Topographic anatomical localization of the motor nerve entry points (MEPs) of the masseter muscle.

PURPOSE: The masseteric nerve, which is a branch of the mandibular nerve, passes lateral to the mandibular notch and then spreads in the muscle to achieve motor innervation. The muscle entry points of these motor branches are the target points of minimally invasive interventions preferred in the treatment of masseter hypertrophy. The aim of this study was to reveal the areas where the motor entry points are concentrated in the muscle by dividing the muscle into topographic regions using reliable anatomic landmarks. METHODS: Bilateral 20 masseter muscles (40 in total) belonging to 20 formalin-fixed cadavers (10 female and 10 male) were examined. The distribution of the nerve in the muscle and its motor entry points were demonstrated and marked on the muscle surface. The masseter muscle was divided into six areas by lines passing through reliable anatomical landmarks (Areas 1-6). RESULTS: The total number of MEPs was 231.The mean distance of the MEPs from the Line-1 was 27.4 ± 11 mm, and the same distance from the Line-6 was 30.32 ± 7.2 mm. Most of the MEPs (123/231) were located in Area-4. Area-6 was the second (82/231) and Area-5 (19/231) was the third. CONCLUSION: We suggest that interventions in Area-4 (especially in the middle part) may have less complications as a result of less relationship with surrounding anatomical structures and more effective with high MEP number.

Structural neuroimaging findings in migraine patients with restless legs syndrome.

PURPOSE: One out of three migraine patients might have accompanying restless legs syndrome (RLS). In our study, we aimed to compare the volumes of the brain structures of migraineurs with and without RLS. METHODS: We had 37 female patients with migraine and 17 females as the control group. Nineteen migraineurs had no RLS (RLS0) and 18 migraineurs had comorbidity of RLS (RLS1). The volumes of the brain structures were obtained by manual measurements, volBrain, and voxel-based morphometry (VBM). Manually, we measured caudate and putamen volumes. We used age, years of education, depression, anxiety scores, and total intracranial volume as covariates. RESULTS: According to VBM analyses, the volumes of the left superior occipital gyrus and precuneus were increased, and the substantia nigra and cuneus were decreased in the RLS1 group compared with the RLS0 group. RLS1 patients had larger superior temporal gyrus, Brodmann area 38, and left insula, and RLS0 patients had larger Brodmann area 22, right superior temporal gyrus, and Heschl gyrus compared with controls. Migraine and RLS0 patients had a smaller corpus callosum anteriorly, whereas RLS1 patients had a smaller splenium. Caudate volumes were larger in migraine patients via the three techniques. There was a positive relation between the caudate and putamen volumes and attack frequency. CONCLUSIONS: Comorbidity of RLS might be a confounding factor in structural neuroimaging studies in migraine. Deficits in the visual network seem to be related to accompanying RLS; deficits in the auditory network are particularly related to migraine.

Subgenual anterior cingulate cortex and hippocampal volumes in depressed youth: The role of comorbidity and age.

OBJECTIVES: Many studies have reported that adults with recurrent major depressive disorder (MDD) have smaller hippocampal volumes than control participants. The data are more variable in youth with MDD, where findings have been inconsistent and the effects of factors such as age and co-morbidity have not been systematically examined. This study therefore assessed hippocampus and subgenual anterior cingulate (sgACC) morphometry in 168 youth, aged 12-25, with or without MDD and comorbid anxiety. METHODS: Structural magnetic resonance imaging (MRI) scans and clinical assessments were obtained from 80 participants with MDD (36 with comorbid anxiety disorder) and 88 age-matched control participants. RESULTS: Participants with MDD had smaller right hippocampi than controls (p=.013). Older depressed participants (20.1-25 years) had smaller hippocampal volumes than younger ones (<20.1 years; p=.05); this age effect was not apparent in controls (p=.46). Depression scores, indexed by the HAMD17, correlated with hippocampal volumes in older depressed youth. Depressed participants with comorbid anxiety had smaller sgACC, but not hippocampal, volumes than those without anxiety (p=.042). LIMITATIONS: Longitudinal, versus cross-sectional, studies can most optimally assess the influence of depression on neurodevelopmental profiles. Though our participants were largely treatment-naïve or in their first week of pharmacotherapy, a handful had extensive treatment histories; thus, treatment history may have influenced brain morphometry. CONCLUSIONS: Age effects were apparent when hippocampal volumes of older and younger participants with MDD were compared; such differences were not apparent in healthy participants. Comorbid anxiety was associated with decreased sgACC volumes suggesting delayed or altered neurodevelopment in a key emotion regulation region.

Cerebellar vermis volume in major depressive disorder.

The vermis is located in the midline of the cerebellum and is involved in the regulation of affect and cognitive processes. Although changes in vermis size have been reported in several psychiatric disorders such as schizophrenia and bipolar disorder, no volumetric studies have been conducted on samples of patients with major depressive disorder (MDD). One-hundred and five adult subjects were recruited: 35 patients who were presenting for first treatment (FT; 22 females), 35 patients with known previous treatment (PT; 22 females), and 35 healthy controls (NC; 22 females), matched for age and gender. We compared the volumes of the total vermis, the anterior lobe (V1), the superior-posterior lobe (V2), and the inferior-posterior lobe (V3), among these study groups. Anterior vermis (V1) was larger in patients with MDD with a long history of antidepressant treatment compared to healthy controls. This finding was evident only in men [F(2, 36) = 9.23, p = .001]. Patients in the FT group did not differ from healthy controls in any vermian region. We found no correlations between vermian subregional volumes and clinical variables such as illness duration or age at onset of illness. We speculate that the larger anterior vermis volumes might arise from abnormalities in connectivity or as compensatory responses to the prefrontal dysfunction noted in patients with MDD but confirmation of this hypothesis awaits further studies.

Shift in the brain network of emotional regulation in midlife women: is the menopausal transition the turning point?

OBJECTIVE: The menopausal transition is marked by hormonal changes and is quite often accompanied by cognitive and emotional complaints. Recent data also suggest a heightened risk for depression. Little is known about the changes in emotional regulation that might contribute to the increased risk of depression in this population. The aim of this study was to examine the brain correlates of emotional regulation in healthy, nondepressed midlife women. METHODS: Functional magnetic resonance imaging was obtained in response to a standardized emotional regulation task. Levels of congruency were set and brain activation was measured during high- and low-conflict-resolution trials. RESULTS: Fourteen women aged 40 to 60 years were enrolled into the study, and 11 were included in the final analyses. Activity associated with resolution of emotional conflict was observed in the dorsolateral prefrontal cortex (P < 0.05). No regions were engaged in the generation/monitoring of emotional conflict. Moreover, there was a significant deactivation of the amygdala in response to fearful faces (P < 0.05). CONCLUSIONS: Unlike similar studies in younger populations, these results suggest a more significant engagement of the dorsolateral prefrontal cortex and less amygdala activation in emotional regulation in midlife women. These findings are, however, consistent with previous studies in older populations. We hypothesize that a shift in emotional regulation circuitry might therefore occur in women during the menopausal transition and possibly contribute to the occurrence of mood and anxiety symptoms in women during/after this period in life.

Correlation of serum BDNF levels with hippocampal volumes in first episode, medication-free depressed patients.

The hippocampus seems to be affected in MDD, and brain-derived neurotrophic factor (BDNF) has positive effects on neurogenesis within the hippocampus. Although there are inconsistencies among study results, a smaller hippocampal volume in depressed patients is thought to be related to the pathophysiology of the disease. We looked at the correlation between serum BDNF (sBDNF) levels and hippocampal volumes (HCV) of first-episode MDD patients (18 female, 7 male; mean age = 32.1 ± 9.3) and healthy controls (17 female, 5 male; mean age = 29.7 ± 6.4). Region of interest analysis was conducted on the images acquired via MRI. sBDNF levels and HCV correlated only in the MDD group (right: r = 0.46, P = 0.02; left: r = 0.47, P = 0.02); however, HCV did not differ between MDD patients and healthy controls (right: F = 2.45, df = 1.46, P > 0.05; left: F = 0.05, df = 1.46, P > 0.05). BDNF may be a factor underlying HCV differences between MDD and healthy control subjects, which become apparent as severe and multiple episodes are experienced.

Increased subgenual prefrontal cortex size in remitted patients with major depressive disorder.

Bilateral reductions in the volume of the anterior cingulate cortex have been reported in patients with major depressive disorder (MDD) when compared with findings in healthy controls. We compared regional brain volumes in the subgenual prefrontal cortex (SGPFC; Brodmann area (BA) 24(sg)), subcallosal gyrus (BA25) and paracingulate gyrus (BA32) in healthy control subjects and a large and well-characterized sample of patients with recurrent MDD, all of whom had received extensive antidepressant therapy. Patients with a remitted episode of MDD had SGPFC volumes larger than those of healthy controls, while those in an active illness episode did not differ from controls. There were no differences in subcallosal gyrus and paracingulate gyrus volumes between patients with MDD and healthy controls, with the exception that women with MDD had smaller paracingulate volumes than their sex-matched controls. This effect was not related to duration of illness, number of previous episodes, age at illness onset, or age at the time of scanning. Our findings demonstrate SGPFC volume increases in association with long-term antidepressant therapy and suggest that this result may be linked to positive clinical response.

Hippocampal metabolic abnormalities at first onset and with recurrent episodes of a major depressive disorder: a proton magnetic resonance spectroscopy study.

The neural underpinnings of major depressive disorder (MDD) are unknown but there is evidence for structural alteration in the hippocampus that may become more pronounced over the course of illness. The aim of the present study was to examine metabolite levels of N-acetyl-aspartate (NAA), Myo-inositol (MI), Glutamate-glutamine (Glx) and choline-containing compounds (GPC and GPC+PCh) in patients presenting for first treatment of a depressive episode compared to those with multiple past episodes and age and sex matched controls. We used single voxel proton magnetic resonance spectroscopy ((1)H-MRS) centered on the hippocampus. Choline-containing compounds were significantly increased in patients with a high past illness burden relative to controls after controlling for hippocampal volume. The group presenting for first treatment had only increases in MI levels compared with matched controls. These results suggest that abnormal membrane turnover in the hippocampus is greater in patients with highly recurrent illness, and provide support for the hypothesis that there are neuronal changes in this region over the course of illness.

A meta-analysis examining clinical predictors of hippocampal volume in patients with major depressive disorder.

BACKGROUND: Some, although not all, studies report small hippocampal volume in patients with major depressive disorder (MDD) relative to healthy controls. Here, we explore the contribution of key demographic and clinical variables to this difference. METHODS: We used meta-analytic techniques to provide an updated analysis of data from 32 magnetic resonance imaging studies of hippocampal volume in patients with MDD. RESULTS: Our analysis confirmed the difference in hippocampal volume, but only among patients with MDD whose duration of illness was longer than 2 years or who had more than 1 disease episode. We found no such effect in studies that included patients who did not fit these criteria. The effect was limited to children and middle-aged or older adults. Analyzed collectively, studies including young adult patients showed equivalent hippocampal volumes across MDD patients and controls, a result that may be attributable to a reduced burden of illness in this population. Age at onset of disease, severity of depression at the time of scanning, sex and slice thickness did not contribute to differences in hippocampal volume between patients with MDD and controls. LIMITATIONS: The small size of many of the clinical and demographic subgroups may have limited statistical power to detect between-group differences. CONCLUSION: Although all studies were cross-sectional, our results suggest that hippocampal volume reductions generally occur after disease onset in patients with MDD. These findings have implications for the timing of clinical interventions aimed at reducing the impact of MDD on neuronal structure and function.

Posterior hippocampal volumes are associated with remission rates in patients with major depressive disorder.

BACKGROUND: The hippocampus (HC) is smaller in patients with recurrent major depressive disorder (MDD), but few longitudinal studies have examined whether volume is associated with clinically meaningful outcomes such as response to treatment. METHODS: We compared regional (head and body/tail) HC volumes in 46 patients with MDD, 14 of whom remitted after 8 weeks of first treatment to HC volumes of 32 patients who were not in remission after 8 weeks. RESULTS: Patients who remitted had larger pretreatment hippocampal body/tail volumes bilaterally compared with those who were not in remission at 8 weeks. This difference was not apparent in either the right or left hippocampal head. CONCLUSIONS: These findings extend a small number of previous reports, suggesting that regional brain volumes might be associated with rate and extent of clinical response to antidepressant medication.

Anterior cingulate volumes in never-treated patients with major depressive disorder.

The anterior cingulate cortex (ACC) is implicated in the cognitive and affective abnormalities observed in mood disorders. Bilateral ACC volume reductions have been reported in patients with major depressive disorder (MDD) when compared to healthy controls. We compared regional brain volumes in the subgenual prefrontal cortex (SGPFC; Brodmann area (BA) 24(sg)), subcallosal gyrus (BA25), and paracingulate gyrus (BA32) in 65 patients receiving a first course of treatment for MDD and 93 healthy control subjects. Patients with more than three episodes of untreated MDD had smaller subcallosal gyrus volumes than healthy controls, while those with three or fewer past untreated episodes did not differ from controls. We also found preliminary evidence that medication-exposed patients had smaller SGPFC volumes than patients with no exposure to medication and healthy controls. There was no evidence that these effects related to mood state, duration of untreated illness, or to patient age. No differences were apparent in paracingulate gyrus volumes between patients and controls. These findings confirm the presence of ACC volume reductions in untreated patients with MDD and suggest that illness burden and short-term medication exposure mediate this change.

Bilateral hippocampal volume increase in patients with bipolar disorder and short-term lithium treatment.

Most previous magnetic resonance imaging (MRI) studies of patients with bipolar disorder (BD) report similar hippocampus (HC) volumes across patients and controls, but because patients studied were heterogeneous with respect to course of illness variables and medication status, the conclusions of these studies remain equivocal. Lithium (Li) is the reference-standard drug for BD and its role as an important agent in neuroprotection and neurogenesis has been documented in human and in animal studies. We compared the volume of the HC, hippocampal head (Hh), and body/tail (Hbt) in three groups with no history of medication use before entry into this study: (a) a group of patients treated with Li for 1-8 weeks and then scanned; (b) a group comprised of patients who were unmedicated at the time of scan; and (c) a group of patients treated with either valproic acid or lamotrigine. Healthy age- and sex-matched comparison subjects were also scanned. HC volumes did not differ between the unmedicated and healthy comparison groups. There was a bilateral increase in volumes of HC and Hh in the Li-treated group compared to the unmedicated group, an effect that was apparent even over a brief treatment period. Our study provides further confirmation that Li can exert structural effects on the HC, which are detectable in vivo. The study emphasizes the need to control for even brief exposure to medication in volumetric studies of the HC.

Bilateral hippocampal volume increases after long-term lithium treatment in patients with bipolar disorder: a longitudinal MRI study.

RATIONALE: The majority of volumetric magnetic resonance imaging (MRI) studies of the hippocampus in patients with bipolar disorder (BD) show no differences in hippocampal volume between patients and healthy controls. Significant variability, however, exists in the medication status of patients included in these studies. In particular, treatment with lithium may exert long-term effects on hippocampal volume, influencing cognitive outcomes in BD patients. OBJECTIVES: To our knowledge, no longitudinal volumetric study has been performed in patients with BD, which would allow for an examination of whether lithium therapy used to treat BD can exert a long-term effect on hippocampal volume. MATERIALS AND METHODS: We examined the effects of lithium on hippocampal volumes and recollective memory performance over a period of 2 to 4 years in 12 patients with BD who had never received pharmacotherapy before lithium initiation. RESULTS: We found bilateral increases in volume of the hippocampus over time. We also found some evidence of improvement in verbal memory performance over the 4-year measurement period as assessed by the California Verbal Learning Test. CONCLUSIONS: Consistent with preclinical literature supporting the neuroprotective effects of lithium, long-term treatment is associated with preservation of recollective memory function and increased hippocampal size in vivo.

[Qualitative and quantitative MRI findings in temporal lobe epilepsy]. / Temporal lob epilepsili olgularda kalitatif ve kantitatif MRG bulgularinin klinik tani degeri.

PURPOSE: Mesial temporal sclerosis is the most common pathological finding in temporal lobe epilepsy (TLE). Accurate identification and localization of this pathology before surgery is obligatory for a good prognosis after the operation. In this study we compared the results of qualitative and quantitative MR findings of the hippocampus in TLE. MATERIALS AND METHODS: The study group consisted of 42 patients with the definitive diagnosis of temporal lobe complex partial seizure and 42 control subjects. Extrahippocampal lesions had been detected in 10 patients. Qualitative evaluation was performed by T2-weighted FSE, fast FLAIR, T1-weighted fast IR sequences on coronal plane. We also performed volumetric measurements of the hippocampus in 32 patients with TLE and compared the results with those of the control group. The mesial temporal lobes were investigated with SVS-proton MR spectroscopy using a PRESS sequence with an echo time of 135 milliseconds and T2 relaxation values. RESULTS: Hippocampal pathology was detected on paracoronal plane at T1-weighted fast IR (84%), T2-weighted FSE (60%) and fast FLAIR (88%) images. On comparing the hippocampal volumes of the patient and control groups, the hippocampal of the control group were found to be significantly larger (p < 0.05). Considering the right-left volume differences, 28 patients (88%) were found to have unilateral hippocampal atrophy. The most consistent MR spectroscopic parameter for definite lateralization was the NAA/Cho + Cr ratio (100%). Accurate epileptic focus lateralizations were made in 27 subjects (84%) by using hippocampal T2 relaxation time, and in 12 subjects (33%) by using temporal white matter T2 relaxation time. CONCLUSION: MR imaging is highly sensitive in detecting and locating abnormalities in the temporal lobe and hippocampus in patients with TLE. Implementation of FLAIR and T1 IR sequences in the routine MR examination of patients with TLE is recommended. With adequate asymmetry index, NAA/Cho + Cr ratio is sensitive in predicting the side of involvement in patients with TLE. For medically intractable TLE patients MRS is a very important guiding tool prior to surgery.

[Functional magnetic resonance imaging in lesions in or near the sensorimotor cortex]. / Duyusal-motor kortekse komsu lezyonlarda fonksiyonel MRG'nin etkinligi.

PURPOSE: To assess the efficiency of functional magnetic resonance imaging (fMRI) in demonstrating motor-sensorial cortical areas in mass lesions neighboring the perirolandic area and investigating its pre-operative sensitivity. MATERIALS AND METHODS: In the study, 20 right-handed patients with different types of intraxial and extraaxial mass lesions in or neighboring the perirolandic area were used. Of the all lesions, 6 were diagnosed as metastatic masses, 2 as oligodendroglioma, 2 as astrocytoma, 5 as glioblastoma multiforme, 2 as meningioma, 2 as arteriovenous malformations and 1 as porencephalic cyst. The study was performed on a 1.5 T unit. Images were acquired at the axial plane using T1 weighted spin echo, T2 weighted fast spin echo and fast FLAIR. Functional imaging was performed by blood-oxygen-level-dependent (BOLD) technique and single-shot gradient echo-planar sequence (SSEPI). During the sequence period a total of 420 images were acquired, each of which had 10 slices. By matching the resource functional images with T1 and T2 weighted anatomical images, the functional anatomy of the brain has been mapped. Sensorial-motor cortex has been activated by the finger-tapping-paradigm. RESULTS: Two patients could not included in the study because of extensive movement artifacts and meaningless BOLD answers. Eighteen of the patients had significant BOLD answers in bilateral peri-central sulcal area and in the center of the supplementary area. Activation areas were obtained neighboring the mass lesions and edema surrounding the lesion. CONCLUSION: fMRI can demonstrate motor-sensorial cortex in situations in which the anatomical order of perirolandic area has been changed by mass lesions. fMRI shows high sensitivity in the evaluation of lesions neighboring the perirolandic area preoperatively. Therefore fMRI can provide important information in patient selection, detection of different surgical choices and planning the surgical intervention.