Texture Analysis to Detect Cerebral Degeneration in Amyotrophic Lateral Sclerosis.

BACKGROUND: Evidence of cerebral degeneration is not apparent on routine brain MRI in amyotrophic lateral sclerosis (ALS). Texture analysis can detect change in images based on the statistical properties of voxel intensities. Our objective was to test the utility of texture analysis in detecting cerebral degeneration in ALS. A secondary objective was to determine whether the performance of texture analysis is dependent on image resolution. METHODS: High-resolution (0.5×0.5 mm2 in-plane) coronal T2-weighted MRI of the brain were acquired from 12 patients with ALS and 19 healthy controls on a 4.7 Tesla MRI system. Image data sets at lower resolutions were created by down-sampling to 1×1, 2×2, 3×3, and 4×4 mm2. Texture features were extracted from a slice encompassing the corticospinal tract at the different resolutions and tested for their discriminatory power and correlations with clinical measures. Subjects were also classified by visual assessment by expert reviewers. RESULTS: Texture features were different between ALS patients and healthy controls at 1×1, 2×2, and 3×3 mm2 resolutions. Texture features correlated with measures of upper motor neuron function and disability. Optimal classification performance was achieved when best-performing texture features were combined with visual assessment at 2×2 mm2 resolution (0.851 area under the curve, 83% sensitivity, 79% specificity). CONCLUSIONS: Texture analysis can detect subtle abnormalities in MRI of ALS patients. The clinical yield of the method is dependent on image resolution. Texture analysis holds promise as a potential source of neuroimaging biomarkers in ALS.

Acute Prevertebral Calcific Tendinitis.

We present a case of neck pain in a middle-aged woman, initially attributed to a retropharyngeal infection and treated with urgent intubation. With the help of computed tomography, the diagnosis was later revised to acute prevertebral calcific tendinitis, a self-limiting condition caused by abnormal calcium hydroxyapatite deposition in the longus colli muscles. It is critical to differentiate between these two disease entities due to dramatic differences in management. A discussion of acute prevertebral calcific tendinitis and its imaging findings is provided below.

Prolonged Delirium Secondary to Hypoxic-ischemic Encephalopathy Following Cardiac Arrest.

Hypoxic-ischemic brain injury encompasses a complex constellation of pathophysiological and cellular brain injury induced by hypoxia, ischemia, cytotoxicity, or combinations of these mechanisms and can result in poor outcomes including significant changes in personality and cognitive impairments in memory, cognition, and attention. We report a case of a male patient with normal premorbid functioning who developed prolonged delirium following hypoxic-ischemic brain insults subsequent to cardiac arrest. The case highlights the importance of adopting a multidisciplinary treatment approach involving the coordinated care of medical and nursing teams to optimise management of patients suffering from such a debilitating organic brain syndrome.

Stimuli-responsive peptide-based ABA-triblock copolymers: unique morphology transitions with pH.

We report the synthesis and solution characterization of poly(L-lysine)-b-poly(propylene oxide)-b-poly(L-lysine) (KPK) triblock copolymers with high lysine weight fractions (>75 wt%). In contrast to PK diblock copolymers in this composition range, KPK triblock copolymers exhibit morphology transitions as a function of pH. Using a combination of light-scattering and microscopy techniques, we demonstrate spherical micelle-vesicle and spherical micelle-disk micelle transitions for different K fractions. We interpret these morphology changes in terms of the energy penalty associated with folding the core P block to form a spherical micelle in relation to the interfacial curvature associated with different charged states of the K block.

Persistent, severe hypoglycemia-induced organic brain syndrome with neurological sequelae: a case report.

Hypoglycemia is a biochemical abnormality and often the rate-limiting step in the treatment of both type 1 and type 2 diabetes mellitus. Left uncorrected and prolonged, hypoglycemia can result in neuronal dysfunction and death, with deficits ranging from measurable cognitive impairments to aberrant behavior, seizures and coma. In this case report, hypoglycemia resulted in severe and persistent neurological (slurred speech and gait abnormalities), cognitive (inattention, disorientation and memory deficits) and behavioral manifestations (verbal hostility and irritability). It highlights the potentially severe neuropsychiatric sequelae following hypoglycemia and is timely for clinicians to be reminded that hypoglycemia prevention needs to be more of a focus of diabetes care in general.

Temperature- and pH-responsive self-assembly of poly(propylene oxide)-b-poly(lysine) block copolymers in aqueous solution.

A series of poly(propylene oxide)-b-poly(L-lysine) (PPO-PK) block copolymers were synthesized using Huisgen's 1,3-dipolar cycloaddition, and the solution self-assembly was studied using transmission electron microscopy, circular dichroism spectroscopy, and dynamic and static light scattering techniques. In contrast to previous studies of poly(lysine)-based block copolymers, PPO-PK exhibits a significant shift in the pH associated with the helix-coil transition of the poly(lysine) block, potentially a result of decreased hydrophobicity in the core PPO block. Given the proximity of the lower critical solution temperature of the PPO block, these materials exhibit both pH and temperature-responsive (i.e., "schizophrenic") self-assembly, the latter of which was interpreted in terms of changes in the second osmotic virial coefficient. Finally, the vesicle morphology obtained from these polymers was studied for the propensity in drug encapsulation and passive release.

First report of Schistosoma mekongi infection with brain involvement.

We describe, to our knowledge, the first reported case of Schistosoma mekongi infection with brain involvement. S. mekongi is a distinct species most closely related to Schistosoma japonicum that is endemic in a defined area of the Mekong River in Laos and Cambodia and characteristically associated with hepatosplenic disease. The patient had an excellent response to praziquantel therapy but required repeated courses of corticosteroid therapy to suppress recrudescent neurological symptoms.