Preserved Cochlear CISS Signal is a Predictor for Hearing Preservation in Patients Treated for Vestibular Schwannoma With Stereotactic Radiosurgery.

BACKGROUND: Hearing preservation is a goal for many patients with vestibular schwannoma. We examined pretreatment magnetic resonance imaging (MRI) and posttreatment hearing outcome after stereotactic radiosurgery. METHODS: From 2004 to 2014, a cohort of 125 consecutive patients with vestibular schwannoma (VS) treated via stereotactic radiosurgery (SRS) were retrospectively reviewed. MRIs containing three-dimensional constructive interference in steady state or equivalent within 1 year before treatment were classified by two radiologists for pretreatment characteristics. "Good" hearing was defined as American Academy of Otolaryngology-Head and Neck Surgery class A. Poor hearing outcome was defined as loss of good pretreatment hearing after stereotactic radiosurgery. RESULTS: Sixty-one patients met criteria for inclusion. Most had tumors in the distal internal auditory canal (55%), separated from the brainstem (63%), oval shape (64%) without cysts (86%), and median volume of 0.85 ±â€Š0.55 cm. Pretreatment audiograms were performed a median of 108 ±â€Š173 days before stereotactic radiosurgery; 38% had good pretreatment hearing. Smaller tumor volume (p < 0.005) was the only variable associated with good pretreatment hearing. 49 (80%) patients had posttreatment audiometry, with median follow-up of 197 ±â€Š247 days. Asymmetrically decreased pretreatment cochlear CISS signal on the side of the VS was the only variable associated with poor hearing outcome (p = 0.001). Inter-rater agreement on cochlear three-dimensional constructive interference in steady state preservation was 91%. CONCLUSIONS: Decreased cochlear CISS signal may indicate a tumor's association with the cochlear neurovascular bundle, influencing endolymph protein concentration and creating an inability to preserve hearing. This important MRI characteristic can influence planning, counseling, and patient selection for vestibular schwannoma treatment.

Prevalence of degenerative changes of the atlanto-axial joints.

BACKGROUND CONTEXT: Degeneration of the atlantodens and atlanto-axial joints is associated with cervical spine pain and may also be associated with an increased risk of dens fracture. However, there is paucity of literature describing the prevalence of specific degenerative changes in the atlantodens and atlanto-axial facet joints. PURPOSE: To document age-related degenerative changes of the cervical spine in a large cohort of patients. STUDY DESIGN/SETTING: This is a retrospective cohort study. PATIENT SAMPLE: Adult trauma patients were admitted to our Level 1 trauma center. OUTCOME MEASURES: Osteoarthritis of the atlantodens and atlanto-axial facet joints of the cervical spine and the presence of intraosseous cyst and calcific synovitis, as determined by computed tomography (CT) scans. METHODS: We conducted a retrospective study of 1,543 adult trauma patients who received a cervical spine CT scan. The anterior atlantodens joint interval was measured. The presence or absence of intraosseous cysts and calcific synovitis was recorded. Degeneration of the atlantodens and atlanto-axial facet joints at age intervals was quantified. RESULTS: The atlantodens interval narrowed linearly with age (R(2)=0.992, p<.001). The prevalence of intraosseous cysts increased exponentially with age from 4.2% to 37.4%, and calcific synovitis increased from 0% to 11.1%. Intraosseous cyst formation generally began in the second and third decades of life and synovitis in the fifth and sixth decades of life. Facet joints also demonstrated age-related changes; however, the rate of degenerative changes was lower than in the atlantodens joint. CONCLUSIONS: To our knowledge, this is the first study that documents specific changes of both atlantodens and atlanto-axial facet joints as a function of age in a large cohort of 1,543 patients. These changes increased exponentially with age and may contribute to pain and limitation in motion. In light of our findings and recent studies demonstrating the association between degeneration and dens fracture in elderly, cervical spine radiographs of elderly patients should be carefully assessed for these changes.

Association between advanced degenerative changes of the atlanto-dens joint and presence of dens fracture.

BACKGROUND: Dens fractures in elderly patients are often related to issues associated with aging. We examined the association between degenerative changes of the atlanto-dens joint and the risk of dens fracture. METHODS: We conducted a retrospective study of trauma patients, fifty-five years of age or older, who had undergone a computed tomography scan of the cervical spine as part of their admission to a single level-I trauma center. There were 1794 patients who met the inclusion criteria; scans were evaluated for all fifty-six who presented with a dens fracture and for a random sample of 736 without a dens fracture. Intraosseous cyst formation, synovitis, and joint space narrowing were recorded from the scans. The prevalence of degenerative changes was compared between patients with and patients without a dens fracture. RESULTS: An intraosseous cyst in the dens was found in 16.4% of the patients without a dens fracture and in 64.3% of those with a fracture (p < 0.001). The dens fracture extended through the existing cyst in twenty-four (66.7%) of thirty-six patients with a cyst and a dens fracture. Retro-dens synovitis was present in 4.2% of the patients without a dens fracture and 25.0% of those with a fracture (p < 0.001). After adjustment for age and sex, both cysts (odds ratio [OR] = 7.7, 95% confidence interval [CI] = 4.2 to 14.1) and synovitis (OR = 4.6, 95% CI = 2.1 to 10.0) were significantly associated with dens fracture. CONCLUSIONS: Intraosseous dens cysts and retro-dens synovitis were associated with dens fracture; those with a dens fracture were nearly eightfold more likely to have an intraosseous cyst and nearly fivefold more likely to have synovitis compared with those without a dens fracture. Because the atlanto-dens joint is a synovial joint, its degeneration can lead to subchondral cyst formation and synovitis and predispose affected individuals to fracture.

Cognitive deficits and delayed neuronal loss in a mouse model of multiple microinfarcts.

Microinfarcts are a common clinical feature of the aging brain, particularly in patients with cognitive decline or vascular or Alzheimer's dementia. However, the natural history of these lesions remains largely unexplored. Here we describe a mouse (C57BL/6J) model of multiple diffuse microinfarcts induced by unilateral internal carotid artery injection of cholesterol crystals (40-70 µm). Microinfarcts were spread throughout the deep cortex, subcortical tissue, and hippocampus and were comprised of a core positive for CD68 (a marker for reactive microglia and macrophages), surrounded by large regions of glial fibrillary acidic protein-positive reactive astrogliosis. Widespread reactive gliosis, including mislocalization of the astrocytic water channel aquaporin 4 persisted long after injury, recovering only after 1 month after stroke. Within the cortex, neuronal cell death progressed gradually over the first month, from ∼35% at 3 d to 60% at 28 d after stroke. Delayed demyelination was also observed in lesions, beginning 28 d after stroke. These findings demonstrate that microinfarct development follows a distinct course compared to larger regional infarcts such as those induced by middle cerebral artery occlusion. The long-lasting gliosis, delayed neuronal loss, and demyelination suggest that the therapeutic window for microinfarcts may be much wider (perhaps days to weeks) than for larger strokes.