Neuroimaging findings of hypercoagulable states: A case report on polycythemia vera (PV).

Vaso-occlusive events leading to neurological complications are a common cause of morbidity and mortality in Polycythemia Vera (PV). Low prevalence and unfamiliarity of clinicians and radiologists to the neurological manifestations and radiological findings often result in delayed diagnosis of this potentially fatal disease. Awareness of a radiologist to the imaging findings of PV and other hypercoagulable states and their full spectrum of presentation is essential for the prevention of neurological complications. There are not many examples of neurological complication of PV. Here, we report a case of a 58-year-old male who presented with stroke. Initial neuroimaging revealed hyperdense dural venous sinuses, multifocal and multi-territorial synchronous, and metasynchromous ischemic infarctions. Prompt laboratory work-up revealed high hematocrit and low serum erythropoietin levels suggesting PV, which was confirmed on bone marrow biopsy.

The Value of White Matter Tractography by Diffusion Tensor Imaging in Altering a Neurosurgeon's Operative Plan.

OBJECTIVE: To investigate if the implementation of white matter (WM) fiber tractography by diffusion tensor imaging in presurgical planning for supratentorial tumors proximal to eloquent WM tracts can alter a neurosurgeon's operative strategy. METHODS: A retrospective review was conducted of patients with supratentorial brain tumors within eloquent WM tracts who underwent diffusion tensor imaging (DTI) tractography as part of their preoperative assessment. These patients were classified into 3 different DTI groups per the radiology reports: group 1, intact WM tracts; group 2, deviated and/or displaced WM bundles; and group 3, patients with an established WM injury (interrupted and/or destroyed tracts). A blinded prospective behavioral study followed, in which 4 neurosurgeons reviewed the preoperative images at 2 different times (magnetic resonance imaging without DTI, followed by a review of the DTI). They provided estimations about the DTI group of each individual eloquent WM category in every patient, and their planned surgical approach. RESULTS: Fifteen patients (mean age, 58.3 years) were included in the study. The neurosurgeons provided a correct DTI group estimation in 53%, 60%, and 57% of the cases that involved motor/sensory pathway tracts, optic tracts, and language tracts, respectively. The neurosurgeons underestimated DTI group 3 in the motor category and in the optic category 75% of the time. DTI did not alter the planned surgical approach. CONCLUSIONS: DTI WM tractography helped neurosurgeons to correctly identify patients with interrupted motor and optic pathway tracts so they could be more aggressive with the extent of tumor resection, despite its inability to alter the operative approach.

Neuropsychological outcome following frontal lobectomy for pharmacoresistant epilepsy in adults.

OBJECTIVE: This retrospective cohort study characterized cognitive and motor outcomes in a large sample of adults who underwent frontal lobe resections for treatment of pharmacoresistant epilepsy. METHODS: Ninety patients who underwent unilateral frontal lobe resection for epilepsy (42 language-dominant hemisphere/48 nondominant hemisphere) between 1989 and 2014 completed comprehensive preoperative and postoperative neuropsychological evaluations that included measures of verbal and nonverbal intellectual functioning, attention/working memory, processing speed, language, executive functioning, verbal and visual memory, and motor functioning. Objective methods were used to assess meaningful change across a wide range of abilities and to identify factors associated with neuropsychological decline following frontal lobectomy. Detailed postoperative neuroimaging analysis was conducted to characterize region, extent, and volume of resection. RESULTS: Forty-eight percent of patients did not demonstrate meaningful postoperative declines in cognition and an additional 42% demonstrated decline in 1 or 2 cognitive domains. When cognitive decline was observed, it usually occurred on measures of intelligence, visuomotor processing speed, or executive functioning. Side and site of resection were unrelated to cognitive outcome, but played a role in decline of contralateral manual dexterity following supplementary motor area resection. Higher preoperative ability, older age at surgery, absence of a malformation of cortical development on MRI, and poor seizure outcome were related to cognitive decline on some measures, but had poor sensitivity in identifying at-risk patients. CONCLUSIONS: The vast majority of patients who undergo frontal lobectomy for treatment of pharmacoresistant epilepsy demonstrate good cognitive and motor outcomes.

Pulmonary Vasculitis: Spectrum of Imaging Appearances.

Pulmonary vasculitis is a relatively uncommon disorder, usually manifesting as part of systemic vasculitis. Imaging, specifically computed tomography, is often performed in the initial diagnostic workup. Although the findings in vasculitis can be nonspecific, they can provide important clues in the diagnosis, and guide the clinical team toward the right diagnosis. Radiologists must have knowledge of common and uncommon imaging findings in various vasculitides. Also, radiologists should be able to integrate the clinical presentation and laboratory test findings together with imaging features, so as to provide a meaningful differential diagnosis.

S100B and S100B autoantibody as biomarkers for early detection of brain metastases in lung cancer.

BACKGROUND: S100B is an astrocytic protein that enters the blood stream when there is disruption of the blood-brain barrier (BBB). Over time, antibodies against S100B develop in the sera of patients who experience persistent or repeated BBB disruptions. We explored the use of serum S100B protein and S100B autoantibodies for the detection of brain metastasis in patients with lung cancer. METHODS: One hundred and twenty eight untreated patients with lung cancer who had brain imaging performed as part of their routine evaluation, participated. Serum S100B protein levels were measured by direct ELISA and S100B autoantibody levels by reverse ELISA. These levels in patients with brain metastases were compared alone and in combination to those without brain metastases. RESULTS: Eighteen (14%) patients had brain metastasis at the time of lung cancer diagnosis. An S100B cutoff of 0.058 ng/mL had a sensitivity of 89% and specificity of 43% for brain metastasis. When an autoantibody threshold of <2.00 absorbance units was used in conjunction with S100B, the sensitivity remained at 89%, and the specificity increased to 58%. The overall accuracy was 51% with S100B alone, improving to 62.5% when combined with autoantibodies. CONCLUSIONS: Serum S100B and S100B autoantibody levels may help to identify which lung cancer patients have brain metastases.

Verbal and non-verbal memory and hippocampal volumes in a memory clinic population.

INTRODUCTION: Better characterization of the relationship between episodic memory and hippocampal volumes is crucial in early detection of neurodegenerative disease. We examined these relationships in a memory clinic population. METHODS: Participants (n = 226) underwent structural magnetic resonance imaging and tests of verbal (Hopkins Verbal Learning Test-Revised, HVLT-R) and non-verbal (Brief Visuospatial Memory Test-Revised, BVMT-R) memory. Correlational analyses were performed, and analyses on clinical subgroups (i.e., amnestic Mild Cognitive Impairment, non-amnestic Mild Cognitive Impairment, probable Alzheimer's disease, intact memory) were conducted. RESULTS: Positive associations were identified between bilateral hippocampal volumes and both memory measures, and BVMT-R learning slope was more strongly positively associated with hippocampal volumes than HVLT-R learning slope. Amnestic Mild Cognitive Impairment (aMCI) participants showed specific positive associations between BVMT-R performance and hippocampal volumes bilaterally. Additionally, analyses of the aMCI group showed trend-level evidence of material-specific lateralization, such that retention of verbal information was positively associated with left hippocampal volume, whereas learning curve and retention of non-verbal information was positively associated with right hippocampal volume. CONCLUSIONS: Findings support the link between episodic memory and hippocampal volumes in a memory clinic population. Non-verbal memory measures also may have higher diagnostic value, particularly in individuals at elevated risk for Alzheimer's disease.

Reducing clinical MRI motion degradation using a prescan patient information pamphlet.

OBJECTIVE: Voluntary patient motion is a common cause of image degradation during MRI and leads to repeated scanning, decreasing efficiency, and increasing costs. We hypothesized that providing an educational pamphlet to patients before their MRI examination could improve image quality and decrease the number of repeated sequences needed because of motion artifacts. SUBJECTS AND METHODS: Over 12 months, we recruited patients undergoing MRI for any neurologic condition. The control group received a routine safety questionnaire concerning MRI scanning. The intervention group was given an additional pamphlet describing the examination and graphically emphasizing the value of remaining still during scanning; comprehension was confirmed by questionnaire. The radiology technologists performing the examinations were blinded to group assignments; they recorded the number of repeated sequences needed because of motion artifacts and assessed image quality on a scale of 0 to 4 (0 = unusable, 4 = perfect). RESULTS: The number of patients requiring repeated MRI sequences (control group vs intervention group: 40 vs 20, respectively; p = 0.009) and the total number of repeated MRI sequences (52 vs 27, p = 0.004) decreased in the group who read the pamphlet compared with the control group. CONCLUSION: Providing a simple educational pamphlet to patients before their MRI examinations that illustrated motion degradation and emphasized the need to remain still significantly reduced the number of repeated sequences deemed necessary by the MRI technologist.

A practical clinical method to quantify language lateralization in fMRI using whole-brain analysis.

Surgery is often the only effective treatment for intractable epilepsy, but its benefits must be balanced by potential disruption of eloquent cortical functions. Wada test is the standard technique to lateralize language before surgery; however, it is invasive and associated with complications. fMRI provides an attractive noninvasive alternative, which has been previously shown to correlate with Wada results. However this correlation is imperfect since standard fMRI laterality indices are dependent on a particular arbitrary statistical threshold used in the data processing. We report a novel automated, threshold-independent fMRI methodology to assess language lateralization, which we hypothesize provides a robust and unbiased pre-operative assessment. This hemispheric histogram analysis method can accurately interrogate language lateralization, as validated against the Wada test. Fifty-nine subjects with intractable epilepsy received preoperative evaluation for language lateralization using fMRI. fMRI data then were analyzed using a novel automated threshold-independent method for determining language lateralization. The methodology generated a lateralization score based on hemispheric activation of language areas and a quality index based on multiple factors, including patient motion and signal-to-noise characteristics. Lateralization scores were compared to Wada test results (51 patients), direct cortical stimulation (3 patients), and subdural grid stimulation (5 patients). Data sets were used to generate a probability score for language lateralization for each subject. The lateralization scores correlated well with the objective measures of language lateralization (r(2)=0.46). Cumulative historical data were utilized to prospectively determine probabilities of language lateralization for individual patients. In conclusion, hemispheric language lateralization can be accurately determined using a novel objective and automated methodology that calculates language lateralization in a threshold-independent manner and can be used to determine the probability of language dominance in individual patients.