Fear Network Model in Panic Disorder: The Past and the Future

The core concept for pathophysiology in panic disorder (PD) is the fear network model (FNM). The alterations in FNM might be linked with disturbances in the autonomic nervous system (ANS), which is a common phenomenon in PD. The traditional FNM included the frontal and limbic regions, which were dysregulated in the feedback mechanism for cognitive control of frontal lobe over the primitive response of limbic system. The exaggerated responses of limbic system are also associated with dysregulation in the neurotransmitter system. The neuroimaging studies also corresponded to FNM concept. However, more extended areas of FNM have been discovered in recent imaging studies, such as sensory regions of occipital, parietal cortex and temporal cortex and insula. The insula might integrate the filtered sensory information via thalamus from the visuospatial and other sensory modalities related to occipital, parietal and temporal lobes. In this review article, the traditional and advanced FNM would be discussed. I would also focus on the current evidences of insula, temporal, parietal and occipital lobes in the pathophysiology. In addition, the white matter and functional connectome studies would be reviewed to support the concept of advanced FNM. An emerging dysregulation model of fronto-limbic-insula and temporooccipito-parietal areas might be revealed according to the combined results of recent neuroimaging studies. The future delineation of advanced FNM model can be beneficial from more extensive and advanced studies focusing on the additional sensory regions of occipital, parietal and temporal cortex to confirm the role of advanced FNM in the pathophysiology of PD.

Promising Neuroimaging Biomarkers in Depression

The neuroimaging has been applied in the study of pathophysiology in major depressive disorder (MDD). In this review article, several kinds of methodologies of neuroimaging would be discussed to summarize the promising biomarkers in MDD. For the magnetic resonance imaging (MRI) and magnetoencephalography field, the literature review showed the potentially promising roles of frontal lobes, such as anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC). In addition, the limbic regions, such as hippocampus and amygdala, might be the potentially promising biomarkers for MDD. The structures and functions of ACC, DLPFC, OFC, amygdala and hippocampus might be confirmed as the biomarkers for the prediction of antidepressant treatment responses and for the pathophysiology of MDD. The functions of cognitive control and emotion regulation of these regions might be crucial for the establishment of biomarkers. The near-infrared spectroscopy studies demonstrated that blood flow in the frontal lobe, such as the DLPFC and OFC, might be the biomarkers for the field of near-infrared spectroscopy. The electroencephalography also supported the promising role of frontal regions, such as the ACC, DLPFC and OFC in the biomarker exploration, especially for the sleep electroencephalogram to detect biomarkers in MDD. The positron emission tomography (PET) and single-photon emission computed tomography (SPECT) in MDD demonstrated the promising biomarkers for the frontal and limbic regions, such as ACC, DLPFC and amygdala. However, additional findings in brainstem and midbrain were also found in PET and SPECT. The promising neuroimaging biomarkers of MDD seemed focused in the fronto-limbic regions.

The Relief Effects of Ramelteon on Refractory Chronic Migraine: A Case Report

The selective melatonin receptor agonism effect of ramelteon is useful for insomnia. Here we wanted to present a refractory chronic migraine case, who had significant improvements in migraine after using ramelteon. The possible mechanism for the ramelteon in the migraine relief might be related to melatonin effects.

The Accompanying Changes in Brain Structure of a Remitted Depression Patient with the Bupropion Treatment

The impacts from the bupropion on the brain structures have seldom been mentioned in the literature. The bupropion is a kind of antidepressant with dual action in the norepinephrine and dopamine receptors. Here we have a case to share about the bupropion-related effects in the brain structure.

Late-onset Quetiapine-related Tardive Dyskinesia Side Effects in a Patient with Psychotic Depression

The atypical antipsychotics were believed to induce less extrapyramidal syndrome, including tardive dyskinesia (TD). Since the introduction of the quetiapine, it is also reported with less TD side effects. It even can relieve the symptoms of severe TD and reduce the risk of TD. The quetiapine's low affinity and fast dissociation from postsynaptic dopamine D2 receptors should give the least risk of producing the symptoms of TD. The quetiapine even can reduce the TD side effects related to clozapine, which has the lowest risk for TD. However, since the first case report of TD side effects related to quetiapine published on 1999, the safety of quetiapine in TD aspect has been questioned. Therefore, we want to share this case report, which was written to describe the severe late-onset TD side effects after long-term use of quetiapine in a patient with psychotic depression. The patient had no significant findings after concurrent comprehensive neurological examinations, magnetic resonance imaging of brain and electroencephalogram since the onset of TD.