Caglar Berk

Reducing hardware-related complications of deep brain stimulation

BACKGROUND Deep brain stimulation (DBS) is used increasingly worldwide for the treatment of Parkinsons disease, dystonia, tremor and pain. As with any implanted system, however, DBS introduces a new series of problems related to its hardware. Infection, malfunction and lead migration or fracture may increase patient morbidity and should be considered when evaluating the risk/benefit ratio of this therapy. This work highlights several factors felt to increase DBS hardware complications. METHODS The authors undertook a prospective analysis of their patients receiving this therapy in two Canadian centres, over a four-year period. RESULTS One hundred and forty-four patients received 204 permanent electrode implants. The average follow-up duration was 24 months. Complications related to the DBS hardware were seen in 11 patients (7.6%). There were two lead fractures (1.4%) and nine infections (6.2%) including two erosions (1.4%). There was a significantly greater risk of infection in patients who underwent staged procedures with externalization. In patients with straight scalp incisions, the rate of infection was higher than that seen with curved incisions. CONCLUSION Hardware complications were not common. A period of externalization of the electrodes for a stimulation trial was associated with an increased infection rate. It is also possible that a straight scalp incision instead of curvilinear incision may lead to an increase in the rate of infection. With a clear understanding of the accepted DBS device indications and their potential complications, patients may make a truly informed decision about DBS technology.

The treatment of trigeminal neuralgia in patients with multiple sclerosis using percutaneous radiofrequency rhizotomy

BACKGROUND Trigeminal neuralgia (TN) has a higher incidence among patients with multiple sclerosis (MS) than in the general population. This cohort of MS patients with TN presents a series of management challenges including poor tolerance of antineuralgic medications and occasional bilateral presentation. We analyzed our surgical series of MS patients presenting with TN who were treated with percutaneous radiofrequency rhizotomy to estimate the success, failure and recurrence rate of this procedure for those patients. METHODS Surgical reports were retrospectively reviewed between the years 1996-2000. Patients with MS and TN who received a percutaneous rhizotomy during that time were included in the study and followed until the end of 2002. Data regarding age, sex, duration of MS and pain, response to medical treatment, pain distribution and surgical outcome were evaluated. RESULTS There were thirteen patients with MS and medically refractory TN treated with percutaneous radiofrequency rhizotomy. The average age at diagnosis for MS was 41 with TN beginning an average of eight years later. Following rhizotomy, complete pain relief without the need for any medication was achieved in 81% of the patients. The addition of medications resulted in pain control in the remaining patients. During a mean follow-up period of 52 months, there was a 50% recurrence rate. There were no complications related to the procedure and the associated facial numbness was well-tolerated. CONCLUSIONS Percutaneous radiofrequency rhizotomy is a safe and effective method for the treatment of TN in patients with MS. The unique susceptibility of this cohort to the side effects of antineuralgic medications may require early consideration of rhizotomy.

Neuroepithelial cysts presenting with movement disorders: two cases.

BACKGROUND The authors present two cases of movement disorders caused by neuroepithelial cysts and highlight their management. Neuroepithelial cysts are ependymal or epithelial lined fluid collections of unknown etiology within the central nervous system parenchyma with no obvious ventricular or subarachnoid connection. Most cysts are asymptomatic, however, some present with seizures, mass effect, or rarely with movement disorders. CASE REPORTS The first patient, a 27-year-old female, presented with progressive weakness, dystonic posturing, tremor, ballismus and choreoathetotic movements of her right upper extremity. Her symptoms improved after stereotactic drainage of a neuroepithelial cyst in her basal ganglia but recurred within a year. The second case, a 56-year-old female, presented with diplopia, nystagmus, gait imbalance and hemiparesis. Her symptoms improved after stereotactic drainage of a midbrain neuroepithelial cyst. The cyst reaccumulated over the next few years and she became symptomatic with left arm tremor and facial weakness. Aspiration was again performed with symptomatic improvement for nine months. Her tremor recurred and a cyst access device was placed stereotactically. She improved and has remained stable for over a year. CONCLUSION Simple stereotactic drainage of neuroepithelial cysts has a high recurrence rate. The authors recommend considering placement of a drainage device to facilitate aspiration of the cyst fluid during follow-up, if needed.

Microelectrode Recording for Pallidotomy: Mandatory, Beneficial or Dangerous?

There is an active debate regarding whether pallidotomy should be performed with microelectrode recording or macroelectrode stimulation. A meta-analysis was performed on the published reports (1992–2000) of unilateral pallidotomy for Parkinson’s disease to determine if the outcome or complications of this procedure significantly differed between these two techniques. Papers were excluded if they followed a cohort of less than ten patients, had follow-up less than three months, or included previously reported patients. There were no significant differences between the two techniques in improvement of dyskinesia (p = 0.66) or UPDRS motor score (p = 0.62). Microelectrode recording had a significantly higher (p = 0.012) intracerebral hemorrhage rate (1.3 ± 0.4%) compared to macroelectrode stimulation (0.2 ± 0.2%).

Percutaneous Biopsy through the Foramen ovale: A Case Report

A 59-year-old man presented with an intracranial mass that involved the cavernous sinus. It was biopsied percutaneously through the foramen ovale and the diagnosis of meningioma was established. The literature was reviewed for the employment of similar procedures and the potential benefits of this technique explored.

Resolution of cerebral vasospasm with trapidil; an animal model

Cerebral vasospasm and rebleeding are important clinical phenomena associated with a high mortality rate. Therefore, any promising finding in the laboratory deserves assessment in clinical practice. The present study was designed to examine the possible effects of trapidil on the basilar artery of the rabbit through a cerebral vasospasm model. This experimental study was carried out on 26 adult New Zealand albino rabbits of both sexes weighing 2.5-3.0 kg. A transclival exposure was performed. Vasospasm was produced by an intracisternal injection of autologous blood. After observation of the vasospasm, trapidil was locally applied in increasing concentrations (10(-5)-10(-4) M). The effect of each concentration was measured independently after 10 minutes for each application and was extended to three hours. Trapidil was shown to have a clear spasmolytic effect on the rabbits basilar artery. These data suggest that trapidil can have a potential use in the treatment of patients suffering from cerebral vasospasm.