rare cause of hyperprolactinaemia. In this paper, we present our experience with two cases of idiopathic giant cell granulomatous hypophysitis manifested by hyperprolactinaemia, and their neuroradiological evaluation including preoperative MRI studies in one of them, and discuss our findings in the light of the literature.

Adult↗
PubMed1993

A pontine tuberculoma mimicking an exophytic brain stem tumor.

A 21 year old man with a five month history of facial paresis, diplopia, and gait disturbance diagnosed with a brain stem tumor at another institution was evaluated. Computed tomography, magnetic resonance imaging, clinical and laboratory evaluations suggested a pontine astrocytoma, and the mass was excised. Pathological diagnosis was a tuberculoma confirmed by postoperative positive Mantoux testing. CT and MRI appearances of tuberculomas have been described, but can not differentiate them completely from other tumors such as astrocytomas. Because the incidence of tuberculomas has increased in recent years and they may mimic exophytic tumors of pons, it is important to include pontine tuberculoma in the differential diagnosis of pontine tumors.

Adult↗