Parkinson's disease and depression: evidence for an alteration of the basal limbic system detected by transcranial sonography

Abstract

Objectives-Depression is a frequent symptom in Parkinson's disease. Compelling evidence suggests a role of the brainstem in the control of mood and cognition. In patients with unipolar depression transcranial sonography (TS) studies have shown structural alteration of the mesencephalic brainstem raphe which could suggest an involvement of the basal limbic system in the pathogenesis of primary mood disorders. The objective of the present study was to evaluate whether a similar alteration could be found in depressed patients with Parkinson's disease using TS. Methods-Thirty patients with Parkinson's disease and 30 age and sex adjusted controls were examined by TS. Raphe echogenicity was rated semiquantitatively. The severity of motor symptoms and depression was rated using standard research instruments. Results-Raphe echogenicity was significantly reduced in depressed patients with Parkinson's disease compared with nondepressed patients with Parkinson's disease and control subjects. Raphe echogenicity correlated negatively with degree of motor impairment, and diVerences in raphe echo between depressed and non-depressed patients with Parkinson's disease were upheld when motor impairment was controlled for. Conclusion-These preliminary findings suggest that, as in unipolar depression, a morphological alteration of the brainstem raphe might be involved in the pathogenesis of depression in Parkinson's disease. This raphe alteration may reflect involvement in the basal limbic system in the pathogenesis of secondary depression. This concept is in line with current knowledge on the pathogenesis of both depression in Parkinson's disease and primary depressive disorders.

Depression, anxiety, and apathy in Parkinson's disease: insights from neuroimaging studies

“…Of the 38 studies on depression, 33 reported findings from one single imaging modality: 19 used either PET [11, 12, 13,15, 16, 17, 18, 19] or SPECT 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 techniques, four used T1‐weighted imaging 31, 32, 33, three used DTI 34, 35, 36, six used resting state functional MRI (RS‐FMRI) 37, 38, 39, 40, 41, 42 and two used TCS methods 43, 44. The remaining four of the 38 studies reported findings from structural T1‐weighted imaging plus another imaging method, including PET 14, DTI 45, task FMRI 46 and RS‐FMRI 47, respectively.…”

“…The other two studies applying TCS demonstrated hypoechogenicity in the brainstem raphe in dPD patients as opposed to HCs and non‐depressed PD patients 43, 48. Using DTI techniques, three out of four studies reported compromised white matter connectivity indexed by decreased fractional anisotropy (FA) in various tracts, including the bilateral anterior cingulate cortex and thalamus and multiple tracts connecting to the left frontal and deep temporal lobes 34, 35, 36.…”

Extrapyramidal symptoms and antidepressant drugs: neuropharmacological aspects of a frequent interaction in the elderly

“…On the other hand neurobiological factors have been demonstrated that support a direct involvement of brain alterations, specifically in limbic structures in the development of depressive symptoms in PD. 10,11 Akinetic-rigid forms can be observed in clinical states other than idiopathic Parkinson's disease, possibly involving other nervous structures. It is relevant to mention that parkinsonian syndromes include iatrogenic parkinsonism and the incidence of drug-induced parkinsonism is high in the elderly due to the frequent presence of multiple pathologies and consequent polypharmacotherapy.…”

Interferon beta-1a-induced depression and suicidal ideation in multiple sclerosis

“…Significant correlation was seen between severity of depression and the lesion load in the temporal lobes, more marked in the right side. Transcranial sonography provided no evidence for structural abnormalities of the ponto-mesencephalic midline as has been seen in patients with unipolar depression as well as in Parkinson's disease patients with depression 29,30 .…”