Primary Angiitis of the Central Nervous System

Towards a histological diagnosis of childhood small vessel CNS vasculitis

BACKGROUND

Primary small vessel CNS vasculitis (sv-cPACNS) is a challenging inflammatory brain disease in children. Brain biopsy is mandatory to confirm the diagnosis. This study aims to develop and validate a histological scoring tool for diagnosing small vessel CNS vasculitis.

METHODS

A standardized brain biopsy scoring instrument was developed and applied to consecutive full-thickness brain biopsies of pediatric cases and controls at a single center. Stains included immunohistochemistry and Hematoxylin & Eosin. Nine North American neuropathologists, blinded to patients' presentation, diagnosis, and therapy, scored de-identified biopsies independently.

RESULTS

A total of 31 brain biopsy specimens from children with sv-cPACNS, 11 with epilepsy, and 11 with non-vasculitic inflammatory brain disease controls were included. Angiocentric inflammation in the cortex or white matter increases the likelihood of sv-cPACNS, with odds ratios (ORs) of 3.231 (95CI: 0.914-11.420, p = 0.067) and 3.923 (95CI: 1.13-13.6, p = 0.031). Moderate to severe inflammation in these regions is associated with a higher probability of sv-cPACNS, with ORs of 5.56 (95CI: 1.02-29.47, p = 0.046) in the cortex and 6.76 (95CI: 1.26-36.11, p = 0.025) in white matter. CD3, CD4, CD8, and CD20 cells predominated the inflammatory infiltrate. Reactive endothelium was strongly associated with sv-cPACNS, with an OR of 8.93 (p = 0.001). Features reported in adult sv-PACNS, including granulomas, necrosis, or fibrin deposits, were absent in all biopsies. The presence of leptomeningeal inflammation in isolation was non-diagnostic.

CONCLUSION

Distinct histological features were identified in sv-cPACNS biopsies, including moderate to severe angiocentric inflammatory infiltrates in the cortex or white matter, consisting of CD3, CD4, CD8, and CD20 cells, alongside reactive endothelium with specificity of 95%. In the first study of its kind proposing histological criteria for evaluating brain biopsies, we aim to precisely characterize the type and severity of the inflammatory response in patients with sv-cPACNS; this can enable consolidation of this population to assess outcomes and treatment methodologies comprehensively.

The role of susceptibility-weighted imaging & contrast-enhanced MRI in the diagnosis of primary CNS vasculitis: a large case series

Primary CNS Vasculitis (PCNSV) is a rare, diverse, and polymorphic CNS blood vessel inflammatory condition. Due to its rarity, clinical variability, heterogeneous imaging results, and lack of definitive laboratory markers, PCNSV diagnosis is challenging. This retrospective cohort analysis identified patients with histological diagnosis of PCNSV. Demographic data, clinical presentation, neuroimaging studies, and histopathologic findings were recorded. We enrolled 56 patients with a positive biopsy of CNS vasculitis. Most patients had cerebral hemisphere or brainstem symptoms. Most brain MRI lesions were bilateral, diffuse discrete to confluent white matter lesions. Frontal lobe lesions predominated, followed by inferior cerebellar lesions. Susceptibility-weighted imaging (SWI) hemorrhages in 96.4% (54/56) of patients, either solitary microhemorrhages or a combination of micro and macrohemorrhages. Contrast-enhanced T1-WIs revealed parenchymal enhancement in 96.3% (52/54 patients). The most prevalent pattern of enhancement observed was dot-linear (87%), followed by nodular (61.1%), perivascular (25.9%), and patchy (16.7%). Venulitis was found in 19 of 20 individuals in cerebral DSA. Hemorrhages in SWI and dot-linear enhancement pattern should be incorporated as MINOR diagnostic criteria to diagnose PCNSV accurately within an appropriate clinical context. Microhemorrhages in SWI and venulitis in DSA, should be regarded as a potential marker for PCNSV.

Case report: A case of primary angiitis of the central nervous system: misdiagnosed for 3.5 years

Introduction

Primary angiitis of the central nervous system (PACNS) is an uncommon inflammatory condition that exclusively affects blood vessels within the brain parenchyma, leptomeninges, and spinal cord. Due to its infrequency and the variability in its clinical presentation and imaging findings, diagnosing PACNS can be challenging.

Case description

In this study, we present the case of a teenager who initially presented with headaches and epilepsy. Comprehensive laboratory tests yield normal results. A series of brain magnetic resonance imaging (MRI) revealed a progression of changes, starting from localized cerebral atrophy and culminating in the development of a contrast-enhanced mass with vasogenic edema. Immune-associated encephalitis and mitochondrial encephalopathy were suspected, but immunologic investigations, mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) sequencing using biopsied muscle, and muscle pathologies were all negative. Ultimately, a diagnosis of PACNS was confirmed through a stereotactic brain biopsy, which took place 3.5 years after the onset of symptoms. The patient responded favorably to treatment with glucocorticoids and cyclophosphamide.

Conclusion

In summary, we have described a case of PACNS characterized by localized cerebral atrophy and tumor-like MRI findings, who was misdiagnosed as immune-associated encephalitis or mitochondrial encephalopathy for 3.5 years. We emphasize the importance of dynamic observation of MRI changes, as well as brain biopsy.

Soluble TREM2 is a potential biomarker for the severity of primary angiitis of the CNS

Background

Primary angiitis of the central nervous system (PACNS) is a severe inflammatory disease, and soluble triggering receptor expressed on myeloid cells 2 (sTREM2) has been reported to be associated with inflammation of the CNS. However, the role of sTREM2 in PACNS remains unknown.

Methods

We obtained serum and cerebrospinal fluid (CSF) samples from 18 patients diagnosed with PACNS, as well as 14 patients diagnosed with other neurological disorders with no evidence of inflammation. sTREM2 concentrations in the samples were detected by enzyme-linked immunosorbent assay. And routine CSF measurements of PACNS patients were analysed, including number of White Blood Cells (WBC), protein, Immunoglobulin G (IgG) index and CSF/serum quotients. Levels of inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, IL-8, IL-1β, and complement C4, also were tested. The modified Rankin scale (mRS), National Institutes of Health Stroke Scale (NIHSS), and activities of daily living (ADL) scores were obtained as indicators of disease severity. In PACNS patients, cerebral lesion volume was evaluated by magnetic resonance imaging.

Results

sTREM2 levels in serum and CSF were significantly elevated in PACNS patients and significantly associated with the mRS, NIHSS and ADL scores as well as inflammatory cytokine levels. Additionally, positive correlations were observed between the cerebral lesion volume and the sTREM2 levels in both blood and CSF. Higher sTREM2 levels in either the blood or CSF seemed to predict a good prognosis in PACNS patients.

Conclusion

Our results indicate an association between serum and CSF sTREM2 levels and the severity of neurological damage. Thus, sTREM2 represents a potential biomarker for monitoring disease and potentially predicting the prognosis of PACNS patients.

Primary Central Nervous System Angiitis Mimicking a Space-Occupying Lesion

Background and Purpose Intracranial space-occupying lesions are a sine qua non for neoplastic lesions; however, occasionally non-neoplastic lesions mimic neoplastic lesions, leading to diagnostic dilemmas. We report our experience with three patients who presented with a progressive hemispheric syndrome and the diagnostic considerations involved in the cases.

Materials and Methods In this retrospective study, we included three patients with primary angiitis of central nervous system (PACNS) who underwent craniotomy and biopsy, suspecting it to be mass lesions. Demographic features, clinical features, radiological features, histopathology, treatment, and clinical outcomes were studied.

Results Majority were males. The male:female ratio was 2:1. Lobar involvement was common. MR brain with contrast showed features of high-grade glioma. Despite hemispheric involvement, there was no mass effect. Perilesional edema was seen in all cases. All underwent craniotomy and biopsy; histopathology was consistent with PACNS. All patients were treated with corticosteroids and cyclophosphamide. Rituximab was used in addition to cyclophosphamide in one patient. At 2 years follow-up, two patients were in disease remission and one patient died due to disease progression.

Conclusion PACNS has a protean clinical manifestation. A high index of suspicion is required in cases with atypical clinical presentations, radiological features, and normal angiograms. Early histological diagnosis and aggressive immunotherapy with high-dose corticosteroids combined with intravenous cyclophosphamide yields favorable outcomes.

Central and Peripheral Nervous System Complications of Vasculitis Syndromes From Pathology to Bedside: Part 1-Central Nervous System

PURPOSE OF REVIEW

The aim of this review is to provide a comprehensive update on the clinical assessment, diagnosis, complications, and treatment of primary central nervous system vasculitis (PCNSV).

RECENT FINDINGS

The developments in neuroimaging, molecular testing, and cerebral biopsy have enhanced clinical assessment and decision making, providing novel insights to prevent misdiagnosis increasing diagnostic certainty. Advances in imaging techniques visualizing the wall of intracranial vessels have improved the possibility to distinguish inflammatory from non-inflammatory vascular lesions. Large recent studies have revealed a more varied histopathological pictures and disclosed an association with amyloid angiopathy. Unfortunately, therapy remains largely empiric. PCNSV is a heterogeneous group of disorders encompassing different clinical subsets that may differ in terms of prognosis and therapy. Recent evidence has described a more benign course, with good response to therapy. New diagnostic techniques will play soon a pivotal role in the appropriate diagnosis and prompt management of PCNSV.

Autoimmune Meningitis and Encephalitis

Meningitis and encephalitis are inflammatory syndromes of the meninges and brain parenchyma, respectively, and may be identified either by finding definitive evidence of inflammation on tissue pathology or by cerebrocpinal fluid (CSF) analysis showing pleocytosis or intrathecal antibody synthesis. Clinicians evaluating undifferentiated meningitis or encephalitis should simultaneously consider autoimmune, infectious, and neoplastic causes, using patient risk factors, clinical syndrome, and diagnostic results including CSF and MRI findings to narrow the differential diagnosis. If an autoimmune cause is favored, an important early diagnostic question is whether a specific neural autoantibody is likely to be identified.

ACR Appropriateness Criteria® Cerebrovascular Diseases-Aneurysm, Vascular Malformation, and Subarachnoid Hemorrhage

Cerebrovascular disease is a broad topic. This document focuses on the imaging recommendations for the varied clinical scenarios involving intracranial aneurysms, vascular malformations, and vasculitis, which all carry high risk of morbidity and mortality. Additional imaging recommendations regarding complications of these conditions, including subarachnoid hemorrhage and vasospasm, are also covered. While each variant presentation has unique imaging recommendations, the major focus of this document is neurovascular imaging techniques. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Elevated intracranial pressure requiring decompressive craniectomy in a child with progressive primary angiitis of the central nervous system: a case report

BACKGROUND

Elevated intracranial pressure is a potentially catastrophic complication of neurologic injury in children. Successful management of elevated intracranial pressure requires prompt recognition and therapy directed at both reducing intracranial pressure and reversing its underlying cause. A rare condition that causes elevated intracranial pressure is childhood primary angiitis of the central nervous system, which is a rare inflammatory central nervous system disease that poses diagnostic and therapeutic challenges. To our knowledge, this is the first reported case of angiography-positive progressive childhood primary angiitis of the central nervous system requiring decompressive hemicraniectomy for refractory elevated intracranial pressure in children.

CASE PRESENTATION

We report the case of a 5-year-old Saudi girl who presented to the pediatric emergency department with fever and new-onset status epilepticus. She had elevated inflammatory markers with radiological and histopathological evidence of angiography-positive progressive childhood primary angiitis of the central nervous system, complicated by elevated intracranial pressure. Despite medical management for both childhood primary angiitis of the central nervous system and elevated intracranial pressure, her neurological status continued to deteriorate and the elevated intracranial pressure became refractory. She developed right uncal, right subfalcine, and tonsillar herniation requiring decompressive hemicraniectomy with a favorable neurological outcome.

CONCLUSION

Decompressive craniectomy might be considered in cases of angiography-positive progressive childhood primary angiitis of the central nervous system with elevated intracranial pressure refractory to medication. A multidisciplinary approach for the decision of decompressive craniectomy is advised to ensure patient safety and avoid possible morbidities and mortality.

Retrospective Analysis of 28 Cases Confirmed for Primary Angiitis of the Central Nervous System by Biopsy

OBJECTIVE

The present study aimed to summarize the clinical characteristics, therapeutic effects, and long-term prognosis of cases confirmed with primary angiitis of the central nervous system (PACNS) by biopsy, analyze the risk factors, and provide clinical guidance for the diagnosis and treatment of the disease.

METHODS

Retrospective analysis was performed on 28 cases of PACNS confirmed by biopsy, and the age, gender, pathological results, course of the disease, imaging manifestations, treatment, and prognosis of the patients were analyzed and summarized.

RESULTS

The cohort (age 16-60 years) comprised of 16 males. The average time from the visit to diagnosis was 6 months. The first symptom was chronic headache in 18 patients. The pathological results were accompanied by demyelination in 10 cases and glial hyperplasia in 6 cases. A total of 27 patients received treatments including glucocorticoid+cyclophosphamide; of these, 3 cases of craniotomy were improved. Among the 28 patients, 15 patients improved after the treatment, 12 patients had no significant improvement, and 1 patient was deceased. Patients with a long course of the disease before diagnosis, a Karnofsky performance status (KPS) score <60 at the time of diagnosis, a behavioral, cognitive abnormality before treatment, and a short-term relapse (0.3-1 month) have a poor outcome.

CONCLUSIONS

PACNS patients are prone to misdiagnosis and mistreatment, with unknown etiology and poor prognosis due to delayed treatment. Therefore, early biopsy, pathological diagnosis, and timely treatment with glucocorticoid shock are recommended, and patients with obvious mass effect should be treated by surgical resection.

Primary CNS lymphoma initially diagnosed as vasculitis

PURPOSE OF REVIEW

A vasculitic pattern of injury seen on brain biopsy can be attributed to a multitude of primary or secondary disorders, leading to diagnostic challenges for clinicians.

RECENT FINDINGS

This report describes the clinical presentation and histopathologic findings in 2 patients who initially received a diagnosis of primary CNS vasculitis, but did not show long-term response to treatment. In both cases, a second biopsy was performed, and the final diagnosis was primary CNS lymphoma (PCNSL).

SUMMARY

Analyzing diagnostically challenging cases can increase recognition of PCNSL and improve outcomes in this rare condition.

Primary Angiitis of the Central Nervous System Mimicking Glioblastoma: A Case Report and Literature Review

Primary angiitis of the central nervous system (PACNS) is a rare disorder resulting in idiopathic inflammation affecting the parenchymal and leptomeningeal vessels confined to the central nervous system (CNS), of which a tumor-like mass lesion is an even rare subtype. We described a case of PACNS initially misdiagnosed as glioblastoma. The patient was a 35 year-old female with right-sided weakness and expressive dysphasia. Brain MRI showed a tumor-like lesion highly suggestive of glioblastoma, therefor surgical removal was done. After a resection and an exhaustive workup, PACNS was ultimately diagnosed. The case illustrates a type of imaging presentation of PACNS that is often misdiagnosed as high-grade glioma. Differentiation between tumor-like PACNS lesions and actual CNS tumors is challenging due to similar MR images. To avoid unnecessary surgical interventions, we summarized previously reported mass-forming PACNS cases in adults from January 1, 2000, to December 31, 2018 and the imaging characteristics of PACNS. Some less commonly used diagnostic methods such as MR spectroscopy may also help clinicians distinguish PACNS from its mimics.

The diagnosis of primary central nervous system vasculitis

The diagnosis of primary central nervous system (CNS) vasculitis is often difficult. There are neither specific clinical features nor a classical clinical course, and no blood or imaging investigations that can confirm the diagnosis. Contrast catheter cerebral angiography is neither specific nor sensitive, yet still underpins the diagnosis in many published studies. Here we describe an approach to its diagnosis, emphasising the importance of obtaining tissue, and present for discussion a new, binary set of diagnostic criteria, dividing cases into only ‘definite’ primary CNS vasculitis, where tissue proof is available, and ‘possible,’ where it is not. We hope that these criteria will be modified and improved by discussion among experts, and that these (improved) criteria may then be adopted and used as the basis for future prospective studies of the clinical features and diagnosis of this difficult and dangerous disorder, particularly for coordinated multicentre therapeutic trials.

Ataxia as the main manifestation of tumor-like primary angiitis of the central nervous system: a case report and literature review

BACKGROUND

Primary angiitis of the central nervous system (PACNS) is a rare disease, and tumor-like primary angiitis of the central nervous system is even rarer. Histopathology is the gold standard for tumor-mimicking PACNS. However, pathological diagnosis is relatively limited due to fewer biopsy opportunities.

CASE PRESENTATION

A 68-year-old male presented with ataxia, and was diagnosed with tumor-like primary angiitis of the central nervous system. The patient underwent Intravenous drip glucocorticoid therapy (10 mg of dexamethasone, daily). After 10 days, the symptoms of the patient were completely relieved. Radiology revealed that the low density lesion in the right cerebellar hemisphere obviously narrowed. Cyclophosphamide therapy was not initiated.

CONCLUSION

It is crucial for clinicians to be aware of changes in radiology that indicate PACNS, since the diagnosis of tumor-like PACNS remains quite challenging. Glucocorticoid therapy is an effective therapy in this condition, and the prognosis can be favorable.

Diagnostic Impact of Intracranial Vessel Wall MRI in 205 Patients with Ischemic Stroke or TIA

BACKGROUND AND PURPOSE

Secondary prevention of ischemic stroke depends on determining the cause of the initial ischemic event, but standard investigations often fail to identify a cause or identify multiple potential causes. The purpose of this study was to characterize the impact of intracranial vessel wall MR imaging on the etiologic classification of ischemic stroke.

MATERIALS AND METHODS

This was a single-center, retrospective study of 205 consecutive patients who were referred for vessel wall MR imaging to clarify the etiology of an ischemic stroke or TIA. An expert panel classified stroke etiology before and after incorporating vessel wall MR imaging results using a modified Trial of Org 10172 in Acute Stroke Treatment system. We measured the proportion of patients with an altered etiologic classification after vessel wall MR imaging.

RESULTS

The median age was 56 years (interquartile range = 44-67 years), and 51% (106/205) of patients were men. Vessel wall MR imaging altered the etiologic classification in 55% (112/205) of patients. The proportion of patients classified as having intracranial arteriopathy not otherwise specified decreased from 31% to 4% (64/205 versus 9/205; P < .001) and the proportion classified as having intracranial atherosclerotic disease increased from 23% to 57% (48/205 versus 116/205; P < .001). Conventional work-up classification as intracranial arteriopathy not otherwise specified was an independent predictor of vessel wall MR imaging impact (OR = 8.9; 95% CI, 3.0-27.2). The time between symptom onset and vessel wall MR imaging was not a predictor of impact.

CONCLUSIONS

When vessel wall MR imaging is performed to clarify the etiology of a stroke or TIA, it frequently alters the etiologic classification. This is important because the etiologic classification is the basis for therapeutic decision-making.

Vasculitis on brain angiography is not always vasculitis: intravascular large B-cell lymphoma mimicking central nervous system vasculitis

A 68-year-old man, with a history of non-Hodgkin's lymphoma in remission, was admitted for homonymous hemianopsia, headaches and subacute progressive cognitive decline. Imaging revealed brain infarcts and angiography suggested vasculitis. A brain biopsy, however, revealed an intravascular large B-cell lymphoma (IVLBL). Central nervous system (CNS) vasculitis and IVLBL of the brain are extremely rare diseases that can have an almost identical clinical presentation. Angiographic findings are very similar but usually are reported as compatible with vasculitis. Brain biopsy or a random skin biopsy are crucial in diagnosing IVLBL as the accuracy of angiographic findings for CNS vasculitis is low.

A Closer Look at Angiitis of the central nervous system

Angiitis of the central nervous system (ACNS) is a rather new disease entity that is defined as vascular inflammation limited to the central nervous system and was formally nominated in 1959. Etiologically, it can be divided into primary and secondary ACNS. However, the potential pathogenesis of ACNS remains unclear. The clinical presentation is variable, and there is no consensus concerning its diagnosis and management. Although the incidence is relatively low, ACNS is still a life-threatening condition. It is essential to get a comprehensive and updated understanding of the disease. In this paper, we reviewed the history, definition, classification, pathogenesis, and clinical manifestations of ACNS. In addition, we focused on the latest investigations and viewpoints regarding the diagnosis and treatment of ACNS.

Diagnosis and Treatment of Primary Central Nervous System Angiitis

PURPOSE OF REVIEW

Primary central nervous system angiitis (PCNSA) is a rare disease. Varying clinical pictures coupled with lack of sensitive and specific diagnostic tests lead to challenges in management of these patients. This unfortunately may lead to both under- or over-diagnosis and unnecessary treatment. It is important to recognize the different conditions that may mimic the clinical and radiologic presentation. We present a contemporary literature review that should update physicians who encounter this patient population.

RECENT FINDINGS

Recent additions to the literature in form of case reports and single-center series show that digital subtraction angiography was the most widely used test to diagnose PCNSA. It is also important to note that brain biopsy is still considered "gold standard" and should be pursued as it not only has information that establishes the diagnosis but also may help in ruling out the diagnosis from mimics. In around 39% of suspected cases, an alternate diagnosis was eventually confirmed highlighting the importance of a comprehensive work-up. For treatment, almost all the literature supports the use of glucocorticoids as the initial treatment and if the patient has a relapse or develops steroid toxicity then the second most commonly used agent was cyclophosphamide. There are increasing reports of benefits with other agents such as methotrexate, azathioprine, mycophenolate, infliximab, and etanercept. The diagnosis and management of PCNSA continues to be a challenge. Formation of prospective patient registries with continued immunologic research for novel targets and immunomodulatory modalities may hold promise for future care of these patients.

Cerebrospinal fluid humoral immunity in the differential diagnosis of multiple sclerosis

BACKGROUND

The diagnostic accuracy of cerebrospinal fluid oligoclonal bands (CSF-OCB) detected by isoelectric focusing (IEF) in patients with multiple sclerosis (MS) was evaluated in our study.

METHODS

Three hundred and twenty-one patients with MS and other central nervous system (CNS) immune mediated disorders were assessed (CIMD). Cerebrospinal fluid and matched serum samples were examined for the presence of OCB by IEF-IB (isoelectric focusing with immunoblotting).

RESULTS

Isolated oligoclonal bands (ISO-OCB) were the only predictor of MS diagnosis independent of age, gender and CSF-OCB. ISO-OCB ≥ 3.5 detected by IEF yielded a sensitivity of 98% and specificity of 87% in distinguishing MS from MS mimickers.

CONCLUSIONS

For the neurologist, a score of ≥ 4 ISO-OCB supports the diagnosis of MS. On the other hand, ISO-OCB ≤3 favors CIMD. Further studies with larger population samples are warranted to confirm these findings.

Variation of a Persistent Primitive Hypoglossal Artery (PPHA) as Incidental Finding in the Diagnostic Clarification of Cerebral Vasculopathy Associated with Intracranial Vasculitis

We present a very rare variation of a persistent primitive hypoglossal artery (PPHA) arising from the internal carotid artery, detected during a diagnostic angiography. A 50-year-old female patient was admitted with an atypical intracranial hematoma in the left frontal lobe. Catheter angiography revealed intracranial vasculopathy with segmental stenoses, a small aneurysm of the right internal carotid artery bifurcation and a "string of beads" appearance of the left carotid artery, consistent with fibromuscular disease. On the left side, a vertebral artery ending in the posterior inferior cerebellar artery (PICA) was detected, whereas on the right side the vertebral artery was aplastic. During selective angiography of the right common carotid artery, a persistent hypoglossal artery was seen supplying the basilar artery. The literature of persistent embryonal carotid-vertebrobasilar anastomosis and their anatomical variations is discussed with respect to clinical importance for ischemia, interventional procedures, and surgery.

Diagnostic Value of Positron Emission Tomography Combined with Computed Tomography for Evaluating Critically Ill Neurological Patients

Purpose

¹⁸F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is a promising new tool for the identification of inflammatory, infectious, and neoplastic foci. The aim of our work was to evaluate the diagnostic value of FDG-PET/CT in patients treated on a neurological/neurosurgical ICU or stroke unit.

Methods

We performed a single-center, 10-year, retrospective evaluation of the value of FDG-PET/CT in critically ill adult patients with severe neurological disease.

Results

42 patients underwent FDG-PET/CT. Of these, 15 were ventilated and 10 were under vasopressor support. We identified four indications for performing FDG-PET/CT: (1) excluding a paraneoplastic etiology in an otherwise unexplained encephalitis, encephalopathy or neuropathy, (2) detecting a large-vessel vasculitis in patients with ischemic stroke, (3) detecting an infectious focus in sepsis, and less frequently (4) evaluating cerebral metabolism. In 22 patients who were evaluated for an unknown malignancy, 5 scans revealed either a previously unknown tumor or unknown metastases of a previously treated malignancy. Of 11 patients investigated for large-vessel vasculitis, 2 showed an inflammation of arteries supplying the brain. Of six sepsis cases, FDG-PET/CT identified an infectious focus in four.

Summary

We found FDG-PET/CT to be a helpful tool in critically ill neurological patients. The results of the FDG-PET/CT had direct therapeutic consequences in the 12 true-positive cases. In 24 of the 29 negative cases, FDG-PET/CT helped exclude alternative diagnoses and/or influenced therapy. Our findings demonstrate the feasibility and diagnostic benefit of FDG-PET/CT in this group of patients.