Herpes zoster complicated by phrenic nerve palsy and respiratory compromise

Background: Herpes zoster can be associated with severe neurological complications.Case presentation: In this article, we describe the case of a 54-year-old man with herpes zoster affecting his right upper chest and neck region complicated by phrenic nerve palsy and respiratory compromise. The diagnosis of herpes zoster was made based on the classic appearance of the rash and associated neuropathic-type pain. The diagnosis of phrenic nerve palsy was made by chest x-ray and ultrasound.Conclusion: Clinicians should be aware of the possibility of phrenic nerve palsy occurring in patients who have herpes zoster affecting the region of C3,4,5 dermatomes. Although symptoms of unilateral diaphragmatic paresis are usually mild, in patients with obesity or comorbid lung disease, new onset phrenic nerve palsy can lead to significant respiratory compromise.Keywords: Herpes zoster, neurologic complication, phrenic nerve palsy, case report

Herpes zoster complicated by phrenic nerve palsy and respiratory compromise

Background: Herpes zoster can be associated with severe neurological complications. Case presentation: In this article, we describe the case of a 54-year-old man with herpes zoster affecting his right upper chest and neck region complicated by phrenic nerve palsy and respiratory compromise. The diagnosis of herpes zoster was made based on the classic appearance of the rash and associated neuropathic-type pain. The diagnosis of phrenic nerve palsy was made by chest x-ray and ultrasound. Conclusion: Clinicians should be aware of the possibility of phrenic nerve palsy occurring in patients who have herpes zoster affecting the region of C3,4,5 dermatomes. Although symptoms of unilateral diaphragmatic paresis are usually mild, in patients with obesity or comorbid lung disease, new onset phrenic nerve palsy can lead to significant respiratory compromise

A 13C/31P surface coil to visualize metabolism and energetics in the rodent brain at 3 Tesla

PurposeWe constructed a 13C/31P surface coil at 3 T for studying cancer metabolism and bioenergetics. In a single scan session, hyperpolarized 13C-pyruvate MRS and 31P MRS was carried out for a healthy rat brain.MethodsAll experiments were carried out at 3 Tesla. The multinuclear surface coil was designed as two coplanar loops each tuned to either the 13C or 31P operating frequency with an LCC trap on the 13C loop. A commercial volume proton coil was used for anatomical localization and B0 shimming. Single tuned coils operating at either the 13C or 31P frequency were built to evaluate the relative performance of the multinuclear coil. Coil performance metrics consisted of measuring Q factor ratio, calculating system input power using a single-pulse acquisition, and acquiring SNR and flip angle maps using 2D CSI sequences. To observe in vivo spectra, a bolus of hyperpolarized [1-13C] pyruvate was administered via tail vein. In vivo13C and endogenous 31P spectra were obtained in a single scan session using 1D slice selective acquisitions.ResultsWhen compared with single tuned surface coils, the multinuclear coil performance showed a decrease in Q factor ratio, SNR, and transmit efficiency. Flip angle maps showed adequate flip angles within the phantom when the transmit voltage was set using an external phantom. Results show good detection of 13C labeled lactate, alanine, and bicarbonate in addition to ATP from 31P MRS.ConclusionsThe coil enables obtaining complementary information within a scan session, thus reducing the number of trials and minimizing biological variability for studies of metabolism and bioenergetics

Travelling-wave nuclear magnetic resonance

Nuclear magnetic resonance (NMR) is one of the most versatile experimental methods in chemistry, physics and biology, providing insight into the structure and dynamics of matter at the molecular scale. Its imaging variant-magnetic resonance imaging (MRI)-is widely used to examine the anatomy, physiology and metabolism of the human body. NMR signal detection is traditionally based on Faraday induction in one or multiple radio-frequency resonators that are brought into close proximity with the sample. Alternative principles involving structured-material flux guides, superconducting quantum interference devices, atomic magnetometers, Hall probes or magnetoresistive elements have been explored. However, a common feature of all NMR implementations until now is that they rely on close coupling between the detector and the object under investigation. Here we show that NMR can also be excited and detected by long-range interaction, relying on travelling radio-frequency waves sent and received by an antenna. One benefit of this approach is more uniform coverage of samples that are larger than the wavelength of the NMR signal-an important current issue in MRI of humans at very high magnetic fields. By allowing a significant distance between the probe and the sample, travelling-wave interaction also introduces new possibilities in the design of NMR experiments and systems