Radiomic features of amygdala nuclei and hippocampus subfields help to predict subthalamic deep brain stimulation motor outcomes for Parkinson‘s disease patients

Background and purpose

The aim of the study is to predict the subthalamic nucleus (STN) deep brain stimulation (DBS) outcomes for Parkinson’s disease (PD) patients using the radiomic features extracted from pre-operative magnetic resonance images (MRI).

Methods

The study included 34 PD patients who underwent DBS implantation in the STN. Five patients (15%) showed poor DBS motor outcome. All together 9 amygdalar nuclei and 12 hippocampus subfields were segmented using Freesurfer 7.0 pipeline from pre-operative MRI images. Furthermore, PyRadiomics platform was used to extract 120 radiomic features for each nuclei and subfield resulting in 5,040 features. Minimum Redundancy Maximum Relevance (mRMR) feature selection method was employed to reduce the number of features to 20, and 8 machine learning methods (regularized binary logistic regression (LR), decision tree classifier (DT), linear discriminant analysis (LDA), naive Bayes classifier (NB), kernel support vector machine (SVM), deep feed-forward neural network (DNN), one-class support vector machine (OC-SVM), feed-forward neural network-based autoencoder for anomaly detection (DNN-A)) were applied to build the models for poor vs. good and very good STN-DBS motor outcome prediction.

Results

The highest mean prediction accuracy was obtained using regularized LR (96.65 ± 7.24%, AUC 0.98 ± 0.06) and DNN (87.25 ± 14.80%, AUC 0.87 ± 0.18).

Conclusion

The results show the potential power of the radiomic features extracted from hippocampus and amygdala MRI in the prediction of STN-DBS motor outcomes for PD patients.

Sleep Dysfunction and Grey Matter Volume

PURPOSE OF REVIEW

With the voxel-based morphometry (VBM), structural imaging studies turned into new directions aiming to explore neurological disorders differently. This approach helps identify possible pathophysiological correlations between neuroanatomical grey matter (GM) structures in patients with sleep dysfunction. This article reviews recent findings on GM structure in various sleep disorders and possible causes of disturbed sleep and discusses the future perspectives.

RECENT FINDINGS

At present, research on the effect of GM volume changes in specific brain areas on the pathogenesis of sleep disturbances is incomplete. It remains unknown if the GM thickness reduction in patients with REM sleep behaviour disorder, obstructive sleep apnea, restless legs syndrome, and insomnia is due to complex disease presentation or direct response to disturbed sleep. Additionally, many VBM studies have yielded inconsistent results showing either reduction or increase in GM. The spatiotemporal complexity of whole-brain networks and state transitions during sleep and the role of GM changes increase new debates. Having multimodal data from large sample studies can help model sleep network dynamics in different disorders and provide novel data for possible therapeutic interventions.

Application of 3D Gel Dosimetry as a Quality Assurance Tool in Functional Leksell Gamma Knife Radiosurgery

Highly precise dose delivery to the target (tumor or cancerous tissue) is a key point when brain diseases are treated applying recent stereotactic techniques: intensity-modulated, image-guided radiotherapy, volumetric modulated arc therapy, Gamma knife radiosurgery. The doses in one single shot may vary between tens and hundreds of Gy and cause significant cell/tissue/organ damages. This indicates the need for implementation of quality assurance (QA) measures which are realized performing treatment dose verification with more than one calibrated quality assurance method or tool, especially when functional radiosurgery with a high dose (up to 40 Gy in our case) shall be delivered to the target using small 4 mm collimator. Application of two dosimetry methods: radiochromic film dosimetry using RTQA2 and EBT3 films and dose gel dosimetry using modified nPAG polymer gels for quality assurance purposes in stereotactic radiosurgery treatments using Leksell Gamma Knife© Icon™ facility is discussed in this paper. It is shown that due to their polymerization ability upon irradiation nPAG gels might be potentially used as a quality assurance tool in Gamma knife radiosurgery: they indicate well pronounced linear dose response in hypo-fractionated (up to 10 Gy) dose range and are sensitive enough to irradiation dose changes with a high (at least 0.2 mm) spatial resolution. Dose assessment sensitivity of gels depends on parameters of a dose evaluation method (optical or magnetic resonance imaging), however, is similar to this estimated using film dosimetry, which is set as a standard dosimetry method for dose verification in radiotherapy.

Delayed intracerebral hemorrhage associated with placement of a deep brain stimulating electrode over two years prior

INTRODUCTION AND IMPORTANCE

Most severe complications of DBS appear in the perioperative period. There are no published case reports of delayed ICH occurring more than three months from electrode implantation. The pathogenesis of delayed ICH remains unclear.

CASE PRESENTATION

We present a 64-year-old male with essential tremor who sustained a delayed intracerebral hemorrhage (ICH) 2.5 years after implantation of a deep brain stimulating electrode.

DISCUSSION

The patient sustained a thalamic-midbrain ICH that may have been related to the positioning of the electrode. An analysis was performed to determine the cause and risk factors that may have contributed. Based on these findings, it is possible that the proximity of the cannula or electrode may have mildly injured the wall of the superior thalamic vein during implantation, or perhaps being in contact with the vein over a longer-term having an effect, which in either of these scenarios can subsequently lead to ICH formation on the sudden rise of intracranial pressure.

CONCLUSION

It emphasizes the importance of proper surgical navigation planning, image- guidance, and the use of image verification.

Brain MRI morphometric analysis in Parkinson's disease patients with sleep disturbances

Background

Sleep disturbances are common in patients with advanced Parkinson disease (PD). The aim of this study was to evaluate a possible association of cortical thickness, cortical and subcortical volume with sleep disturbances in PD patients.

Methods

Twenty-eight PD patients (14 men and 14 women, median age 58 years) were evaluated for sleep disturbances with PDSS and underwent brain MRI. Control group consisted of 28 healthy volunteers who were matched by age and gender. Automated voxel based image analysis was performed with the FreeSurfer software.

Results

PD patients when compared to controls had larger ventricles, smaller volumes of hippocampus and superior cerebellar peduncle, smaller grey matter thickness in the left fusiform, parahipocampal and precentral gyruses, and right caudal anterior cingulate, parahipocampal and precentral hemisphere gyruses, as well as smaller volume of left rostral middle frontal and frontal pole areas, and right entorhinal and transverse temporal areas. According to the Parkinson’s disease Sleep Scale (PDSS), 15 (53.58%) patients had severely disturbed sleep. The most frequent complaints were difficulties staying asleep during the night and nocturia. The least frequent sleep disturbances were distressing hallucinations and urine incontinence due to off symptoms. Patients who fidgeted during the night had thicker white matter in the left caudal middle frontal area and lesser global left hemisphere cortical surface, especially in the lateral orbitofrontal and lateral occipital area, and right hemisphere medial orbitofrontal area. Patients with frequent distressful dreams had white matter reduction in cingulate area, and cortical surface reduction in left paracentral area, inferior frontal gyrus and right postcentral and superior frontal areas. Nocturnal hallucinations were associated with volume reduction in the basal ganglia, nucleus accumbens and putamen bilaterally. Patients with disturbing nocturia had reduction of cortical surface on the left pre- and postcentral areas, total white matter volume decrease bilaterally as well in the pons.

Conclusions

PD patients with nocturnal hallucinations had prominent basal ganglia volume reduction. Distressful dreams were associated with limbic system and frontal white matter changes, meanwhile nocturia was mostly associated with global white matter reduction and surface reduction of cortical surface on the left hemisphere pre- and postcentral areas.

Sporadic Creutzfeldt-Jakob disease with unusual initial presentation as posterior reversible encephalopathy syndrome: a case report

BACKGROUND

Creutzfeldt - Jakob disease (CJD) is a rapidly progressive and fatal neurodegenerative prion disease. MRI findings are included in diagnostic criteria for probable CJD, giving a sensitivity and specificity more than 90%, but the atypical radiological presentations in the early stage of the disease could cause the diagnostic difficulties. CJD can be definitively diagnosed by histopathological confirmation, brain biopsy or at autopsy.

CASE PRESENTATION

We present a case of 53-year-old woman with a history of a rapidly progressive dementia with symptoms of visual impairment, increased extrapyramidal type muscle tonus, stereotypical movements and ataxic gait resulting in the patient's death after13 months. The clinical symptoms deteriorated progressively to myoclonus and akinetic mutism already on the 14th week. The series of diagnostic examinations were done to exclude the possible causes of dementia. Initial MRI evaluation as posterior reversible encephalopathy syndrome (PRES) on the 9th week after the onset of symptoms created us a diagnostic conundrum. Subsequent MRI findings of symmetrical lesions in the basal ganglia (nucleus caudatus, putamen) on the 13th week and EEG with periodic sharp wave complexes (PSWC) in frontal regions on the 18th week allowed us to diagnose the probable sCJD. The histopathological findings after brain biopsy on the 14th week demonstrated the presence of the abnormal prion protein deposits in the grey matter by immunohistochemistry with ICSM35, KG9 and 12 F10 antibodies and confirmed the diagnosis of sCJD.

CONCLUSIONS

In this article we focus our attention on a rare association between radiological PRES syndrome and early clinical stage of sCJD. Although concurrent manifestation of these conditions can be accidental, but the immunogenic or neuropeptide mechanisms could explain such radiological MRI findings. A thorough knowledge of differential diagnostic of PRES may be especially useful in earlier diagnosis of sCJD.

Extended pterional approach for initial surgical management of craniopharyngiomas: a case series

AIM

Treatment of craniopharyngiomas remains challenging. The aim of this study was to evaluate results of initial surgical management of craniopharyngiomas via the extended pterional approach.

MATERIAL AND METHODS

Nineteen patients (10 female; median age of 23 years; ranging from 10 months to 67 years) undergone initial surgery for craniopharyngiomas through the extended pterional approach. Data were retrospectively collected by reviewing medical records, operative reports and imaging results.

RESULTS

The median size of craniopharyngiomas was 3.2 cm (range 1.3 - 4.8). Visual deterioration (n=12) and headache (n=10) were the most common symptoms on admission. After surgery, one patient died due to medical complications, 12 patients developed diabetes insipidus and eight patients developed anterior pituitary dysfunction. Median follow-up period was 9 years (range 2 - 13). Patients with progression of craniopharyngioma (n=5) when compared to patients without progression of craniopharyngioma (n=14) were significantly younger at the time of surgery, had less visual deterioration before surgery and had higher rates of not changed vision after surgery. Children had larger craniopharyngiomas when compared to adults.

CONCLUSION

Initial surgery for craniopharyngioma via the extended pterional approach is a safe and effective treatment option with low postoperative mortality, and acceptable postoperative morbidity and recurrence rate.

Transsphenoidal surgery for microprolactinomas in women: results and prognosis

BACKGROUND

Long-term dopamine agonist (DA) therapy is recommended as a first-line approach for the management of microprolactinomas. However, DA therapy may be poorly tolerated by some patients, and therefore some patients continue to prefer surgery over DA therapy.

AIM

The aim of our study was to evaluate factors associated with favorable outcomes after surgical treatment of microprolactinomas in women.

METHODS

Thirty-two women (mean age 31.0 ± 8.2 years) with confirmed microprolactinomas who were operated using transsphenoidal approach were included to the study. Twenty-two (61 %) women had previous DA therapy and ten (39 %) women preferred surgery as a first treatment. Mean follow-up was 4.2 ± 2.7 years. Surgery was considered to be effective and remission achieved if serum prolactin was normal without DA therapy and there were no signs of tumor re-growth on neuroimaging.

RESULTS

Nine (47.4 %) patients in whom remission was achieved did not receive preoperative DA therapy when compared to one (7.7 %) patient in whom remission was not achieved (p = 0.02). Remission after operation was achieved in nine out of ten (90 %) patients who did not receive DA therapy compared to ten out of 22 patients (45.5 %) who were treated with DAs (p = 0.01). The independent factor associated with good outcome following surgical treatment was no preoperative DA therapy (RR = 14.57 (1.43-148.1), p = 0.02). Surgical complications were permanent diabetes insipidus in two patients (6.3 %) and transient DI in five (15.6 %) patients.

CONCLUSIONS

The main factor associated with favorable microprolactinoma surgery outcome in women was the absence of preoperative DA therapy.

Effects of different kinds of meshes on postoperative adhesion formation in the New Zealand White rabbit

The aim of this study was to compare the effect of different kinds of surgical meshes on postoperative adhesion formation. Forty-two New Zealand White rabbits were studied. The rabbits were grouped into six groups, according to the type of surgical meshes (Prolene, Mersilene, Vypro, polytetraflouroethylene (PTFE), Proceed and control group) implanted into the peritoneum cavity. Thirty days after the operation, the relaparotomies were carried out, and any adhesions observed between the implanted mesh and tissues were evaluated and graded. The mean adhesion degree was 9.2 in the Mersilene mesh group, 9.5 in the Prolene mesh group, 9.7 and in the Vypro mesh group (P > 0.05). The mean adhesion degree was 1 in the control group, 2.75 in the Proceed mesh group and 2.25 in the PTFE mesh group. There was a significant difference in adhesion degree between the control, Proceed and PTFE groups and the Prolene, Mersilene and Vypro mesh groups. The adhesion degree was significantly lower in the Proceed and PTFE mesh groups when comparing them with the Prolene, Mersilene and Vypro meshes.