137 research outputs found
Increased gray matter volumes in lithium-treated bipolar disorder patients
No full textLithium's neurotrophic effects have been reported in several in vitro and ex vivo studies. Preliminary human studies with magnetic resonance imaging (MRI) and spectroscopy have recently provided evidence of lithium-induced increases in gray matter volumes and N-acetyl-aspartate levels. In order to further examine the hypothesis that lithium treatment would relate to detectable increases in gray matter brain content, we blindly measured gray and white matter volumes in MRI images of 12 untreated and 17 lithium-treated bipolar patients and 46 healthy controls. Using multivariate analysis of covariance with age and gender as covariates, we found that total gray matter volumes were significantly increased in lithium-treated (747.9 +/- 69.8 cm(3)) compared with untreated patients (639.2 +/- 91.2 cm(3); F = 10.6; d.f. = 1, 25; P = 0.003) and healthy individuals (675.8 +/- 61.8 cm(3); F = 17.4; d.f. = 1, 59; P < 0.001), suggesting in vivo effects of lithium on gray matter, which could possibly reflect lithium's neurotrophic effects
MRI study of corpus callosum in patients with borderline personality disorder. A pilot study
No full textThis pilot study examined the integrity of the corpus callosum in a sample of patients with borderline personality disorder (BPD), as abnormalities in inter-hemispheric communication could possibly be involved in illness pathophysiology. We utilized magnetic resonance imaging (MRI) signal intensity (SI) and morphometric measures. Ten BPD and 20 healthy control subjects were assessed for current and past Axis I and Axis II comorbidities and histories of childhood abuse. Regional CC SI and areas were measured with semi-automated software from three-dimensional gradient echo imaging scans. Analysis of covariance was conducted to evaluate the results. No significant differences were observed between BPD and controls in the SI or area of any CC region. Abnormalities in interhemispheric connectivity do not appear necessary for the development of BPD. Further studies with larger samples are needed to confirm this preliminary finding
The subgenual prefrontal cortex of child and adolescent bipolar patients: a morphometric MRI study
No full textThe subgenual prefrontal cortex (SGPFC) plays an important role in emotional processing. We carried out a magnetic resonance imaging (MRI) study comparing the volume of the SGPFC in child and adolescent bipolar patients and healthy controls. The sample consisted of 15 children and adolescents who met DSM-IV criteria for bipolar disorder (mean age +/- S.D.=15.5 +/- 3.5 years) and 21 healthy adolescents (mean age +/- S.D.=16.9 +/- 3.8 years). MR images were obtained with a 1.5 T GE Signa Imaging System with Signa 5.4.3 software. SGPFC volumes were measured with the semi-automated software MedX (Sensor Systems, Sterling, VA, USA). ANCOVA was performed to compare SGPFC volumes between groups, using age, gender and intra-cranial volume (ICV) as covariates. The volumes (mean +/- S.D.) of the right and left SGPFC for bipolar patients were 291.27 +/- 88.70 mm(3) and 284.86 +/- 83.98 mm(3), respectively. For healthy controls, the right and left SGPFC volumes were 284.95 +/- 73.33 mm(3) and 307.55 +/- 73.67 mm(3), respectively. There were no statistically significant differences between groups regarding right or left SGPFC volumes. We found no evidence of volumetric abnormalities in the SGPFC of bipolar children and adolescents
Reduced Left Anterior Cingulate Volumes in Untreated Bipolar Patients
No full textBACKGROUND:
Functional and morphologic abnormalities of the cingulate cortex have been reported in mood disorder patients. To examine the involvement of anatomic abnormalities of the cingulate in bipolar disorder, we measured the volumes of this structure in untreated and lithium-treated bipolar patients and healthy control subjects, using magnetic resonance imaging (MRI).
METHODS:
The volumes of gray matter at the right and left anterior and posterior cingulate cortices were measured in 11 bipolar patients not taking any psychotropic medications (aged 38 +/- 11 years, 5 women), 16 bipolar patients treated with lithium monotherapy (aged 33 +/- 11 years, 7 women), and 39 healthy control subjects (aged 37 +/- 10 years, 14 women). Volumetric measurements were made with T1-weighted coronal MRI images, with 1.5-mm-thick slices, at 1.5T, and were done blindly.
RESULTS:
Using analysis of covariance with age and intracranial volume as covariates, we found that untreated bipolar patients had decreased left anterior cingulate volumes compared with healthy control subjects [2.4 +/-.3 cm3 and 2.9 +/-.6 cm3, respectively; F(1,58) = 6.4, p =.042] and compared with lithium-treated patients [3.3 +/-.5 cm3; F(1,58) = 11.7, p =.003]. The cingulate volumes in lithium-treated patients were not significantly different from those of healthy control subjects.
CONCLUSIONS:
Our findings indicate that anatomic abnormalities in left anterior cingulate are present in bipolar patients. Furthermore, our results suggest that lithium treatment might influence cingulate volumes in bipolar patients, which could possibly reflect postulated neuroprotective effects of lithium
Reduced N-Acetyl-Aspartate Levels In The Dorsolateral Prefrontal Cortex Of Adolescent Bipolar Patients
No full textOBJECTIVE:
Converging evidence implicates prefrontal circuits in the pathophysiology of bipolar disorder. Proton spectroscopy studies performed in adult bipolar patients assessing prefrontal regions have suggested decreased levels of N-acetylaspartate (NAA), a putative marker of neuronal integrity. In order to examine whether such abnormalities would also be found in younger patients, a 1H spectroscopy study was conducted that focused on the dorsolateral prefrontal cortex of children and adolescents with bipolar disorder.
METHOD:
The authors examined the levels of NAA, creatine plus phosphocreatine, and choline-containing molecules in the left dorsolateral prefrontal cortex of 14 bipolar disorder patients (mean age=15.5 years, SD=3, eight female) and 18 healthy comparison subjects (mean age=17.3, SD=3.7, seven female) using short echo time, single-voxel in vivo 1H spectroscopy. Absolute metabolite levels were determined using the water signal as an internal reference.
RESULTS:
Bipolar patients presented significantly lower NAA levels and a significant inverse correlation between choline-containing molecules and number of previous affective episodes. No differences were found for other metabolites.
CONCLUSIONS:
These findings suggest that young bipolar patients have decreased NAA levels in the dorsolateral prefrontal cortex, similar to what was previously reported in adult patients. Such changes may reflect an underdevelopment of dendritic arborizations and synaptic connections. These neuronal abnormalities in the dorsolateral prefrontal cortex of bipolar disorder youth are unlikely to represent long-term degenerative processes, at least in the subgroup of patients where the illness had relatively early onset
1H MRS study of dorso-lateral prefrontal cortex in healthy individuals before and after lithium administration
No full textThe mechanism of action of lithium is still largely unknown. However, recent animal and human studies suggested the possible neuroprotective effects of this medication. In particular, a recent magnetic resonance spectroscopy (MRS) study showed the increase of cortical brain levels of N-acetyl-aspartate (NAA), a putative marker of neuronal integrity/functioning, in both bipolar patients and normal controls after 4 weeks of lithium administration. We investigated the effects of lithium on NAA levels in a sample of healthy individuals using in vivo 1H MRS in dorsolateral prefrontal cortex (DLPFC), a region likely implicated in the pathophysiology of bipolar disorder. In vivo short echo-time 1H-MRS measurements of 8 cm3 single voxels placed bilaterally in the DLPFC were conducted at baseline and after 4 weeks of lithium administration on 12 healthy individuals (mean age+/-SD = 25.0+/-9.8 years; six males). After lithium administration, no significant differences in NAA, phosphocreatine plus creatine, glycerophosphocholine plus phosphocholine (or choline-containing molecules), and myo-inositol absolute levels or ratios were found in DLPFC (paired t-tests, p > 0.05). Contrary to prior MRS reports in bipolar patients, we found that lithium administration did not significantly increase NAA levels in the DLPFC of healthy individuals. Future longitudinal studies will be needed to further investigate whether chronic lithium treatment increases NAA levels in other brain regions in healthy individuals, and whether it promotes changes in these levels in specific brain regions in bipolar patients
MRI study of thalamic volumes in bipolar and unipolar patients and healthy individuals
No full textThe thalamus is a key structure in brain anatomic circuits potentially involved in the pathophysiology of mood disorders. Available findings from studies that examined this brain region in mood disorder patients have been conflicting. To examine the hypothesis of anatomical abnormalities in the thalamus in patients with mood disorders, we conducted a magnetic resonance imaging (MRI) study in 25 bipolar patients (mean age+/-S.D.=34.4+/-9.8 years), 17 unipolar patients (mean age+/-S.D.=42.8+/-9.2 years), and 39 healthy control subjects (mean age+/-S.D.=36.6+/-9.7 years). Thalamic volumes Gray Matter were measured blindly with a semi-automated technique. Multivariate analysis of variance, with age and gender as covariates, revealed no significant differences in left or right thalamic volumes among bipolar patients, unipolar patients and healthy individuals. There were no significant effects of gender, age at illness onset, episode type, number of episodes, length of illness, or family history of mood disorders on thalamic measurements. Although functional abnormalities in the thalamus are likely to be implicated in the pathophysiology of mood disorders, no abnormalities in thalamic size appear present in bipolar or unipolar individuals
Anatomical MRI Study Of Basal Ganglia In Major Depressive Disorder
No full textThe basal ganglia form a part of the brain neuroanatomic circuits that may be involved in mood regulation. Decreases in basal ganglia volumes have been previously reported in major depressive disorder patients in comparison to healthy controls. In this study, we measured caudate, putamen, and globus pallidus volumes in 25 patients with major depressive disorder (4 M; age+/-S.D.=41+/-11 years) and 48 healthy controls (29 M; age+/-S.D.=35+/-10 years), using high-resolution magnetic resonance imaging (MRI), in an attempt to replicate prior findings. Unlike most previous studies, we did not find significant differences between patient and control groups in basal ganglia volumetric measures. Nonetheless, there was a significant interaction between diagnosis and cerebral hemisphere, with MDD patients showing decreased asymmetry in globus pallidus volumes in comparison with healthy controls. Furthermore, in the patient group, left putamen volumes correlated inversely with length of illness, and left globus pallidus volume correlated directly with number of prior depressive episodes. These findings suggest that abnormalities in lateralization and possibly neurodegenerative changes in basal ganglia structures participate in the pathophysiology of major depressive disorder
Anatomical abnormalities in cingulate cortex in children and adolescents with bipolar disorder
No full textOBJECTIVE:
In vivo imaging studies have suggested anatomical and functional abnormalities in the anterior cingulate in adults with mood disorders. This anatomical magnetic resonance imaging study examined the cingulate cortex in children and adolescents with bipolar disorder and matched healthy comparison subjects.
METHOD:
Sixteen patients (mean age=15.5 years, SD=3.4) with DSM-IV bipolar disorder and 21 matched healthy comparison subjects (mean age=16.9 years, SD=3.8) were studied. Three-dimensional gradient echo imaging was performed (TR=25 msec, TE=5 msec, slice thickness=1.5 mm) in a 1.5-T GE Signa magnet. Cingulate volumes were compared by using analysis of covariance, with age and intracranial volume as covariates.
RESULTS:
The patients with bipolar disorder had significantly smaller mean volumes relative to the healthy subjects in the left anterior cingulate (mean=2.49 cm(3 [SD=0.28] versus 3.60 cm3 [SD=0.12], respectively), left posterior cingulate (2.53 cm3 [SD=0.32] versus 2.89 cm3 [SD=0.09]), and right posterior cingulate (2.19 cm3 [SD=0.13] versus 2.28 cm3 [SD=0.08]). No significant between-group difference was found for the right anterior cingulate (2.64 cm3 [SD=0.21] versus 2.71 cm3 [SD=0.10]).
CONCLUSIONS:
The findings indicate smaller cingulate volumes in children and adolescents with bipolar disorder, suggesting that such abnormalities may be present early in the illness course
Anatomic evaluation of the orbitofrontal cortex in major depressive disorder
No full textThe orbitofrontal cortex (OFC) plays a major role in neuropsychologic functioning including exteroceptive and interoceptive information coding, reward-guided behavior, impulse control, and mood regulation. This study examined the OFC and its subdivisions in patients with MDD and matched healthy control subjects.
METHODS:
Magnetic resonance imaging (MRI) was performed on 31 unmedicated MDD and 34 control subjects matched for age, gender, and race. Gray matter volumes of the OFC and its lateral and medial subdivisions were measured blindly.
RESULTS:
The MDD patients had smaller gray matter volumes in right medial [two-way analysis of covariance F(1,60) = 4.285; p =.043] and left lateral OFC [F(1,60) = 4.252; p =.044]. Left lateral OFC volume correlated negatively with age in patients but not in control subjects. Male, but not female patients exhibited smaller left and right medial OFC volumes compared with healthy control subjects of the same gender.
CONCLUSIONS:
These findings suggest that patients with MDD have reduced OFC gray matter volumes. Although this reduction might be important in understanding the pathophysiology of MDD, its functional and psychopathologic consequences are as yet unclear. Future studies examining the relationship between specific symptomatic dimensions of MDD and OFC volumes could be especially informative
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