Edema-like marrow signal intensity (ELMSI) associated with nonossifying fibroma (NOF) on MRI: an uncommon finding in a common bone lesion.

OBJECTIVE: To investigate the association between nonossifying fibroma (NOF) and perilesional edema-like marrow signal intensity (ELMSI) on MRI and discuss the clinical and diagnostic implications of this finding. MATERIALS AND METHODS: A retrospective search for "nonossifying fibroma" and "NOF" on knee MRI reports of patients up to 20 years of age over a 5-year period was performed. A total of 77 patients (34 males, 43 females, ages 11-20) were identified, and each MRI was reviewed to evaluate for ELMSI associated with the NOF. Statistical analysis was performed to determine if there was a correlation with the presence of perilesional ELMSI and age, gender, lesion size, or signal characteristics. RESULTS: Twelve patients out of 77 (16%) had ELMSI associated with a NOF. Excluding patients who had additional findings of pathologic fracture (n = 2), a known potential complication of NOFs, and edema related to an adjacent osteoid osteoma (n = 1), a total of 9 patients (12%) had otherwise unexplained perilesional ELMSI. There was no statistically significant difference between patients with vs. without perilesional ELMSI with respect to age (p = 0.08), gender (p = 0.28), lesion size (p = 0.52), or appearance on fluid-sensitive sequences (p = 0.81). CONCLUSION: ELMSI can be seen about NOFs encountered around the knee joint on MRI, which may represent active healing and/or involutional change of this "do not touch" lesion in cases where no other explanation is identified.

Occult fracture propagation in patients with isolated greater trochanteric fractures: patterns and management.

OBJECTIVE: To demonstrate the degrees of occult intertrochanteric extension on MRI in patients with a greater trochanteric fracture on radiography or computer tomography (CT) and whether these patients undergo conservative or surgical management with hardware. MATERIALS AND METHODS: Retrospective review was performed of 146 patients (104 females, 42 males, ages 33-102) who had follow-up MRI after identification of a greater trochanteric fracture without intertrochanteric extension on radiography or CT. Extent of intertrochanteric extension was recorded. Subsequently, EMR review was performed to see if patients underwent surgery. Specific note was made of hardware type. Analysis was performed to determine if there is a correlation with fracture type and surgical management as well as fracture type and age and gender. RESULTS: Nineteen patients had horizontal greater trochanter fractures without intertrochanteric extension; none underwent surgery. Seventeen patients had a vertical fracture along the lateral femoral cortex; one underwent surgery. Thirty-three patients had a fracture with intertrochanteric extension less than 50% in the mid coronal plane; 21 underwent surgery. Forty patients had intertrochanteric extension greater than 50% in the midcoronal plane not contacting the medial cortex; 28 underwent surgery. Thirty-seven patients had fractures contacting the medial cortex; 28 underwent surgery. There was significant difference with fractures extending 50% or greater of the midline of the intertrochanteric region undergoing surgical management compared with fractures less than 50% (p < 0.0001). CONCLUSION: MRI identifies the presence and extent of occult intertrochanteric fractures in patients with greater trochanteric fractures. Description of intertrochanteric fractures on MRI helps determine the patient's treatment course and influence surgical decisions.

The use of an upper extremity hemodialysis access site for stenting of the superior mesenteric artery for chronic mesenteric ischemia.

We report the use of an upper extremity hemodialysis access site to facilitate endovascular treatment of the superior mesenteric artery in the setting of chronic mesenteric ischemia. A 64-year-old woman with end-stage renal disease on hemodialysis presented with worsening symptoms associated with chronic mesenteric ischemia. Her left upper extremity interposition graft within the fistula access site was selected to avoid a hostile aortoiliac system and in consideration of the potential benefits it provided over transfemoral, transbrachial, and transradial sites. The procedure was technically successful without complication. Hemodialysis access sites, such as the interposition graft within the fistula of this patient, are a potential route of upper extremity access for mesenteric interventions in patients with end-stage renal disease on hemodialysis.

A case report and review of thoracic spinal angiolipoma.

BACKGROUND: While it is a rare entity, spinal angiolipomas are well-defined benign tumors that have been described sporadically in the literature starting from the late 1800s. Composed of mature lipomatous and angiomatous elements, these tumors manifest neurological symptoms due to progressive spinal cord or root compression. We present a case of a thoracic spinal angiolipoma and review the relevant literature. CASE DESCRIPTION: A 68-year-old male with ongoing bilateral lower extremity weakness was found on enhanced magnetic resonance imaging to have an extradural mass in the thoracic spine causing cord compression. A T4-T8 laminectomy and complete excision of the epidural mass resulted in reversal of the patient's neurological symptoms. Histopathology identified the mass as a thoracic spinal angiolipoma. CONCLUSION: Given its uncommon occurrence and excellent prognosis, our report serves as a reminder to always consider spinal angiolipoma in the differential diagnosis of epidural masses.

Lithium increases synaptic GluA2 in hippocampal neurons by elevating the δ-catenin protein.

Lithium (Li+) is a drug widely employed for treating bipolar disorder, however the mechanism of action is not known. Here we study the effects of Li+ in cultured hippocampal neurons on a synaptic complex consisting of δ-catenin, a protein associated with cadherins whose mutation is linked to autism, and GRIP, an AMPA receptor (AMPAR) scaffolding protein, and the AMPAR subunit, GluA2. We show that Li+ elevates the level of δ-catenin in cultured neurons. δ-catenin binds to the ABP and GRIP proteins, which are synaptic scaffolds for GluA2. We show that Li+ increases the levels of GRIP and GluA2, consistent with Li+-induced elevation of δ-catenin. Using GluA2 mutants, we show that the increase in surface level of GluA2 requires GluA2 interaction with GRIP. The amplitude but not the frequency of mEPSCs was also increased by Li+ in cultured hippocampal neurons, confirming a functional effect and consistent with AMPAR stabilization at synapses. Furthermore, animals fed with Li+ show elevated synaptic levels of δ-catenin, GRIP, and GluA2 in the hippocampus, also consistent with the findings in cultured neurons. This work supports a model in which Li+ stabilizes δ-catenin, thus elevating a complex consisting of δ-catenin, GRIP and AMPARs in synapses of hippocampal neurons. Thus, the work suggests a mechanism by which Li+ can alter brain synaptic function that may be relevant to its pharmacologic action in treatment of neurological disease.