Diffusion tensor imaging eigenvalues: preliminary evidence for altered myelin in cocaine dependence.

Reduced fractional anisotropy (FA) in Diffusion Tensor Imaging (DTI) has been reported in cocaine dependent subjects compared to non-drug using controls. There are several pathological mechanisms that could be responsible for these findings, since FA can be reduced through damage to axonal tracts and by neuronal loss. One way of obtaining more information about pathology underlying changes in FA on DTI is diffusion tensor eigenvalues, representing diffusion along the fiber tract (lambda(1)) or perpendicular to the fiber tract (lambda(T)). Thirteen cocaine dependent subjects and 18 healthy controls underwent full brain DTI. Eigenvalues lambda(1) and lambda(T) of the corpus callosum were compared between cocaine users and controls. For lambda(T) there was a significant interaction of group x region of corpus callosum. Exploratory analysis of the subregions showed higher lambda(T) in the genu of the anterior corpus callosum of cocaine dependent subjects compared to control subjects. For lambda(1) there was no significant interaction of group x region of corpus callosum. Based on prior studies suggesting that alteration or damage to myelin increases diffusion perpendicular to the direction of fiber tracts (lambda(T)) with minimal effect on lambda(1) these findings are consistent with altered myelin in the corpus callosum in cocaine dependent subjects.

Impulsivity and BOLD fMRI activation in MDMA users and healthy control subjects.

The correlation between scores on the Barratt Impulsiveness Scale (BIS) and activation measured by functional magnetic resonance imaging in a dorsolateral prefrontal cortical (DLPFC) activating task was examined in 15 MDMA-using subjects and 19 controls. A significant correlation between BIS scores and DLPFC activation was found, supporting a role for the DLPFC in BIS-measured impulsivity.

Reduced anterior corpus callosum white matter integrity is related to increased impulsivity and reduced discriminability in cocaine-dependent subjects: diffusion tensor imaging.

Brain imaging studies find evidence of prefrontal cortical dysfunction in cocaine-dependent subjects. Similarly, cocaine-dependent subjects have problems with behaviors related to executive function and impulsivity. Since prefrontal cortical axonal tracts cross between hemispheres in the corpus callosum, it is possible that white matter integrity in the corpus callosum could also be diminished in cocaine-dependent subjects. The purpose of this study was to compare corpus callosum white matter integrity as measured by the fractional anisotropy (FA) on diffusion tensor imaging (DTI) between 18 cocaine-dependent subjects and 18 healthy controls. The Barratt Impulsiveness Scale (BIS-11) and a continuous performance test: the Immediate and Delayed Memory Task (IMT/DMT) were also collected. Results of the DTI showed significantly reduced FA in the genu and rostral body of the anterior corpus callosum in cocaine-dependent subjects compared to controls. Cocaine-dependent subjects also had significantly higher BIS-11 scores, greater impulsive (commission) errors, and reduced ability to discriminate target from catch stimuli (discriminability) on the IMT/DMT. Within cocaine dependent subjects there was a significant negative correlation between FA in the anterior corpus callosum and behavioral laboratory measured impulsivity, and there was a positive correlation between FA and discriminability. The finding that reduced integrity of anterior corpus callosum white matter in cocaine users is related to impaired impulse control and reduced ability to discriminate between target and catch stimuli is consistent with prior theories regarding frontal cortical involvement in impaired inhibitory control in cocaine-dependent subjects.

Barriers to proliferation of electronic medical records.

BACKGROUND: Error reduction, quality improvement and lowering of cost can all be achieved through electronic integration of healthcare providers. Proliferation of standard electronic health records/ electronic medical records (EHR/EMR) software is an essential precursor of this integration. Proliferation of EHR/EMR software has not occurred in the United States. OBJECTIVE: To characterise users and non-users of EHR/EMR software, identify potential barriers to proliferation, examine the extent of standardisation across reported EHR/EMR and suggest possible solutions to identified barriers. METHODS: We performed a secondary analysis of member survey data collected by the American Academy of Family Physicians (AAFP) in January 2003. The purpose of the survey was to measure interest in an AAFP-sponsored EHR/EMR service. We examined demographic and purchasing data from the survey by gender, population density, region and age. We also counted the number of different software vendors reported by users of an EHR/EMR to assess the number of users with unique software. RESULTS: Of the 35,554 members contacted, 5517 (15.5%) responded. Of those responding, 1297 (23.5%) reported use of an EHR/EMR. Of the members responding, 81% reported interest in EHR/EMR software and 61% reported cost as a major reason for not purchasing it. At least 264 different EHR/ EMR software programs are currently in use. On average, the percentage of respondents with the same EHR/EMR software is 0.4%. DISCUSSION: The number of AAFP members with unique EHR/EMR software is very large. Fragmentation, caused by the use of hundreds of unique systems, is a major barrier to proliferation of these systems. Many of the barriers to proliferation could be mitigated through the tools and techniques available through Free and Open Source Software (FOSS).

Metcalfe's law predicts reduced power of Electronic Medical Record software.

Error reduction, quality improvement and lowering of cost can all be achieved through electronic integration of health care providers. Despite the existence of clinical computing software for decades, meaningful linkage between health care providers has not occurred. We hypothesize that a major reason is reduction in network value through incompatible clinical software among hundreds of health care entities.