Biomedical subjects

Belinda Ivanovski

Publications and source records attributed to Belinda Ivanovski.

7 recordsLinked to original sources

PubMed2006

Reduced activation to implicit affect induction in euthymic bipolar patients: an fMRI study.

OBJECTIVE: To examine whether euthymic bipolar patients engage similar or contrasting brain regions as healthy subjects when responding to implicit affect induction. METHODS: The study examined 10 euthymic patients with bipolar I disorder, and 10 age- and gender-matched healthy subjects using event-related functional magnetic resonance imaging (fMRI) while subjects engaged in a modified word-based memory task designed to implicitly evoke negative, positive or no affective change. The activation paradigm involved nominating whether a target word was contained within a previously presented word list using specified response keys. RESULTS: The fMRI task produced significantly greater activation in healthy subjects as compared to patients in response to both negative and positive affect in the anterior and posterior cingulate, medial prefrontal cortex, middle frontal and right parahippocampal gyri. Only negative affect produced significantly greater activation in the postcentral gyrus, inferior parietal lobule, thalamus and putamen and only positive affect achieved the same in the precentral, superior temporal and lingual gyri, precuneus, cuneus, caudate, pons, midbrain and cerebellum. There were no brain regions in which responses were greater in patients as compared to healthy subjects. There were no statistically significant differences between the groups with respect to speed or accuracy. CONCLUSIONS: Diminished prefrontal, cingulate, limbic and subcortical neural activity in euthymic bipolar patients as compared to healthy subjects is suggestive of emotional compromise that is independent of cognitive and executive functioning. This finding is of clinical importance and has implications both for the diagnosis and treatment of bipolar disorder. Future studies should aim to replicate these findings and examine the development of bipolar disorder, investigating in particular the effects of medication.

Adult↗

PubMed2006

Cognitive compromise in bipolar disorder with chronic cannabis use: cause or consequence?

This article briefly reviews the neuropsychological deficits associated with bipolar disorder and examines how substance abuse, in particular chronic cannabis use, may contribute to these. The focus of the article is cannabis, owing to its popularity in patients with bipolar disorder, although many studies focus on its use in conjunction with other substances. The findings are contextualized within bipolar disorder, examining functional outcome.

Bipolar Disorder↗

PubMed2005

An emotional Stroop functional MRI study of euthymic bipolar disorder.

OBJECTIVE: To identify the brain regions associated with emotional processing in euthymic bipolar patients. METHODS: The study examined 12 euthymic bipolar patients using functional magnetic resonance imaging (fMRI) while performing an emotional Stroop (eStroop) task. The task comprised emotionally valent and neutral words presented in alternating blocks that was designed to implicitly induce affect. In conjunction with fMRI, galvanic skin responses (GSR) were measured to monitor arousal. RESULTS: Euthymic bipolar patients had diminished activation in response to the affective stimuli in both cortical and subcortical brain regions when compared with healthy subjects. In particular, patients had less activation in the left ventral prefrontal cortex suggesting a potential trait deficit. Patients were slower to react than healthy controls, but did not differ with respect to accuracy. CONCLUSIONS: Euthymic bipolar patients are perhaps constrained in their ability to engage affective processing. Diminished ventral prefrontal cortex activation corroborates previous reports of a potential trait deficit, suggesting that 'all is not well in euthymia', although the effects of medication cannot be overlooked.

Adult↗

PubMed2005

A matter of motion or an emotional matter? Management of depression in Parkinson's disease.

Depression is one of the most frequent comorbidities occurring in Parkinson's disease, affecting up to 50% of patients. Depression is associated with severe negative symptoms and has been shown to contribute to an increased rate of decline of both cognitive and motor function, profoundly impacting on the patient's quality of life. The symptoms of depression overlap with the motor features of Parkinson's disease, making detection difficult. Moreover, the lack of specialized screening tools means that depression remains undiagnosed and untreated in a high percentage of patients. However, depression in Parkinson's disease, when identified early, can be effectively treated with a variety of antidepressant medications, improving quality of life and preserving daily function. The focus of this review is to provide an overview of current knowledge regarding depression in Parkinson's disease, followed by a practical discussion addressing the issues of the detection, diagnosis and treatment.

Antidepressive Agents↗

PubMed2004

Cognitive generation of affect in bipolar depression: an fMRI study.

Individuals with bipolar disorder manifest the full spectrum of emotions ranging from depression to mania. In attempting to understand the functional substrates of mood we attempted to identify brain regions associated with the cognitive generation of affect in bipolar depressed patients. We therefore examined ten depressed female subjects with bipolar affective disorder, and ten age-matched and sex-matched healthy comparison subjects using functional magnetic resonance imaging (fMRI) while viewing alternating blocks of captioned pictures designed to evoke negative, positive or no affective change. The activation paradigm involved the presentation of the same visual materials over three experiments alternating (experiment 1) negative and reference; (experiment 2) positive and reference and (experiment 3) positive and negative captioned pictures. The stimuli produced activation in both patients and comparison subjects in brain regions previously implicated in the generation and modulation of affect, in particular the prefrontal and anterior cingulate cortices. The activation in patients, when compared with healthy subjects, involved additional subcortical regions, in particular the amygdala, thalamus, hypothalamus and medial globus pallidus. Patients and comparison subjects displayed differential sensitivity to affective change with negative (experiment 1) and positive (experiment 2) affect induction producing converse patterns of activation. We conclude that bipolar depressed patients perhaps recruit additional subcortical limbic systems for emotional evaluation and this may reflect state-related or trait-related dysfunction. The differential patterns of activation inform us about bipolar depression and have potential diagnostic and therapeutic significance.

Adult↗

PubMed2004

Cognitive generation of affect in hypomania: an fMRI study.

OBJECTIVE: To identify the brain regions associated with the cognitive generation of affect in hypomanic bipolar patients. METHODS: The study examined 10 hypomanic female subjects with bipolar affective disorder, and 10 age- and sex-matched comparison subjects using functional magnetic resonance imaging (fMRI) while viewing alternating blocks of captioned-pictures designed to evoke negative, positive or no affective change. The activation paradigm involved the presentation of the same visual materials over three experiments alternating (a) negative and reference, (b) positive and reference and (c) positive and negative captioned-pictures. RESULTS: The stimuli produced activation in both patients and comparison subjects in brain regions previously implicated in the generation and modulation of affect, in particular the prefrontal cortex. Activation in patients involved additional subcortical regions namely the caudate and thalamus. CONCLUSIONS: This preliminary study suggests that hypomanic patients recruit additional subcortical limbic systems for emotional evaluation when advanced prefrontal cortical processing is no longer sufficient. The differential patterns of activation inform us about bipolar disorder and may have potential diagnostic and therapeutic significance.

Adult↗

PubMed2004

Bipolar disorder: it's all in your mind? The neuropsychological profile of a biological disorder.

OBJECTIVE: To compare and contrast the neuropsychological profile of the 3 phases of bipolar disorder (BD) to achieve a better definition of BD and to identify potential state and trait deficits. METHODS: We conducted a search for English-language papers published in journals from 1965 onward, using the following terms in Medline and Embase: neuropsychology or neuropsychological and BD, depression, mania, and euthymia. We scrutinized suitable subheadings and retrieved familiar papers and literature. RESULTS: We initially identified more than 100 articles and then excluded reviews and papers that did not directly administer neuropsychological tests. This left 27 papers, which we further examined and the findings of which we tabulated and discussed. Cognitive and executive functioning deficits were found, including set-shifting, verbal fluency, planning, attention, and memory. CONCLUSIONS: The neuropsychological deficits found in bipolar depression, mania or hypomania, and euthymia provide important insights into the pathophysiology of BD and may, in future studies, form the basis of clinically meaningful subtypes.

Bipolar Disorder↗