Dorsal Root Ganglion Stimulation to Treat Focal Postsurgical and Diffuse Chronic Pain: A Case Report.

Dorsal root ganglion stimulation (DRG-S) is widely accepted for treating focal pain syndromes. We present the case of a 46-year-old woman with severe lumbar radiculopathy with an implanted spinal cord stimulator (SCS) that had lost efficacy. She developed an incisional hernia after undergoing a minimally invasive, extreme lateral interbody fusion and SCS explant. After herniorrhaphy, she presented with severe pain at the T10-T11 dermatomes, which we treated with DRG-S. One-year after lumbar fusion, her refractory lumbar and radicular pain returned, which we ultimately treated with bilateral T12+S1 DRG-S. DRG-S was thus used to successfully treat focal postsurgical and diffuse chronic pain.

Lumbar Dorsal Root Ganglion Stimulation Lead Placement Using an Outside-In Technique in 4 Patients With Failed Back Surgery Syndrome: A Case Series.

Dorsal root ganglion stimulation (DRG-S) has shown promise as a treatment for low back pain. The traditional anterograde placement of DRG-S leads can be challenging in patients with anatomical changes from prior back surgery. We describe an "outside-in" placement technique of DRG-S leads in 4 patients with histories of multiple lumbar surgeries, which made the traditional anterograde placement not feasible. At long-term follow-up, the patients experienced substantial pain relief and improvement in quality of life, with no complications. The outside-in lead placement technique may be an efficacious alternative to the traditional techniques in patients with anomalous anatomy from prior surgery.

Long-term vitamin A deficiency induces alteration of adult mouse spermatogenesis and spermatogonial differentiation: direct effect on spermatogonial gene expression and indirect effects via somatic cells.

The objective of this study was to further understand the genetic mechanisms of vitamin A deficiency (VAD) induced arrest of spermatogonial stem-cell differentiation. Vitamin A and its derivatives (the retinoids) participate in many physiological processes including vision, cellular differentiation and reproduction. VAD affects spermatogenesis, the subject of our present study. Spermatogenesis is a highly regulated process of differentiation and complex morphologic alterations that leads to the formation of sperm in the seminiferous epithelium. VAD causes early cessation of spermatogenesis, characterized by degeneration of meiotic germ cells, leading to seminiferous tubules containing mostly type A spermatogonia and Sertoli cells. These observations led us to the hypothesis that VAD affects not only germ cells but also somatic cells. To investigate the effects of VAD on spermatogenesis in mice we used adult Balb/C mice fed with Control or VAD diet for an extended period of time (6-28 weeks). We first observed the chronology, then the extent of the effects of VAD on the testes. Using microarray analysis of isolated pure populations of spermatogonia, Leydig and Sertoli cells from control and VAD 18- and 25-week mice, we examined the effects of VAD on gene expression and identified target genes involved in the arrest of spermatogonial differentiation and spermatogenesis. Our results provide a more precise definition of the chronology and magnitude of the consequences of VAD on mouse testes than the previously available literature and highlight direct and indirect (via somatic cells) effects of VAD on germ cell differentiation.

Methylation patterns of Brahma during spermatogenesis and oogenesis: potential implications.

To compare methylation profiles and expression levels of Brahma at different stages of spermatogenesis, and to identify the methylation pattern during oogenesis, we analyzed gene expression and methylation patterns in murine germ cells at various developmental stages. The methylation levels of CpG islands within Brahma increased during spermatogenesis and decreased during oogenesis. This change in methylation pattern correlates with the change in expression of Brahma during spermatogenesis. As the degree of methylation increases, the expression decreases. The change in methylation is opposite during oogenesis, which suggests opposite expression levels.