Screening for Platelet Dysfunction and Use of Prophylactic Tranexamic Acid in Patients Undergoing Deep Brain Stimulation: A Retrospective Analysis of Incidence and Outcome of Intracranial Hemorrhage.

INTRODUCTION: The rate of intracranial hemorrhage (ICH) after deep brain stimulation (DBS) is between 1.5 and 6.1%, with prolonged deficits occurring in 0.4-2.5% of the patients. This retrospective study investigates whether the prophylactic administration of tranexamic acid (TA) to patients with abnormal platelet function detected preoperatively by platelet function analyzer (PFA) lowered the risk for an ICH event. METHODS: We performed a systematic review of the medical records of 485 consecutively admitted patients who underwent bilateral DBS surgery in a single-center university hospital setting between 2009 and 2018. The cohort was split into two groups. In one group, preoperative PFA screening was performed (n = 156, patients recruited from 2014 to 2018), and TA was administered if platelet function was abnormal. No preoperative PFA was performed in the second group (n = 359, patients recruited from 2009 to 2013). Both cohorts were analyzed for the occurrence of ICH, defined by (i) detection of ICH in routine postoperative magnetic resonance/computed tomography imaging or (ii) in non-routine imaging for the onset of new neurological symptoms. RESULTS: Fourteen of the 156 screened patients (9%) showed reproducible PFA-100 closure abnormalities (3 with von Willebrand disease, 11 with no identifiable cause of platelet dysfunction). Two of the 156 patients (1.3%) in this cohort revealed an ICH on imaging, 1 of whom (0.6%) exhibited a prolonged neurological deficit as a result of ICH. In the cohort without platelet testing, 11 of the 329 patients (3.3%) demonstrated ICH on imaging, of whom 5 (1.5%) suffered from a prolonged neurological deficit. CONCLUSION: In this retrospective study, the screening and the administration of TA appeared to lower the risk of an ICH by 1.8%. One patient with von Willebrand disease suffered an ICH despite TA treatment. A prospective study is needed to clarify the impact of platelet testing and TA administration on the of incidence ICH.

Fear of disease progression in adult ambulatory patients with brain cancer: prevalence and clinical correlates.

BACKGROUND: Fear of progression (FoP) is frequent in patients with cancer and of high clinical relevance. Despite the often devastating prognosis of brain cancer, FoP has not yet been assessed in neurooncological patients. OBJECTIVE: The aim of this study was thus the assessment of FoP and its clinical correlates. METHODS: In an ambulatory setting, 42 patients with a primary brain tumour completed the Fear of Progression questionnaire FoP-Q-12. Clinical correlates of FoP were assessed via a variety of measures, including patients' physical state (Karnofsky Performance Status, KPS), cancer-related psychosocial distress (Distress Thermometer, DT), anxiety (General Anxiety Disorder Scale, GAD-7), depression (Patient Health Questionnaire, PHQ-9), Quality of Life (Short Form Health Survey, SF-8), and unmet supportive care needs (Supportive Care Needs Survey, SCNS). RESULTS: Eighteen patients (42%) suffered from high FoP (i.e. scored ≥ 34 in the FoP-Q-12). According to the 12 items of the FoP-Q-12, the greatest fears were worrying about what would happen to their family and being afraid of severe medical treatments. No sociodemographic variables (e.g. age, gender) or medical tumour characteristics (e.g. tumour malignancy, first or recurrent tumour) were related to FoP. Patients with more severe physical symptoms reported higher FoP. Patients with higher FoP were more anxious, more depressed, reported lower Quality of Life, and suffered from more unmet supportive care needs. CONCLUSION: Our results demonstrate that FoP is frequent and of high clinical relevance for neurooncological patients. Its assessment is not sufficiently covered by instruments for assessment of other areas of psychological morbidity (e.g. general anxiety). Moreover, FoP cannot be predicted by objective characteristics of the patients and disease. Thus, the routine screening for FoP is recommended in neurooncological patients. Clinicians should bear in mind that patients with high FoP are likely to suffer from high emotional distress and unmet supportive care needs and initiate treatment accordingly.

A missing piece? Neuropsychiatric functioning in untreated patients with tumors within the cerebellopontine angle.

PURPOSE: To date, little is known about neuropsychiatric symptoms in patients with tumors within the cerebellopontine angle (CPA). These, however, might be of clinical relevance. Aim of this study was thus to assess possible impairment in cognition, elevation in mood symptoms, and fatigue in this specific patient group. METHODS: Forty-five patients with an untreated CPA tumor (27 vestibularis schwannoma, 18 meningioma) were tested within a cross-sectional observational study in a single institution prior to neurosurgical treatment. Patients were administered a multifaceted battery comprising of widely-used tests for assessment of neuropsychiatric functioning. RESULTS: The majority of the included patients (69%) showed neurocognitive impairment, most frequently in the areas of attention and visuo-motor speed (e.g., alertness) (62%) as well as visuo-construction (44%). Impaired structural integrity of the brain stem was accompanied by more serious neurocognitive deficits. About one-third of the sample reported clinically relevant depression and/or anxiety and an even higher proportion (48%) described high levels of fatigue. Cognitive and affective symptoms as well as fatigue contributed significantly to patients' Quality of Life, indicating the clinical relevance of neuropsychiatric symptoms in patients with CPA tumors. CONCLUSIONS: Although patients with untreated CPA tumors often suffer from devastating and prominent physical symptoms, neuropsychiatric problems are also frequent. Including these aspects in the routine clinical assessment and initiating treatment accordingly might thus improve clinical management of the patients and improve Quality of Life.

Comparison of the Battery Life of Nonrechargeable Generators for Deep Brain Stimulation.

OBJECTIVE: Nonrechargeable deep brain stimulation (DBS) generators must be replaced when the battery capacity is exhausted. Battery life depends on many factors and differs between generator models. A new nonrechargeable generator model replaced the previous model in 2008. Our clinical impression is that the earlier model had a longer battery life than the new one. We conducted this study to substantiate this. METHODS: We determined the battery life of every DBS generator that had been implanted between 2005 and 2012 in our department for the treatment of Parkinson's disease, and compared the battery lives of the both devices. We calculated the current used by estimating the total electrical energy delivered (TEED) based on the stimulation parameters in use one year after electrode implantation. RESULTS: One hundred ninety-two patients were included in the study; 105 with the old and 86 with the new model generators. The mean battery life in the older model was significantly longer (5.44 ± 0.20 years) than that in the new model (4.44 ± 0.17 years) (p = 0.023). The mean TEED without impedance was 219.9 ± 121.5 mW * Ω in the older model and 145.1 ± 72.7 mW * Ω in the new one, which indicated significantly lower stimulation parameters in the new model (p = 0.00038). CONCLUSION: The battery life of the new model was significantly shorter than that of the previous model. A lower battery capacity is the most likely reason, since current consumption was similar in both groups.

Cognitive screening in patients with intracranial tumors: validation of the BCSE.

This study presents the first validation of the Brief Cognitive Status Exam (BCSE) against two other screening tools for cognitive impairment in patients with intracranial tumors. 58 patients and 22 matched healthy controls completed the BCSE, the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). Patients were additionally tested with a comprehensive neuropsychological battery. Based on this assessment, they were classified as cognitively impaired or unimpaired on five cognitive domains. Analyses revealed a comparable feasibility of the BCSE relative to the MoCA and the MMSE, but a smaller range of assessed functions (e.g., no correlation with the domain visual-spatial functions). The ability to separate patients and healthy controls was extremely poor for BCSE and MMSE (sensitivity of 38.6 % and less), but moderate for MoCA (sensitivity 68.97 %). Detection of cognitive impairment in patients was worst with BCSE (sensitivity 37 %; MoCA 92.9 %, MMSE 44.4 %) as compared to neuropsychological testing. Moreover, prediction of cognitive outcome was also worst for the BCSE (AUC = .713, NPV = 50 %). An optimal cut-off of 50.5 increased the results slightly. In summary, the BCSE showed good feasibility but no sufficient results in separating healthy individuals from patients or detecting cognitive impairment in patients. Consequently, as a screening measure, we would recommend the MoCA instead of the BCSE. However, since even the MoCA failed to detect cognitive impairment, our study supports the view that reliable results could only be obtained with a comprehensive neuropsychological battery.

Symptomatic spinal cavernous malformations: indication for microsurgical treatment and outcome.

PURPOSE: We demonstrate clinical features, therapy and outcome of 14 patients with symptomatic spinal cavernous malformations (CM). METHODS: We retrospectively reviewed all patients who underwent microsurgical treatment of symptomatic spinal CM during the last decade in our department through an analysis of our database. RESULTS: We analyzed the data of 14 patients (11 females, 3 males) with symptomatic spinal CM in a range of 16-77 years (mean age 47.8 years). Seven patients (50%) experienced significant improvement of their symptoms rapidly after surgery. The remaining seven patients presented new non pre-existing complaints, which improved gradually with a favourable outcome at the last follow-up examination in six cases. CONCLUSION: Microsurgical treatment under perioperative electrophysiological monitoring is justified to prevent severe neurofunctional deterioration in symptomatic spinal CM. Although some of the patients deteriorate after surgery, the symptoms are rapidly declining with a favourable outcome in majority of them.

A rare case of extradural lumbar nerve root cavernoma.

We present a very rare case of an extradural nerve root cavernoma of the lumbar spine. The patient had signs of radiculopathy for the last 3 years. Conservative treatment was unsuccessful. The MRI-image revealed a lesion mimicking neurinoma of the left L3 nerve root. Surgical removal of the lesion was performed by an extreme lateral transmuscular approach. Intraoperatively, the lesion showed signs of intratumoural bleeding. In the histological analysis, a cavernoma of the nerve root was established. Despite the benign nature of these very rare lesions, complete surgical removal should be performed since a spontaneous regression is not to be expected and surgery relieves the patients from their symptoms.

Does magnetic resonance imaging produce further benefit for detecting a bleeding source in subarachnoid hemorrhage of unknown origin?

BACKGROUND: Spontaneous subarachnoid hemorrhage (SAH) without evidence of a bleeding source on the first digital subtraction angiogram (DSA) - also called SAH of unknown origin - is observed in up to 27% of all cases. Depending on the bleeding pattern on CT scanning, SAH can be differentiated into perimesencephalic (PM-SAH) and non-perimesencephalic SAH (NON-PM-SAH). The aim of our study was to investigate the effectiveness of magnetic resonance imaging (MRI) for detecting a bleeding source in SAH of unknown origin. METHODS: We retrospectively reviewed 1,226 patients with spontaneous SAH between January 1991 and December 2008 in our department. DSA was performed in 1,068 patients, with negative results in 179 patients. RESULTS: Forty-seven patients were categorized as having PM-SAH and 132 patients as having NON-PM-SAH. MRI of the brain and the craniocervical region was performed within 72 h after diagnosis of SAH and demonstrated no bleeding sources in any of the PM-SAH and NON-PM-SAH patients (100% negative). CONCLUSIONS: In our experience MRI did not produce any additional benefit for detecting a bleeding source after SAH with a negative angiogram. The costs of this examination exceeded the clinical value. Despite our results MRI should be discussed on a case-by-case basis because rare bleeding sources are periodically diagnosed in cases of NON-PM-SAH.

Chemokine expression in the white matter spinal cord precursor niche after force-defined spinal cord contusion injuries in adult rats.

Inflammatory cascades induced by spinal cord injuries (SCI) are localized in the white matter, a recognized neural stem- and progenitor-cell (NSPC) niche of the adult spinal cord. Chemokines, as integrators of these processes, might also be important determinants of this NSPC niche. CCL3/CCR1, CCL2/CCR2, and SDF-1alpha/CXCR4 were analyzed in the ventrolateral white matter after force defined thoracic SCI: Immunoreactivity (IR) density levels were measured 2 d, 7 d, 14 d, and 42 d on cervical (C 5), thoracic (T 5), and lumbar (L 5) levels. On day post operation (DPO) 42, chemokine inductions were further evaluated by real-time RT-PCR and Western blot analyses. Cellular phenotypes were confirmed by double labeling with markers for major cell types and NSPCs (nestin, Musashi-1, NG2, 3CB2, BLBP). Mitotic profiles were investigated in parallel by BrdU labeling. After lesion, chemokines were induced in the ventrolateral white matter on IR-, mRNA-, and protein-level. IR was generally more pronounced after severe lesions, with soaring increases of CCL2/CCR2 and continuous elevations of CCL3/CCR1. SDF-1alpha and CXCR4 IR induction was focused on thoracic levels. Chemokines/-receptors were co-expressed with astroglial, oligodendroglial markers, nestin, 3CB2 and BLBP by cells morphologically resembling radial glia on DPO 7 to DPO 42, and NG2 or Musashi-1 on DPO 2 and 7. In the white matter BrdU positive cells were significantly elevated after lesion compared with sham controls on all investigated time points peaking in the early time course on thoracic level: Here, chemokines were co-expressed by subsets of BrdU-labeled cells. These findings suggest an important role of chemokines/-receptors in the subpial white matter NSPC niche after SCI.

Spinal cord compression caused by idiopathic intradural arachnoid cysts of the spine: review of the literature and illustrated case.

Intradural spinal arachnoid cysts with cord compression are rare. When becoming symptomatic they cause variable symptoms involving gait disturbance, paraparesis or tetraparesis and neuropathic pain, decreasing significantly the patients' life quality. The extension of such cysts averages 3.7 vertebral bodies. The diagnosis is clinical and radiological with the use of MRI, CT myelography or a combination of both. The best treatment option is complete removal of the cyst. However, even when paresis is regressing there is no good recovery from neuropathic pain. Laminectomy approach can cause postoperative complications especially when the cyst(s) expand(s) in more than one level. Alternatively, a cyst fenestration can be performed, including the levels of the maximal spinal cord compression. The clinical outcome is as good as after the cyst resection enabling the patient to walk again. The neuropathic pain may persist and require medication. A clinical case is presented, and the literature is reviewed. In the present case we report a patient with intradural arachnoid cysts extending from T6 to L2 and causing severe gait ataxia as well as neuropathic pain and hypaesthesia. The spinal-cord was compressed at T8 and T12. Surgical treatment with partial cyst resection in the compressed levels with an interlaminar approach brought similar results as complete resection. The patient was able to walk without help which was not possible before surgery. The cysts' extension is impressive as well as the minimal operative procedure.

The effect of lung-protective permissive hypercapnia in intracerebral pressure in patients with subarachnoid haemorrhage and ARDS. A retrospective study.

OBJECTIVE: Lung protective ventilation has a beneficial effect in treating patients with acute respiratory distress syndrome (ARDS). An effect of this ventilation modality is hypercapnia, which leads to increased cerebral blood flow. Since increased cerebral blood flow can induce brain oedema the question arises whether lung protective ventilation can be applied in patients with subarachnoid haemorrhage. METHODS: We retrospectively analysed 12 patients with subarachnoid haemorrhage who were ventilated with lung protective ventilation since they suffered of ARDS. Tidal volume was 5-8 ml/kg body weight, and positive end expiratory pressure was 10-15 cm H2O. Intracerebral pressure was continuously measured by intracerebral probe. RESULTS: Despite of hypercapnia (pCO2 50-60 mmHg) there was no increase of the intracerebral pressure. Lung protective ventilation could be safely performed in patients with subarachnoid haemorrhage. CONCLUSION: Patients with higher Hunt and Hess grades of subarachnoid haemorrhage who are predominantly intubated and ventilated and most of them suffer from ARDS can receive lung protective ventilation. In our small patient collective, the occurring hypercapnia did not influence (increase) the intracerebral pressure.

Gliosarcoma: clinical experiences and additional information with MR spectroscopy.

Gliosarcomas represent about 2% of glioblastoma multiforme (WHO grade IV). They have mixed features of glial and sarcomatous components. The clinical presentation and prognosis are similar to glioblastoma. Between 1997 and 2006, 16 patients with intracranial gliosarcoma were treated in the Department of Neurosurgery in Kiel, Germany. Median age was 63 years (52-79 years). Eleven patients were men and five were women. Six tumors were in the frontal lobe, four in the temporal lobe, three parietal, two in the thalamic area and one in the occipital lobe. Pre-operatively, in two patients, we could perform magnetic resonance (MR) spectroscopy. There was lactate peak, which is a sign of local necrosis and hypoxia. Median survival time in our patient group was 7 months (2-11 months). On histological examination, we found glial fibrillary acid protein positive cells surrounded by sarcomatous tissue and reticular fibers. The proliferation index MIB-1 was between 20 and 70%. The prognosis in this patient group is still poor. MR spectroscopy and location of the tumor adjacent to the dura with inhomogeneous contrast enhancement might give hints pre-operatively for the differential diagnosis of gliosarcoma. Further works with adjuvant chemotherapy are necessary.

Severe hyponatraemia in the setting of hypopituitarism associated with empty sella and herniation of the optic chiasm and gyrus rectus.

We present a patient with progressive weakness over months caused by untreated hyponatraemia. When hyponatraemia became severe, the patient could not move without help, was lethargic and had endocrinological dysfunction. Symptomatic therapy brought no improvement. MRI of the brain showed empty sella with gross herniation of the optic chiasma, gyrus rectus and third ventricle. After fluid and salt supplementation was combined with hydrocortisone, the patient regained his strength and could leave the hospital. Panhypopituitarism caused by empty sella should always be considered when hyponatraemia is not responsive to salt and fluid substitution alone. Additional hydrocortisone supplementation can be life saving.

Do Adaptors Shorten the Battery Life of Nonrechargeable Generators for Deep Brain Stimulation?

OBJECTIVE: Generators implanted for deep brain stimulation must be replaced after several years. If a Kinetra generator is replaced by the Activa-PC, an adaptor will be required to attach it to the original extension cables. On the basis of our clinical impression that the battery life of the Active-PC generator was shorter when an adaptor was used, we performed this retrospective study. METHODS: We determined the battery lifetimes of deep brain stimulation generators that had been implanted in our department. The inclusion criterion was the initial implantation of a Kinetra generator that was later replaced by an Activa-PC with adaptor, which itself was subsequently also replaced. These patients were compared with an Activa-PC control group without an adaptor but identical with regard to number of battery exchanges, disease, and target. RESULTS: There were 28 patients in the study group and 14 in the control group. Battery lifetime of the Activa-PC with adaptor (32.4 ± 7.7 months) was significantly shorter than that of the Kinetra (53.5 ± 15.7 months, P = 0.000006). The battery life of Activa-PC without an adaptor (35.3 ± 8.2 months) did not differ significantly from that of the Activa-PC with an adaptor (P = 0.333). CONCLUSIONS: The battery lifetime in a replacement Activa-PC is shorter than that in the original Kinetra generator. Adaptors have no significant effect on battery life. Patients should be informed that the battery in their new generator must be checked more frequently than before.

Assessment of preoperative anxiety in neurosurgical patients: Comparison of widely used measures and recommendations for clinic and research.

OBJECTIVE: Preoperative anxiety is frequent in neurosurgical patients and of high clinical relevance (e. g., associated with anestesiological requirements and surgery outcome). Little however is known about the quality of instruments for assessment of preoperative anxiety in this specific patient group and setting. This paper therefore focused on the psychometric properties of widely used questionnaires. Aim of this study was thus to enable both the clinician and the researcher to select appropriate instruments for assessment of surgery-related anxiety. PATIENTS AND METHODS: The following instruments for assessment of preoperative anxiety were administered in a pseudo-randomized order one day prior to surgery in sample of 158 neurosurgical patients: The State Trait Operation Anxiety Inventory (STOA) - state scale, the Amsterdam Preoperative Anxiety and Information Scale (APAIS), and the one-item visual analogue scale (VAS). The questionnaires were psychometrically tested according to classical test theory (validity, reliability, diagnostic accuracy). RESULTS: Construct validity was supported in all applied measures (convergent and divergent validity, known-group comparisons). For the STOA state, we found a one factor scale structure and thus no support for the proposed subscales covering cognitive and affective anxiety. The proposed scale structure of the APAIS, measuring anxiety and information requirement, was replicated. Internal consistency as indicator for reliability of the STOA and the APAIS was excellent (Cronbach's alpha = 0.937/0.868). All instruments showed adequate diagnostic accuracy with the most favourable results of the STOA. CONCLUSIONS: All instruments included in this study can be recommended for assessment of surgery-related anxiety in neurosurgical patients with regard to their psychometric properties. Each instrument offers distinct advantages. Thus, clinicians and researchers can base their individual choice on specific aims and available resources.

Breaking Bad News to Patients with Intracranial Tumors: The Patients' Perspective.

OBJECTIVE: Bad news refers to information that subjectively impedes a patient's future prospects. Patients with intracranial tumors potentially face numerous pieces of bad news. This study assessed the patients' perspective regarding the content of bad news, patients' preferences for the communication of bad news, and clinical consequences of mismatch of patients' communication preferences. METHODS: We included 42 patients with an intracranial tumor shortly after neurosurgical tumor removal. Patients' preferences for communication of bad news was assessed via the Measure of Patients' Preferences Scale. Various areas of patients' psychosocial well-being were included (e.g., depression or quality of life). RESULTS: At this early stage of the disease trajectory, patients with a brain tumor had already received on average 2.2 (standard deviation, 1.38; range, 0-6) pieces of bad news. For most patients, these pieces included receiving the initial diagnosis. Patients reported a multitude of communication preferences, some highly specific for patients with brain tumors. On average, 30% of these preferences were not matched with the physicians' behavior. Communication mismatch was associated with lower patient satisfaction regarding information but no other areas of psychosocial well-being. CONCLUSIONS: Communicating bad news to the patient with a brain tumor in a way that is appreciated by the patient is a complex and demanding endeavor for the treating physician. Meeting patients' needs not only requires the skills regarding the communication of cancer-related news but also accounting for the specific needs ascribable to the neurologic features of the disease (e.g., regarding neuropsychological impairment or neurosurgical treatment).

Surgery-Related Coping in Surgery Patients with Intracranial Tumors.

BACKGROUND: Neurosurgical brain tumor removal poses a unique threat for patients while also minimizing instrumental control. Thus, psychological processes used by patients to cope with surgery-related anxiety are of utmost importance. This is the first study to assess both nature and effectiveness of surgery-related coping efforts in neuro-oncological patients. METHODS: We included 70 inpatients with an intracranial tumor before neurosurgical treatment. For assessment of patients' coping efforts, we used the Coping with Surgical Stress Scale, which includes the 5 subscales: Rumination, Optimism and Trust, Turning to Social and Religious Resources, Threat Avoidance, and Information Seeking. The extent of operation-specific anxiety was assessed via the State-Trait-Operational-Anxiety Inventory. Effectiveness of coping efforts was assessed via relations to other areas of psychosocial well-being (e.g., depression or health-related quality of life). RESULTS: All patients reported using a variety of coping strategies, most frequently from the area of Optimism and Trust, which was associated with less surgery-related anxiety and better emotional well-being. By contrast, Rumination was positively correlated with surgery-related anxiety and psychiatric morbidity. Mediator analyses supported a model in which surgery-related anxiety initiates coping efforts, which then distinctively mediates the influence of patients' anxiety on psychosocial well-being. CONCLUSIONS: Neuro-oncologic patients undertake considerable psychological effort to cope with surgery-related anxiety. The majority of patients use coping strategies facilitating emotional adjustment. A minority of patients, however, report extensive rumination, which negatively influences psychosocial well-being. Our results stress the importance of the doctor-patient relationship and offer implications for targeted interventions.

Spatial and Cellular Expression Patterns of Erythropoietin-Receptor and Erythropoietin during a 42-Day Post-Lesional Time Course after Graded Thoracic Spinal Cord Impact Lesions in the Rat.

Erythropoietin (Epo) exhibits promising neuroregenerative potential for spinal cord injury (SCI), and might be involved in other long-term sequelae, such as neuropathic pain development. The current studies investigated the time courses and spatial and cellular patterns of Epo and erythropoietin receptor (EpoR) expression along the spinal axis after graded SCI. Male Long Evans rats received 100 kdyn, 150 kdyn, and 200 kdyn thoracic (T9) contusions from an Infinite Horizon impactor. Sham controls received laminectomies. Anatomical and quantitative immunohistochemical analyses of the EpoR/Epo expression along the whole spinal axis were performed 7, 15, and 42 postoperative days (DPO) after the lesioning. Cellular expression was investigated by double- and triple-labeling for EpoR/Epo with cellular markers and proliferating cells in subgroups of 5-bromo-2-deoxyuridine pre-treated animals. Prolonged EpoR/Epo-expression was confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Quantified EpoR/Epo immunoreactivities in pain-related spinal cord regions and ventrolateral white matter (VLWM) were correlated with the mechanical sensitivity thresholds and locomotor function of the respective animals. EpoR and Epo were constitutively expressed in the ventral horn neurons and vascular and glial cells in the dorsal columns (DC) and the VLWM. After SCI, in addition to expression in the lesion core, EpoR/Epo immunoreactivities exhibited significant time- and lesion grade-dependent induction in the DC and VLWM along the spinal axis. EpoR and Epo immunoreactive cells were co-stained with markers for astroglial, neural precursor cell and vascular markers. In the VLWM, EpoR- and Epo-positive proliferating cells were co-stained with glial fibrillary acidic protein (GFAP) and nestin. The DC EpoR/Epo immunoreactivities exhibited linear relationships with the behavioral correlates of post-lesional chronic pain development at DPO 42. SCI leads to long-lasting multicellular EpoR/Epo induction beyond the lesion core in the spinal cord regions that are involved in central pain development and regenerative processes. Our studies provide a time frame to investigate the effects of Epo application on motor function or pain development, especially in the later time course after lesioning.

Complications of Impulse Generator Exchange Surgery for Deep Brain Stimulation: A Single-Center, Retrospective Study.

BACKGROUND: Nonrechargeable deep brain stimulation impulse generators (IGs) with low or empty battery status require surgical IG exchange several years after initial implantation. The aim of this study was to investigate complication rates after IG exchange surgery and identify risk factors. METHODS: We retrospectively analyzed complications following IG exchange surgery from 2008 to 2015 in our department. Medical records of all patients who underwent IG exchange surgery were systematically reviewed. The shortest follow-up time was 19 months. RESULTS: From 2008 to 2015, 438 IGs were exchanged in 319 patients. Overall complication rate was 8.90%. Infection developed in 12 patients (2.74%). Six patients (1.37%) experienced local wound erosions. Hardware malfunctions were present in 11 patients (2.51%), and local hemorrhage was observed in 3 cases (0.68%). Repeated fixation of the IG was required in 2 patients (0.46%). Traction of the connecting cables necessitated surgical revision in 2 patients (0.46%). In 2 cases (0.46%), the IG was placed abdominally or exchanged for a smaller device owing to patient discomfort resulting from the initial positioning. One 80-year-old patient (0.23%) had severely worsening heart failure and died 4 days after IG exchange surgery. CONCLUSIONS: IG exchange surgery, although often considered a minor surgery, was associated with a complication rate of approximately 9% in our center. Patients and physicians should understand the complication rates associated with IG exchange surgery because this information might facilitate selection of a rechargeable IG.