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Maja Trost

Publications and source records attributed to Maja Trost.

6 recordsLinked to original sources
PubMed2006

Network modulation by the subthalamic nucleus in the treatment of Parkinson's disease.

Deep brain stimulation of the subthalamic nucleus (STN DBS) has become an accepted tool for the treatment of Parkinson's disease (PD). Although the precise mechanism of action of this intervention is unknown, its effectiveness has been attributed to the modulation of pathological network activity. We examined this notion using positron emission tomography (PET) to quantify stimulation-induced changes in the expression of a PD-related covariance pattern (PDRP) of regional metabolism. These metabolic changes were also compared with those observed in a similar cohort of patients undergoing STN lesioning. We found that PDRP activity declined significantly (P < 0.02) with STN stimulation. The degree of network modulation with DBS did not differ from that measured following lesioning (P = 0.58). Statistical parametric mapping (SPM) revealed that metabolic reductions in the internal globus pallidus (GPi) and caudal midbrain were common to both STN interventions (P < 0.01), although declines in GPi were more pronounced with lesion. By contrast, elevations in posterior parietal metabolism were common to the two procedures, albeit more pronounced with stimulation. These findings indicate that suppression of abnormal network activity is a feature of both STN stimulation and lesioning. Nonetheless, these two interventions may differ metabolically at a regional level.

Aged↗
PubMed2004

The metabolic topography of posthypoxic myoclonus.

Posthypoxic myoclonus (PHM) is a syndrome of action and intention myoclonus that occurs in some patients who survive a cardiac arrest. Using PET and statistical parametric mapping, the authors observed a significant bilateral increase in glucose metabolism in the ventrolateral thalamus and pontine tegmentum in patients relative to controls. Interventions such as deep brain stimulation that interrupt networks that involve these structures may be useful in patients with severe PHM.

Adult↗
PubMed2003

Dystonia update.

PURPOSE OF REVIEW: Dystonia is a movement disorder with a complex and not fully understood pathophysiology. Its better understanding would enable more focused treatment for the disorder. In this review, we provide an overview of recent studies of the pathophysiology of primary and secondary dystonia, with an emphasis on functional brain imaging. Potential mechanisms underlying the beneficial effects of deep brain stimulation for dystonia are also summarized. RECENT FINDINGS: The recognition of dysfunction at different levels of the nervous system has extended the classical notions of localized striatal abnormalities in primary dystonia. Recent biochemical studies have revealed evidence of abnormal torsion activity in DYT1 dystonia. Abnormal patterns of brain metabolism have also been identified using functional brain imaging in different dystonia genotypes. These findings, in conjunction with new electrophysiological techniques, can be utilized to help define a common mechanism for the neural dysfunction in dystonia. SUMMARY: New insights into the pathophysiology of dystonia have been provided by recent studies using electrophysiology, biochemistry and human genetics, as well as functional brain imaging studies. These advances together may create the basis for new therapies for this disorder.

Basal Ganglia↗
PubMed2003

Evolving metabolic changes during the first postoperative year after subthalamotomy.

OBJECT: Short-term benefit from unilateral subthalamotomy for advanced Parkinson disease (PD) is associated with metabolic alterations in key targets of subthalamic nucleus (STN) and globus pallidus (GP) output. In this study positron emission tomography (PET) scanning was used to assess these changes and their relation to long-term benefits of subthalamotomy. METHODS: To determine whether the early postoperative changes persisted at longer-term follow up, the authors assessed six patients with advanced PD by using [18F]fluorodeoxyglucose-PET at 3 and 12 months postsurgery. The authors compared each of the postoperative images with baseline studies, and assessed interval changes between the short- and long-term follow-up scans. Clinical improvement at 3 and 12 months was associated with sustained metabolic decreases in the midbrain GP internus (GPi), thalamus, and pons of the lesioned side (p < 0.01). The activity of a PD-related multiregional brain network, which correlated with bradykinesia and rigidity, was reduced at both postoperative time points (p < 0.05). Comparisons of 3- and 12-month images revealed a relative metabolic increase in the GP externus (GPe) (p < 0.001), which was associated with worsening gait, postural stability, and tremor at long-term follow up. CONCLUSIONS: These findings indicate that subthalamotomy may have differential effects on each of the functional pathways that mediate parkinsonian symptomatology. Sustained relief of akinesia and rigidity is associated with suppression of a pathological network involving the GPi and its output. In contrast, the recurrence of tremor may relate to changes in the function of an STN-GPe oscillatory network.

Adult↗
PubMed2002

Primary dystonia: is abnormal functional brain architecture linked to genotype?

The DYT1 dystonia mutation is associated with an abnormal metabolic brain network characterized by hypermetabolism of the basal ganglia, supplementary motor area, and the cerebellum. In this study, we quantified the activity of this network in carriers of other dystonia mutations to determine whether this functional abnormality is linked to genotype. The findings suggest that the DYT1 metabolic topography is not genotype specific and may be present in carriers of other dystonia mutations.

Adult↗