Paul Larson, Peter Nakaji, Walter Stummer, and John Pollina
Asham Khan, John Pollina, and Jeffrey P. Mullin
Simon Morr, Hakeem J. Shakir, Lindsay J. Lipinski, Vassilios G. Dimopoulos, Jody Leonardo, and John Pollina
Vertebral fractures are the most common osteoporotic fracture. Bone density testing and medical treatment with bisphosphonates or parathormone are recommended for all patients with an osteoporotic fracture diagnosis. Inadequate testing and treatment of patients presenting with low-impact fractures have been reported in various specialties. Similar data are not available from academic neurosurgery groups. The authors assessed compliance with treatment and testing of osteoporosis in patients with vertebral compression fractures evaluated by the authors’ academic neurosurgery service, and patient variable and health-systems factors associated with improved compliance.
Data for patients who underwent percutaneous kyphoplasty for compression fractures was retrospectively collected. Diagnostic and medical interventions were tabulated. Pre-, intra-, and posthospital factors that had been theorized to affect the compliance of patients with osteoporosis-related therapies were tabulated and statistically analyzed.
Less than 50% of patients with kyphoplasty received such therapies. Age was not found to correlate with other variables. Referral from a specialist rather than a primary care physician was associated with a higher rate of bone density screening, as well as vitamin D and calcium therapy, but not bisphosphonate/parathormone therapy. Patients who underwent preoperative evaluation by their primary care physician were significantly more likely to receive bisphosphonates compared with those only evaluated by a hospitalist. Patients with unprovoked fractures were more likely to undergo multiple surgeries compared with those with minor trauma.
These results suggest poor compliance with current standard of care for medical therapies in patients with osteoporotic compression fractures undergoing kyphoplasty under the care of an academic neurosurgery service.
Ioannis Siasios, Eftychia Z. Kapsalaki, Kostas N. Fountas, Aggeliki Fotiadou, Alexander Dorsch, Kunal Vakharia, John Pollina, and Vassilios Dimopoulos
Diffusion tensor imaging (DTI) for the assessment of fractional anisotropy (FA) and involving measurements of mean diffusivity (MD) and apparent diffusion coefficient (ADC) represents a novel, MRI-based, noninvasive technique that may delineate microstructural changes in cerebral white matter (WM). For example, DTI may be used for the diagnosis and differentiation of idiopathic normal pressure hydrocephalus (iNPH) from other neurodegenerative diseases with similar imaging findings and clinical symptoms and signs. The goal of the current study was to identify and analyze recently published series on the use of DTI as a diagnostic tool. Moreover, the authors also explored the utility of DTI in identifying patients with iNPH who could be managed by surgical intervention.
The authors performed a literature search of the PubMed database by using any possible combinations of the following terms: “Alzheimer's disease,” “brain,” “cerebrospinal fluid,” “CSF,” “diffusion tensor imaging,” “DTI,” “hydrocephalus,” “idiopathic,” “magnetic resonance imaging,” “normal pressure,” “Parkinson's disease,” and “shunting.” Moreover, all reference lists from the retrieved articles were reviewed to identify any additional pertinent articles.
The literature search retrieved 19 studies in which DTI was used for the identification and differentiation of iNPH from other neurodegenerative diseases. The DTI protocols involved different approaches, such as region of interest (ROI) methods, tract-based spatial statistics, voxel-based analysis, and delta-ADC analysis. The most studied anatomical regions were the periventricular WM areas, such as the internal capsule (IC), the corticospinal tract (CST), and the corpus callosum (CC). Patients with iNPH had significantly higher MD in the periventricular WM areas of the CST and the CC than had healthy controls. In addition, FA and ADCs were significantly higher in the CST of iNPH patients than in any other patients with other neurodegenerative diseases. Gait abnormalities of iNPH patients were statistically significantly and negatively correlated with FA in the CST and the minor forceps. Fractional anisotropy had a sensitivity of 94% and a specificity of 80% for diagnosing iNPH. Furthermore, FA and MD values in the CST, the IC, the anterior thalamic region, the fornix, and the hippocampus regions could help differentiate iNPH from Alzheimer or Parkinson disease. Interestingly, CSF drainage or ventriculoperitoneal shunting significantly modified FA and ADCs in iNPH patients whose condition clinically responded to these maneuvers.
Measurements of FA and MD significantly contribute to the detection of axonal loss and gliosis in the periventricular WM areas in patients with iNPH. Diffusion tensor imaging may also represent a valuable noninvasive method for differentiating iNPH from other neurodegenerative diseases. Moreover, DTI can detect dynamic changes in the WM tracts after lumbar drainage or shunting procedures and could help identify iNPH patients who may benefit from surgical intervention.