Hussam A. Yacoub

Reversible Confluent Deep White Matter Abnormalities: A New Variant of Posterior Reversible Encephalopathy Syndrome

We describe a confluent deep white matter abnormalities variant of PRES, further strengthening the notion that PRES is a disorder of radiological heterogeneity. We present 2 cases of PRES with findings of diffuse but reversible vasogenic edema located in the deep periventricular white matter regions of bilateral hemispheres without a clearly posterior distribution. We feel that this represents a rare variant of PRES on imaging, thus adding to the existing radiological spectrum for this entity. Both of our patients presented with malignant hypertension (mean arterial blood pressure of 200 mmHg) and developed neurological symptoms that included encephalopathy, seizure, headache, and vision changes. Additionally, both patients presented with significant subcortical white matter edema that improved dramatically on follow-up imaging. The clinical and radiological improvement in both patients occurred following successful blood pressure management. It is possible that the deep white matter changes of PRES are seen exclusively in the setting of severe accelerated hypertension. Our case reports reveal that, in patients with hypertensive encephalopathy, a deep white matter pattern of diffuse signal changes may not necessarily indicate chronic ischemic changes and follow-up imaging studies are essential to rule out a diagnosis of PRES.

Open Heart Surgery Does Not Increase the Incidence of Ipsilateral Ischemic Stroke in Patients with Asymptomatic Severe Carotid Stenosis

BACKGROUND AND PURPOSE We evaluated the incidence of perioperative stroke following the institutions 2007 practice change of discontinuing combined carotid endarterectomy and open heart surgery (OHS) for patients with severe carotid stenosis. METHODS In this retrospective cohort study, we compared 113 patients undergoing coronary artery bypass grafting, aortic valve replacement, or both from 2007 to 2011 with data collected from 2001 to 2006 from a similar group of patients. Our aim was to assess whether the practice change led to a greater incidence of stroke. RESULTS A total of 7350 consecutive patients undergoing OHS during the specified time period were screened. Of these, 3030 had OHS between 2007 and 2011 but none were combined with carotid artery surgery (new cohort). The remaining 4320 had OHS before 2007 and 44 had combined procedures (old cohort). Of patients undergoing OHS during the 10-year period of observation, 230 had severe (>80%) carotid stenosis. In the old cohort (before 2007), carotid stenosis was associated with perioperative stroke in 2.5% of cases. None of the 113 patients having cardiac procedures after 2007 received combined carotid artery surgery; only 1 of these patients harboring severe carotid stenosis had an ischemic stroke (.9%) during the perioperative period. The difference in stroke incidence between the 2 cohorts was statistically significant (P = .002). CONCLUSION The incidence of stroke in patients with severe carotid artery stenosis undergoing OHS was lower after combined surgery was discontinued. Combined carotid and OHS itself seems to be an important risk factor for stroke.

Pathogenesis, clinical course and neuro-radiological signs of Proprionibacterium acnes cerebritis: Case report and literature review

Abstract The clinical and neuroimaging characteristics of brain infections related to Propionibacterium acnes are not well-characterized, making early diagnosis and treatment a challenge. More recently, life-threatening central nervous system infections with P. acnes are being reported with increasing frequency as complications of neurointerventional procedures. We present a rare case of P. acnes cerebritis that occurred as a sequela of bare platinum aneurysm coiling and a contaminant of percutaneous angiographic intervention. We include an extensive review of the literature describing the pathogenesis of P. acnes and neuro-radiological signs of brain infections related to this pathogen.

The Heart and Stroke.

Globally, stroke is the fifth leading cause of death in Western countries after cancer and heart disease. There are several ways in which stroke and heart disease interrelate. Cardiogenic stroke occurs when (1) clots embolize from the heart and reach the brain via the arterial circulation, or (2) as a result of severe heart failure and cerebral hypoperfusion. Medications as well as certain cardiac procedures performed to treat heart disease can lead to adverse neurological complications such as ischemic stroke. Many vascular diseases are also known to affect both the heart and the brain. For example, there is a strong correlation between cardiac disease and cerebral atherosclerosis, which escalates the risk of thrombotic stroke. Lastly, central nervous system diseases can influence the heart and its function.

Carotid Endarterectomy in a Patient with Severe Internal Carotid Artery Stenosis with Persistent Trigeminal Artery and Ischemia of the Anterior and Posterior Circulation

Occurrence of cerebral ischemia in the posterior circulation as a result of severe internal carotid artery disease and persistent trigeminal artery is rare. An 81-year-old man with medical history of hypertension and ischemic stroke presented with dizziness, nausea, and mild dysarthria. Magnetic resonance imaging of the brain revealed acute infarcts in the left internal carotid artery territory. CT angiogram revealed a persistent trigeminal artery (PTA) and severe atherosclerosis. The patient developed new neurological symptoms and repeat imaging revealed new acute infarcts in the PTA distribution. After undergoing a left carotid endarterectomy with no complications, the patient was discharged to a skilled nursing facility with no recurrence of ischemic stroke. This case adds a rare complication of an infrequent vascular anomaly to the limited body of the literature.

Isolated Cranial Nerve-III Palsy Secondary to Perimesencephalic Subarachnoid Hemorrhage

We describe isolated cranial nerve-III palsy as a rare clinical finding in a patient with perimesencephalic subarachnoid hemorrhage. In this unusual case, the patient presented with complete cranial nerve-III palsy including ptosis and pupillary involvement. Initial studies revealed subarachnoid hemorrhage in the perimesencephalic, prepontine, and interpeduncular cisterns. Angiographic studies were negative for an intracranial aneurysm. The patients neurological deficits improved with no residual deficits on follow-up several months after initial presentation. Our case report supports the notion that patients with perimesencephalic subarachnoid hemorrhage have an excellent prognosis. Our report further adds a case of isolated cranial nerve-III palsy as a rare initial presentation of this type of bleeding, adding to the limited body of the literature.