Tethered Spinal Cord due to Thoracic Spinal Cord Lipoma: Minimally Invasive Surgical Management Case Report and Literature Review

An unusual case of a thoracic spine lipoma presenting with profound progressive numbness along with difficult to interpret preoperative imaging is discussed. A uniquely minimally invasive surgical treatment approach with successful outcome and improved neurologic symptoms is presented. A literature review and discussion of the benefits and limitations of a minimally invasive surgical technique are provided. A male presented with several months of progressive bilateral lower extremity numbness that ascended to the mid-thoracic spine. Spine magnetic resonance imaging demonstrated a 9 mm intradural, thoracic spinal mass, which was thought preoperatively to represent an arachnoid cyst with an adhesion or a localized dural ectasia. Subsequent imaging demonstrated a band at the cranial margin of the mass appearing to tether the spinal cord to the dorsal-lateral spinal canal without an arachnoid cyst or osseous defect. Surgical exploration revealed an intradural exophytic, intramedullary fatty mass tethering the spinal cord to the dorsolateral dura. An abnormal patch of dura was observed overlying the fatty attachment but no dural defect was identified. Pathology demonstrated fragments of fibroconnective tissue, scattered mature adipocytes, and entrapped meningeal cells, yielding the diagnosis of a spinal cord lipoma. Follow up imaging demonstrated no residual tethering of the spinal cord

Metal-binding amino acid ligands commonly found in metalloproteins differentially fractionate copper isotopes

Abstract Copper (Cu) is a cofactor in numerous key proteins and, thus, an essential element for life. In biological systems, Cu isotope abundances shift with metabolic and homeostatic state. However, the mechanisms underpinning these isotopic shifts remain poorly understood, hampering use of Cu isotopes as biomarkers. Computational predictions suggest that isotope fractionation occurs when proteins bind Cu, with the magnitude of this effect dependent on the identity and arrangement of the coordinating amino acids. This study sought to constrain equilibrium isotope fractionation values for Cu bound by common amino acids at protein metal-binding sites. Free and bound metal ions were separated via Donnan dialysis using a cation-permeable membrane. Isotope ratios of pre- and post-dialysis solutions were measured by MC-ICP-MS following purification. Sulfur ligands (cysteine) preferentially bound the light isotope (63Cu) relative to water (Δ65Cucomplex-free = − 0.48 ± 0.18‰) while oxygen ligands favored the heavy isotope (65Cu; + 0.26 ± 0.04‰ for glutamate and + 0.16 ± 0.10‰ for aspartate). Binding by nitrogen ligands (histidine) imparted no isotope effect (− 0.01 ± 0.04‰). This experimental work unequivocally demonstrates that amino acids differentially fractionate Cu isotopes and supports the hypothesis that metalloprotein biosynthesis affects the distribution of transition metal isotopes in biological systems

Technical challenges to anterior temporal lobectomy after laser interstitial thermal therapy for mesial temporal lobe epilepsy: technical note

Mesial temporal sclerosis (MTS) is a frequent cause of medically refractory epilepsy, for which laser interstitial thermal therapy (LITT) is an effective treatment. However, experience with the technical considerations posed by additional surgery after an initial LITT procedure is lacking. The authors present the case of a 12-year-old female with medically refractory temporal lobe epilepsy and left MTS who underwent LITT at a separate institution prior to referral. This patient had no change in early postoperative seizure control (Engel class IVB) and then her seizures worsened despite ongoing medical treatment (Engel class IVC). Post-LITT MRI revealed sparing of the mesial hippocampus head, a poor prognostic factor. The authors describe the technical details illustrated by this case of secondary, stereotactic electroencephalography-guided mesial temporal resection following LITT. The case was managed with anterior temporal lobectomy including the resection of residual hippocampus and amygdala