[Spontaneous craniocervical dissection]. / Spontane Dissektionen der hirnversorgenden Arterien.

Spontaneous craniocervical dissection is one of the main causes of stroke in juvenile and middle-aged patients. It is caused by intramural hematoma which may result in stenosis or even occlusion of the artery. Clinical manifestation varies from local pain to ischemic complications. The imaging modality of choice is magnetic resonance imaging (MRI) which is able to detect all characteristic signs of dissection. Intramural hematoma is detected with thin slice fat-saturated 3D black-blood images. However, with the use of special imaging techniques, questionable findings can be clarified and especially the more difficult to detect intradural dissection can be accurately diagnosed. Acute treatment depends on the severity of neurological symptoms and their duration. Factors like the location of the dissection, cerebral infarction or hemorrhage influence the choice of medication for primary and secondary prophylaxis. Resorption of the intramural hematoma often leads to spontaneous recanalization within a few months.

[Time is brain : Time management in acute stroke treatment]. / "Time is brain" : Zeitmanagement in der akuten Schlaganfallversorgung.

BACKGROUND: Thrombolysis with recombinant tissue plasminogen activator (rt-PA) and interventional thrombectomy are evidence-based causative therapies in acute stroke; however, the clinical benefit for the patient has been proven to be highly time-dependent. METHODS: A review of critical time intervals in acute stroke management and possibilities for modification is presented. RESULTS: Both prehospital and in-hospital times can be reduced with proven clinical benefits. The means to achieve time reductions are diverse and require clear workflow guidelines and continuous training. CONCLUSION: Optimization of time management during the complete acute diagnostics and treatment procedure by avoiding specific delays and streamlining universal workflow is of utmost importance regarding the efficiency and safety of treatment.

Substantia nigra hyperechogenicity is related to decline in verbal memory in healthy elderly adults.

BACKGROUND AND PURPOSE: Deficits in cognition have been reported in Parkinson's disease (PD) already in the early and even in the pre-motor stages. Whilst substantia nigra hyperechogenicity measured by transcranial B-mode sonography (TCS) represents a strong PD marker and is associated with an increased risk for PD in still healthy individuals, its association with cognitive performance in prodromal PD stages is not well established. METHODS: Two different cohorts of healthy elderly individuals were assessed by TCS and two different neuropsychological test batteries covering executive functions, verbal memory, language, visuo-constructional function and attention. Cognitive performance was compared between individuals with hyperechogenicity (SN+) and without hyperechogenicity (SN-). RESULTS: In both cohorts, SN+ individuals performed significantly worse than the SN- group in tests assessing verbal memory (word list delayed recall P = 0.05, logical memory II P < 0.017). Significant differences in Mini-Mental State Examination score (cohort 1, P = 0.02) and executive function tests (cohort 2, Stroop Color-Word Reading, P = 0.004) could only be shown in one of the two cohorts. No between-group effects were found in other cognitive tests and domains. CONCLUSIONS: These results indicate that individuals with the PD risk marker SN+ perform worse in verbal memory compared to SN- independent of the assessment battery. Memory performance should be assessed in detail in individuals at risk for PD.

The PRIPS study: screening battery for subjects at risk for Parkinson's disease.

BACKGROUND AND PURPOSE: Screening batteries to narrow down a target-at-risk population are essential for trials testing neuroprotective compounds aiming to delay or prevent onset of Parkinson's disease (PD). METHODS: The PRIPS study focuses on early detection of incident PD in 1847 at baseline PD-free subjects, and assessed age, male gender, positive family history, hyposmia, subtle motor impairment and enlarged substantia nigra hyperechogenicity (SN+). RESULTS: After 3 years follow-up 11 subjects had developed PD. In this analysis of the secondary outcome parameters, sensitivity and specificity of baseline markers for incident PD were calculated in 1352 subjects with complete datasets (10 PD patients). The best approach for prediction of incident PD comprised three steps: (i) prescreening for age, (ii) primary screening for positive family history and/or hyposmia, and (iii) secondary screening for SN+. CONCLUSION: With this approach, one out of 16 positively screened participants developed PD compared to one out of 135 in the original cohort. This corresponds to a sensitivity of 80.0%, a specificity of 90.6% and a positive predictive value of 6.1%. These values are higher than for any single screening instrument but still too low for a feasible and cost-effective screening strategy which might require longer follow-up intervals and application of additional instruments.

Relation of risk factors and putative premotor markers for Parkinson's disease.

As both risk and premotor markers are increasingly discussed to play a key role in the pre-diagnostic phase of Parkinson's disease (PD) the aim of this study was to determine the relation between the risk factors hyperechogenicity of the substantia nigra (SN+) and/or positive family history of PD (faPD+) and putative premotor markers for PD. In a cross-sectional analysis of data of the PRIPS cohort, 1,149 volunteers older than 50 years free of PD were included. In addition to the risk factors SN+ and faPD+, olfactory dysfunction was tested using the Sniffin' sticks test and motor examination was performed. History of depression and constipation was evaluated by a semi-structured interview. Of all 1,149 individuals, 880 had none of the risk markers (76.6%), 143 persons (12.4%) had SN+, 84 (7.3%) were classified as faPD+ and 42 (3.7%) persons had both risk factors. Volunteers with SN+ showed olfactory dysfunction and mild motor impairment (p ≤ 0.001) more often. Depression was more prominent in individuals having two risk factors (p = 0.05). An accumulation of premotor markers was seen in the SN+ group with or without concomitant faPD+, but not in persons with faPD+ only. The profile of premotor markers seems to differ in participants having SN+ and/or faPD+, with SN+ showing the overall highest association with most premotor markers, which implies that SN+ might be a strong indicator for a neurodegenerative process.

Stent-assisted mechanical recanalization for treatment of acute intracerebral artery occlusions.

BACKGROUND AND PURPOSE: The purpose of this study was to demonstrate a new approach to the use of a self-expanding stent in the treatment of acute ischemic stroke. METHODS: Twenty-two consecutive patients with acute intracerebral artery occlusions were treated with a self-expandable intracranial stent, which was withdrawn in its unfolded state. For this technique, we used the Solitaire AB/FR, which is the only intracranial stent that is fully recoverable. Eight patients had an occlusion of the basilar artery, 12 had a middle cerebral artery occlusion, and 2 had terminal carotid artery occlusions; 6 of these had to be treated first for an acute occlusion originating in the internal carotid artery. Recanalization results were assessed by follow-up angiography immediately after the procedure. Neurologic status was evaluated before and after treatment (90-day follow-up) according to the National Institutes of Health Stroke Scale and modified Rankin scale. RESULTS: Successful revascularization was achieved in 20 of 22 (90.9%) patients (thrombolysis in cerebral infarction [TICI] 2a/b and 3), a TICI 3 state was accomplished in 12 patients, and partial recanalization or slow distal branch filling with filling of more than two-thirds of the vessel territory was achieved in 8 patients (TICI 2b). There was immediate flow restoration in 21 of 22 (95.4%) cases after deployment of the device. The stent was removed in its unfolded state in all patients. The mean time from stroke symptom onset to recanalization was 277 minutes, with a standard deviation of 118 minutes. Mean National Institutes of Health Stroke Scale score on admission was 19.4, with a standard deviation of 5.7. Almost two-thirds of the patients (63.6%) improved by > 10 points on the National Institutes of Health Stroke Scale at discharge, and 50% showed a modified Rankin scale score of ≤ 2 at 90 days (59% with a modified Rankin scale ≤ 3). Mortality was 18.1%. In 1 case, an asymptomatic intracranial hemorrhage was detected on control computed tomography, and 2 patients had a symptomatic intracranial hemorrhage. CONCLUSIONS: Withdrawal of an unfolded, fully recoverable, intracranial stent yielded very promising angiographic and clinical results. It combines the advantages of prompt flow restoration and mechanical thrombectomy.

Substantia nigra echomorphology and motor cortex excitability.

The aim of our study was to investigate the relation between substantia nigra (SN) echomorphology and indices of motor cortex excitability. Nigral hyperechogenicity in healthy individuals is thought to represent an SN abnormality or predisposition to Parkinson's disease (PD) and its prevalence is greater in the very old. Our study involved 20 old healthy subjects (aged 72-84 years) known to have normal (n=10) or abnormal (n=10) SN echomorphology. All were in good health with no overt neurological signs. SN morphology was assessed with transcranial sonography through the pre-auricular bone window. Motor cortical excitability and intracortical inhibition were assessed with transcranial magnetic stimulation (TMS) over the first dorsal interosseus motor area. Single stimuli were delivered during relaxation and voluntary contraction and paired stimuli were delivered during relaxation. Each cortical hemisphere was analysed separately. The response to single-pulse TMS (in motor cortex ipsilateral to the target SN) did not differ between groups. However, a significant difference between groups was observed in the paired pulse paradigm (conditioning stimulus intensity: 70% resting motor threshold; interstimulus interval: 2 ms). The conditioned motor evoked potential amplitude was significantly larger ipsilateral to the hyperechogenic SN than in controls (P=0.014). Thus, healthy subjects with SN hyperechogenicity exhibit significantly less intracortical inhibition within the motor cortex than subjects with normal echomorphology. Decreased intracortical inhibition is also observed in PD patients. This study provides further evidence that SN hyperechogenicity in healthy individuals is associated with changes characteristic of PD supporting a role for this feature as a vulnerability marker or state marker for subtle nigral dopaminergic dysfunction.

Hyperechogenicity of the substantia nigra in healthy controls is related to MRI changes and to neuronal loss as determined by F-Dopa PET.

Transcranial ultrasound (TCS) has been shown to reveal hyperechogenicity of the substantia nigra (SN) in Parkinsonian patients and in about 10% of healthy controls. It is hypothesized that SN hyperechogenicity in healthy subjects is a vulnerability marker for idiopathic Parkinson's disease (IPD). Although there is strong evidence that the echomarker results from increased local iron content, the exact pathophysiological mechanisms remain incompletely understood. Thus, prognostic impact can only be estimated. We examined 14 subjects with SN hyperechogenicity (SN+) (7 IPD patients and 7 controls) and 7 healthy controls without the echomarker (SN-) by a magnetic resonance imaging method (MRI; T2 relaxation times) known to reveal tissue inhomogeneity following abnormal iron content and by F-Dopa PET to assess nigrostriatal function.

Cross-sectional study discloses a positive family history for Parkinson's disease and male gender as epidemiological risk factors for substantia nigra hyperechogenicity.

Hyperechogenicity of the substantia nigra (SN) has been proposed to be a typical finding in Parkinson's disease (PD) and a marker of vulnerability to nigrostriatal dysfunction in healthy subjects. This large cross-sectional study including 1120 subjects older than 50 years without any signs of PD was performed to evaluate the association of SN hyperechogenicity and other proposed epidemiological risk factors for PD. Among all variables assessed only family history of PD and male gender proved to be significantly associated with SN hyperechogenicity, indicating a genetic predisposition for the ultrasound marker.

Peri-interventional Subarachnoid Hemorrhage During Mechanical Thrombectomy with stent retrievers in Acute Stroke: A Retrospective Case-Control Study.

BACKGROUND: Mechanical thrombectomy with stent retrievers in acute stroke has emerged as a promising new technique with the highest recanalization rate of the therapeutic procedures available so far. However, endovascular treatment is also associated with the risk of specific complications. One of those is the occurrence of peri-interventional subarachnoid hemorrhage (SAH), which has been reported in 5-16 % of the cases. Interestingly, this rate is higher than that of angiographically detectable perforations (0-3 %), leaving the majority of peri-interventional SAH to be due to angiographically occult perforations. Little is known about the influence of this finding on clinical outcome. The purpose of this study was to investigate the clinical relevance of SAH due to occult perforations during thrombectomy with stent retrievers. METHODS: Postinterventional computed tomography (CT) scans of 217 consecutive patients with acute occlusions of intracerebral arteries who were treated with stent retrievers in our department between October 2009 and October 2012 were retrospectively analyzed. RESULTS: SAH was found on postinterventional CT scans in 5.5 % of the cases. Seven cases were included for further analysis and matched to controls by the following characteristics: (1) site of occlusion, (2) result of the recanalization procedure according to the modified thrombolysis in cerebral infarction score, (3) administration of intravenous recombinant tissue plasminogen activator, (4) presence of proximal extracranial occlusion, (5) age, and (6) sex. Comparison of the angiographic data of the two cohorts showed no significant difference in the length of the procedures or the number of maneuvers needed for recanalization, nor were there significant differences in clinical outcomes as measured by NIHSS and mRS scores. Secondary symptomatic ICH occurred in one case in either cohort and led to death in both cases. The rate of asymptomatic ICH within the first 24 h after recanalization was significantly higher in the group with peri-interventional SAH (57 vs. 0 %, P = 0.018). CONCLUSIONS: This small retrospective case-control study did not reveal a significant influence of peri-interventional SAH due to angiographically occult perforations on neurologic outcome of patients treated with stent retrievers.

Does ultrasound disclose a vulnerability factor for Parkinson's disease?

Transcranial ultrasound is a new tool allowing the detection of abnormalities in the echomorphology of the substantia nigra (SN) in patients with Parkinson's disease (PD). Several lines of evidence suggest that the changes in the echo-pattern represent a risk factor as: i) the majority of PD patients exhibit this echo-feature, ii) the presence of such changes in healthy controls is related to a reduced (18)F-Dopa-uptake and clinical signs of nigrostriatal dysfunction. The reason for the change of echogenicity is suggested to be an increased iron content in the substantia nigra causing oxidative stress and neuronal cell damage. This hypothesis of changes in SN echomorphology reflecting a risk factor of PD has to be proved in longitudinal studies.

Competitive neural trees for pattern classification.

This paper presents competitive neural trees (CNeT's) for pattern classification. The CNeT contains m-ary nodes and grows during learning by using inheritance to initialize new nodes. At the node level, the CNeT employs unsupervised competitive learning. The CNeT performs hierarchical clustering of the feature vectors presented to it as examples, while its growth is controlled by forward pruning. Because of the tree structure, the prototype in the CNeT close to any example can be determined by searching only a fraction of the tree. This paper introduces different search methods for the CNeT, which are utilized for training as well as for recall. The CNeT is evaluated and compared with existing classifiers on a variety of pattern classification problems.

Treatment of closed tibia shaft fractures: a survey from the 1997 Orthopaedic Trauma Association and Osteosynthesis International--Gerhard Küntscher Kreis meeting.

OBJECTIVE: To identify any consensus of opinion regarding treatment and outcome of a closed mid-shaft tibia fracture among orthopedic surgeons. DESIGN: Survey. SETTING: 1997 combined meeting of the Orthopaedic Trauma Association and Osteosynthesis International-Gerhard Küntscher Kreis. MAIN OUTCOME MEASUREMENT: Percentage of responses to key questions. Proportion test (nonparametric) for statistical significance. RESULTS: There is no consensus of opinion regarding treatment for this fracture type. Wide variation exists between and within the different subgroups of orthopaedic surgeons surveyed. CONCLUSIONS: This brings into focus the spectrum of acceptable care for the management of fractures. More studies must be conducted to identify optimal treatment for closed mid-shaft tibia fractures.

Cerebrovascular resistance and blood flow velocity changes after carotid endarterectomy.

BACKGROUND: To study the pattern of cerebral blood flow velocity and cerebral resistance changes after carotid endarterectomy. PATIENTS AND METHODS: In 81 patients (mean age +/- SD, 64 +/- 8 years) with unilateral carotid endarterectomy (CEA) the systolic, diastolic and mean blood velocities, and the pulsatility index (PI) were recorded in both middle cerebral arteries preoperatively and repetitively postoperatively with the use of transcranial Doppler ultrasound (TCD). RESULTS: In the middle cerebral artery ipsilateral to CEA mean blood velocity was increased 6 hours (64 +/- 25 cm/sec; p < 0.005) and 7 days (54 +/- 15 cm/sec; p < 0.05) after CEA and had returned to the preoperative level (49 +/- 11 cm/sec) after 3 months. Compared to preoperatively (0.86 +/- 22), the PI was significantly increased at 6 hours examination (1.03 +/- 23, p < 0.005), and remained increased thereafter. A pathologically increased mean blood velocity (> 83 cm/sec) 6 hours after CEA occurred in 11 patients, two of them developed a slight hyperperfusion syndrome. In the contralateral middle cerebral artery, only the diastolic blood velocity showed significant changes (preoperatively, 35 +/- 12 cm/sec; 3 months after CEA, 33 +/- 8 cm/sec; p < 0.05). CONCLUSIONS: Using TCD, hemodynamic changes occur predominantly in the middle cerebral arteries ipsilateral to CEA. Early postoperative TCD studies may be of help to identify patients at risk to develop a hyperperfusion syndrome.

Assessing the criminal responsibility of individuals with multiple personality disorder: legal cases, legal theory.

This article discusses the criminal responsibility of individuals diagnosed with multiple personality disorder (MPD). First, it reviews how courts understand and assess criminal responsibility. Second, it gives an overview of how courts have applied the doctrine of criminal responsibility to individuals with MPD. Third, it explains what legal theorists say about this question. Finally, it uses a case example to illustrate how various theorists would assess the responsibility of a criminal defendant with MPD.

Testimonial privilege and the problem of death: the Vincent Foster case and beyond.

This article discusses what happens to testimonial privilege following a patient's death. First, the article reviews the concepts of confidentiality and testimonial privilege. Second, the article discusses the case of Jaffe v. Redmond, in which the Supreme Court ruled that testimonial privilege applies to licensed psychotherapists under Rule 501 of the Federal Rules of Evidence. Third, the article examines the case of Swidler & Berlin v. United States, in which the Supreme Court directly addressed the question of whether testimonial privilege survives death. Finally, the article comments on the implications of these rulings for mental health professionals.

O'Connor v. Donaldson: retelling a classic and finding some revisionist history.

This article discusses the 1975 Supreme Court opinion O'Connor v. Donaldson. The article first examines the due process clause of the Fourteenth Amendment, the basis for the O'Connor ruling. It then looks carefully at the Court's conclusions, with particular attention to the Court's reasoning and analysis. The article goes on to look at how the Supreme Court has interpreted O'Connor on subsequent occasions and suggests that the Court has often misconstrued its own decision. The article concludes by offering thoughts and commentary on the O'Connor opinion and its progeny.

Old duties and new: recovered memories and the question of third-party liability.

This article addresses how courts have analyzed the question of third-party liability in a class of cases that has recently challenged settled law. In these cases a patient recovers apparent memories of sexual abuse during the course of a therapy. Based on these memories and perhaps with the therapist's aid and encouragement, the patient identifies a family member as the perpetrator, often in a legal or other public forum. The accused family member then brings a lawsuit against the therapist for negligent treatment of the patient. The legal question to be determined is whether the therapist owes a duty of care to the third-party family member. The article first examines the concept of duty from a historical perspective. The article next looks at the method of analysis courts have used to approach the question of third-party liability in recovered memory cases. The article's third section examines how several state courts have applied this analysis to actual cases. Finally, the article evaluates the most compelling arguments on both sides of the issue and raises additional arguments suggested by the state court analyses.