Pressurized intraperitoneal aerosol chemotherapy (PIPAC) in patients with peritoneal surface malignancies (PSM): a prospective single-center registry study.

PURPOSE: Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new, palliative approach for patients with peritoneal surface malignancies (PSMs). Its main goals are to control symptoms and ascites. For this experimental procedure, treatment efficacy and patient safety need to be closely monitored. METHODS: We performed a prospective registry study for patients with PSMs. Cisplatin (C) (7.5 mg/m2 body surface) and doxorubicin (D) (1.5 mg/m2) were administered laparoscopically via PIPAC. RESULTS: Between November 2015 and June 2020, we recorded data from 108 patients and 230 scheduled procedures. Tumor burden, patient fitness, quality of life, operating time and in-hospital stay remained stable over consecutive procedures. We recorded 21 non-access situations and 14 intraoperative complications (11 intestinal injuries, and three aspirations while inducing anesthesia). Three or more previous abdominal surgeries or cytoreductive surgery (CRS) with intraperitoneal hyperthermic chemoperfusion (HIPEC) were risk factors for non-access and intestinal injuries (χ2, p ≤ 0.01). Five Grade IV and three Grade V postoperative complications according to the Clavien-Dindo Classification (CDC) occurred. Median overall survival was 264 days (interquartile range 108-586). Therapies were primarily discontinued because of death (34%), progressive (26%), or regressive (16%) disease. CONCLUSION: PIPAC is effective in stabilizing PSMs and retaining quality of life in selected patients. Earlier abdominal surgeries and CRS with HIPEC should be considered when determining the indication for PIPAC. Randomized controlled studies are needed to evaluate PIPAC's therapeutic benefits compared to systemic chemotherapy (sCHT) alone. TRIAL REGISTRATION: NCT03100708 (April 2017).

Laparoscopic conversion of omega loop gastric bypass to Roux-en-Y gastric bypass for Barrett's esophagus: case report.

BACKGROUND: The number of mini gastric bypass / one anastomosis bypass (MGB-OAGB) procedures in bariatric patients that have been performed world-wide has drastically increased during the past decade. Nevertheless, due to the risk of subsequent biliary reflux and development of ulcer and neoplastic (pre)lesions caused by long-time bile exposure, the procedure is still controversially discussed. In here presented case report, we could endoscopically demonstrate a transformation from reflux oesophagitis to Barrett's metaplasia most likely caused by bile reflux after mini-gastric bypass. To our knowledge, this is a first case study that shows development of Barrett's metaplasia after MGB-OAGB. CASE PRESENTATION: We present the case of a 50-year-old female which received a mini-gastric bypass due to morbid obesity (body mass index (BMI) 42.4 kg/m2). Because of history gastroesophageal reflux disease (GERD), a fundoplication had been performed earlier. Preoperative gastroscopy showed reflux esophagitis (Los Angeles classification grade B) with no signs of Barrett's metaplasia. Three months post mini-gastric bypass, the patient complained about severe bile reflux under 40 mg pantoprazole daily. Six months postoperative, Endoscopically Barrett's epithelium was detected and histopathologically confirmed (C1M0 after Prague classification). A conversion into Roux-en-Y gastric bypass was performed. The postoperative course was without complications. In a follow up after 6 months the patient denied reflux and showed no signs of malnutrition. CONCLUSIONS: The rapid progress from inflammatory changes of the distal esophagus towards Barrett's metaplasia under bile reflux in our case is most likely a result of previous reflux disease. Nevertheless, bile reflux appears to be a potential decisive factor. Study results regarding presence of bile reflux or development of endoscopically de-novo findings after MGB-OAGB are widely non-conclusive. Long-term prospective studies with regular endoscopic surveillance independent of clinical symptoms are needed.

Bariatric surgery in liver cirrhosis.

Introduction: Obesity is frequently associated with its hepatic manifestation, the nonalcoholic fatty liver disease (NAFLD). The most effective treatment for morbid obesity is bariatric surgery (BS) also improving NAFLD and liver function. In patients where NAFLD has already progressed to liver cirrhosis, BS can be considered a high-risk procedure. Hence, consideration of the procedure and the most appropriate timing is crucial. Material and Methods: Obese patients suffering from NAFLD who underwent BS from two German University Medical Centers were retrospectively analyzed. Results: Twenty-seven patients underwent BS. Most common procedures were laparoscopic Roux-en-Y-gastric (RYGB) and laparoscopic sleeve gastrectomy (SG). All patients suffered from liver cirrhosis Child A. A preoperative transjugular portosystemic shunt (TIPS) was established in three patients and failed in another patient. Postoperative complications consisted of wound healing disorders (n = 2), anastomotic bleeding (n = 1), and leak from the staple line (n = 1). This patient suffered from intraoperatively detected macroscopic liver cirrhosis. Excess weight loss was 73% and 85% after 1 and 2 years, respectively. Two patients suffered from postoperative aggravation of their liver function, resulting in a higher Child-Pugh score, while three could be removed from the waiting list for a liver transplantation. Conclusion: BS leads to weight loss, both after SG and RYGB, and potential improvement of liver function in liver cirrhosis. These patients need to be considered with care when evaluated for BS. Preoperative TIPS implantation may reduce the perioperative risk in selected patients.

[Possibilities and perspectives of hyperspectral imaging in visceral surgery]. / Möglichkeiten und Perspektiven der Hyperspektralbildgebung in der Viszeralchirurgie.

HyperSpectral Imaging (HSI) technology enables quantitative tissue analyses beyond the limitations of the human eye. Thus, it serves as a new diagnostic tool for optical properties of diverse tissues. In contrast to other intraoperative imaging methods, HSI is contactless, noninvasive, and the administration of a contrast medium is not necessary. The duration of measurements takes only a few seconds and the surgical procedure is only marginally disturbed. Preliminary HSI applications in visceral surgery are promising with the potential of optimized outcomes. Current concepts, possibilities and new perspectives regarding HSI technology together with its limitations are discussed in this article.

Determination of the transection margin during colorectal resection with hyperspectral imaging (HSI).

PURPOSE: This study evaluated the use of hyperspectral imaging for the determination of the resection margin during colorectal resections instead of clinical macroscopic assessment. METHODS: The used hyperspectral camera is able to record light spectra from 500 to 1000 nm and provides information about physiologic parameters of the recorded tissue area intraoperatively (e.g., tissue oxygenation and perfusion). We performed an open-label, single-arm, and non-randomized intervention clinical trial to compare clinical assessment and hyperspectral measurement to define the resection margin in 24 patients before and after separation of the marginal artery over 15 min; HSI was performed each minute to assess the parameters mentioned above. RESULTS: The false color images calculated from the hyperspectral data visualized the margin of perfusion in 20 out of 24 patients precisely. In the other four patients, the perfusion difference could be displayed with additional evaluation software. In all cases, there was a deviation between the transection line planed by the surgeon and the border line visualized by HSI (median 1 mm; range - 13 to 13 mm). Tissue perfusion dropped up to 12% within the first 10 mm distal to the border line. Therefore, the resection area was corrected proximally in five cases due to HSI record. The biggest drop in perfusion took place in less than 2 min after devascularization. CONCLUSION: Determination of the resection margin by HSI provides the surgeon with an objective decision aid for assessment of the best possible perfusion and ideal anastomotic area in colorectal surgery.

[Special situations of preconditioning and prehabilitation in oncological visceral surgery]. / Spezialsituationen der Präkonditionierung und Prähabilitation in der onkologischen Viszeralchirurgie.

BACKGROUND: Prehabilitation prior to complex visceral oncological surgery is playing an increasingly important role. OBJECTIVE: The aim of this review article is to present special situations of preconditioning in visceral oncological patient cohorts. The following conditions were defined as special situations with subsequently increased risk profile: cardiopulmonary comorbidities, geriatric patients, neoadjuvant therapy and simultaneous fatigue. MATERIAL AND METHODS: A selective literature review based on a search in the electronic databases MEDLINE, PubMed, Cochrane Library and the International Standard Randomization Controlled Trial Number (ISRCTN) was performed. RESULTS: The identification of high-risk patients is an essential part of the preoperative evaluation conducted by the anesthesiologist prior to surgery. The cardiovascular and the pulmonary risk profile are determined by means of prediction indices evaluating patient-specific and surgery-related risk factors. The increased use of new oral anticoagulants and dual platelet aggregation inhibition requires individualized treatment strategies. Numerous studies have shown clinically relevant effects of exercise therapy interventions throughout all phases of oncological treatment. In addition to positive effects on therapy-associated side effects, sport can also counteract the effects of sedentary behavior in cancer patients and improve the health-related quality of life. The effectiveness of sport and exercise therapies as well as psychological interventions in oncological patients with fatigue (CRF) is broad, with important components being motivation and compliance. DISCUSSION: In high-risk patients an interdisciplinary approach to planning and conduction of prehabilitation is essential for the early detection and optimization of perioperative risk factors and potential complications. The aim is faster recovery, reduced morbidity and mortality and the possibility to improve long-term survival and quality of life.

[Preconditioning prior to visceral oncological surgery : A paradigm shift in visceral surgery?] / Präkonditionierung vor viszeralonkologischen Operationen : Ein Paradigmenwechsel in der Viszeralchirurgie?

BACKGROUND: Postoperative complications after complex visceral oncological surgery can lead to substantial impairment of patients. In addition, preoperative physical performance and the severity of postoperative complications determine the long-term recovery process of physical function. Therefore, preconditioning in the preoperative period should be an important part of the preoperative/neoadjuvant treatment. OBJECTIVE: The aim of this article is a critical appraisal of current concepts of prehabilitation as well as their development potential and applicability in visceral surgery. MATERIAL AND METHODS: Based on a selective literature review, current studies and implemented concepts are presented and therapy algorithms are provided. RESULTS: This study differs in primary outcome, design and temporal framework of the intervention. The study results showed positive effects of an active increase in physical fitness in the preoperative period with respect to the quality of life, convalescence and postoperative pulmonary complication rate. DISCUSSION: In addition to the assessment of the individual risk of complications by means of spiroergometry, a targeted nutrition and exercise program can increase the individual performance level prior to visceral surgery and, thus, influence the postoperative risk of complications. The performance should be understood as a modifiable risk factor, which can also be positively influenced in the preoperative phase, even in a short time period. Individual preoperative care optimizes the physical and psychological situation of patients. To ensure the required individual care, approaches must be created and pursued, which can be implemented in a decentralized way.

Achalasia-an unnecessary long way to diagnosis.

Although achalasia presents with typical symptoms such as dysphagia, regurgitation, weight loss, and atypical chest pain, the time until first diagnosis often takes years and is frustrating for patients and nevertheless associated with high costs for the healthcare system. A total of 563 patients were interviewed with confirmed diagnosis of achalasia regarding their symptoms leading to diagnosis along with past clinical examinations and treatments. Included were patients who had undergone their medical investigations in Germany. Overall, 527 study subjects were included (male 46%, female 54%, mean age at time of interview 51 ± 14.8 years). Dysphagia was present in 86.7%, regurgitation in 82.9%, atypical chest pain in 79%, and weight loss in 58% of patients before diagnosis. On average, it took 25 months (Interquartile Range (IQR) 9-65) until confirmation of correct diagnosis of achalasia. Though, diagnosis was confirmed significantly quicker (35 months IQR 9-89 vs. 20 months IQR 8-53; p < 0.01) in the past 15 years. The majority (72.1%) was transferred to three or more specialists. Almost each patient underwent at least one esophagogastroduodenoscopy (94.2%) and one radiological assessment (89.3%). However, esophageal manometry was performed in 70.4% of patients only. The severity of symptoms was independent with regard to duration until first diagnosis (Eckardt score 7.14 ± 2.64 within 12 months vs. 7.29 ± 2.61 longer than 12 months; P = 0.544). Fifty-five percent of the patients primarily underwent endoscopic dilatation and 37% a surgical myotomy. Endoscopic dilatation was realized significantly faster compared to esophageal myotomy (1 month IQR 0-4 vs. 3 months IQR 1-11; p < 0.001). Although diagnosis of achalasia was significantly faster in the past 15 years, it still takes almost 2 years until the correct diagnosis of achalasia is confirmed. Alarming is the fact that although esophageal manometry is known as the gold standard to differentiate primary motility disorders, only three out of four patients had undergone this diagnostic pathway during their diagnostic work-up. Better education of medical professionals and broader utilization of highly sensitive diagnostic tools, such as high-resolution manometry, are strictly necessary in order to correctly diagnose affected patients and to offer therapy faster.

[Economic aspects of oncological esophageal surgery : Centralization is essential]. / Ökonomische Aspekte der onkologischen Ösophaguschirurgie : Zentralisierung ist essenziell.

The incidence of esophageal carcinoma has increased in recent years in Germany. The aim of this article is a discussion of the economic aspects of oncological esophageal surgery within the German diagnosis-related groups (DRG) system focusing on the association between minimum caseload requirements and outcome quality as well as costs. The margins for the DRG classification G03A are low and quickly exhausted if complications determine the postoperative course. A current study using nationwide German hospital discharge data proved a significant difference in hospital mortality between clinics with and without achieving the minimum caseload requirements for esophagectomy. Data from the USA clearly showed that besides patient-relevant parameters, the caseload of a surgeon is relevant for the cost of treatment. Such cost-related analyses do not exist in Germany at present. Scientific validation of reliable minimum caseload numbers for oncological esophagectomy is desirable in the future.

Neurostimulation for Parkinson's disease with early motor complications.

BACKGROUND: Subthalamic stimulation reduces motor disability and improves quality of life in patients with advanced Parkinson's disease who have severe levodopa-induced motor complications. We hypothesized that neurostimulation would be beneficial at an earlier stage of Parkinson's disease. METHODS: In this 2-year trial, we randomly assigned 251 patients with Parkinson's disease and early motor complications (mean age, 52 years; mean duration of disease, 7.5 years) to undergo neurostimulation plus medical therapy or medical therapy alone. The primary end point was quality of life, as assessed with the use of the Parkinson's Disease Questionnaire (PDQ-39) summary index (with scores ranging from 0 to 100 and higher scores indicating worse function). Major secondary outcomes included parkinsonian motor disability, activities of daily living, levodopa-induced motor complications (as assessed with the use of the Unified Parkinson's Disease Rating Scale, parts III, II, and IV, respectively), and time with good mobility and no dyskinesia. RESULTS: For the primary outcome of quality of life, the mean score for the neurostimulation group improved by 7.8 points, and that for the medical-therapy group worsened by 0.2 points (between-group difference in mean change from baseline to 2 years, 8.0 points; P=0.002). Neurostimulation was superior to medical therapy with respect to motor disability (P<0.001), activities of daily living (P<0.001), levodopa-induced motor complications (P<0.001), and time with good mobility and no dyskinesia (P=0.01). Serious adverse events occurred in 54.8% of the patients in the neurostimulation group and in 44.1% of those in the medical-therapy group. Serious adverse events related to surgical implantation or the neurostimulation device occurred in 17.7% of patients. An expert panel confirmed that medical therapy was consistent with practice guidelines for 96.8% of the patients in the neurostimulation group and for 94.5% of those in the medical-therapy group. CONCLUSIONS: Subthalamic stimulation was superior to medical therapy in patients with Parkinson's disease and early motor complications. (Funded by the German Ministry of Research and others; EARLYSTIM ClinicalTrials.gov number, NCT00354133.).

Kinematic effects of subthalamic stimulation on reach-to-grasp movements in Parkinson's disease.

BACKGROUND: Parkinsonian patients demonstrate particular difficulties when performing sequential motor tasks compared to simple movements indicating an important role of the basal ganglia in switching between different motor programs. OBJECTIVE: To investigate the impact of subthalamic stimulation on the kinematics of composed reach-to-grasp movements and on isolated movement segments. METHODS: 11 age matched controls and 16 PD patients with subthalamic stimulation were examined without medication with stimulation switched on and off. All subjects were instructed to perform three different externally cued hand movements: 1) The complete reach-to-grasp movement consisting of hand transport to and precision grip around a target. 2) The isolated reach movement to the grip device 3) The isolated precision grip and button press. Kinematic data were recorded with a 3D ultrasound movement analysis system (CMS 70 P4-V5, Zebris, Germany). RESULTS: The effect of subthalamic stimulation was accentuated during the reach phase compared to the grip formation during the composed movement. Stimulation induced kinematic changes of the composed movement were comparable to those of both isolated submovements. CONCLUSION: Subthalamic stimulation improved certain aspects of all three hand movement types but did not differentially impact the composed reach-to-grasp task compared to the simple submovements. We assume that the complete reach-to-grasp task is encoded in a single generalised motor program which is affected by stimulation.

Outcome of craniocerebral gunshot injuries in the civilian population. Prognostic factors and treatment options.

AIM: Gunshot wounds to the head are rare in Europe. They may be inflicted by low-velocity handguns, captive bolt guns and tear gas cartridges and mostly result from suicide attempts. The experience of neurosurgeons with this kind of traumatic injury is decreasing; the aim of this study was therefore to analyse prognostic factors which help to decide whether or not to operate and to discuss treatment options. METHODS: Thirty patients with gunshot head injuries treated in our hospital from 1993 to 2008 were retrospectively evaluated. Glasgow Coma Scale (GCS) score, pupil reactivity, lesion localisation, number of bone fragments, intracranial pressure (ICP), midline shift, hypotension, and dural penetration were analysed for their prognostic value. Surgically and non-surgically treated patients were evaluated separately. Complications were registered. RESULTS: A low GCS of 3-8, fixed pupils, >2 bone fragments, bilobar or posterior fossa/brainstem lesions and ICP >45 mmHg were indicators of a poor prognosis. CONCLUSION: Patients with a GCS of 3-8 and two non-reactive pupils should not be operated. If one or both of the pupils are reactive, surgery should be performed irrespective of the GCS score, except in patients with translobar/transventricular wounds. Even if there are no clear contraindications to surgery, the outcome is expected to be poor in patients with a low GCS score, midline shift >10 mm, >2 bone fragments in the brain, and a bilobar, posterior fossa/brainstem or ventricular lesion and ICP >45 mmHg. When surgery is performed the wound and the missile or bone track should be debrided meticulously, the wound and dura should be closed in a watertight fashion and antibiotic prophylaxis as well as tetanus serum should be given.

Acute subdural hematoma in the elderly; clinical and CT factors influencing the surgical treatment decision.

OBJECTIVE: Acute subdural hematomas (aSDH) are severe traumatic brain injuries. Older patients have a higher mortality rate. In the present study the computed tomography (CT) and neurological deficits caused by aSDH were used as prognostic factors to define the outcome and surgical treatment indication in older patients. METHODS: The affect of the Glasgow Coma Scale (GCS) score on initial presentation, pupil abnormalities, parenchymal lesions, SDH-thickness, midline shift and intracranial pressure (ICP) in the outcome of older patients (>or=65 years old) admitted to our hospital between 1993 and 2006 with aSDH was evaluated. The outcome was assessed with the Glasgow Outcome Scale (GOS). The data were collected retrospectively. Statistical analysis was performed with Chi-square test and ANOVA. RESULTS: Older patients have a high mortality after aSDH. A low GCS score (3-8), pupil abnormalities, the presence of contusions and subarachnoid bleeding, midline shift>aSDH thickness as well as a highly elevated ICP>40 mmHg are unfavorable factors in the prognosis of aSDH. CONCLUSION: Patients with a GCS of 13-15 can be observed clinically (the expected outcome is very good). Comatose patients (GCS 3-8) with bilateral dilatation of the pupils should not be operated (very high mortality rate). If the GCS score is <13 and both pupils or only one are reactive to light and the midline shift<10 mm, surgery is indicated. If the midline shift is >10 mm and aSDH thickness>midline shift, surgery is also indicated. If in the same patient group midline shift>SDH thickness and ICP>40 mmHg, surgery is not indicated.

Intracranial trigeminal nerve metastasis of a desmoplastic neurotropic melanoma: case report.

BACKGROUND: Desmoplastic neurotropic mela-noma is a rare and highly malignant variant of melanoma. Solitary nervus trigeminus and Gasserian ganglion metastasis of a neurotropic melanoma has not been previously described in the literature. CASE DESCRIPTION: A 69-year-old man presented to our clinic with trigeminal neuralgia. 4 years previously he underwent tumor removal with an initial diagnosis of amelanotic malignant cutaneous melanoma; 1 year later, because of tumor recurrence, the patient underwent neck dissection, chemotherapy and radiation. Magnet resonance imaging (MRI) disclosed an enhancement of the Gasserian ganglion and tumor extension along the mandibular and maxillar nerves of the intracranial part of the trigeminal nerve suggestive of tumor. The intraoperative macroscopic appearance of the tumor was compatible with a neurinoma. Histopathological studies proved the tumor to be a desmoplastic neurotropic melanoma (DNM) that was related to the previously treated malignant melanoma. CONCLUSION: A metastatic tumor arising solely in a trigeminal nerve from a cutaneous malignant melanoma is quite rare; to our knowledge this may be the first report of such a case in the literature.

Accuracy and distortion of deep brain stimulation electrodes on postoperative MRI and CT.

OBJECTIVE: Postoperative monitoring of the electrode position is important to evaluate the best stimulation site in deep brain stimulation. MR imaging is excellent for ruling out postoperative complications e.g. haemorrhage, but its accuracy in electrode localisation is still controversial. The reasons for this are the size of the artefact around the electrode and its unclear relation to the electrode position (concentric or eccentric). The goal of this study was to determine the relation and size of these artefacts to the electrodes by comparing the position of the electrodes in postoperative MR and CT imaging. MATERIAL AND METHODS: Five patients underwent deep brain stimulation of the subthalamic nucleus due to levodopa-induced motor complications in Parkinson's disease. A stereotactic CT and a non-stereotactic MR were performed for postoperative localisation of the electrode position. The stereotactic MR for planning of the trajectories and targets was done under general anaesthesia. The latter two were fused to the stereotactic MR and the position of the DBS electrode contacts was determined on CT and MRI. The size of the artefact was measured at the level of each contact in two directions, anterior to posterior (AP) and lateral. Altogether 40 contacts were evaluated. RESULTS: Mean size of the CT-artefact was 2.6 mm AP (range, 2.0-3.2 mm) and 2.6 mm laterally (range, 2.0-3.8 mm). In comparison, mean size on the MRI was 3.5 mm AP (range, 2.9-5.3 mm) and 3.8 mm laterally (range, 2.9-4.8 mm). A trajectory with a 1.2 mm diameter (size of the DBS electrode) was centred on the electrodes' artefact of the CT and the MRI. The difference between the contact coordinates was calculated as deviation of the artefact around the electrode on the MR. Mean deviation was 0.2 mm on the x-axis (range, 0-0.5 mm), 0.5 mm on the y-axis (range, 0-1.1 mm) and 0.3 mm on the z-axis (range, 0-0.7 mm). There were no significant differences (t-test, p > 0.4). CONCLUSION: The size of the electrodes' artefact was smaller on CT compared to MR. Furthermore, the position was not precisely concentric around the electrode. Nevertheless, the mean deviation after measuring the contact position in both CT and MR was less than 1 mm in all three planes. Both techniques are eligible for postoperative localisation of DBS electrodes, with a small imprecision of the non-stereotactic MR compared to the stereotactic CT. This might be compensated by the fact that postoperative MR can rule out asymptomatic postoperative complications e.g. haemorrhages or infarctions, without radiation exposure of the patient.

Electrode implantation for deep brain stimulation in dystonia: a fast spin-echo inversion-recovery sequence technique for direct stereotactic targeting of the GPI.

OBJECTIVE: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is an effective treatment for medically refractory primary dystonia. We present our technique for direct preoperative visualization of the target using a fast spin-echo inversion-recovery (FSE-IR) sequence. METHODS: Twenty-three consecutive patients (mean age 41 years, range 9-68 years, male to female ratio 11:12) with severe dystonia were operated using a combination of FSE-IR imaging for direct visualization of the globus pallidus internus with stereotactic, gadolinium-enhanced T1-MPRage images. The complete procedure, including stereotactic MRI, was performed under general anesthesia with propofol and remifentanyl. We used multichannel microdrive systems (Medtronic; Alpha-Omega) to introduce up to five parallel microelectrodes for microelectrode recordings (MER) and test stimulation with the central trajectory directed at the anatomically predefined target. The initial standard coordinates in relation to the mid-commissural point (mid-AC-PC) were as follows: lateral 21 mm, anterior 3 mm, and inferior 2 mm, which were then adapted to the individual case based on direct visualization of the target area and further refined by the intraoperative neurophysiology. RESULTS: In ten patients (43%) atlas-based standard coordinates were modified based on the direct visualization of the GPi in the FSE-IR images (bilaterally in seven patients, unilaterally in three). The modified targets ranged from 18.5 to 23.5 mm (mean 20.76 mm) laterally, 1-7 mm (mean 2.75 mm) anteriorly and 1-2 mm (mean 1.95 mm) inferiorly to the mid-AC-PC. We implanted the permanent electrode based on the results of MER and intraoperative stimulation performed to determine the threshold for pyramidal tract responses on the central trajectory in 67%, medially in 16%, anteriorly in 11%, laterally in 4%, dorsally in 2%. The procedure resulted in excellent clinical benefits (average reduction of the Burke-Fahn-Marsden Dystonia Rating Score (BFMDRS) or the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) were respectively 65.9%, range 20.9-91.4%) within the first year after surgery. Safety was demonstrated by the absence of intracranial bleeding or other surgical complications causing neurological morbidity. CONCLUSION: Inversion recovery sequences are an excellent tool for direct visualization of the GPi. These images can be fused to stereotactic MRI or CCT and may help to improve anatomical targeting of the GPi for the implantation of DBS electrodes.

Failure of deep brain stimulation of the posterior inferior hypothalamus in chronic cluster headache - report of two cases and review of the literature.

OBJECTIVE: Deep brain stimulation (DBS) has become a standard procedure for movement disorders such as Parkinson's disease, essential tremor or dystonia. Recently, deep brain stimulation of the posterior hypothalamus has been shown to be effective in the treatment of drug-resistant chronic cluster headache. METHODS: DBS of the posterior inferior hypothalamus was performed on two patients with chronic cluster headaches, one 55-year-old man with medically intractable chronic cluster headache since 1996, and one 31-year-old woman with a chronic form since 2002. Both patients showed continuous worsening headaches in the last years despite high dose medical treatment. The patients fulfilled the published criteria for DBS in chronic cluster headaches. Electrodes were implanted stereotactically in the ipsilateral posterior hypothalamus according to the published coordinates (2 mm lateral, 3 mm posterior, 5 mm inferior) referenced to the mid-AC-PC line. RESULTS: The intra- and postoperative course was uneventful and postoperative MRI control documented regular position of the DBS electrodes. The current stimulation parameters were at 12 months postoperatively 0 neg., G pos.; 5.5 V; 60 micros; 180 Hz (Case 1) and 0 neg., G pos.; 3.0 V; 60 micros; 185 Hz, at 3 months postoperatively (Case 2). Surgery- or stimulation-related side effects were not observed. Both patients showed initial pain reduction in the first days whereas 12 respectively 3 month follow-up did not show a significant reduction in attack frequency or intensity. CONCLUSION: Deep brain stimulation of the posterior inferior hypothalamus is an experimental procedure and should be restricted to selected therapy-refractory patients and should be performed in centers experienced in patient selection and performance of DBS as well as postoperative pain treatment. A prospective multi-centre study is necessary to evaluate its effectiveness.

Children's spatial behavior is differentially affected after traumatic brain injury.

Spatial behavior in 20 children with severe traumatic brain injury (TBI) and 20 healthy controls was investigated using the Kiel Locomotor Maze. Children had to remember defined locations in an experimental chamber with completely controlled intra- and extra-maze cues until learning criterion was reached. In a second experiment, spatial orientation strategies were assessed. Children with TBI were shown to be impaired in spatial learning and spatial memory. Spatial orientation was found to be deficient even in cases where spatial learning and memory proved to be unimpaired, especially in tasks that demanded the use of relational place strategies. Children who suffered a TBI at an early age proved to be more severely impaired in spatial learning and orientation than older children.

Analysis of gait in cervical myelopathy.

Gait disorders are a frequent symptom of cervical spondylotic myelopathy (CSM). Twelve patients with CSM underwent gait analysis before and after decompressive surgery. They were assessed on a walkway and a treadmill and compared with a healthy matched control group. The following features were observed in the CSM group before surgery: significantly reduced gait velocity and step length (P<0. 05), prolonged double support, increased step width, and reduced ankle joint extension during treadmill walking. Knee and hip kinematics did not differ from controls. Two months after surgery, spatio-temporal parameters had moved towards normal values, velocity, step length and cadence had increased significantly, and there was reduction of step width during treadmill walking, indicating improved equilibrium. Gait analysis is an objective tool to document functional recovery after decompressive surgery in CSM.