Biomedical subjects

F P MacMaster

Publications and source records attributed to F P MacMaster.

5 recordsLinked to original sources

PubMed2001

Left medial temporal cytosolic choline in early onset depression.

OBJECTIVE: Previous studies have linked the choline (Cho) resonance seen in proton magnetic resonance spectroscopy (1H-MRS) to major depressive disorder (MDD). We endeavoured to clarify the possible involvement of cytosolic choline in the amygdala (anterior medial temporal region) of juvenile subjects with MDD. METHOD: A total of 11 age- and sex-matched MDD and control pairs aged 14 to 18 years participated in long-echo proton magnetic resonance spectroscopic imaging (1H-MRSI) of the amygdala. Compounds available include N-acetyl-aspartate (NAA), creatine-phosphocreatine (Cr) and choline-containing compounds. RESULTS: Subjects with depression demonstrated lower left amygdala Cho-Cr ratios, compared with control subjects (paired t = 2.624, df 10, P = 0.025). Left amygdala NAA-Cr and right amygdala Cho-Cr and NAA-Cr did not differ significantly between subjects with depression and control subjects. In subjects with depression, simple regression revealed a negative trend between left amygdala Cho-Cr and Beck Depression Inventory (BDI) score (F = 3.509, P = 0.098). Right amygdala NAA-Cr and Cho-Cr did not differ significantly. CONCLUSION: Cytosolic choline appears to be involved in the pathophysiology of early-onset MDD, likely secondary to corticosteroid-neuroendocrine-driven changes.

Adolescent↗

PubMed2000

Decrease in caudate glutamatergic concentrations in pediatric obsessive-compulsive disorder patients taking paroxetine.

OBJECTIVE: To measure in vivo neurochemical changes in the caudate nucleus in pediatric obsessive-compulsive disorder (OCD) before and after treatment. METHOD: Single-voxel proton magnetic resonance spectroscopic (1H-MRS) examinations of the left caudate were conducted in 11 psychotropic drug-naive children, aged 8 to 17 years, with OCD before and after 12 weeks of monotherapy with the selective serotonin reuptake inhibitor paroxetine (10-60 mg/day) and 11 healthy children aged 8 to 17 years. A different sample of 8 pediatric OCD patients and 8 healthy children had a 1H-MRS examination of occipital cortex. RESULTS: Caudate glutamatergic concentrations (Glx) were significantly greater in treatment-naive OCD patients than in controls but declined significantly after paroxetine treatment to levels comparable with those of controls. Decrease in caudate Glx was associated with decrease in OCD symptom severity. Occipital Glx did not differ between OCD patients and controls. CONCLUSIONS: These preliminary findings provide new evidence of Glx abnormalities in the caudate nucleus in pediatric OCD and suggest that paroxetine treatment may be mediated by a serotonergically modulated reduction in caudate Glx.

Adolescent↗

PubMed1999

Neurobiology of childhood obsessive-compulsive disorder.

Despite the observation that obsessive-compulsive disorder (OCD) frequently has its onset during childhood or adolescence, most studies have examined OCD in adults. Because pediatric OCD patients are near illness onset with limited or no medication exposure, this population represents a unique window through which to view the neurobiology of OCD. In this article, the authors summarize data from existing studies of pediatric OCD and attempt to interpret the data within the context of a neurobiologic discourse based largely on research in adults. The authors review current neuroanatomic models of OCD and examine neuroimaging and neuropsychologic studies designed to test those models. In addition, the authors examine irregularities of neurotransmitter systems though to be involved in OCD.

Adolescent↗

PubMed1998

Case study: caudate glutamatergic changes with paroxetine therapy for pediatric obsessive-compulsive disorder.

Neurobiological models for obsessive-compulsive disorder (OCD) have consistently implicated the caudate nucleus in the pathophysiology of this disorder. OCD symptoms improved markedly in a 9-year-old boy treated with paroxetine, a selective serotonin reuptake inhibitor, for whom pre/posttreatment proton magnetic resonance spectroscopic examinations were acquired to assess the relationship between neurochemical profile in the caudate nucleus, symptom severity, and treatment with paroxetine. Striking changes of the glutamate resonance in the caudate were observed after 12 weeks of paroxetine treatment. These data provide further support for glutamatergic-serotonin pathway involvement in the caudate nucleus of OCD patients.

Caudate Nucleus↗

PubMed1997

Corpus callosal morphology in treatment-naive pediatric obsessive compulsive disorder.

1. Abnormalities in association circuits have been described in Obsessive Compulsive Disorder (OCD) and may reflect neurodevelopmental abnormalities. Primary and association cortices are topographically mapped in the corpus callosum (CC). The authors hypothesized alterations in CC subdivisions that connect association, but not primary cortices in pediatric OCD. The authors predicted that normal age-related increases in CC area would be absent in OCD. 2. The authors compared the midsagittal magnetic resonance images of 21 psychotropic-naive, nondepressed OCD patients, 7.2-17.7 years, and 21 case-matched healthy controls. Total CC area as well as that of the anterior, middle and posterior genu, anterior and posterior bodies, isthmus, and the anterior, middle and the posterior splenii were measured. 3. All of the CC regions except the isthmus were significantly larger in OCD patients than in controls. CC area correlated significantly with OCD symptom severity but not illness duration. The age-related increase in CC size seen in normal subjects was absent in OCD patients. 4. These findings support theories of abnormal association cortex development in OCD but also suggest possible abnormalities of other primary cortical regions as well.

Adolescent↗