Continuous hypertonic saline therapy and the occurrence of complications in neurocritically ill patients.

OBJECTIVE: To evaluate potential side effects of continuous hypertonic 3% saline (CHS) as maintenance fluid in patients with brain injury. METHODS: Retrospective chart analysis of prospectively collected data. PATIENTS: Patients admitted to the neurosurgical intensive care unit for >4 days with traumatic brain injury, stroke, or subarachnoid hemorrhage with a Glasgow Coma Scale <9 and elevated intracranial pressure (ICP) or at risk of developing elevated ICP were included. Based on physician preference, one group was treated with 3% CHS at a rate of 1.5 mL/kg/bw as maintenance fluid. The other group received 0.9% normal saline (NS). Two percent saline was used in the CHS group to wean patients off 3% CHS or when sodium was above 155. Data on serum sodium, blood urea nitrogen, creatinine, ICP, infection rate, length of stay, rates of deep vein thrombosis, and pulmonary emboli and dural thrombosis were collected prospectively. RESULTS: One hundred seven patients in the CHS group and 80 in the NS group met the inclusion criteria. The incidence of moderate hypernatremia (Na >155 mmol/L) and severe hypernatremia (Na >160 mmol/L) was significantly higher in the CHS therapy group than in the NS group. No significant relationship between CHS infusion and renal dysfunction was found. Moderate and severe hypernatremia was associated with a higher risk of elevated blood urea nitrogen and creatinine levels. Acute renal failure was not seen in these patients. A total of 53.3% in the CHS group and in 16.3% in the NS group (p < 0.0001) had raised ICP (>25 mm Hg), consistent with the physicians decision to use CHS in patients with elevated ICP. CONCLUSIONS: CHS therapy was not associated with an increased rate of infection, deep vein thrombosis, or renal failure. However, there was a significant risk of developing hypernatremia. We conclude that CHS administration in patients with severe injuries is safe as long as sodium levels are carefully monitored.

Trigeminal and occipital peripheral nerve stimulation for craniofacial pain: a single-institution experience and review of the literature.

OBJECT: Treatment of chronic neuropathic pain in the region of the head and face presents a challenge for pain specialists; patients who do not respond to conventional treatment modalities usually continue to suffer from pain due to the lack of reliable medical and surgical approaches. Peripheral nerve stimulation (PNS) has been used to treat neuropathic pain for many decades, but only recently has it been applied systematically to the craniofacial region. To advance the study of this treatment option, the authors present their initial experience with this approach, summarize published data on the use of PNS in treatment of craniofacial pain, and discuss some technical details of the craniofacial PNS procedure. METHODS: A review of prospectively collected data in 30 patients who underwent PNS surgery for craniofacial pain was performed. The pain location, duration, cause, and previous treatments were analyzed, along with the surgical details, initial and long-term results, complications, and repeated operations. Stimulated nerves in this group included supraorbital (seven patients), infraorbital (six), and occipital (21); in 19 patients more than one nerve was stimulated. Twenty-two patients proceeded with implantation of a permanent system after the trial. Of these, at the time of the latest evaluation (mean follow-up duration 35 months), in two patients the devices had been removed because of pain improvement over time, in three the devices were removed due to loss of effectiveness (two cases) or late infection (one), and the rest are enjoying either complete (15 patients) or partial (two patients) pain relief. Three patients underwent repeated operation due to lead erosion, infection, or migration. CONCLUSIONS: Peripheral nerve stimulation appears to be a safe and effective approach in the treatment of craniofacial neuropathic pain. The growing body of literature supports a wider acceptance of this approach in the field of pain surgery.

Spectral iEEG markers precede SSEP events during surgery for subarachnoid hemorrhage.

OBJECTIVE: During neurosurgical intracranial vascular manipulations, surgeons need early feed-back on the effects of temporary vascular occlusion. In surgical practice, commonly the amplitude of somatosensory evoked potentials (SSEP) is monitored. However, the latency between an ischemic event and the drop of SSEP amplitude may amount to several minutes. Therefore intracranial electroencephalogram (iEEG) is tested for its predictive value. METHODS: During surgery in 13 patients, SSEP was recorded simultaneously with iEEG. iEEG was analyzed real-time in the frequency domain. Spectral observables of the iEEG were validated on the basis of SSEP by computing the statistical correlation first for the whole data set, then for salient events occurring in the SSEP in the group of patients, and finally for salient events occurring in single patients. RESULTS: Placement of subdural strip electrodes was compatible with standard surgical routine. Maximal correlation between time series of iEEG and SSEP was found for relative alpha power, which preceded the drop of SSEP by 7min. CONCLUSIONS: iEEG is feasible during neurosurgical intracranial vascular manipulations. Monitoring relative alpha power detects salient events earlier than SSEP. SIGNIFICANCE: Early detection of salient events facilitates early reaction of the surgeon and may thereby aid to further reduce intraoperative morbidity.

Bioabsorbable instrumentation for single-level cervical degenerative disc disease: a radiological and clinical outcome study.

OBJECT: The authors present the radiological and clinical outcome data obtained in patients who underwent single-level anterior cervical discectomy and fusion (ACDF) for cervical spondylosis and/or disc herniation; bioabsorbable plates were used for instrumentation. The use of metallic plates in ACDF has gained acceptance as a stabilizing part of the procedure to increase fusion rates, but when complications occur with these devices, the overall effectiveness of the procedure is compromised. As a possible solution, bioabsorbable implants for ACDF have been developed. This study investigates the feasibility and radiological and clinical outcomes of the bioabsorbable plates for ACDF. METHODS: The radiological and clinical outcomes of 30 patients were investigated retrospectively. All patients presented with cervical radiculopathy or myelopathy and underwent single-level ACDF in which a bioabsorbable anterior cervical plate and an allograft bone spacer were placed at a level between C-3 and C-7. Radiological outcome was assessed based on the fusion rate, subsidence, and Cobb angle of the surgical level. Clinical outcome was determined by using a visual analog scale, the Neck Disability Index, and the Odom criteria. RESULTS: There were no intraoperative complications, and no hardware failure was observed. No signs or symptoms of adverse tissue reaction caused by the implant were seen. Two reoperations were necessary due to postoperative blood collections. The overall complication rate was 16.7%. After 6 months, radiographic fusion was seen in 92.3% of patients. Subsidence at 11.3 +/- 7.2 months was 3.1 +/- 5.8 mm (an 8.2% change over the immediately postoperative results), and the change in the sagittal curvature was -2.7 +/- 2.7 degrees . The visual analog scale score for neck and arm pain and Neck Disability Index improved significantly after surgery (p < 0.001). Overall at 19.5 months postoperatively, 83% of the patients had favorable outcomes based on the Odom criteria. CONCLUSIONS: Absorbable instrumentation provides better stability than the absence of a plate but graft subsidence and deformity rates may be higher than those associated with metal implants. There were no device-related complications, but adverse late effects cannot be excluded. The fusion rate and outcome are comparable to the results achieved with metallic plates. The authors were satisfied with the use of bioabsorbable plates as a reasonable alternative to metal, avoiding the need for lifelong metallic implants.

Peripheral neurostimulation for treatment of intractable occipital neuralgia.

OBJECTIVE: Medically intractable pain caused by occipital neuralgia (ON) can be very difficult to control with traditional pain management. Peripheral nerve stimulation (PNS) may serve as a good alternative to destructive surgical manipulations used currently for the treatment of severe ON. METHODS: We analyzed records of 14 consecutive patients (9 women and 5 men; mean age, 43.3 yr) with intractable ON treated with PNS during the period from April 2002 to November 2004. Five patients had unilateral and nine had bilateral PNS electrodes inserted for trial, which was considered successful if patient reported at least 50% decrease of pain on the visual analogue scale. Ten patients proceeded with system internalization, and their long-term results were analyzed. RESULTS: At the time of the last follow-up examination (5-32 mo, mean 22 mo), seven patients (70%) with implanted PNS systems continue to experience beneficial effects of stimulation, including adequate pain control, continuous employment, and decrease in oral pain medications intake. Two patients had their systems explanted because of loss of stimulation effect or significant improvement of pain, and one patient had part of his hardware removed because of infection. CONCLUSION: Overall, the beneficial effect from chronic stimulation in our series persisted in more than half of the patients for whom procedure was considered and in 80% of those who significantly improved during the trial and proceeded with internalization. Thus, chronic PNS may be a safe and relatively effective method for long-term treatment of chronic pain syndrome in patients with medically intractable ON.

Trigeminal branch stimulation for intractable neuropathic pain: technical note.

Intractable neuropathic facial pain resulting from injury to the peripheral branches of the trigeminal nerve presents a significant challenge for neurologists, pain specialists, and neurosurgeons. In this paper, we describe our technique of peripheral nerve stimulation of the infraorbital and supraorbital nerves to treat patients with medically intractable facial pain. Stimulation of the infraorbital and supraorbital nerves is performed using percutaneously inserted electrodes that are positioned in the epifascial plane, traversing the course of the infraorbital or supraorbital nerves. The temporary electrodes are inserted under fluoroscopic guidance and are anchored to the skin. A trial lasting a few days is followed, if successful, by insertion of a permanent electrode that is tunneled under the skin behind the ear toward the infraclavicular pocket, which houses the implantable pulse generator. Our technique of electrode insertion to stimulate the infraorbital or supraorbital nerves has been successfully used in several patients with neuropathic trigeminal pain of various etiologies. In patients who underwent permanent electrode implantation, stimulation resulted in long lasting pain relief; complications were rare and minor. We conclude that trigeminal branch stimulation is a simple technique that can be used in selected patients with neuropathic pain in the distribution of the infraorbital or supraorbital nerves. This procedure may provide relief of medically intractable pain, without the need for destructive procedures or more central modulation approaches.