Thomas J. Carr

Membrane phospholipid metabolism and schizophrenia: an in vivo 31P-MR spectroscopy study

Membrane phospholipid metabolism was studied with 31P magnetic resonance spectroscopy in the left dorsal prefrontal cortex of 19 male, medicated, schizophrenic patients and compared to 18 normal male controls matched in age, education and parental education level. The schizophrenic patients had significantly decreased phosphomonoester levels (PMEs, metabolites predominantly involved in the synthesis of membrane phospholipids). Phosphodiester levels (PDEs, breakdown products of membrane phospholipids) were not statistically different in schizophrenic patients compared to controls. However, a significant increase in the PDE levels was observed in the newly diagnosed patient subgroup. This observed pattern of the PMEs and PDEs would be consistent with the presence of an abnormal neurodevelopment early in the illness of schizophrenia.

A short echo proton magnetic resonance spectroscopy study of the left mesial-temporal lobe in first-onset schizophrenic patients

BACKGROUND Past 1H magnetic resonance spectroscopy (MRS) studies of the temporal lobe in schizophrenic patients have shown decreased levels of N-acetylaspartate (NAA) suggesting reduced neuronal density in this region. However, the measured volumes have been large and included contributions from mostly white matter. METHODS Short echo 1H MRS was used to measure levels of NAA and other metabolites (i.e., glutamate and glutamine) from a 6 cm3 volume in the left mesial-temporal lobe of 11 first-episode schizophrenic patients and 11 healthy control subjects of comparable age, gender, handedness, education, and parental education levels. Spectra were quantified without operator interaction using automated software developed in our laboratory. Metabolite levels were normalized to the internal water concentration of each volume studied. Images were also obtained to determine temporal lobe gray and white matter volumes. RESULTS No significant differences were found between levels of NAA or other metabolites, or gray and white matter volumes, in first-episode schizophrenic patients and comparison subjects. CONCLUSIONS Since the volume studied was small compared to previous studies and contained mostly gray matter, this result suggests consequential NAA decreases may be restricted to regions of white matter.

An MRI study of subgenual prefrontal cortex in patients with familial and non-familial bipolar I disorder

BACKGROUND Over the past few years there has been an interest in the use of magnetic resonance imaging (MRI) to study specific brain regions in bipolar disorder. The present study compared the grey matter volume in the subgenual prefrontal cortex in patients with familial and non-familial bipolar disorder and normal control subjects. METHODS MRI brain scans were performed on 12 patients with bipolar I disorder including six patients with a positive family history of bipolar disorder as well as eight control subjects. RESULTS There was a significant reduction in the grey matter volume in the right subgenual prefrontal cortex, but not in the left subgenual prefrontal cortex. A family history x sex interaction with right prefrontal cortex volume was also observed as a trend. For females, a positive family history was associated with reduced right prefrontal cortex volumes; for males, a positive family history was associated with increased right prefrontal cortex volumes. LIMITATIONS Small sample size, reduced statistical power. CONCLUSION These data add to the emerging literature on structural changes in the subgenual prefrontal cortex in bipolar disorder, especially in patients with a positive family history.

A 1H-decoupled 31P chemical shift imaging study of medicated schizophrenic patients and healthy controls

BACKGROUND Current 31P spectroscopy research in schizophrenia has examined phospholipid metabolism by measuring the sum of phosphomonoesters and the sum of phosphodiester-containing molecules. Proton decoupling was implemented to measure the individual phosphomonoester and phosphodiester components. This is the first study employing this technique to examine schizophrenic patients. METHODS Multivoxel two-dimensional chemical shift in vivo phosphorous-31 magnetic resonance spectroscopy with proton decoupling was used to examine a 50-cm3 volume in prefrontal, motor, and parieto-occipital regions in the brain. Eleven chronic medicated schizophrenic patients were compared to 11 healthy controls of comparable gender, education, parental education, and handedness. RESULTS A significant increase in the mobile phospholipid peak area and its full width at half maximum was observed in the medicated schizophrenic patients compared to the healthy controls in the prefrontal region. Inorganic orthophosphate and phosphocholine were lower in the schizophrenic group in the prefrontal region. CONCLUSIONS The increased sum of phosphodiester [mobile phospholipid + glycerol-3-phosphoethanolamine (GPEth) + glycerol-3-phosphocholine (GPCh)] in schizophrenic patients, measured in earlier studies, arises from the phospholipid peak (MP) and not the more mobile phosphodiesters (GPEth, GPCh) as was originally suspected. A decrease in the phosphocholine component of the phosphomonoesters was also observed in the schizophrenic patients. These findings are consistent with an abnormality in membrane metabolism in the prefrontal region in schizophrenics.

Adenocarcinoma of the Esophagus in a Patient with Paraesophageal Hernia

A 67-year-old female with a known paraesophageal hernia presented with dysphagia and weight loss. Workup revealed distal esophageal obstruction without a mass lesion. At operation a distal esophageal