Updated Outlook of Cerebral Amyloid Angiopathy and Inflammatory Subtypes: Pathophysiology, Clinical Manifestations, Diagnosis and Management.

Cerebral amyloid angiopathy (CAA) is a common untreatable cause of lobar hemorrhages and cognitive decline in the older population. Subset of patients present with its inflammatory subtype with rapid decline in cognitive functions and neurological deficits. Most commonly the underlying pathophysiology of this disease is deposition of insoluble amyloid protein into blood vessel walls which results in vessel fragility leading to local neurotoxicity which may eventually leads to lobar hemorrhages and cognitive decline. The term "Amyloid Spell" encompasses transient focal neurological deficits which is commonly misdiagnosed as seizures or transient ischemic attack in the emergency department. Radiologic findings in these patients may reveal microbleeds, cortical superficial siderosis, white matter hyperintensities, and cerebral edema which support the clinical diagnosis which could be otherwise challenging. CAA diagnostic criteria require CT (Edinburgh Criteria) or MRI imaging, or neuropathology. The diagnosis can be suspected without imaging or neuropathology but cannot be confirmed. This review article provides a critical outlook on different types of presentations, updated diagnostic criteria and management of CAA patients illustrating underlying mechanisms associated with neuronal injury secondary to amyloid deposition.

Intraprocedural Back Pain Associated with Awake Neuroendovascular Procedures.

BACKGROUND AND PURPOSE: The prevalence and characteristics of intraprocedural back pain is not well studied in awake patients undergoing neuroendovascular procedures. METHODS: We performed a prospective study as part of quality improvement initiative in which all patients who underwent neuroendovascular procedures in awake state were inquired regarding presence, severity (using a numeric rating scale score ranging from 0 [no pain] to 10 [worst pain possible]), and location (using anatomical chart) of back pain immediately after the procedure. The primary endpoint was the proportion of patients with moderate to severe pain (score of ≥3). RESULTS: A total of 100 (41.3%) of 242 patients reported intraprocedural back pain with a median severity of 5/10 (range 1-10). The mean age was 58.7 ± 16.2 years. The mean duration of the procedure was 82.3 minutes (range 15-410 minutes). The pain was classified as moderate to severe in 86 of 100 patients. The locations of pain were identified in lumbar (n = 77), thoracic (n = 6), cervical (n = 7), cervical and lumbar (n = 8), and cervical with thoracolumbar (n = 2) regions. There was a significant relationship between patients' history of the previous neck and/or back surgery and frequency of moderate to severe back pain (P = .02). No significant relationship was observed between frequency of none to mild and moderate to severe back pain among the strata by patients' age, body mass index, or duration of procedures. CONCLUSIONS: The relatively high prevalence of intraprocedural back pain in patients undergoing neuroendovascular procedures in awake state must be recognized, and strategies to reduce the occurrence need to be identified.

The Effect of Ticagrelor on Platelet Reactivity in Patients with Clopidogrel Resistance Undergoing Neuroendovascular Procedures.

BACKGROUND AND PURPOSE: Suboptimal platelet inhibition by clopidogrel (clopidogrel resistance) may be associated with high rates of stent thrombosis and ischemic events. Our objective was to determine if ticagrelor, a P2Y12 receptor inhibitor, can result in platelet inhibition in patients with clopidogrel resistance. METHODS: A thromboelastography-platelet mapping assay was used in all patients undergoing neuroendovascular procedures requiring oral clopidogrel. In patients with suboptimal platelet inhibition (<60%) on clopidogrel, ticagrelor was imitated after an oral bolus of 180 mg followed by 90 mg twice daily and the platelet mapping assay was repeated. The primary endpoint was hemorrhagic complications classified as major (hemoglobin decrease >5 g/dL or intracranial hemorrhage with deficits), minor (hemoglobin decrease 3-5 g/dL or intracranial hemorrhage without residual deficits), or insignificant. RESULTS: Suboptimal platelet inhibition on clopidogrel was seen in 70 of 106 patients undergoing neuroendovascular procedures. There was a significantly higher magnitude of platelet inhibition with ticagrelor compared with clopidogrel in patients with clopidogrel resistance (mean ± SD: 85.90 ± 10.74% vs. 29.26 ± 17.71%; P < .001); 50 of 70 patients showed optimal inhibition. Two patients had major (fatal) hemorrhagic events (both received either intravenous thrombolytics and/or eptifibatide infusion). Three patients had minor hemorrhagic events, and two patients had insignificant hemorrhagic events. Four of seven hemorrhagic events occurred in patients with optimal response to clopidogrel, two occurred in patients with suboptimal response to ticagrelor, and one occurred in a patient with optimal response to ticagrelor. CONCLUSIONS: Oral ticagrelor can augment platelet inhibition in patients who have clopidogrel resistance.

Internal Carotid Artery Aplasia in a Patient With Nail-Patella Syndrome.

Nail-patella syndrome (NPS) is a rare disorder characterized by abnormal development of ectodermal and mesodermal tissues. Classically, NPS presents as a triad of nail dysplasia, dysplastic patellae, and bony exostoses of the ilia known as "iliac horns." Apart from dermatological and skeletal abnormalities, patients may also have involvement of ophthalmologic and renal systems. The underlying molecular etiology in NPS is the mutation of LMX1B homeobox gene which results in loss of function of its protein also called LMX1B, a DNA-binding protein belonging to the larger LIM-homeodomain transcription factor family. Normal LMX1B gene and protein function are essential for dorsalization of the vertebrate limb bud, development of anterior eye structures, skull formation, and differentiation and migration of neurons in the central nervous system. We report a case of confirmed NPS presenting with congenital aplasia of the internal carotid artery and believe this is the first report of cerebrovascular developmental abnormality associated with NPS.

Herpes Simplex Virus Encephalitis: Atypical Presentation as a Right Middle Cerebral Artery Stroke.

Herpes simplex virus encephalitis (HSVE) is a medical emergency associated with high mortality and morbidity. Definitive diagnosis is established by history, clinical examination, neuroimaging studies, supportive electroencephalogram (EEG) findings, and cerebrospinal fluid (CSF) analysis. We report a case of HSVE presenting as a stroke mimic in a 76-year-old female with a history of atrial fibrillation on warfarin. She was admitted to our medical intensive care unit with intermittent fever, lethargy, and new onset left-sided hemiparesis. A computed tomography (CT) of the head showed a right middle cerebral artery (MCA) acute ischemic stroke with midline shift and a dense right MCA sign. Brain magnetic resonance imaging (MRI) showed evidence of acute stroke with consideration of herpes encephalitis. CSF analysis was positive for herpes simplex virus (HSV) type one. She recovered with high-dose intravenous acyclovir therapy. Our patient was a diagnostic dilemma, initially being diagnosed with an acute ischemic stroke and yet found to have HSVE, which mimicked an acute ischemic stroke. Delay in treatment may result in devastating clinical outcomes that may include severe cognitive, focal neurological deficits, persistent seizures, and even death. This case highlights the importance of a multidisciplinary approach and the need for increased awareness of an atypical presentation of HSVE among emergency physicians, neurologist, intensivists, and radiologists.

The novel use of Onyx for the rapid treatment of a traumatic carotid injury.

Penetrating neck injury causing internal carotid artery (ICA) transection is nearly always fatal. The novel use of Onyx Liquid Embolic System (Onyx LES) for rapid hemostasis of a traumatic cervical ICA transection is reported. A patient with a gunshot wound to the face and neck underwent emergent catheter angiography which revealed contrast extravasation from the right cervical ICA consistent with traumatic transection. The ipsilateral cerebral hemisphere showed collateral blood supply from the posterior communicating artery, and ipsilateral external carotid artery anastomoses of the facial, ethmoidal and ophthalmic arteries. Rapid endovascular repair of the transected cervical ICA was performed using Onyx LES. Onyx34 was injected at a rapid rate of 1 ml/min into the right ICA. Injection was continued until cast formation completely occluded the proximal cervical ICA but preserved the external carotid artery. This method very rapidly controlled bleeding and should be considered in these cases.

Critical care issues in stroke and subarachnoid hemorrhage.

The outcomes of devastating neurological emergencies such as stroke and subarachnoid hemorrhage may be measurably improved by timely treatment in a neurointensive care unit (NICU). Optimal care requires a multidisciplinary approach, with attention to a wide range of treatment issues. This review examines the key therapeutic concerns in the NICU management of acute ischemic and hemorrhagic stroke and subarachnoid hemorrhage, including mechanical ventilation, blood pressure management, cardiac monitoring, intracranial pressure assessment, vasospasm, seizures, sedation, fluids, electrolytes, and nutrition. The discussion of mechanical ventilation includes rapid sequence induction and intubation, indication for intubation and extubation, and prognostic factors in mechanical ventilation. Differing blood pressure management concerns in hemorrhagic and ischemic events are discussed, and specific target blood pressures and pharmacologic interventions are reviewed. The discussion of cardiac monitoring includes concurrent stroke and cardiac ischemia and arrhythmias, cardiac imaging, anticoagulation, and vasopressor therapy. The importance, monitoring and management of cerebral blood flow and intracranial pressure (ICP) are discussed, and strategies for treatment of elevated ICP are outlined in detail. The discussion of vasospasm includes evaluation, prophylaxis, and treatment with medications, hypervolemic hemodilution, and angioplasty. Management of seizure and status epilepticus in stroke and subarachnoid hemorrhage are reviewed and current algorithms are presented. The management of fluids, electrolytes and enteral nutrition are also reviewed.