Physical Examination Is Predictive of Cauda Equina Syndrome: MRI to Rule Out Diagnosis Is Unnecessary.

STUDY DESIGN: Cross-sectional cohort study. OBJECTIVES: Cauda equina syndrome (CES) is a neurologic emergency, and delay in diagnosis can result in irreversible impairment. Our purpose was to determine the value of physical examination in diagnosis of CES in patients complaining of bladder and/or bowel complications in the emergency department. METHODS: Adult patients at one tertiary academic medical center that endorsed bowel/bladder dysfunction, underwent a lumbar magnetic resonance imaging (MRI), and received an orthopedic spine surgery consultation from 2008 to 2017 were included. Patients consulted for trauma or tumor were excluded. A chart and imaging review was performed to collect demographic, physical examination, and treatment data. Sensitivity, specificity, and negative and positive predictive values were calculated, and fast-and-frugal decision trees (FFTs) were generated using R. RESULTS: Of 142 eligible patients, 10 were diagnosed with CES. The sensitivity and specificity of the exam findings were highest for bulbocavernosus reflex (BCR) (100% and 100%), followed by rectal tone (80% and 86%), postvoid residual bladder (80% and 59%), and perianal sensation (60% and 68%). The positive predictive value was high for BCR (100%), but low for other findings (13% to 31%). However, negative predictive values were consistently high for all examinations (96% to 100%). Two FFTs utilizing combinations of voluntary rectal tone, perianal sensation, and BCR resulted in no false negatives. CONCLUSIONS: A combination of physical examination findings of lower sacral function is an effective means of ruling out CES and, with further study, may eliminate the need for MRI in many patients reporting back pain and bowel or bladder dysfunction.

Beyond Adjustment: Authoring a (Re)learned Reality.

A survivor of a traumatic brain injury makes sense of his injury and reflects on the unique individuality of injury.

High-pressure high-temperature phase diagram of organic crystal paracetamol.

High-pressure high-temperature (HPHT) Raman spectroscopy studies have been performed on the organic crystal paracetamol in a diamond anvil cell utilizing boron-doped heating diamond anvil. Isobaric measurements were conducted at pressures up to 8.5 GPa and temperature up to 520 K in five different experiments. Solid state phase transitions from monoclinic Form I → orthorhombic Form II were observed at various pressures and temperatures as well as transitions from Form II → unknown Form IV. The melting temperature for paracetamol was observed to increase with increasing pressures to 8.5 GPa. This new data is combined with previous ambient temperature high-pressure Raman and x-ray diffraction data to create the first HPHT phase diagram of paracetamol.

Polymorphism in paracetamol: evidence of additional forms IV and V at high pressure.

The structural phase stability of N-(4-hydroxyphenyl) acetamide (paracetamol) has been studied at ambient temperature up to 23 GPa using Raman spectroscopy. Spectral changes have provided further evidence for a highly kinetically driven Form I → II transition that occurs as a mixed phase from 4.8 to 6.5 GPa, and might complete as early as 7 GPa. Upon further compression to 8.1 GPa, a drastic shift in spectral signature was observed providing the first evidence for a previously undiscovered Form IV of paracetamol. Additional shifts in mode intensities were observed near 11 GPa indicating a potential restructuring of the hydrogen bonding network and/or structural modification to a potentially new Form V. Phase boundaries at 7 and 8 GPa were confirmed under hydrostatic conditions using Raman spectroscopy. Spectral changes indicate that the transition Form IV → V occurs near 11 GPa. Multiple ab initio harmonic frequency calculations at different levels of theory were performed with a B3LYP/6-31G** being used to provide a more robust mode assignment to our experimentally obtained Raman modes. High pressure X-ray diffraction (XRD) was performed up to 21 GPa, which provided further evidence for a highly kinetically driven Form I → II transition in agreement with our Raman measurements. In addition, the XRD provided further evidence for the existence of Form IV near 8 GPa and Form V near 11 GPa with Form V persisting up to 21 GPa.