Left Distal Internal Carotid Artery Research Articles

A Case of Orbital Infarction Syndrome in a Patient with Hemophagocytic Lymphohistiocytosis

Purpose: To report a case of orbital infarction syndrome in a patient with hemophagocytic lymphohistiocytosis (HLH).Case summary: A 70-year-old woman with diabetes mellitus and hypertension was referred to the Department of Ophthalmology for sudden-onset left upper eyelid ptosis after being diagnosed with HLH. After 3 days, the best corrected visual acuity in the right eye was 0.8, while there was no light perception in the left eye. In the left eye, the ocular motility examination showed limitations in all fields of gaze. On fundus examination, optic disc pallor, retinal hemorrhage, and narrowed retinal arteries were observed in the left eye. Fluorescein angiography showed no blood flow in the retinal arteries and veins in the left eye. On neck computed tomography angiography, the left distal internal carotid artery was narrowed. Orbit computed tomography showed exophthalmos and extraocular muscle hypertrophy in the left eye. Orbit magnetic resonance imaging confirmed optic nerve edema, enhancement of the optic nerve sheath, and high signal intensity of the intraocular fat in the left eye. Slit-lamp examination revealed ischemia of the anterior segment and ischemic necrosis of the eyelid in the left eye. The patient was diagnosed with orbital infarction syndrome.Conclusions: Several factors may lead to ischemia of the orbital tissues in patients with HLH, including coagulopathy, an increased incidence of blood clots, and inflammation in the orbit. It is necessary to consider the possibility of orbital infarction syndrome when HLH patients present with visual loss, ocular movement limitations, and anterior segment ischemia.

Abstract 13325: Novel Heterozygous EFEMP2 Variant Detected in a Patient With Bilateral Internal Carotid Artery Dissection and Oligodontia

Cutis laxa is a rare connective tissue disorder characterized by sagging or inelastic skin. This phenotype is caused by multiple genotype variants. Biallelic variants in the EFEMP2 gene cause cutis laxa subtype IB characterized by aortic aneurysm, arterial tortuosity, arterial stenosis, joint laxity, arachnodactyly, emphysema, and retrognathia. EFEMP2 encodes fibulin-4, an extracellular matrix protein involved in elastogenesis and modulation of TGF-beta signaling. To date, monoallelic variants in EFEMP2 have not been described as pathogenic. Furthermore, oligodontia has not been associated previously with variants in EFEMP2 . We describe a 67-year-old male with a past medical history of left distal internal carotid artery (ICA) pseudoaneurysm and dissection, right distal ICA dissection, arterial tortuosity, and oligodontia who was found to have a heterozygous variant of uncertain significance in EFEMP2: c.1279_1289del11, p.Arg427CysfsX27. The variant has not been observed previously in large population cohorts and causes a shift in reading frame that substitutes the carboxyl terminal 17 amino acids with 26 alternative amino acids. This carboxyl terminal variant of EFEMP2 has been predicted to interact with PITX2 in yeast two-hybrid analyses. Furthermore, variants in PITX2 have been associated with dental agenesis, including oligodontia. We hypothesize that heterozygous variants in EFEMP2 represent a new syndrome characterized by arteriopathy and dental agenesis.

Cranial nerve VII on gadolinium contrast-enhanced magnetic resonance imaging in the case of Bell’s palsy

Bell’s palsy is a rapid unilateral peripheral paralysis of cranial nerve VII whose etiology is varied, most commonly associated with an acute infectious or inflammatory demyelinating process. Nerve injury can result in edema because of increased permeability of vascular structures, which can sometimes be seen as a locus of enhancement of magnetic resonance imaging (MRI). Bell’s palsy is typically considered a clinical diagnosis and the specificity and sensitivity of imaging have been poorly studied. Herein is describe a case of a 73-year-old male who presented to the emergency department with left-sided facial droop and no other focal neurological abnormalities. With a history of a Janus kinase 2 (JAK2) mutation and the new initial facial drooping, acute cerebrovascular insult was high on the differential. Initial labs and computerized tomography (CT) head were inconclusive, but MRI showed pronounced enhancement of the left distal internal carotid artery (ICA) with contiguous enhancement of the labyrinthine, geniculate, and tympanic segments of the left facial nerve. Diagnosing Bell’s palsy can be a challenge as there are numerous postulated etiologies stemming from trauma, infection, and neoplasm; with infection (particularly viral) postulated to be the most likely source. Though MRI is currently not validated as a tool in expediting Bell’s palsy diagnosis, findings such as the enhancement seen here provide some insight into the benefit of MRI as a diagnostic modality in some cases. This case is unique both for the diagnostic dilemma between stroke and Bell’s palsy and the potential for MRI imaging to help guide clinical decision-making into treatment.

Ischemic Stroke with Cerebral Vasculopathy in POEMS Syndrome

Ischemic stroke caused by the cerebral vasculopathy is a rare complication of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome. We present a case of recurrent ischemic strokes caused by cerebral vasculopathy in a patient with POEMS syndrome. A 34-year-old man presented with gait disturbance and dizziness. Brain magnetic resonance imaging demonstrated acute ischemic stroke in the middle cerebral artery-anterior cerebral artery (MCA-ACA) border zones of bilateral hemispheres. Repeated angiographic studies showed progressive worsening of the left distal internal carotid artery, ACA, and MCA stenoses, along with sustained steno-occlusion of right MCA. Key Words: POEMS syndrome, Vascular disease, Stroke

Transcranial Doppler Peak Systolic Velocities Overestimate The Risk Of Stroke In Sickle Cell Anemia

▪ BackgroundChildren with sickle cell anemia (SCA) have a high risk of stroke that can be estimated by transcranial Doppler ultrasonography (TCD). The gold standard TCD measurement to determine the risk of primary stroke is the time-averaged mean of the maximum velocity (TAMMV) in specific intracranial arteries. Peak systolic velocity (PSV), a different TCD measurement, has been proposed as an alternative method for risk stratification, especially for imaging TCD (TCDi) techniques (Jones et al. 2005). Although PSV has been little studied for this purpose, some centers use PSV in addition to TAMMV for the classification of risk of stroke by TCD for clinical care. A systematic bias in the classification of risk of stroke by PSV (higher or lower compared to TAMMV) would substantially affect medical resources and patient outcomes. ObjectiveDescribe the test performance characteristics of PSV compared to TAMMV for the classification of risk of stroke in children with SCA and determine the suitability of PSV for classification of TCDs in clinical practice. MethodsWe studied all patients in our center with homozygous HbSS, sickle-β0-thalassemia, or sickle-Hb D disease (all genotypes referred to here as SCA) who were ≥2 years of age and had a clinical TCD (all by TCDi technique) between 1998-2013. For each patient, the single most recent TCD performed >30 days from a transfusion was used, except for patients receiving chronic transfusions for whom the TCD before the initiation of chronic transfusions was used. Patients were included only once in this analysis. The highest TAMMV and PSV were recorded for the distal internal carotid artery (DICA), bifurcation and middle cerebral artery on the right and left sides of the brain. The TAMMV in each vessel was classified using modified STOP velocity criteria for TCDi: <155, normal; 155-184, conditional; ≥185 abnormal. The PSV in each vessel was classified using criteria proposed by Jones et al.: <200, normal; 200-249, conditional; ≥250 abnormal. Two overall TCD classifications, using either TAMMV or PSV, were made according to standard STOP methods by considering the worst (most abnormal) classification of any vessel as the overall classification. The primary outcome was the multi-level agreement between overall TCD classification based on TAMMV and PSV as measured by the kappa statistic. Kappa was also calculated for individual vessels to determine if agreement differed by anatomic site. Coefficients of determination (r2) were calculated using Pearson correlation. ResultsWe studied 120 patients with SCA [mean age 12.0 years ± 6.0 (S.D.); 51.1% male]. Fifty-nine (49%) had at least one prior transfusion that was given a mean of 588 (median 387) days before the TCD (none ≤40 days). The distribution of overall TCD classification by simultaneous TAMMV and PSV is shown in the Figure (Panel A). The distribution of classifications by TAMMV, compared to PSV, better approximates the expected distribution in a screening population. Classifications by PSV were skewed higher, giving more conditional and abnormal results, when compared to classification by TAMMV (P<0.0001). Kappa was 0.488 (P<0.001) for overall TCD classification, indicating only moderate agreement between the TAMMV and PSV methods. Agreement between TAMMV and PSV classification was highest (“substantial”) in the right and left DICA (k: 0.657–0.717, P<0.001). Agreement was only moderate in all other vessels (k: 0.428–0.539, P<0.001). Compared to TAMMV, use of PSV resulted in misclassification of 28% of overall TCD interpretations (Figure, Panel B); 32 studies (27%) were up-coded (27 normal to conditional; 5 conditional to abnormal). Only 1 study was down-coded (abnormal to conditional). Considering TAMMV and PSV as continuous variables, TAMMV accounted for 84.2-90.2% (r2) of the variation in PSV across different vessels; so, approximately 10-15% of the variability in PSV is not explained by TAMMV. [Display omitted] ConclusionsThe use of PSV (rather than TAMMV) to classify TCDs overestimates the risk of stroke for almost one-third of children with SCA. This systematic bias will unnecessarily increase anxiety, the frequency of follow-up testing, and use of chronic transfusions for primary stroke prophylaxis. PSV should not be used for primary classification of TCDs in clinical practice.Jones A et al. Can peak systolic velocities be used for prediction of stroke in sickle cell anemia? Pediatr Radiol. 2005;35:66-72. Disclosures:No relevant conflicts of interest to declare.

Vasculopathy after intracystic bleomycin administration for a recurrent cystic craniopharyngioma

Intracystic bleomycin (ICB) administration is known to be effective in the treatment of cystic craniopharyngiomas (CRPs) and rarely causes serious complications. The authors report a case of vasculopathy after ICB injection for a recurrent cystic CRP. A 5-year-old boy presented with the cystic recurrence of a CRP. A catheter and Ommaya system were inserted into the cyst, followed by a leakage test 2 weeks later. Bleomycin was delivered at 3 mg per week for 14 weeks (total dose 42 mg). Four months later, the patient's activity decreased and right hemiparesis occurred. Magnetic resonance imaging and cerebral angiography demonstrated a recurrent multicystic mass and infarction at the left middle cerebral artery territory with stenosis/occlusion of the left distal internal carotid artery and posterior cerebral artery. During the operation to remove the recurrent cystic mass, fibrotic stenoocclusion of the left intracranial arteries was identified. The cyst was totally removed. However, additional multiple border zone infarctions occurred in the left hemisphere, and the patient became wheelchair bound. Leakage of ICB was considered as the most probable cause of the cerebral vasculopathy and corresponding infarction. A leakage test may not always guarantee a leakage-free status even if the test is negative. Direct bypass surgery should have been considered to prevent a high risk of postoperative infarction in this case of a recurrent CRP with confirmed vasculopathy.

Direct Thrombus Imaging as a Means to Control the Variability of Mouse Embolic Infarct Models

High experimental variability in mouse embolic stroke models could mask the effects of experimental treatments. We hypothesized that imaging thrombus directly would allow this variability to be controlled. We optically labeled thrombi with a near-infrared fluorescent (NIRF) probe C15 that is covalently linked to fibrin by factor-XIIIa. Labeled thrombus was injected into the left distal internal carotid artery (ICA) of C57/BL6 mice (n=47), near its bifurcation, and laser-Doppler cerebral-blood-flow (CBF) was assessed for 30 minutes. NIRF thrombus imaging was done ex vivo at 24 hours. CBF variably decreased to 43.9±17.3% at 5 minutes (rCBF; 11.2∼80.4%). NIRF thrombus imaging at 24 hours showed variability in distribution (ICA bifurcation, adjacent and/or remote areas) and burden (2279±1270 pixels; 0∼5940 pixels). Final infarct size was also variable (21.0±10.3%; 4.7∼60.3% of the bihemispheric volume). Despite this heterogeneity, a strong thrombus-infarct correlation was maintained. The left hemispheric target infarct size (% of the hemisphere) correlated with thrombus burden, as a stronger predictor of infarct volume (P<0.001, r=0.50) than rCBF (P=0.02, r=-0.34). The infarct size was best predicted by a combination of thrombus imaging and CBF: left-hemispheric big-thrombi (>1865 pixels)/low-rCBF (≤42%) had an infarct volume of 56.9±10.4% (n=12), big-thrombi/high-rCBF had 45.9±23.5% (n=11), small-thrombi/low-rCBF 35.7±17.3% (n=11) and small-thrombi/ high-rCBF 27.3±16.4% (n=12). This is the first study to demonstrate that the highly heterogeneous nature of the mouse embolic stroke model can be characterized and managed by using near-infrared fluorescent thrombus imaging combined with CBF monitoring to stratify animals into useful subgroups.

Fibromuscular Dysplasia of the Distal Internal Carotid and Middle Cerebral Artery

Fibromuscular dysplasiais an uncommon condition of idiopathic, non-inflammatory and non-atherosclerotic disease of the musculature of arterial walls. The disease is rare, but it commonly affects young and middle aged women. Isolated intracranial cerebral fibromuscular dysplasia is extremely rare because cerebral fibromuscular dysplasia usually affects extracranial vessels. A 20-year-old woman was admitted with light hemiplegia and global aphasia. Brain MRI and MRA demonstrated acute left middle cerebral artery territory infarction with a multifocal stenosis and dilatation of the left middle cerebra artery and left internal carotid. The characteristic conventional cerebral angiographic findings demonstrated a typical string-of-beads appearance in the left distal internal carotid artery and proxiaml portion of the left middle cerebral artery, which suggested a medial type fibromuscular dysplasia. We report a case of isolated intracranial fibromuscular dysplasia with left middle cerebral artery territory infarction. Fibromuscular dysplasia should he considered as a stroke risk factors in children and young adults, especially in patients with no known cardiovascular risk factors.

Dissection of the internal carotid artery mimicking episodic cluster headache

Sirs: Internal carotid artery dissection (ICAD) is one of the most frequent causes of stroke in young patients [1,2]. Diagnosis may be delayed by misinterpreting local signs of dissection. Typical features of cluster headache (CH) have rarely been reported as presenting symptoms of ICAD [3–7]. Our case shows that subtle clinical features may point to symptomatic forms of CH, and therefore both history taking and clinical examination must be particularly accurate. Three weeks prior to admission, a 38-year-old man had a first attack of severe left-sided retroorbital pain extending into the mouth and ear, fluctuating over three days with pain maximum in the evening. He noted nasal congestion, tearing and hanging of the left eyelid. The pain subsided; however, mild ear pain persisted. An additional pain attack occurred one week later, in the evening, lasting for several hours. The history was negative for headache. A first episode of CH was suspected by his general practitioner. Oral sumatriptan prompted no relief. Thoracic CT was ordered to exclude a mass lesion in the lung apex and ocular pressure was found to be normal. On admission, the main complaint was a new attack of severe left-sided retroorbital and temporal pain. On examination the patient had hyperlacrimation, conjunctival injection and Horner‘s syndrome on the left without any further cranial nerve abnormalities. Oxygen inhalation and local nasal lidocaine were not effective, nasal sumatriptan resulted in partial relief. Neurosonography revealed a resistance flow pattern of the left distal internal carotid artery (ICA) without signs of atherosclerosis. Magnetic resonance imaging (MRI) and angiography (MRA) of the brain and neck demonstrated intramural haematoma and stenosis of the left distal ICA (Fig. 1), but no ischaemic lesions. Based on these findings we diagnosed a left ICAD. Treatment consisted of acetylsalicylic acid (ASA) 100 mg daily for stroke prevention [8] and verapamil 240 mg daily for prophylaxis of pain attacks. The attacks disappeared within two weeks, but a moderate continuous pain persisted in the left lower face. Clinical signs of ICAD are often dissociated with initial pain and local signs followed by retinal or cerebral ischaemic events [1]. In a series of 65 ICAD patients, pain was the presenting symptom in 58.5%, typically unilateral and localized, a painful Horner‘s syndrome was the initial sign in 29%, in two cases, pain mimicked CH [2]. Five similar cases have been reported [3–7]: in all Horner‘s syndrome persisted in pain free intervals, autonomic parasympathetic signs variably included lacrimation, conjunctival injection and nasal congestion, duration and character of pain was less stereotyped than in CH. In ICAD, Horner‘s syndrome is secondary to vessel wall injury affecting the pericarotid sympathetic nerve fibers [1]. The pain of dissection may trigger a physiological trigeminal-autonomic reflex in susceptible patients, resulting in parasympathetic symptoms. Experimentally, this reflex can be activated by painful stimulation of the first trigeminal branch with injection of capsaicin inducing ipsilateral parasympathetic activation as measured by vasodilatation of the ICA [9]. In CH it is hypothesized that increased susceptibility to trigeminal input or increased parasympathetic outflow from the brain stem activate the trigeminalautonomic reflex during an acute attack [10]. In patients with typical pain and autonomic features suggesting CH persistent Horner‘s syndrome, absence of pain free periods, variability in both pain attack duration and pain characteristics, as in our case, should raise suspicion of ICAD. Clinical features alone may not reliably distinguish primary CH from symptomatic forms of CH. Neurosonography as a screening tool [11] and brain MRI with contrast-enhanced MRA for confirmation of the diagnosis are useful in these patients. Treatment recommendations of ICAD are not based on controlled-randomized Dr. M. Hardmeier, MD (&) Prof. C. Gobbi AE Prof. A. Steck Prof. P. Lyrer AE S. Engelter, MD Dept. of Neurology University Hospital Basel Petersgraben 4, 4031 Basel Switzerland Tel.: +41-61/265-4151 Fax: +41-61/265-4100 E-Mail: mhardmeier@uhbs.ch

Recurrent embolic stroke originating from an internal carotid aneurysm in a young adult

An unruptured intracranial aneurysm is an uncommon but possible embolic source to the brain. We report a young patient who developed recurrent ischemic strokes occurring mainly in the left internal carotid arterial territory within a short interval; the first stroke occurred midway through a long-distance race, and the second stroke occurred immediately following a bowel movement. The angiographical contrast deficit indicated a thrombus in the left anterior cerebral artery as a result of the embolism. A saccular aneurysm of the left distal internal carotid artery was the only detectable potential embolic source. Initially anticoagulant therapy was given, and then surgical clipping of the aneurysm was performed. The patient has been free from stroke recurrence. As a cause of ischemic stroke in young adults, a carotid saccular aneurysm should be considered. Hard exercise and a Valsalva maneuver may be important triggers of thrombus detachment from the aneurysm.