Parkinson's disease-like midbrain sonography abnormalities are frequent in depressive disorders

Abstract

Substantia nigra (SN) hyperechogenicity is a characteristic transcranial sonography (TCS) finding in idiopathic Parkinson's disease. SN hyperechogenicity, found also in approximately 10% of healthy adults, was related to a subclinical malfunction of the nigrostriatal dopaminergic system on PET studies and is, therefore, thought to represent a risk marker for Parkinson's disease. Epidemiological findings suggest an increased risk in subjects with depression. To find out whether frequency of SN hyperechogenicity is increased in depression, we performed TCS of brainstem and basal ganglia in 200 subjects: 55 controls without depression and without Parkinson's disease, 55 subjects with depression without Parkinson's disease (D+ PD-), 45 Parkinson's disease patients without depression (D- PD+) and 45 Parkinson's disease patients with depression (D+ PD+). Marked SN hyperechogenicity was found in 13% of controls, 40% of D+ PD- (chi2 test, P = 0.001), 69% of D- PD+ (vs D+ PD-, P = 0.004) and 87% of D+ PD+ patients (vs D- PD+, P = 0.04). Reduced echogenicity of brainstem raphe, thought to reflect alteration of the serotonergic system, was more frequent in depressed than in non-depressed subjects, irrespective of presence of Parkinson's disease, confirming earlier reports. The combined finding of marked SN hyperechogenicity and reduced raphe echogenicity in Parkinson's disease patients, however, was clearly associated with a history of depression prior to Parkinson's disease onset, whereas in D+ PD- patients this combined TCS abnormality was related to motor asymmetry. In D+ PD+ patients with depression prior to Parkinson's disease onset (n = 12), larger SN echogenic sizes correlated with younger age at Parkinson's disease onset (Spearman test, r = -0.607, P = 0.036). TCS findings of other basal ganglia did not differ between the groups studied. Data suggest that in subjects with depression nigrostriatal vulnerability is frequent, and that TCS might be useful to detect individuals at risk for developing Parkinson's disease.

Structural abnormality of the substantia nigra in children with attention-deficit hyperactivity disorder

“…21 An enlarged echogenic substantia nigra area has also been reported in individuals with Parkinson disease and depression, who concomitantly showed altered echogenicity of the raphe nuclei as a presumptive structural trait marker of a disturbed serotonergic system. 22 Because we did not determine the structure of the raphe nuclei in this study, we cannot draw any conclusions about what further neurotransmitter systems may be altered in children with ADHD. …”

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

“…A study using TCS and T2‐weighted imaging showed decreased echogenicity but increased hyperintensity in the mesencephalic midline structure in depressed PD patients, thereby suggesting an alteration in the basal limbic system in dPD 44. 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.…”

“…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.…”

Transcranial Sonography (TCS) of Brain Parenchyma in Movement Disorders: Quality Standards, Diagnostic Applications and Novel Technologies

“…tion of the central serotonergic system [26,36]. Also PD and Huntington's disease patients with associated depression often exhibit this TCS feature [36 -38].…”