High-Resolution Three-Dimensional Computed Tomography for Assessing Complications Related to Intrathecal Drug Delivery

BACKGROUND

The assessment of the functionality of intrathecal drug delivery (IDD) systems remains difficult and time-consuming. Catheter-related problems are still very common, and sometimes difficult to diagnose.

OBJECTIVES

The aim of the present study is to investigate the accuracy of high-resolution three-dimensional computed tomography (CT) in order to detect catheter-related pump dysfunction.

STUDY DESIGN

An observational, retrospective investigation.

SETTING

Academic medical center in Germany.

METHODS

We used high-resolution three dimensional (3D) computed tomography with volume rendering technique (VRT) or fluoroscopy and conventional axial-CT to assess IDD-related complications in 51 patients from our institution who had IDD systems implanted for the treatment of chronic pain or spasticity.

RESULTS

Twelve patients (23.5%) presented a total of 22 complications. The main type of complication in our series was catheter-related (50%), followed by pump failure, infection, and inappropriate refilling. Fluoroscopy and conventional CT were used in 12 cases. High-resolution 3D CT VRT scan was used in 35 instances with suspected yet unclear complications. Using 3D-CT (VRT) the sensitivity was 58.93% - 100% (CI 95%) and the specificity 87.54% - 100% (CI 95%).The positive predictive value was 58.93% - 100% (CI 95%) and the negative predictive value: 87.54% - 100% (CI 95%).Fluoroscopy and axial CT as a combined diagnostic tool had a sensitivity of 8.3% - 91.7% (CI 95%) and a specificity of 62.9% - 100% (CI 95%). The positive predictive value was 19.29% - 100% (CI 95%) and the negative predictive value: 44.43% - 96.89% (CI 95%).

LIMITATIONS

This study is limited by its observational design and the small number of cases.

CONCLUSION

High-resolution 3D CT VRT is a non- invasive method that can identify IDD-related complications with more precision than axial CT and fluoroscopy.

Increased coherence among striatal regions in the theta range during attentive wakefulness

The striatum, the largest component of the basal ganglia, is usually subdivided into associative, motor and limbic components. However, the electrophysiological interactions between these three subsystems during behavior remain largely unknown. We hypothesized that the striatum might be particularly active during exploratory behavior, which is presumably associated with increased attention. We investigated the modulation of local field potentials (LFPs) in the striatum during attentive wakefulness in freely moving rats. To this end, we implanted microelectrodes into different parts of the striatum of Wistar rats, as well as into the motor, associative and limbic cortices. We then used electromyograms to identify motor activity and analyzed the instantaneous frequency, power spectra and partial directed coherence during exploratory behavior. We observed fine modulation in the theta frequency range of striatal LFPs in 92.5 ± 2.5% of all epochs of exploratory behavior. Concomitantly, the theta power spectrum increased in all striatal channels (P < 0.001), and coherence analysis revealed strong connectivity (coefficients >0.7) between the primary motor cortex and the rostral part of the caudatoputamen nucleus, as well as among all striatal channels (P < 0.001). Conclusively, we observed a pattern of strong theta band activation in the entire striatum during attentive wakefulness, as well as a strong coherence between the motor cortex and the entire striatum. We suggest that this activation reflects the integration of motor, cognitive and limbic systems during attentive wakefulness.

Mesenchymal stem cells maintain TGF-beta-mediated chondrogenic phenotype in alginate bead culture

This article addresses the stability of chondrogenic phenotype and the transdifferentiation potential of bone marrow-derived mesenchymal stem cells (MSCs) at distinct stages of differentiation. Differentiated MSCs were expected to maintain cartilage-like gene expression pattern in the absence of any chondrogenic growth factor or in the presence of osteogenic signals. MSCs encapsulated in alginate beads were treated with transforming growth factor (TGF)-beta 3 for 3, 6, or 14 days and then cultured in absence of TGF-beta for the remainder of the 2-week culture period. Additionally, cells were cultured in osteogenic medium after TGF-beta-mediated chondroinduction. Gene expression of col2a1, aggrecan, COMP, alkaline phosphatase (AP), and correlating protein synthesis was analyzed. After short-term stimulation with TGF-beta, MSCs maintained a chondrogenic phenotype. Chondrogenic gene expression and protein synthesis directly correlated with the extent of stimulation time and the concentration of TGF-beta. Pretreatment with TGF-beta could prevent AP mRNA expression of encapsulated MSCs. TGF- beta stimulation within the first 3 days of culture seems to be crucial for the expression of a chondrogenic phenotype. Fully differentiated and encapsulated MSCs are not able to transdifferentiate into osteoblasts. These findings give rise to a better understanding of the behavior of cartilage grafts affected by local factors of osteochondral transplantation sites in vivo.

Interstitial irradiation for CNS lesions

In this study, we investigated the efficacy of brachytherapy in the treatment of 138 patients with intracranial neoplasms of the CNS. Of the total number of patients, 50 presented with glioblastoma multiforme, 45 presented with low-grade glioma, 19 presented with anaplastic astrocytoma, 23 presented with metastases and 1 presented with meningioma. During the execution of this study, seeds of 125I (10-20 mCi) were inserted into the lesions to aim the irradiation at a low dose of 60 Gy in the margin of benign lesions or 1 cm beyond the radiological border of malignant lesions, which were visualized on CT scan. The results of this procedure were evaluated in terms of the survival rates, which were assessed by Kaplan-Meier curves. Significant relationships were not observed between the volume and location of the lesions, the whole-brain radiotherapy and chemotherapy, and the survival time of the patients. A low Karnofsky Index score and older age were associated with a short survival time. In light of the above, it was concluded that interstitial irradiation is a safe and effective method of treatment for brain tumors.

Bulbar Trigeminal Stereotactic Nucleotractotomy for Treatment of Facial Pain

Many pharmacological and surgical treatments are available for the treatment of chronic facial pain. However, many of them are expensive and often very ineffective. Past publications suggested that bulbar trigeminal stereotactic nucleotractotomy is a very useful procedure for the treatment of neuropathic or oncologic facial pain. The authors describe the results of treatment with stereotactic nucleotractotomy in 58 patients with chronic facial pain. The intensity of the pain was evaluated according to the visual analogue scale, and daily life activities were also evaluated. The conclusion was that this procedure is a safe and effective method for treatment of postherpetic neuralgia, Wallenberg's syndrome and oncologic facial pain but not of trigeminal neuralgia.

Chronic Pain after Spinal Cord Injury: Clinical Characteristics

The clinical characteristics of chronic pain in spinal cord injury patients are controversial. The authors prospectively evaluated 81 patients with chronic pain due to spinal cord lesions. The mean pain intensity according to the visual analogue scale was 9.4. The most common description of pain was a sensation of burning. The initial pain was more severe in patients presenting with myelopathy due to gunshot injuries (p < 0.001). The pain intensity was not associated with the magnitude of the spinal lesion, location of the lesion, occurrence of myofascial pain syndrome or onset of pain. Pain after spinal cord injury was severe, males were more frequently affected and it was more intense when it was the result of gunshot injury. In about 38% of the patients, pharmacological and rehabilitative procedures were effective. Dorsal root entry zone lesion was effective for the treatment of transitional pain in patients with complete section of the spinal cord, spinal cord stimulation was effective for patients with partial lesions of the spinal cord and intrathecal opioid infusion was effective for both conditions.

MR and CT imaging in the Dyke-Davidoff-Masson syndrome. Report of three cases and contribution to pathogenesis and differential diagnosis

Cerebral hemiatrophy or Dyke-Davidoff-Masson syndrome is a condition characterized by seizures, facial asymmetry, contralateral hemiplegia or hemiparesis, and mental retardation. These findings are due to cerebral injury that may occur early in life or in utero. The radiological features are unilateral loss of cerebral volume and associated compensatory bone alterations in the calvarium, like thickening, hyperpneumatization of the paranasal sinuses and mastoid cells and elevation of the petrous ridge. The authors describe three cases. Classical findings of the syndrome are present in variable degrees according to the extent of the brain injury. Pathogenesis is commented.