Vessel wall enhancement in herpes simplex virus central nervous system vasculitis

Infection is a well-known cause of cerebral vasculopathy and vasculitis. We report a 36-year-old woman with cerebral vasculitis and ischemic stroke secondary to herpes simplex virus (HSV). MRI studies revealed a pontine stroke with basilar artery stenosis and vessel wall gadolinium enhancement. This case demonstrates the ability of HSV to cause a focal brainstem vasculitis and the utility of enhanced MRI in the diagnosis of stroke related to HSV central nervous system vasculitis.     

Praxis and writing in a right-hander with crossed aphasia

Studies of patients with brain lesions have demonstrated that language and praxis are mediated by dissociable networks. However, language has the capacity to influence the selection of purposeful actions. The abilities to use language and to program purposeful movements are often mediated by networks that have anatomic proximity. With hemispheric injury, the diagnosis of apraxia is often confounded by the specific influence of language impairments on the ability to select and produce transitive gestures. We report a patient who illustrates this confound. This patient is a right-handed man who developed global aphasia and neglect after a right hemispheric stroke. His right hand remained deft, and when asked to produce specific transitive gestures (pantomimes), he often performed normally but did make some body part as object and perseverative errors. However, he did not demonstrate the temporal or spatial errors typical of ideomotor apraxia. He also had a perseverative agraphia. Our patient’s left hemisphere praxis system appeared to be intact, and the error types demonstrated during production of transitive gestures cannot be attributed to a degradation of postural and movement (praxis) programs mediated by his left hemisphere. The praxis errors types are most consistent with a deficit in the ability to select the necessary praxis programs. Thus, our patient appeared to have dissociation between language and praxis programs that resulted in body part as object and perseverative errors.     

Cerebral venous thrombosis: continental disparities

Cerebral venous thrombosis (CVT) usually accounts for < 1% of all strokes. Global disparity and diversity in their demographics, etiology, clinical features, radiological presentation, and mortality have not been previously explored. A systematic search was performed for publications in PubMed using key words “cerebral venous thrombosis,” “Cerebral vein thrombosis,” and “Cortical vein Thrombosis.” A total of 600 relevant studies were abstracted with strict selection criteria, and a total of 7048 patient’s data were used for the final analysis. The frequency and relative frequency statistics were used to describe the data. Cases reported were Europe-3152, Asia-2722, North America-852, Africa-122, Australia-121, and South America-79. Overall male to female ratio was 1:2.2; among clinical characteristics, headache was the most common symptom and hematological factors were the most common etiology. Location of the thrombosis was described mostly in the transverse sinus. Intercontinental differences in relation to demographics, etiology, clinical features, radiological presentation, and mortality were identified. CVT can have significant disparity in their demographics, etiology, clinical features, radiological presentation, and mortality when compared from one continent to other. It is important for the worldwide physicians to recognize these differences and to follow the most recent guidelines, diagnostic methods, and treatment to insure the best outcome and prognosis.     

Role of vasopressin and its antagonism in stroke related edema

Although many approaches have been tried in the attempt to reduce the devastating impact of stroke, tissue plasminogen activator for thromboembolic stroke is the only proved, effective acute stroke treatment to date. Vasopressin, an acute‐phase reactant, is released after brain injury and is partially responsible for the subsequent inflammatory response via activation of divergent pathways. Recently there has been increasing interest in vasopressin because it is implicated in inflammation, cerebral edema, increased intracerebral pressure, and cerebral ion and neurotransmitter dysfunctions after cerebral ischemia. Additionally, copeptin, a byproduct of vasopressin production, may serve as a promising independent marker of tissue damage and prognosis after stroke, thereby corroborating the role of vasopressin in acute brain injury. Thus, vasopressin antagonists have a potential role in early stroke intervention, an effect thought to be mediated via interactions with aquaporin receptors, specifically aquaporin‐4. Despite some ambiguity, vasopressin V1a receptor antagonism has been consistently associated with attenuated secondary brain injury and edema in experimental stroke models. The role of the vasopressin V2 receptor remains unclear, but perhaps it is involved in a positive feedback loop for vasopressin expression. Despite the encouraging initial findings we report here, future research is required to characterize further the utility of vasopressin antagonists in treatment of stroke. © 2014 Wiley Periodicals, Inc.