Neuropsychiatric complications and neuroimaging characteristics after deep brain stimulation surgery for Parkinson's disease.

Psychiatric complications after subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease patients are common. The aim of this study was to evaluate a possible role of cortical thickness, cortical and subcortical volume for neuropsychiatric complications after STN-DBS implantation surgery. Twenty-two Parkinson's disease patients underwent STN-DBS. Control group consisted of 18 healthy volunteers who were matched by age and gender. All Parkinson's disease patients and control subjects underwent neuropsychological assessment and brain MRI. Control group subjects had normal MRI and neurocognitive testing results. Seven (31.8%) Parkinson's disease patients developed neuropsychiatric complications (psychosis and delirium) after STN-DBS implantation surgery with full recovery in short follow up. Two Parkinson's disease patients were excluded from further analysis, because they did not match image processing and analysis quality control. Volumetric analysis showed significant differences in cortical thickness between STN-DBS patients with and without postoperative neuropsychiatric complications in 13 gyruses on the right hemisphere (superior frontal, caudal middle frontal, pars triangularis and opercularis, temporal lobe, superior and inferior parietal, supramarginal) and in 7 gyruses on the left hemisphere (caudal middle frontal, inferior and middle temporal, pre and postcentral, superior parietal and supramarginal). White matter volume analysis showed also its reduction in the left caudal middle frontal area. Moreover, white matter volume and surface area reduction implicating that this area can be the most important for postoperative neuropsychiatric complication risk. Study results suggest that neuropsychiatric complications are common in Parkinson's disease patients after STN-DBS implantation and can be associated with excitation of frontal-striatum-thalamus and temporal-parietal circuits.

Ultrasonographic (TCS) and clinical findings in overlapping phenotype of essential tremor and Parkinson's disease (ET-PD).

BACKGROUND: Essential tremor (ET) and Parkinson's disease (PD) are considered distinct disorders. The aim of the study was to look for a link or any distinguishing features by transcranial sonography (TCS), together with the clinical examination findings in a group of patients with overlapping phenotype of ET and PD (ET-PD). METHODS: A prospective observational case-control study was carried out from the 3rd January 2011 until 30th January 2013 at the Hospital of Lithuanian University of Health Sciences. The final study group consisted of 15 patients with ET-PD, 116 patients with ET-only and 141 patients with PD-only. The control group included 101 subjects. Clinical diagnosis was of a diagnostic standard. RESULTS: The main ultrasonographic findings in the ET-PD group were similar to those of the PD-only: hyperechogenicity of the substantia nigra (66.7%, p < 0.001) and nuclei raphe interruptions/absence (38.5%, p < 0.001). The single distinguishing TCS finding in ET-PD group was a lentiform nucleus hyperechogenicity (26.7%), however this was only significant when compared to controls (p = 0.006). An asymmetrical onset of symptoms (73.3%) in ET-PD group was characteristic to PD-only. The ET-PD patients had the longest disease duration (median 6 years, p < 0.001), the most frequent rate of positive family history (53.3%, p = 0.005), rather low prevalence of cogwheel rigidity (26.7%, p < 0.001), and higher mean Hoehn & Yahr scores compared to PD-only (2.6 ± 0.8 vs. 1.8 ± 0.8, p = 0.012). CONCLUSIONS: The main TCS findings of the present study in patients with overlapping ET-PD phenotype were similar to the PD-only group. The highest positive family history rate among ET-PD patients indicates a strong hereditary predisposition and needs genetic underpinnings. Some ET patients, who look like they may be developing co-morbid PD clinically, may have an alternative diagnosis for Parkinsonism, which could be delineated by TCS examination.

Specificity of transcranial sonography in parkinson spectrum disorders in comparison to degenerative cognitive syndromes.

BACKGROUND: Hyperechogenicity of the substantia nigra (SN+), detected by transcranial sonography (TCS), was reported as a characteristic finding in Parkinson's disease (PD), with high diagnostic accuracy values, when compared mainly to healthy controls or essential tremor (ET) group. However, some data is accumulating that the SN + could be detected in other neurodegenerative and even in non-neurodegenerative disorders too. Our aim was to estimate the diagnostic accuracy of TCS, mainly focusing on the specificity point, when applied to a range of the parkinsonian disorders, and comparing to the degenerative cognitive syndromes. METHODS: A prospective study was carried out at the Hospital of Lithuanian University of Health Sciences from January until September 2011. Initially, a TCS and clinical examination were performed on 258 patients and 76 controls. The General Electric Voluson 730 Expert ultrasound system was used. There were 12.8% of cases excluded with insufficient temporal bones, and 4.3% excluded with an unclear diagnosis. The studied sample consisted of the groups: PD (n = 71, 33.2%), ET (n = 58, 27.1%), PD and ET (n = 10, 4.7%), atypical parkinsonian syndromes (APS) (n = 3, 1.4%), hereditary neurodegenerative parkinsonism (HDP) (n = 3, 1.4%), secondary parkinsonism (SP) (n = 23, 10.8%), mild cognitive impairment (MCI) (n = 33, 15.4%), dementia (n = 13, 6.1%), and control (n = 71). RESULTS: There were 80.3% of PD patients at stages 1 & 2 according to Hoehn and Yahr. At the cut-off value of 0.20 cm² of the SN+, the sensitivity for PD was 94.3% and the specificity - 63.3% (ROC analysis, AUC 0.891), in comparison to the rest of the cohort. At the cut-off value of 0.26 cm², the sensitivity was 90% and the specificity 82.4%.The estimations for the lowest specificity for PD, in comparison to the latter subgroups (at the cut-off values of 0.20 cm² and 0.26 cm², respectively) were: 0% and 33.3% to APS, 33.3% and 66.7% to HDP, 34.8% and 69.6% to SP, 55.2% and 82.8% to ET, 75% and 91.7% to dementia. CONCLUSIONS: The high sensitivity of the test could be employed as a valuable screening tool. But TCS is more useful as a supplementary diagnostic method, due to the specificity values not being comprehensive.

Magnetic resonance imaging after most common form of concussion.

BACKGROUND: Until now there is a lack of carefully controlled studies with conventional MR imaging performed exclusively in concussion with short lasting loss of consciousness (LOC). METHODS: A MR investigation was performed within 24 hours and after 3 months in 20 patients who had suffered a concussion with a verified loss of consciousness of maximally 5 minutes. As a control group, 20 age- and gender matched patients with minor orthopaedic injuries had a MR investigation using the same protocol. RESULTS: In a concussion population with an average LOC duration of 1. 4 minutes no case with unequivocal intracranial traumatic pathology was detected. CONCLUSION: An ordinary concussion with short lasting LOC does not or only seldom result in a degree of diffuse axonal injury (DAI) that is visualized by conventional MR with field strength of 1.0 Tesla (T). Analysis of earlier MR studies in concussion using field strength of 1.5 T as well as of studies with diffusion tensor MR imaging (MR DTI) reveal methodological shortcomings, in particular use of inadequate control groups. There is, therefore, a need for carefully controlled studies using MR of higher field strength and/or studies with MR DTI exclusively in common concussion with LOC of maximally 5 minutes.