Ahmet Bekar

Percutaneous Controlled Radiofrequency Trigeminal Rhizotomy for the Treatment of Idiopathic Trigeminal Neuralgia: 25-year Experience with 1600 Patients

OBJECTIVEThe objective of this study was to evaluate the effectiveness of percutaneous, controlled radiofrequency trigeminal rhizotomy (RF-TR). The outcome of 1600 patients with idiopathic trigeminal neuralgia after RF-TR was analyzed after a follow-up period of 1 to 25 years. METHODSA total of 1600 patients with idiopathic trigeminal neuralgia underwent 2138 percutaneous radiofrequency rhizotomy procedures between 1974 and 1999. Sixty-seven patients had bilateral idiopathic trigeminal neuralgia, and 36 of them were treated with bilateral RF-TR; 1216 patients (76%) were successfully managed with a single procedure, and the remainder were treated with multiple procedures. Benzodiazepines and narcotic analgesics were used for anesthesia because patient cooperation during the procedures was essential so that the physician could create selective, controlled lesions. RESULTSThe average follow-up time was 68.1 ± 66.4 months (range, 12–300 mo). Acute pain relief was accomplished in 97.6% of patients. Complete pain relief was achieved at 5 years in 57.7% of the patients who underwent a single procedure. Pain relief was reported in 92% of patients with a single procedure or with multiple procedures 5 years after the first rhizotomy was performed. At 10-year follow-up, 52.3% of the patients who underwent a single procedure and 94.2% of the patients who underwent multiple procedures had experienced pain relief; at 20-year follow-up, 41 and 100% of these patients, respectively, had experienced pain relief. No mortalities occurred. After the first procedure was performed, early pain recurrence (<6 mo) was observed in 123 patients (7.7%) and late pain recurrence was observed in 278 patients (17.4%). Complications included diminished corneal reflex in 91 patients (5.7%), masseter weakness and paralysis in 66 (4.1%), dysesthesia in 16 (1%), anesthesia dolorosa in 12 (0.8%), keratitis in 10 (0.6%), and transient paralysis of Cranial Nerves III and VI in 12 (0.8%). Permanent Cranial Nerve VI palsy was observed in two patients, cerebrospinal fluid leakage in two, carotid-cavernous fistula in one, and aseptic meningitis in one. CONCLUSIONPercutaneous, controlled RF-TR represents a minimally invasive, low-risk technique with a high rate of efficacy. The procedure may safely be repeated if pain recurs.

Risk factors and complications of intracranial pressure monitoring with a fiberoptic device.

We prospectively investigated the complications associated with intraparenchymal intracranial pressure (ICP) monitoring using the Camino intracranial pressure device. A fiberoptic ICP monitoring transducer was implanted in 631 patients. About half of the patients (n=303) also received an external ventricular drainage set (EVDS). The durations (mean+/-SD) of ICP monitoring in patients without and with an EVDS were 6.5+/-4.4 and 7.3+/-5.1 days, respectively. Infection occurred in 6 patients with only an ICP transducer (6/328, 1.8%) and 24 patients with an EVDS also (24/303, 7.9%). The duration of monitoring had no effect on infection, whereas the use of an EVDS for more than 9 days increased infection risk by 5.11 times. Other complications included transducer disconnection (2.37%), epidural hematoma (0.47%), contusion (0.47%), defective probe (0.31%), broken transducer (0.31%), dislocation of the fixation screw (0.15%), and intraparenchymal hematoma (0.15%). In conclusion, intraparenchymal ICP monitoring systems can be safely used in patients who either have, or are at risk of developing, increased ICP.

Percutaneous Controlled Radiofrequency Rhizotomy in the Management of Patients with Trigeminal Neuralgia due to Multiple Sclerosis

Summary Between the years 1974 and 1999, 1,672 patients with medically intractable trigeminal neuralgia (TN) were treated by percutaneous controlled radiofrequency (RF) rhizotomy by the senior author and co-workers at the Department of Neurosurgery, Ankara University School of Medicine. Sixteen hundred cases (95.7%) were found to have idiopathic TN, while 72 cases (4.3%) were classified as symptomatic. In the latter group, TN was found to be caused by multiple sclerosis (MS) in 17 cases (23.6%), one of whom had bilateral TN. All patients having TN with MS (17 cases) underwent percutaneous controlled radiofrequency rhizotomy (25 procedures) as the procedure of choice. The MS patients were followed for an average of 60 months (range: 6–141 months). Complete pain relief was achieved with a single procedure in 12 of the 17 MS cases (70.6%). Early (less than 2 weeks) pain recurrence was seen in two patients (11.8%), while the overall recurrence rate was 29.4%. A second procedure was required to control TN in three cases (17.6%), a third in one (5.9%), and twice for each side for the case with bilateral TN (5.9%). Pain was completely relieved in 14 cases (82.4%) with single or multiple RF rhizotomies. In three cases (17.6%), partial pain control was achieved with RF rhizotomy, and the patients continued to receive adjunctive medical therapy. No complications were observed. All 17 patients (100%) were classified to have done well with RF rhizotomy. Satisfactory results and good long-term pain control were obtained in patients having TN due to MS with percutaneous controlled RF rhizotomy. The authors propose that RF rhizotomy may be a safe and effective procedure in the neurosurgical armamentarium for the treatment of patients having TN due to MS.

Effects of perioperatively administered bupivacaine and bupivacaine-methylprednisolone on pain after lumbar discectomy.

Study Design. A prospective, randomized, controlled trial that compared the efficacy of different protocols of local tissue infiltration with bupivacaine or bupivacaine-methylprednisolone at the surgical site for pain relief after lumbar discectomy. Objective. To determine the efficacy of preemptive wound infiltration with bupivacaine and bupivacaine-methylprednisolone after lumbar discectomy. Summary of Background Data. Patients usually have significant pain after lumbar discectomy. Wound infiltration with bupivacaine or bupivacaine-methylprednisolone is one method to address this. Methods. Seventy-five patients were randomly allocated to 5 equal groups as follows: Group I (n = 15) had the musculus multifidi near the operated level infiltrated with 30 mL 0.25% bupivacaine and 40 mg methylprednisolone just before wound closure; Group II (n = 15) had the same region infiltrated with 30 mL 0.25% bupivacaine alone before closure; Group III (n = 15) had this region infiltrated with 30 mL 0.25% bupivacaine and 40 mg methylprednisolone before the incision was made; in Group IV (n = 15), this region infiltrated with 30 mL 0.25% bupivacaine alone before incision; and Group C (controls, n = 15) had this region infiltrated with 30 mL 0.9% NaCl just before wound closure. Demographics, vital signs, postoperative pain scores, and morphine usage were recorded. Results. All 4 groups treated with bupivacaine or bupivacaine-methylprednisolone (by preemptive or preclosure wound infiltration) showed significantly better results than the control group for most parameters. The treated groups had lower parenteral opioid requirements after surgery, lower incidences of nausea, and shorter hospital stays. Further, the data indicate that, compared with infiltration of these drugs at wound closure, preemptive injection of bupivacaine or bupivacaine-methylprednisolone into muscle near the operative site provides more effective analgesia after lumbar discectomy. Conclusion. In addition, our data suggest that preemptive infiltration of the wound site with bupivacaine alone provides similar pain control to preemptive infiltration of the wound site with bupivacaine and methylprednisolone combined.

Citicoline improves functional recovery, promotes nerve regeneration, and reduces postoperative scarring after peripheral nerve surgery in rats

BACKGROUND Citicoline has been shown to have beneficial effects in a variety of CNS injury models. The aim of this study was to test the effects of citicoline on nerve regeneration and scarring in a rat model of peripheral nerve surgery. METHODS Seventy adult Sprague-Dawley rats underwent a surgical procedure involving right sciatic nerve section and epineural suturing. Rats were assigned to the control or experiment groups to receive a topical application of 0.4 mL of saline or 0.4 mL (100 micromol/L) of citicoline, respectively. Macroscopic, histological, functional, and electromyographic assessments of nerves were performed 4 to 12 weeks after surgery. RESULTS In the control versus citicoline-treated rats, SFI was -90 +/- 1 versus -84 +/- 1 (P < .001), -76 +/- 4 versus -61 +/- 3 (P < .001), and -66 +/- 2 versus -46 +/- 3 (P < .001) at 4, 8, and 12 weeks after surgery, respectively. At 12 weeks after surgery, axon count and diameter were 16400 +/- 600 number/mm(2) and 5.47 +/- 0.25 microm versus 22250 +/- 660 number/mm(2) (P < .001) and 6.65 +/- 0.28 microm (P < .01) in the control and citicoline-treated groups, respectively. In citicoline-treated rats, histomorphological axonal organization score at the repair site was (3.4 +/- 0.1) significantly better than that in controls (2.6 +/- 0.3) (P < .001). Peripheral nerve regeneration evaluated by EMG at 12 weeks after surgery showed significantly better results in the citicoline group (P < .05). Nerves treated with citicoline demonstrated reduced scarring at the repair site (P < .001). CONCLUSION Our results demonstrate that citicoline promotes regeneration of peripheral nerves subjected to immediate section suturing type surgery and reduces postoperative scarring.

Secondary insults during intrahospital transport of neurosurgical intensive care patients

Secondary insults occuring after injury have been prospectively assessed in seven head-injured patients who required intrahospital transfer to a computerized tomography unit for re-evaluation of their brain injury. During transportation the intracranial pressure, blood pressure, and arterial blood gases were monitored. A significant increase in intracranial pressure was observed during transport (p<0.01). The conclusion is that patients should be ventilated and have appropriate sedation and analgesia. This could provide some protection against secondary insults.

Unilateral Blindness due to Patient Positioning During Cervical Syringomyelia Surgery: Unilateral Blindness After Prone Position

During spinal surgery using a horseshoe headrest with the patient in the prone position, the possibility of central retinal artery occlusion (CRAO) increases, and its cause can be attributed primarily to excessive extraocular pressure, a very rare complication. This report describes a case of CRAO, occurring in an adult, after cervical syringomyelia surgery in which a horseshoe headrest was used.

Complications of brain tissue pressure monitoring with a fiberoptic device.

Seventy-five patients with intracranial hypertension whose Glasgow Coma Score (GCS) was 8 or below and in whom intracranial pressure (ICP) was monitored were examined for complications of this procedure. In 20 of the 75 patients we used only an intraparenchymal fiberoptic ICP monitoring transducer, while, in the remaining 55 patients, who required CSF drainage, a ventricular drainage set (VDS) was used in addition to ICP monitoring. The duration of monitoring with the ICP transducer alone was approximately 5.1 ± 2.6 das (min. 1, max. 13) and that of ICP monitoring with VDS was 6.2 ± 3.1 days (min. 1, max. 13). In 8 cases a total of 9 complications were experienced (12 %). These complications were infection in 3 cases (4 %), epidural hematoma in 2 cases (2.7 %), disconnection in 2 cases (2.7 %) and contusion in 2 cases (2.7 %). Although none of the 44 patients who were monitored for less than 5 days experienced infection, 3 of the 31 patients monitored for longer than 5 days did experience infection (9.7 %) (p < 0.05). None of the 20 patients who underwent ICP monitoring only experienced infection. However, 3 of the 55 patients in whom the ventricular drainage set was implanted in addition to the transducer for ICP monitoring experienced infection (p < 0.05).Owing to its minimally invasive nature, low complication rate, and accuracy in monitoring the parenchyma pressure, the Camino fiberoptic intraparenchymal monitor has become the system of choice in our clinic.

A case of primary spinal intramedullary lymphoma

A 41-year-old male presented to our clinic with a 1-month history of left hemiparesis. He had marked left arm weakness. The diagnostic work-up revealed an intramedullary mass at spinal level C2-4. Laminectomies were performed at C2-3-4 and the tumor was subtotally resected. Histological examination identified the mass as a non-Hodgkins diffuse B-cell lymphoma. The patient was treated with corticosteroids, chemotherapy, and adjuvant radiotherapy. The residual tumor tissue had completely disappeared by 6 months of follow-up; however, the patient presented with intraventricular metastasis at 11 months postsurgery.

The Promoter Hypermethylation Status of GATA6, MGMT, and FHIT in Glioblastoma

Glioblastoma (GBM) is an aggressive and lethal cancer, accounting for the majority of primary brain tumors in adults. GBMs are characterized by large and small alterations in genes that control cell growth, apoptosis, angiogenesis, and invasion. Epigenetic alterations also affect the expression of cancer genes, either alone or in combination with genetic mechanisms. The current evidence suggests that hypermethylation of promoter CpG islands is a common epigenetic event in a variety of human cancers. A subset of GBMs is also characterized by a locus-specific and genome-wide decrease in DNA methylation. Epigenetic alterations are important in the molecular pathology of GBM. However, there are very limited data about these epigenetic alterations in GBM. Alterations in promoter methylations are important to understand because histone deacetylases are targets for drugs that are in clinical trial for GBMs. The aim of the current study was to investigate whether the promoter hypermethylation of putative tumor suppressor genes was involved in GBM. We examined the methylation status at the promoter regions of GATA6, MGMT, and FHIT using the methylation-specific polymerase chain reaction in 61 primary GBMs. Our results reveal that there is no promoter hypermethylation of FHIT in the examined GBM tissue specimens. In contrast, the promoter hypermethylation of GATA6 and MGMT was detected in 42.8 and 11.11% of GBMs, respectively. The frequency of MGMT promoter hypermethylation was low in the group of patients we evaluated. In conclusion, our study demonstrates that promoter hypermethylation of MGMT is a common event in GBMs, whereas GATA6 is epigenetically affected in GBMs. Furthermore, inactivation of FHIT by epigenetic mechanisms in GBM may not be associated with brain tumorigenesis.