Capgras syndrome: a clinical manifestation of watershed cerebral infarct complicating the use of extracorporeal membrane oxygenation

Etiologic Subtypes of Watershed Infarcts

BACKGROUND

Two types of watershed infarcts (WI) are recognized. Internal WI are usually attributed to either severe stenosis in large arteries or acute hypotensive events, whereas external WI are thought to be caused by embolism. The aim of this study was to determine the etiologic background and prognosis of external and internal WI in our patients.

METHODS

We reviewed the medical records and diffusion-weighted images of the patients who were admitted to our stroke unit with acute ischemic stroke between January 2012 and November 2014. The demographics, clinical features, radiologic investigations, and other etiologic tests of the patients with internal or external WI were recorded. We determined etiologic stroke subtypes according to the automated Causative Classification System.

RESULTS

Fifty-three patients with WI were detected in our registry. Twenty-two (41.5%) of them were women. The mean age was 69 ± 12.8 (33-98) years. Twenty-one (39.6%) patients had external WI: 7 (33.3%) of them had large-artery atherosclerosis (LAA), 8 (38.1%) patients had cardioembolism, 3 (14.3%) patients had stroke due to other causes (vasculitis; n = 3), and etiologic subtype was undetermined in 3 patients (14.3%). Thirty-two (60.4%) patients had internal WI: 21 (65.6.%) of them had LAA, 5 (15.6%) patients had cardioembolism, 3 (9.4%) patients had stroke due to other causes (aneurysm; n = 1, hypercoagulability due to chronic myeloid leukemia; n = 1, vasculitis; n = 1), and etiologic subtype of 3 (9.4%) patients remained cryptogenic. LAA was significantly associated with internal WI (P = .024). Hypertension was more common in patients with internal WI (P = .035).

CONCLUSIONS

In this series, cardioembolism was the most common etiologic subtype in the patients with external WI, whereas internal WI were significantly associated with LAA. Uncommon causes should also be investigated in cryptogenic patients.

Cerebral microbleeds after use of extracorporeal membrane oxygenation in children

Cerebral microbleeds (CMB) on gradient-recalled echo (GRE) magnetic resonance imaging (MRI) are rarely seen in children, yet have been described following vascular procedures in adults. Extracorporeal membrane oxygenation (ECMO) has been associated with vascular injury and neurological events in children, but there have been no reports to date of GRE MRI findings in children treated with ECMO. We reviewed MRI scans for all vascular neurology consultations in children treated with ECMO at an academic medical center over a 5-year period. In 6 of 12 cases, GRE was acquired as others were unstable or had contraindications to MRI. All 6 of 6 (100%) GRE cases (mean age 2.1 years, 7 female, 5 male) demonstrated CMB. CMB were multiple (>3 lesions), situated in cortical or lobar regions, with a striking predominance (5/6 cases) for the right carotid distribution. Other than CMB, no cases demonstrated intracranial hemorrhage. CMB may be noted on GRE MRI after ECMO and may reflect vascular damage from gaseous emboli.

Capgras syndrome in postictal delirium

A 34-year-old man with a seizure disorder had not been taking anticonvulsant medications regularly. A previous pattern of recurrent seizures resolved after restarting anticonvulsant drugs. Recent seizure episodes were followed by delirium and presentation of Capgras syndrome. A variety of functional and organic etiologies for Capgras syndrome are known. This syndrome has been documented in cases of postictal delirium. These symptoms along with delirium ended with seizure control once back on anticonvulsant medicines.

Compression of the Rostral Ventrolateral Medulla by a Vagal Schwannoma of the Cerebellomedullary Cistern Presenting with Refractory Neurogenic Hypertension: Case Report

OBJECTIVE:

The rostral ventrolateral medulla is thought to serve as a final common pathway for the integration of central cardiovascular information and to be important for the mediation of central pressor responses. An association between essential hypertension and neurovascular compression of the rostral ventrolateral medulla has been reported. This may be mediated by an increase in sympathetic tone.

CLINICAL PRESENTATION:

Schwannomas arising from the lower cranial nerves (Cranial Nerves IX-XI) are rare, constituting only 3% of all intracranial schwannomas unassociated with neurofibromatosis. The majority of these tumors present as jugular foramen lesions and, less commonly, they occur along the extracranial course of these nerves. An intracisternal location is extremely rare. Fewer than 15 cases of pathologically proven intracisternal vagal schwannomas in the absence of neurofibromatosis have been reported.

INTERVENTION:

We report a case of vagal schwannoma in the cerebellomedullary cistern causing distortion of the vagal root entry zone and presenting with refractory neurogenic hypertension. Total microsurgical excision of this tumor, arising from one of the rootlets of the vagus nerve, was achieved. Immediately postoperatively, blood pressure decreased markedly, and despite our effort to maintain the blood pressure with fluids, the patient developed a cerebral infarction in the watershed zone.

CONCLUSION:

We discuss the proposed mechanism of hypertension, and the perioperative management, stressing blood pressure control. A review of the literature regarding vagal schwannomas is also presented. To the best of our knowledge, this is the first case report of a cerebellomedullary cistern vagal schwannoma presenting with neurogenic hypertension.

Psychophysiological evidence for altered information processing in delusional misidentification syndromes

Recent research provides evidence that delusional misidentification syndromes (DMS) are associated with cognitive deficits. However, the underlying mechanisms of these deficits are not known. Since the P300 component of event-related potentials (ERPs) is related to fundamental aspects of working memory (WM), the present study is focused on P300 elicited during a WM test in DMS patients, as compared to those of healthy controls. Nine patients with DMS and 11 healthy controls, matched for age, sex and educational level were tested with a computerized version of the digit span test of the Wechsler batteries. Auditory ERPs were measured during the anticipatory period of the test. DMS patients showed significant reductions in P300 amplitude at the right frontal region compared to healthy controls. P300 latency in the central midline brain region was significantly prolonged in the DMS group. Each of these measures classified correctly 90% of the two groups. Moreover, the memory performance of the patient group was significantly lower, relatively to healthy controls. These findings provide evidence supporting the suggestion that DMS is associated with psychophysiological alterations occurring at the right frontal region, which mediates automatic processes, as well as with an irregular allocation of attentional resources, involving the interhemispheric circuitry, possibly due to gray matter degeneration. Finally, present work points to a need for further research investigating the characteristics, causes, course and treatment of severe cognitive deficits associated with DMS.

Emotions, behaviours and mood changes in stroke

The brain mediates and integrates all cognitive activities, emotional experiences and finally behaviours. Stroke is undoubtedly a privileged disease for human behavioural studies, because of its high incidence. Recent advances in high-resolution magnetic resonance imaging techniques and functional neuroimaging allow both the precise localization of lesions and on-line visualization of the activity of cerebral areas and networks. Nevertheless, the neuropsychiatry of stroke remains uncertain in its relationship with brain dysfunction. Clinical studies on registry populations, single case studies, and functional neuroimaging data provide interesting findings, but differences in methods and great individual intervariability still prevent a complete understanding of emotional perception and behavioural responses in stroke. We adopted an anatomical-functional model as an operational framework in order to systematize the recent literature on emotional, behavioural and mood changes after stroke. The dysfunction of the areas subserving fundamental and executive functions induces behavioural and affective changes (such as depression, anxiety, apathy) that reflect the dysfunction of the whole system. Conversely, lesions in the system of instrumental functions induce signature syndromes (aphasia, anosognosia). At any delay from stroke, the diagnosis and treatment of mood and behavioural changes are a priority for clinicians and healthcare professionals to improve the quality of life of patients.