Neurophysiological findings in conus medullaris infarction-a case report and systematic review of the literature.

INTRODUCTION: Conus medullaris infarction (CMI) is a rare vascular phenomenon that has been scarcely reported in the literature. While previous studies have described the clinical and radiological features of CMI, little attention has been paid to its associated neurophysiological findings. METHODS: We present a case of idiopathic CMI and its neurophysiological findings, then present our findings from a systematic review of other reports of CMI with neurophysiological features found via PubMed search. RESULTS: Nine articles describing ten cases of CMI with associated neurophysiological data were found, in addition to our case. Out of all 11 cases, 7 cases (64%) had absent F-waves on the first nerve conduction study (NCS) performed as early as 4 h after onset, 5 of whom demonstrated reappearance of F-waves on subsequent follow-up NCS. Seven patients (64%) had diminished compound muscle action potentials (CMAPs), which was usually detectable on NCS performed between day 8 and day 18 of onset. None of them showed recovery of CMAPs in follow-up studies. Four patients (36%) had absent H-reflexes and two patients (18%) had sensory abnormalities. Electromyography (EMG) was reported in seven patients (64%), showing reduced recruitment as early as day 1 of onset, and denervation potentials as early as 4 weeks after onset. CONCLUSION: Absent F-waves and diminished CMAPs are the most common NCS abnormalities in CMI. Absent F-waves are detectable very early but tend to recover on subsequent NCS, while diminished CMAPs are detectable later but do not seem to resolve. Further research to determine the utility of neurophysiological studies in CMI diagnosis and prognostication is needed.

Relevance of Brain Regions' Eloquence Assessment in Patients With a Large Ischemic Core Treated With Mechanical Thrombectomy.

OBJECTIVE: Individualized patient selection for mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) and large ischemic core (LIC) at baseline is an unmet need. We tested the hypothesis that assessing the functional relevance of both infarcted and hypoperfused brain tissue would improve the selection framework of patients with LIC for MT. METHODS: We performed a multicenter, retrospective study of adults with LIC (ischemic core volume >70 mL on MRI diffusion-weighted imaging) with MRI perfusion treated with MT or best medical management (BMM). Primary outcome was 3-month modified Rankin Scale (mRS), favorable if 0-3. Global and regional eloquence-based core perfusion mismatch ratios were derived. The predictive accuracy for clinical outcome of eloquent regions involvement was compared in multivariable and bootstrap random forest models. RESULTS: A total of 138 patients with baseline LIC were included (MT n = 96 or BMM n = 42; mean age ± SD, 72.4 ± 14.4 years; 34.1% female; mRS 0-3: 45.1%). Mean core and critically hypoperfused volume were 100.4 mL ± 36.3 mL and 157.6 ± 56.2 mL, respectively, and did not differ between groups. Models considering the functional relevance of the infarct location showed a better accuracy for the prediction of mRS 0-3 with a c statistic of 0.76 and 0.83 for logistic regression model and bootstrap random forest testing sets, respectively. In these models, the interaction between treatment effect of MT and the mismatch was significant (p = 0.04). In comparison, in the logistic regression model disregarding functional eloquence, the c statistic was 0.67 and the interaction between MT and the mismatch was insignificant. CONCLUSIONS: Considering functional eloquence of hypoperfused tissue in patients with a large infarct core at baseline allows for a more precise estimation of treatment expected benefit. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, in patients with AIS and LIC, considering the functional eloquence of the infarct location improves prediction of disability status at 3 months.

Hemispheric cerebral blood flow predicts outcome in acute small subcortical infarcts.

The association between baseline perfusion measures and clinical outcomes in patients with acute small subcortical infarcts (SSIs) has not been studied in detail. Post-processed acute perfusion CT and follow-up diffusion-weighted imaging of 71 patients with SSIs were accurately co-registered. Relative perfusion values were calculated from the perfusion values of the infarct lesion divided by those of the mirrored contralateral area. The association between perfusion measures with clinical outcomes and the interaction with intravenous thrombolysis were studied. Additionally, the perfusion measures for patients having perfusion CT before and after thrombolysis were compared. Higher contralateral hemispheric cerebral blood flow (CBF) was the only independent predictor of an excellent clinical outcome (modified Rankin Scale of 0-1) at 3 months (OR = 1.3, 95% CI 1.1-1.4, P = 0.001) amongst all the perfusion parameters, and had a significant interaction with thrombolysis (P = 0.04). Patients who had perfusion CT after thrombolysis demonstrated a better perfusion profile (relative CBF ≥1) than those who had perfusion CT before thrombolysis (After:45.5%, Before:21.1%, P = 0.03). This study implies that for patients with SSIs, hemispheric CBF is a predictor of clinical outcome and has an influence on the effect of intravenous thrombolysis.

Isolated Infarctions of the Conus Medullaris: Clinical Features and Outcomes.

OBJECTIVE: This study aims to describe the clinical features and outcomes of patients with isolated infarctions of the conus medullaris, and to identify factors associated with poor functional outcomes. MATERIALS AND METHODS: We performed a systematic review and retrospective analysis on the clinical characteristics and outcomes of patients with isolated conus medullaris infarctions reported in literature over the past 30 years. RESULTS: We analyzed a total of 19 cases; 18 identified in literature from January 1991 to June 2021, together with our patient. Their median age was 56 years (range 28-79), with twice as many females as males. Pain was prominent at onset (15/19, 79%), only a third had vascular risk factors (7/19, 37%), and half had no significant preceding activities or events (9/19, 47%). Almost all experienced paraplegia or paraparesis (16/19, 84%), in which upper motor neuron features were rare (3/19, 16%). The underlying cause was unknown in half (10/19, 53%). Functional outcomes appeared fair, with nearly half being capable of unassisted ambulation (9/11, 82%). Patients with vascular risk factors (67% vs 13%, p = 0.024) or with identified underlying causes (78% vs 13%, p = 0.007) were less likely to walk unassisted. CONCLUSION: Isolated conus medullaris but should be considered in patients with acute cauda equina syndrome, especially in females. Patients with vascular risk factors, or with known causes of infarction, are less likely to walk unassisted. DWI sequences should be included in conventional MRI sequences when evaluating patients with acute cauda equina syndrome.

Intraperitoneal focal fat infarction: the great mimicker in the acute setting.

The term intraperitoneal focal fat infarction (IFFI) includes various self-limiting clinical conditions that are caused by focal fatty tissue necrosis. Most of the cases of IFFI concern torsion or infarction of the greater omentum or the epiploic appendages. However, although rarely, perigastric ligaments can also undergo torsion also leading to fat infarction. IFFI clinically may mimic other pathologies, such as acute appendicitis or diverticulitis, making their clinical diagnosis a challenge. Ultrasound (US) and computed tomography (CT) have a high sensitivity and specificity for the diagnosis of IFFI excluding other pathologies, and in most cases, the clinical evolution is spontaneously favorable, thus helping to reduce the need for unnecessary surgical intervention. We review cases with IFFI in order to identify specific involvement patterns. Cases of epiploic appendages reported to an acute, subacute, and more chronic phase in order to present the self-limiting nature of this entity and the resultant absorption. We also present cases with falciform ligament infarction, as well as primary ("whirl sign" on CT due to greater omentum torsion) and secondary omental infarctions. The aim of this pictorial review is not only to extensively explore the imaging findings of IFFI but to also describe the clinical presentation and pathophysiology of the prementioned conditions.

Deficiency of Adenosine Deaminase 2 in Adults and Children: Experience From India.

OBJECTIVE: Deficiency of adenosine deaminase 2 (DADA2) is a potentially fatal monogenic syndrome characterized by variable manifestations of systemic vasculitis, bone marrow failure, and immunodeficiency. Most cases are diagnosed by pediatric care providers, given the typical early age of disease onset. This study was undertaken to describe the clinical phenotypes and treatment response both in adults and in children with DADA2 in India. METHODS: A retrospective analysis of pediatric and adult patients with DADA2 diagnosed at various rheumatology centers across India was conducted. Clinical characteristics, diagnostic findings, and treatment responses were analyzed in all subjects. RESULTS: In total, 33 cases of DADA2 were confirmed in this cohort between April 2017 and March 2020. Unlike previous studies, nearly one-half of the confirmed cases presented during adulthood. All symptomatic patients exhibited features of vasculitis, whereas constitutional symptoms and anemia were more common in pediatric patients. Cutaneous and neurologic involvement were common, and 18 subjects had experienced at least one stroke. In addition, the clinical spectrum of DADA2 was expanded by recognition of novel features in these patients, including pancreatic infarction, focal myocarditis, and diffuse alveolar hemorrhage. Treatment with tumor necrosis factor inhibitors (TNFi) was initiated in 25 patients. All of the identified disease manifestations showed marked improvement after initiation of TNFi, and disease remission was achieved in 19 patients. Two cases were complicated by tuberculosis infection, and 2 deaths were reported. CONCLUSION: This report presents the first case series of patients with DADA2 from India, diagnosed by adult and pediatric care providers. The findings raise awareness of this syndrome, particularly with regard to its presentation in adults.

Vagus nerve stimulation reduces spreading depolarization burden and cortical infarct volume in a rat model of stroke.

Cortical spreading depolarization (SD) waves negatively affect neuronal survival and outcome after ischemic stroke. We here aimed to investigate the effects of vagus nerve stimulation (VNS) on SDs in a rat model of focal ischemia. To this end, we delivered non-invasive VNS (nVNS) or invasive VNS (iVNS) during permanent middle cerebral artery occlusion (MCAO), and found that both interventions significantly reduced the frequency of SDs in the cortical peri-infarct area compared to sham VNS, without affecting relative blood flow changes, blood pressure, heart rate or breathing rate. In separate groups of rats subjected to transient MCAO, we found that cortical stroke volume was reduced 72 h after transient MCAO, whereas stroke volume in the basal ganglia remained unchanged. In rats treated with nVNS, motor outcome was improved 2 days after transient MCAO, but was similar to sham VNS animals 3 days after ischemia. We postulate that VNS may be a safe and efficient intervention to reduce the clinical burden of SD waves in stroke and other conditions.

Idiopathic spontaneous extensive iliocaval thrombosis presenting with renal infarct.

We describe an extremely rare case of idiopathic spontaneous extensive venous thrombosis in a young man involving the inferior vena cava, the iliac veins and both renal veins associated with right haemorrhagic renal infarction with non-functioning right kidney.

Conus Medullaris Infarction Involving the Paraspinal Muscles and Nerve Roots.

Spinal cord infarctions account for less than 1% of all strokes. The segmental artery supplies the spinal cord, vertebrae, nerve roots, and paraspinal muscles. To our knowledge, this is the first case of spinal cord infarction involving multiple distinct infarcts at various sites, including the lumbar vertebrae, conus medullaris, dorsal thoracolumbar spinal cord, paraspinal muscles, and nerve roots.

Effects of Aerobic Exercise on Tau and Related Proteins in Rats with Photochemically-Induced Infarction.

BACKGROUND: Recent evidence indicates brain ischemia is associated with accumulations of abnormal tau and related proteins. However, the effects of aerobic training on these proteins have not been evaluated. OBJECTIVE: We aimed to evaluate the effect of aerobic exercise on the phosphorylation and acetylation of tau and on the expressions of tau related proteins in a rat stroke model and to compare the effects of aerobic exercise with those observed in our previous study on task specific training (TST). METHODS: Twenty-four Sprague- Dawley rats with photothrombotic cortical infarction were used in the current study. The rehabilitation group (RG) received treadmill training 40 min/day for 28 days, whereas the sedentary group (SG) did not receive any type of training. Functional tests such as the single pellet reaching task, rotarod, and radial arm maze tests were performed weekly for 4 weeks post-infarction. RESULTS: Levels of p-taus396 and p-AMPK were found to be lower in ipsilateral cortices in the RG than in the SG (p < 0.05). Levels of p-taus262, Ac-tau, p-GSK3ßS9, p-Akt, p-Sin1, and p-P70-S6K were significantly lower in ipsilateral than in contralateral cortices in the RG (p < 0.05). Aerobic training also improved motor, balance, and memory functions. CONCLUSION: Aerobic training inhibited the phosphorylation and acetylation of tau and modulated the expressions of tau related proteins after stroke by modifying the p70-S6K pathway and p-AMPK. By comparison with our previous study on the effects of TST, we have evidence to suggest that TST and aerobic exercise differ, although both types of rehabilitation inhibit tau phosphorylation and acetylation.

Relationship between Presence of Visceral Infarction and Functional Outcome among Patients with Acute Ischemic Stroke.

INTRODUCTION: Evidence of visceral infarction is often found in patients with acute ischemic stroke. It remains uncertain whether there exists a relationship between visceral infarction and functional outcomes among patients with stroke. OBJECTIVE: The aim of this study was to evaluate whether evidence of visceral infarction is associated with functional outcomes among patients with stroke. METHODS: Among patients with acute ischemic stroke enrolled in the Cornell AcutE Stroke Academic Registry (CAESAR) from 2011 through 2016, we included those with a contrast-enhanced abdominal computed tomographic scan within 1 year of admission. Our outcome was ambulatory status at discharge from acute stroke hospitalization, categorized as walking without assistance, walking with assistance, and unable to walk. We used ordinal logistic regression to examine the association between visceral infarction and discharge ambulatory status after adjustment for demographics, stroke risk factors, stroke severity (NIH Stroke Scale), and stroke subtype. RESULTS: Among 2,116 ischemic stroke patients registered in CAESAR from 2011 to 2016, 259 had contrast-enhanced abdominal computed tomographic imaging, of whom 48 (19%) had evidence of visceral infarction. After adjustment for demographics, stroke risk factors, stroke severity, and stroke subtype, the presence of visceral infarction was associated with a worse ambulatory status at discharge (global OR for better ambulatory status, 0.4; 95% CI, 0.2-1.0, p = 0.046). CONCLUSIONS: We found that the presence of visceral infarction was associated with poor functional outcomes at the time of hospital discharge. These findings suggest that such findings are not necessarily benign and are at the least a marker of poor outcomes.

Flinders sensitive line rats are resistant to infarction following transient occlusion of the middle cerebral artery.

BACKGROUND: Depression is a common complication of stroke and increases the risk of mortality and disability. Pre-stroke depression is a possible risk factor for stroke and has also been linked to adverse outcomes. The underlying mechanisms linking depression and stroke remain unclear. Preclinical models may provide novel insights, but models reflecting both conditions are lacking. METHODS: In this study, we investigated the effects of a 45-min transient middle cerebral artery occlusion (MCAo) on infarct size in male adult Flinders Sensitive Line rats, a genetic animal model of depression, and their control strains Flinders Resistant Line and Sprague-Dawley rats. Infarct size was assessed by tetrazolium chloride (TTC) and microtubule-associated protein 2 (MAP2) staining after 48 h of reperfusion. Angiograms of the vascular structure of naïve animals were produced with a µ-CT scanner. RESULTS: Both Flinders strains had significantly smaller infarcts following MCAo compared to Sprague-Dawley rats. This effect does not appear to be due to changes in cerebrovascular architecture, as indicated by an initial exploration of vascular organization using angiograms, or body temperature regulation. CONCLUSIONS: Our study suggests that the rat strain does not influence infarct volumes following MCAo.

Acute Renal Infarction Treated With Local Intra-arterial Thrombolysis.

A 53-year-old man with stable coronary disease and dyslipidemia was admitted with sudden pain of severe intensity in the left flank. Selective catheterization of the left renal artery, followed by alteplase infusion for 6 hours, resolved the patient's symptoms.

Clinical, neuroimaging, and nerve conduction characteristics of spontaneous Conus Medullaris infarction.

BACKGROUND: Spontaneous conus medullaris infarction is a rare disease. We describe two patients with spontaneous conus medullaris infarction presenting as acute cauda equina syndrome and their unique electromyography (EMG) findings. CASE PRESENTATION: Two patients developed acute low back pain with mild asymmetric paraparesis, loss of perianal sensation and sphincter dysfunction. Ankle deep tendon reflexes were reduced in bilaterally. Neither patient had cardiovascular risk factors. Magnetic Resonance imaging showed infarction in the conus medullaris. Functional recovery was good in both patients, but progressive asymmetric calf wasting and sphincter dysfunction remained. EMG studies at follow-up of at least 3 years demonstrate active denervation at the muscles innervated by the first sacrum anterior horn cells. CONCLUSION: Spontaneous conus medullaris infarction can occur in healthy individuals and presents as cauda equina syndrome. Findings of needle EMG studies indicate a progressive course of sacrum anterior horn cell disorder during long-term follow-up.

Cocaine as a rare cause of locked-in syndrome: a case report.

INTRODUCTION: In the United States, cocaine is a commonly used drug of abuse. It is also a recognized contributing factor for both hemorrhagic and ischemic strokes. However, cocaine-induced basilar artery thrombosis has rarely been reported in the literature. CASE PRESENTATION: Our patient was a 51-year-old African American woman with a history of polysubstance abuse who presented to the emergency department for acute behavior changes. Later, during admission, she had a dramatic decrease in motor strength in all extremities and a positive Babinski reflex bilaterally. The results of her toxicology reports were positive for cocaine; in addition, results of magnetic resonance angiography and magnetic resonance imaging were consistent with acute thrombosis and subsequent infarction of the basilar artery. Her mental status improved, but she was only able to communicate via movements of her eyes. CONCLUSION: Our patient developed locked-in syndrome after use of cocaine. Given the prevalence of its use in the United States, cocaine use should be included among the potential causes of locked-in syndrome.

Clinical Study of Thirteen Patients with Spinal Cord Infarction.

BACKGROUND: A concept of sensory tracts in the spinal cord has been established in relation to a dorsolateral pathway which is located in the posterior part of the lateral column and conveys the deep sense. METHODS: The clinical status at onset, neurological symptoms, and magnetic resonance imaging (MRI) findings in 13 patients of spinal cord infarction were studied. RESULTS: The clinical status was acute in 11 patients and subacute in 2 patients. Palsy of the extremities was noted in 11 patients. Segmental sensory disturbance was shown in all patients. One patient showed disturbance of all senses and paraplegia, which indicated transverse myelopathy. In the other 12 patients, 11 patients showed impairment of pain sense although joint position sense was preserved, excluding 1 patient whose sensory disturbance showed dysesthesia alone. In these 11 patients, soft touch and vibration senses were impaired in 7 patients. Abnormality of spinal cord MRI was detected 7 patients. The lesions were located in the cervical cord in 3 patients, cervical to thoracic cord in 1 patient, and thoracic cord in 3 patients. CONCLUSIONS: In the 11 patients in whom pain sense was impaired and joint position sense was preserved, involvement of the anterior spinal cord artery (ASCA) was the mainstay. Impairment of vibration sense was accompanied in 7 patients in patients of ASCA infarction. It was speculated that impairment of vibration sense can occur in patients with ASCA infarction whose ischemia spread to the dorsolateral pathway in the posterior part of the lateral column.

Acute Spinal Cord Infarction Presenting With Chest Pain and Neurogenic Shock: A Case Report.

BACKGROUND: Spinal cord infarction (SCI) is rare, accounting for approximately 1% of strokes. CASE REPORT: We present the case of a 63-year-old male who presented to the emergency department (ED) with chest pain and acute-onset generalized weakness and was ultimately diagnosed with SCI secondary to suspected occlusion of the artery of Adamkiewicz. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: SCI may present diagnostic challenges, with its predilection for mimicking other major emergency conditions, such as acute aortic dissection, aortic aneurysm rupture, spinal cord compressive myelopathy, or transverse myelitis. Its consequences are often significantly disabling initially, though patients may experience subsequent clinical improvement. It is important to include SCI in the differential for patients with chest or back pain coupled with neurologic symptoms.