Publications by authors named "Karson C"

Charles Bonnet Syndrome (CBS) is diagnosed when a patient who is psychiatrically intact experiences visual hallucinations in the setting of significant visual acuity or field loss. The exact pathophysiology of the CBS hallucinations remains largely unknown. The main theories include the deafferentation theory and perceptual release theory.

View Article and Find Full Text PDF
Article Synopsis
  • - Scabies is a common skin condition caused by a mite, leading to very itchy bumps, typically found in specific areas like hands, groin, and armpits, but can occasionally spread widely and worsen into severe forms like crusted scabies.
  • - A case study of a 69-year-old man reveals that he developed crusted scabies alongside other health issues, including immune thrombocytopenic purpura and muscle weakness, after self-medicating with corticosteroids.
  • - Despite effective treatment for scabies, the patient tragically died from bacterial sepsis, highlighting the risk of misdiagnosis and complications that can arise from using immunosuppressive medications to treat mistaken diagnoses.
View Article and Find Full Text PDF

Objective: This study analyzed hospital readmission rates of patients with schizophrenia who were treated with long-acting injectable antipsychotics (LAIs) or with oral antipsychotics after being discharged from a hospitalization.

Methods: Medical claims of patients with schizophrenia who were ages 18-64 and had a first hospitalization for a serious mental illness (index hospitalization, October 2007 through September 2012) and at least one prescription for a first- or second-generation antipsychotic were analyzed from the Truven Health MarketScan Multi-State Medicaid Database. Analyses were conducted for patients with a sole diagnosis of schizophrenia (N=1,450) and for all patients with schizophrenia (N=15,556), which added patients with a codiagnosis of bipolar disorder or major depressive disorder.

View Article and Find Full Text PDF

Background: Treatment during first-episode psychosis (FEP) or early schizophrenia may affect the rates of relapse and remission, as well as cognitive functioning, over time. Prolonged duration of psychosis is associated with a poor prognosis, but the effects of treatment in patients with FEP or early schizophrenia on the long-term outcomes are not well defined.

Objective: To understand the long-term effects of treatment with antipsychotic agents on remission, relapse, and cognition in patients with FEP or early schizophrenia.

View Article and Find Full Text PDF

Background: Database analyses have indicated that medical treatment for schizophrenia varies among racial groups. This study assessed antipsychotic use and healthcare utilization across races in Medicaid-insured patients with schizophrenia.

Methods: A Medicaid database of inpatient/outpatient medical claims and outpatient prescription claims for more than 28 million enrollees in 11 geographically diverse states was analyzed.

View Article and Find Full Text PDF

Objective: Evaluate utilization of inpatient healthcare resources and associated costs after 12 months of treatment using long-acting injectable (LAI) antipsychotic medications among a large sample of Medicaid-insured patients categorized by different age groups.

Method: Adult patients with schizophrenia were identified from the Thomson Reuters MarketScan Research database (1/1/2006-12/31/2010) before initiation of treatment using LAI antipsychotic agents. Utilization of inpatient healthcare resources and associated direct medical costs were compared for 12-month baseline and 12-month follow-up periods.

View Article and Find Full Text PDF

The nominal species Brachidontes exustus (Linnaeus, 1758) is a cryptic complex. Long polymerase chain reactions and direct sequencing by primer walking was used to determine the complete F type mitochondrial genome of the Gulf of Mexico clade. The genome is 16,600 bp long and contains a single large unassigned presumptive control region, 13 protein-coding genes, 23 tRNA genes, and 2 rRNA genes, all coded for on the heavy chain.

View Article and Find Full Text PDF

This study evaluated the impact of using long-acting injectable (LAI) antipsychotics for a longer treatment duration versus a short duration on health care resource utilization among Medicaid-insured schizophrenia patients. Schizophrenia patients 13 years or older initiating LAI antipsychotics were identified from the Truven Health Analytics MarketScan Research Medicaid database between July 1, 2005, and June 30, 2010. The study population was grouped into 2 study cohorts (longer-usage-duration cohort: ≥ 180 days of supply and short-usage-duration cohort: <180 days of supply).

View Article and Find Full Text PDF

Objective: This study compared healthcare resource usage and costs before and after initiating LAI antipsychotics among Medicaid-insured schizophrenia patients.

Methods: Schizophrenia patients ≥13 years of age initiating LAI antipsychotics were identified from the Thomson Reuters MarketScan® Research Medicaid database between 7/1/2005 and 6/30/2010. Patients were required to have 6 months of continuous medical/prescription drug coverage prior to LAI initiation (baseline period) and during a variable follow-up period.

View Article and Find Full Text PDF

Objective: Because reduction of psychotic symptoms in schizophrenia does not result in adequate community functioning, efforts have shifted to other areas, such as cognitive impairment. The U.S.

View Article and Find Full Text PDF

It has been hypothesized that schizophrenia arises from cell membrane abnormalities due to changes in phospholipid (PL) composition and metabolism. We have used high resolution, in vitro 31P nuclear magnetic resonance (NMR) to characterize the PLs in left frontal cortex (gray matter) of postmortem brain from four schizophrenics and five controls. High resolution 31P NMR spectra were obtained in an organic-solvent system to resolve PL classes (headgroups) and in a sodium-cholate, aqueous dispersion system to resolve phosphatidylcholine (PC) molecular species.

View Article and Find Full Text PDF

We have previously demonstrated elevation of the extracellular signal-regulated kinase (ERK) pathway in the cerebellum from patients with schizophrenia, an illness that may involve dysfunction of the N-methyl-D-aspartate (NMDA) receptor. Since the NMDA antagonist, phencyclidine (PCP), produces schizophrenic-like symptoms in humans, and abnormal behavior in animals, we examined the effects of chronic PCP administration in time- and dose-dependent manner on ERK and two other members of mitogen-activated protein kinase family, c-Jun N-terminal protein kinase (JNK) and p38, in rat brain. Osmotic pumps for PCP (18 mg/kg/day) and saline (controls) were implanted subcutaneously in rats for three, 10, and 20 days.

View Article and Find Full Text PDF

Background: We investigated the levels of transcription factors associated with activation of the mitogen-activated protein (MAP) kinase pathway in schizophrenics using postmortem brain samples. These studies were done to determine whether our previous findings of abnormal levels of the MAP kinases in the cerebellar vermis were linked to additional downstream targets of this signal transduction pathway.

Method: We measured the protein levels of 3 transcription factors in nuclear fractions of postmortem samples from cerebellar vermis of 10 patients with schizophrenia and 13 control subjects: Elk-1, cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), and activating transcription factor 2 (ATF-2).

View Article and Find Full Text PDF

Fluorine-19 NMR spectra were acquired from extracts of tissues from heads of rats given the antipsychotic drug trifluoperazine (TFP). Contributions to the in vivo (19)F spectra from tissues other than brain were negligible. The in vivo (19)F resonance at -62.

View Article and Find Full Text PDF

Localized in vivo proton magnetic resonance spectroscopy at 4.7 T was used to examine the brains of rats that were given the antipsychotic drugs haloperidol, clozapine, or olanzapine for 1 week. Spectra were collected before and during treatment.

View Article and Find Full Text PDF

Background: Mitogen-activated protein kinases (MAPKs) are important mediators of signal transduction from the cell surface to the nucleus and have been implicated in the integration of a variety of physiologic processes in most cells, including neurons. To investigate the possible involvement of MAPKs in schizophrenia, we compared the levels of the MAPK intermediates in postmortem brain tissue obtained from schizophrenic and control subjects. Our focus was on the cerebellar vermis because of evidence suggesting that schizophrenia is associated with abnormalities of structure, function, and signal transduction in this brain region.

View Article and Find Full Text PDF

The P1 midlatency auditory evoked potential was studied in female rape victims with Posttraumatic Stress Disorder (PTSD) and compared to an age-matched female control group; and in male combat veterans with PTSD and compared to three groups of age-matched male control subjects. Sensory gating of the P1 potential was determined using a paired click stimulus paradigm in which the stimuli were presented at 250, 500 and 1000 msec interstimulus intervals (ISI). Results showed that sensory gating of the P1 potential was significantly decreased at the 250 msec ISI, and that there was a numerical, but not a statistically significant, decrease in sensory gating at the other intervals tested in both male and female PTSD subjects compared to all control groups.

View Article and Find Full Text PDF

Localized, in vivo 1H magnetic resonance spectroscopy has been performed in a number of brain regions of neuropsychiatric interest in male and female control subjects to determine if gender and region affect the measured metabolite ratios. In contrast to some previous reports, no significant differences were seen in any region for any metabolite ratio between males and females. As expected, significant variations with brain region were seen for metabolite ratios for the total group of subjects.

View Article and Find Full Text PDF

An impairment of prefrontal cortical functioning in schizophrenia ('hypofrontality') has been suggested by clinical, neuroimaging, and postmortem brain tissue studies. We used Western immunoblot and Northern hybridization analyses of postmortem brain tissue obtained from 14 schizophrenic patients and 12 control patients of similar ages to measure tissue levels of synaptophysin (a structural synaptic vesicle protein) and of SNAP-25 (a 25-kDa presynaptic protein), and their encoding mRNAs, in Brodmann's area 10 of prefrontal cortex. There were significant decreases in tissue levels of both of these proteins in prefrontal cortex of schizophrenic patients relative to controls.

View Article and Find Full Text PDF

Schizophrenia is a disorder with an unclear pathophysiology, despite numerous attempts to elucidate its etiology. We have employed proton magnetic resonance spectroscopy in vivo to explore the neurochemistry of several brain regions (left frontal and temporal cortices, left basal ganglia, and left and right thalamus) in patients with schizophrenia and in normal control subjects. We have also examined patients in different medication states.

View Article and Find Full Text PDF

Recent findings using volumetric MRI techniques have revealed that patients with combat-related and noncombat-related posttraumatic stress disorder (PTSD) have reductions in right hippocampal volume. Twenty-one veterans with PTSD and eight age-matched control veterans were studied using proton magnetic resonance spectroscopy to test the hypothesis that the N-acetyl-L-aspartic acid/creatine (NAA/Cr) ratio would be decreased in the right medial temporal lobe structures of patients with PTSD compared to controls. Patients with PTSD displayed significantly lower NAA/Cr ratio for the right medial temporal lobe relative to the left (P < or = 0.

View Article and Find Full Text PDF

Some evidence suggests that thalamic dysfunction could explain some of the signs and symptoms of schizophrenia. We measured the absolute concentrations of amino acid metabolites in thalamus, frontal pole, and cerebellar vermis in extracts of postmortem brains from 8 schizophrenics and 10 controls using high-resolution 1H-magnetic resonance spectroscopy. The concentrations of N-acetyl aspartate, glutamate, and valine tended to be reduced in the thalamus of the schizophrenic group.

View Article and Find Full Text PDF
Article Synopsis
  • This study used a paired stimulus approach to examine the P1 auditory evoked potential in Vietnam War veterans with PTSD and compared them to three other groups: alcohol dependents, combat-exposed normals, and combat-unexposed normals.
  • The results showed that veterans with PTSD had significantly less habituation of the P1 potential compared to the other groups, indicating a possible sensory gating issue in their brainstem.
  • Additionally, the level of P1 potential habituation in the PTSD group was significantly linked to the severity of their PTSD reexperiencing symptoms, like nightmares and flashbacks.
View Article and Find Full Text PDF

The objective was to replicate a reported decrease of choline acetyltransferase (ChAT) in the mesopontine tegmentum of deceased schizophrenics and to see if such a decrease is related to their cognitive status as measured during life. Rigorous antemortem psychiatric evaluations were performed on our large population of schizophrenic patients. Mesopontine tissue was collected promptly following death from eight of these patients, from an additional five schizophrenics without systematic premortem psychiatric evaluation, and from control subjects.

View Article and Find Full Text PDF

A high proportion of neurons in the cerebellum and in cholinergic brainstem nuclei stain positive for nicotinamide adenine dinucleotide phosphate-diaphorase (NADPHd), which is a nitric oxide synthase (NOS). Recent evidence suggests that schizophrenia may involve increased numbers of NADPHd-stained neurons in different areas of the subcortex. This led us to examine the actual concentration of NOS in postmortem brain specimens of cerebellum, and the relevant regions of brainstem tegmentum, to see if NOS concentrations were also increased in schizophrenia.

View Article and Find Full Text PDF