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Biomedical subjects

H M Göksel

Publications and source records attributed to H M Göksel.

8 recordsLinked to original sources
PubMed2005

Cervical spinal cord stimulation increases cerebral cortical blood flow in an experimental cerebral vasospasm model.

BACKGROUND: Cerebral microcirculatory changes during cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH) are still controversial and uncertain. The aim of our study is to demonstrate that spinal cord stimulation (SCS) augments cerebral cortical microcirculatory blood flow in an experimental cerebral vasospasm model by using Laser Doppler Flowmetry (LDF). METHOD: The experiments were carried out on 24 New Zealand rabbits. Three experimental groups were designed. In group 1, Cerebral cortical blood flow (CCoBF) was evaluated by LDF in 8 rabbits. In group 2, Intracisternal saline injection and cervical epidural electrode placement without SCS were performed in 8 animals before LDF. In group 3, LDF was performed before and after SCS on the 4th day of SAH in 8 rabbits. CCoBF parameters obtained from LDF data were compared. FINDINGS: The occurrence of vasospasm after SAH was demonstrated with significant changes in LDF values. In all SAH animals, SCS resulted in significant increase (approximately 30%) in CCoBF. This increase was observed to continue even after the cessation of the stimulation. CONCLUSIONS: These results indicate that SCS improves cortical ischemia due to vasospasm after induced SAH. The cervical SCS may constitute a new therapeutic modality in treating disturbed CCoBF due to vasospasm.

Animals↗
PubMed2004

The effects of the electrical stimulation of the nasal mucosa on cortical cerebral blood flow in rabbits.

The cerebral vessels have sympathetic, parasympathetic, and sensory innervations. A sensory innervation of the cerebral vessels originating in the trigeminal ganglion has been described in a number of species by several investigations. It has been shown that the electrical stimulation of the trigeminal ganglion causes an increase of cerebral blood flow (CBF). The aim of our present study is to stimulate the trigeminal ganglion with an extracranial and non-invasive method. A stimulating electrode was put in the nasal mucosa via right nares of rabbits and trigeminal ganglion was stimulated orthodromically via nasociliary nerve (NCN). Variations in the cortical CBF were evaluated by laser Doppler flowmetry. In experiment group, CBF increased together with the beginning of electrical stimulation. The flow values were remained high as long as the stimulation. In post-stimulation period, the CBF was decreased gradually and returned to the baseline values at 120s. This study demonstrated that the electrical stimulation of the NCN branch of the trigeminal nerve increases the cortical CBF under physiological conditions.

Animals↗
PubMed2003

Primary multiple cerebral hydatid cysts with unusual features.

We present a case of 45 years old female patient with two primary cerebral hydatid cysts, each localised in separate hemispheres. Detailed studies revealed no evidence of hydatid disease elsewhere in the body. The cysts were removed by two separate operations. Though the cyst in the right posterior parietal lobe was delivered unruptured, seven months later a new cyst was detected in the same cavity, which seems to show relatively rapid growth in a year, and was also removed unruptured. This case is presented here for its unusual features such as having two primary cerebral hydatid cysts simultaneously in separate hemispheres, one of which partly localised intraventricularly, and the occurrence of a new cyst in the same cavity following intact removal of the previous cyst.

Brain Diseases↗
PubMed2003

Vertebral plasma cellular osteomyelitis.

Plasma cellular osteomyelitis is a chronic recurrent, unifocal or multifocal inflammatory disorder, which has an unknown aetiology. The infectious focus or foci may occur in different sites of the skeleton. This unusual clinical entity has been reported in over 200 cases in the relevant literature, but the involvement of the spine with plasma cellular osteomyelitis has not been reported before. Because of the rarity of this disease and the possible difficulty in differentiating plasma cell osteomyelitis, both clinically and histopathologically from the other similar afflictions of the spine, we describe our case.

Aged↗
PubMed2001

Nitric oxide synthase inhibition attenuates vasoactive response to spinal cord stimulation in an experimental cerebral vasospasm model.

BACKGROUND: The basic mechanism of delayed cerebral vasospasm following subarachnoid haemorrhage (SAH) has been intensively investigated. It is thought that nitric oxide (NO) is a basic mediator of the cerebral vasodilator mechanism. Previous clinical and experimental studies have shown a cerebral vasodilator effect of high cervical spinal cord stimulation (SCS) however, the mechanism of this effect is still controversial. We investigated the contribution of the vasodilator effect of NO to this mechanism in an experimental SAH model using rabbits. METHOD: Four experimental groups, were designated: Group 1. Cerebral blood flow (CBF) was evaluated by transcranial Doppler ultrasonography (TDU) in 8 rabbits. Group 2. In 4 animals, intracisternal saline injection and cervical epidural electrode placement without SCS were performed before TDU. Group 3. TDU was performed before and after SCS on the fourth day of SAH in 8 rabbits. Group 4. In 8 animals, N-Nitro-L-Arginine Methyl Esther (L-NAME) was administered intracisternally on the fourth day of SAH, at a dose of 0.6 mg/kg, 45 minutes before SCS. CBF parameters, obtained via measurements or calculations from TDU data, were compared. FINDINGS: The occurrence of vasospasm after SAH was demonstrated with significant changes in TDU parameters (high peak systolic velocity and positive values of the degree of stenosis). In all SAH animals, SCS resulted in significant vasodilation. Even after the injection of L-NAME, SCS still had a significant vasodilatory effect in SAH animals, but there was also a significant difference in CBF parameters in the SCS-only group when compared with the L-NAME treatment before SCS group. INTERPRETATION: The mechanism of the cerebral vasodilatory effect of SCS remains controversial. Our results revealed the contribution of a neurohumoral effect which can be partially prevented by use of an NO synthase inhibitor.

Animals↗
PubMed2001

The therapeutic effect of continuous intracisternal L-Arginine infusion on experimental cerebral vasospasm.

BACKGROUND: Recent studies on the pathogenesis of cerebral vasospasm following subarachnoid haemorrhage (SAH) suggest a breakdown of the balance between the vasoconstrictor and vasodilator systems. A shortage of a major cerebral vasodilator, nitric oxide (NO), has been accused of causing this breakdown. We investigated the effect of continuous intracisternal infusion of a NO precursor, L-Arginine, in a rabbit SAH model. METHOD: Three experimental groups were designated: Group 1--Cerebral blood flow (CBF) data was obtained via transorbital Doppler ultrasonography (TDU) in 8 normal rabbits. Group 2--Intracisternal catheter placement and TDU study during saline infusion were performed in 8 animals at the 4th day of SAH, Group 3--SAH occurred in 8 animals. 4 days later, L-Arginine was infused intracisternally for 1 hour, while TDU was performed before and during infusion. CBF parameters which were obtained via TDU measurement or calculations, were compared. FINDINGS: The results of TDU revealed significant vasospasm in all SAH animals, as well as resolution of vasospasm with L-Arginine infusion. After 20 minutes of infusion, a steady and sustained vasodilation was obtained in the third group. The analysis of CBF data revealed a significant difference in SAH values, and no difference in control animals. INTERPRETATION: Our results support the contribution of the "NO shortage" concept in the pathogenesis of cerebral vasospasm and overconsumption of L-Arginine during the post-SAH period may cause this shortage. L-Arginine treatment may be useful for the prophylaxis and treatment of cerebral vasospasm. The intracisternal infusion method can eliminate the short action time disadvantage of L-Arginine.

Animals↗
PubMed2001

Evaluation of cerebral vasospasm with transcranial magnetic stimulation: an experimental study.

Despite the current use of several different methods for diagnosis and follow-up of cerebral vasospasm after subarachnoid hemorrhage, an easy, quick, reliable, and noninvasive method is still needed for evaluation of this entity. We investigated the value of transcranial magnetically evoked motor potential changes during the vasospasm period in a rabbit experimental subarachnoid hemorrhage model. We also recorded motor evoked potential changes after deferoxamine treatment during vasospasm. Our results reveal a significant increase in latency periods of evoked potentials during the angiographically proven vasospasm period (34.5%) over those in sham-operated rabbits (9.5%). With deferoxamine treatment, only a minor increase in latency periods (4.5%) was detected after subarachnoid hemorrhage. These results suggest the potential value of evoked motor potential recording as a diagnostic tool in cases of cerebral vasospasm.

Animals↗