Cerebral angiography of bacterial infection

Headaches and Vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability making this a disorder of paramount importance to all clinicians. Headache may be an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. Primary neurologic vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible.

Cerebral perfusion using ASL in patients with COVID-19 and neurological manifestations: A retrospective multicenter observational study

BACKGROUND AND PURPOSE

Cerebral hypoperfusion has been reported in patients with COVID-19 and neurological manifestations in small cohorts. We aimed to systematically assess changes in cerebral perfusion in a cohort of 59 of these patients, with or without abnormalities on morphological MRI sequences.

METHODS

Patients with biologically-confirmed COVID-19 and neurological manifestations undergoing a brain MRI with technically adequate arterial spin labeling (ASL) perfusion were included in this retrospective multicenter study. ASL maps were jointly reviewed by two readers blinded to clinical data. They assessed abnormal perfusion in four regions of interest in each brain hemisphere: frontal lobe, parietal lobe, posterior temporal lobe, and temporal pole extended to the amygdalo-hippocampal complex.

RESULTS

Fifty-nine patients (44 men (75%), mean age 61.2 years) were included. Most patients had a severe COVID-19, 57 (97%) needed oxygen therapy and 43 (73%) were hospitalized in intensive care unit at the time of MRI. Morphological brain MRI was abnormal in 44 (75%) patients. ASL perfusion was abnormal in 53 (90%) patients, and particularly in all patients with normal morphological MRI. Hypoperfusion occurred in 48 (81%) patients, mostly in temporal poles (52 (44%)) and frontal lobes (40 (34%)). Hyperperfusion occurred in 9 (15%) patients and was closely associated with post-contrast FLAIR leptomeningeal enhancement (100% [66.4%-100%] of hyperperfusion with enhancement versus 28.6% [16.6%-43.2%] without, p = 0.002). Studied clinical parameters (especially sedation) and other morphological MRI anomalies had no significant impact on perfusion anomalies.

CONCLUSION

Brain ASL perfusion showed hypoperfusion in more than 80% of patients with severe COVID-19, with or without visible lesion on conventional MRI abnormalities.

Parainfectious cerebral vasculopathy complicating bacterial meningitis: Acute-short lived vasospasm followed by delayed-long lasting vasculitis

Bacterial meningitis is a serious, life-threatening infection of the meninges. Several radiological studies highlight prominent structural alterations occurring in the cerebral vasculature, leading to significant cerebrovascular consequences during bacterial meningitis. Beginning with reflexive arterial vasospasm , cerebrovascular disease during bacterial meningitis proceeds through a orderly sequence of arterial vasculitis with inflammatory cell infiltration, medial smooth muscle migration and proliferation, medial necrosis, adventitial fibrosis and eventual intimal stenosis. As such, this review focuses on changes occurring within cerebral arteries during disease progression, highlighting the various structural modifications occurring in the arterial vessels that contribute to disturbances in cerebral hemodynamics and, ultimately, cerebrovascular consequences during bacterial meningitis.

Vasculitis related to viral and other microbial agents

Vasculitis due to infection may occur as a consequence of the inflammation of vessel walls due to direct or contiguous infection, type II or immune complex-mediated reaction, cell-mediated hypersensitivity, or inflammation due to immune dysregulation triggered by bacterial toxin and/or superantigen production. As immunosuppressive therapy administered in the absence of antimicrobial therapy may increase morbidity and fail to effect the resolution of infection-associated vascular inflammation, it is important to consider infectious entities as potential inciting factors in vasculitis syndromes. The causality between infection and vasculitis has been established in hepatitis B-associated polyarteritis nodosa (HBV-PAN) and hepatitis C-associated (cryoglobulinemic) vasculitis (HCV-CV). The review summarizes the recent literature on the pathophysiological mechanisms and the approaches to the management of HBV-PAN and HCV-CV. Roles of other viral and microbial infections, which either manifest as vasculitic syndromes or are implicated in the pathogenesis of primary vasculitides, are also discussed.

Headaches and vasculitis

Vasculitis is a spectrum of clinicopathologic disorders defined by inflammation of arteries of veins of varying caliber with variable tissue injury. Headache may be an important clue to vasculitic involvement of central nervous system (CNS) vessels. CNS vasculitis may be primary, in which only intracranial vessels are involved in the inflammatory process, or secondary to another known disorder with overlapping systemic involvement. A suspicion of vasculitis based on the history, clinical examination, or laboratory studies warrants prompt evaluation and treatment to forestall progression and avert cerebral ischemia or infarction.

Percutaneous transluminal angioplasty in a patient with vasospasm due to staphylococcal meningitis

Arterial large vessel vasculopathy is an unusual complication of bacterial meningitis in adults that may result in cerebral ischemia and severe neurological sequelae. Previous therapy has included antimicrobials with no specific vascular interventions. The authors report their experience with a patient with bacterial meningitis who developed a vasculopathy with neurological deficits. Percutaneous intracranial intervention was used successfully with anatomical and functional improvement.

Emergent neuroimaging of intracranial infection/inflammation

Infectious and inflammatory processes of the intracranial compartment often result in acute clinical presentations. The possible causes are legion. Clues to the diagnosis involve clinical presentation, laboratory analysis, and neuroimaging. This article reviews some of the salient factors in understanding intracranial infection/ inflammation, including pathophysiology and neuroimaging protocols/findings, and provides some examples and a few "pearls and pitfalls."

Inflammation and cerebral vasospasm after subarachnoid hemorrhage

Morbidity and mortality of patients with aneurysmal subarachnoid hemorrhage (aSAH) is significantly related to the development of chronic cerebral vasospasm. Despite extensive clinical and experimental research, the pathophysiology of the events that result in delayed arterial spasm is not fully understood. A review of the published literature on cerebral vasospasm that included but was not limited to all PubMed citations from 1951 to the present was performed. The findings suggest that leukocyte-endothelial cell interactions play a significant role in the pathophysiology of cerebral vasospasm and explain the clinical variability and time course of the disease. Experimental therapeutic targeting of the inflammatory response when timed correctly can prevent vasospasm, and supplementation of endothelial relaxation by nitric oxide-related therapies and other approaches could result in reversal of the arterial narrowing and improved outcomes in patients with aSAH.

Role of inflammation (leukocyte-endothelial cell interactions) in vasospasm after subarachnoid hemorrhage

BACKGROUND

Delayed vasospasm is the leading cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). This phenomenon was first described more than 50 years ago, but only recently has the role of inflammation in this condition become better understood.

METHODS

The literature was reviewed for studies on delayed vasospasm and inflammation.

RESULTS

There is increasing evidence that inflammation and, more specifically, leukocyte-endothelial cell interactions play a critical role in the pathogenesis of vasospasm after aSAH, as well as in other conditions including meningitis and traumatic brain injury. Although earlier clinical observations and indirect experimental evidence suggested an association between inflammation and chronic vasospasm, recently direct molecular evidence demonstrates the central role of leukocyte-endothelial cell interactions in the development of chronic vasospasm. This evidence shows in both clinical and experimental studies that cell adhesion molecules (CAMs) are up-regulated in the perivasospasm period. Moreover, the use of monoclonal antibodies against these CAMs, as well as drugs that decrease the expression of CAMs, decreases vasospasm in experimental studies. It also appears that certain individuals are genetically predisposed to a severe inflammatory response after aSAH based on their haptoglobin genotype, which in turn predisposes them to develop clinically symptomatic vasospasm.

CONCLUSION

Based on this evidence, leukocyte-endothelial cell interactions appear to be the root cause of chronic vasospasm. This hypothesis predicts many surprising features of vasospasm and explains apparently unrelated phenomena observed in aSAH patients. Therapies aimed at preventing inflammation may prevent and/or reverse arterial narrowing in patients with aSAH and result in improved outcomes.

Clinical and laboratory characteristics of cerebral infarction in tuberculous meningitis: a comparative study

Cerebral infarction as a complication of tubercular (TB) meningitis is not uncommon, but an adequate comparison of patients with and without stroke has not been carried out. This study was performed to evaluate the clinical characteristics of cerebral infarction secondary to TB meningitis, and to investigate predictive factors for cerebral infarction in patients with TB meningitis. Patients with TB meningitis were recruited over a period of 56 months. They were divided into two groups, those with and those without stroke. Demographic features and clinical, laboratory, and neuroradiological findings were compared between the two groups. We classified strokes into subtypes using neuroimaging findings. Of the 38 patients who were diagnosed with TB meningitis, eight also experienced cerebral infarction. The percentage of cerebrospinal fluid leukocytes that were neutrophils was significantly higher in patients with stroke (68%) than in patients without stroke (31%; p=0.0001). Upon initial CT imaging, meningeal enhancement was found in 11 patients, and of these patients, six experienced stroke. There were no significant differences between the groups with respect to other clinical and laboratory features, including demographic features, time between meningitis onset and treatment initiation, peripheral white blood cell count, and cerebrospinal fluid findings. Five of the eight patients who developed stroke had lacunar infarcts. One of the three patients with territorial nonlacunar infarction died due to herniation. When treating patients with TB meningitis, the possibility of cerebral infarction should be considered when patients develop focal neurological signs, meningeal enhancement on a CT scan, and sustained polymorphic cerebrospinal fluid pleocytosis.

Cerebral vasospasm in shunt infection

OBJECTIVE

In bacterial shunt infection, CNS inflammation is a frequently observed complication that may cause vascular complications including vasospasms. Here, we describe the first patient with shunt infection-induced cerebral vasospasms.

METHODS

A 35 year old woman with a ventriculoperitoneal shunt that was implanted years before developed facial nerve palsy and somnolence one week before admission to the hospital.

RESULTS

After admission, the shunt was removed, and an external ventricular drainage was inserted. Microbiological analyses revealed coagulase-negative Staphylococcus on abdominal and cranial catheters. Follow-up NMR showed infarctions. Transcranial doppler sonography and cerebral arteriography revealed severe generalized cerebral vasospasms. Inspite of triple-H therapy and intraarterial spasmolysis, bilateral anterior and media artery infarction evolved. The patient was dismissed in a vegetative state.

CONCLUSIONS

This case shows that severe cerebral vasospasms are a serious complication in patients with bacterial shunt infection that should be considered in patients, that don't improve following adequate antibiotic treatment.

Leukocyte-endothelial cell interactions in chronic vasospasm after subarachnoid hemorrhage

Leukocyte-endothelial cell interactions appear to be the root cause of chronic vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). Early clinical observations and indirect experimental evidence suggested an association between inflammation and chronic vasospasm. Early clinical observations in patients with post-hemorrhagic vasospasm included pyrexia, leukocytosis and the presence of circulating immune complexes. Inflammatory infiltrates and increased levels of immunoglobulins and complement fractions within spastic cerebral arteries also provided early evidence for an inflammatory mechanism underlying chronic vasospasm. Early indirect experimental evidence included the ability to reproduce chronic vasospasm with the introduction of inflammatory agents into the subarachnoid space and the inhibition of vasospasm with anti-inflammatory agents. Currently, however, there is an increasing body of direct molecular evidence that demonstrates the pivotal role of leukocyte-endothelial cell interactions in the development of chronic vasospasm. Cell adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1) and endothelial (E)-selectin mediate interactions between circulating leukocytes and cerebral endothelium. Following aSAH, ICAM-1 is up-regulated in cerebral endothelial cells and along with other cell adhesion molecules, can be detected in the serum and cerebrospinal fluid (CSF) of patients with post-hemorrhagic vasospasm. Monoclonal antibody blocking experiments have demonstrated that the prevention of leukocyte extravasation into the subarachnoid space prevents chronic vasospasm. Similarly, drugs like ibuprofen, which prevent ICAM-1 up-regulation and transendothelial cell migration of leukocytes, prevent vasospasm. In this review, we highlight early observations that suggested an association between inflammation and post-hemorrhagic vasospasm, detail the role of leukocyte-endothelial cell interactions in the development of chronic vasospasm and discuss therapeutic implications of an inflammatory etiology of post-hemorrhagic cerebral vasospasm.

DELAYED CEREBRAL VASOSPASM SECONDARY TO BACTERIAL MENINGITIS AFTER LUMBOSACRAL SPINAL SURGERY

OBJECTIVE

Delayed cerebral vasospasm is an under-recognized complication of meningitis. This case report is important because it is the first to definitively associate vasospasm with meningitis using catheter angiography. Furthermore, it is the first to correlate the time course of delayed cerebral vasospasm with meningitis.

CLINICAL PRESENTATION

We present a patient who developed a partial expressive aphasia 9 days after developing meningitis, consistent with cerebral vasospasm, after lumbosacral spinal surgery.

INTERVENTION

Vasospasm was confirmed by angiography and transcranial Doppler sonography, and symptoms responded to hypervolemia, hypertension, and hemodilution therapy.

CONCLUSION

If a patient develops neurological symptoms consistent with a timeline of delayed cerebral vasospasm in the setting of meningitis, angiographic evaluation and appropriate therapy should be pursued.

Supra- and Infratentorial Subdural Empyema Secondary to Septicemia in a Patient With Liver Abscess-Case Report-

An 81-year-old man presented with subdural empyema in the left parietotemporal convexity 2 months after treatment under diagnoses of liver abscess and septicemia. Systemic investigation found no evidence of otorhinological or other focal infection except for liver abscess. Emergency drainage of pus was performed via a single burr hole and additional intravenous antibiotics were administered. Six weeks later, magnetic resonance imaging revealed subdural empyema in the right cerebellopontine angle in addition to recurrence of pus in the left parietotemporal subdural space. Ischemic changes were also shown in the right cerebellar hemisphere and brainstem. Although subdural empyema secondary to septicemia is rare, the possibility of this type of intracranial infection must be kept in mind, especially in compromised patients with septicemia.

Cerebral blood flow velocity and perfusion in purulent meningitis: a comparative TCD and 99M-TC-HMPAO-SPECT study

In 15 patients (median age 33 years; range 17-74 years) suffering from acute pneumococcal (10 cases) and meningococcal (five cases) meningitis, cerebral blood flow velocity (CBFV) was measured in the M1 - segment of the middle cerebral artery (MCA) by transcranial Doppler sonography, and cerebral perfusion changes were evaluated by 99m-Tc-hexamethylpropylene amine oxime single photon emission computed tomography (HMPAO SPECT). The objective of the study was to test whether increased CBFV during the acute phase of purulent meningitis reflects hyperemia, and to evaluate focal perfusion abnormalities and their correlation to CBFV changes. In eight patients with marked side-differences in CBFVs during the acute phase of the disease SPECT scans were normal in five. In three patients unilateral perfusion defects correlated with the side of higher CBFV. In seven patients presenting with symmetrically elevated CBFV, SPECT scans were normal in four and revealed focal abnormalities in the remaining three. Follow up SPECT scans were normal in 14/15 patients. The results of our study suggest that elevated CBFV in acute bacterial meningitis does not reflect cerebral hyperemia. Focal cerebral perfusion defects occur independently from functional alterations in the cerebral macrovasculature. A causative pathophysiologic relationship of high CBFV and focal perfusion defects cannot be drawn from these data.

Serial transcranial Doppler study in meningitis

Serial transcranial doppler studies were carried out in 12 patients, who developed meningitis during their hospital stay. Blood flow velocities in large basal vessels of the anterior circle of Willis were correlated with CSF pleocytosis and CSF sugar values. Mean blood flow velocities were found to be directly proportional to the CSF white blood cell (WBC) count and were inversely proportional to the CSF sugar values. Blood flow velocities were higher when CSF WBC count was raised. With only one exception these velocities decreased progressively with a fall in the CSF WBC count. At the time of meningitis there occurred a reduction in CSF sugar values and the blood flow velocities were significantly higher. With increase in CSF sugar values there occurred a gradual fall in the blood flow velocities.

Abnormalities of cerebral blood flow in the acute phase of bacterial meningitis in adults

The frequency, course and clinical significance of changes in regional cerebral blood flow (rCBF) during bacterial meningitis were investigated in 14 adult patients. The results of 99mTc-hexamethylpropylene amine oxime (HMPAO) single photon emission computed tomography (SPECT) were compared with the clinical signs and findings using cerebral angiography and conventional CT. HMPAO SPECT was performed 2-15 days (median 4.5 days) after the onset of neurological disease. Decreased HMPAO accumulation was detected in 13 patients. SPECT studies revealed focal hypoperfusion corresponding to the clinical symptoms in 6 patients suffering from hemiparesis or hemiataxia. Conventional cranial CT disclosed brain infarction in only 1 patient. Focal hypoperfusion was also found in 7 of 8 patients without clinical evidence of focal neurological deficits. In 6 patients, HMPAO SPECT findings were abnormal although cerebral angiography was normal. At follow-up examinations 3-45 weeks after the acute disease, abnormalities revealed by HMPAO SPECT had improved or had even disappeared in all patients studied. Our results indicate that reduced rCBF is a frequent finding in bacterial meningitis in the adult. In most patients it probably represents a functional and reversible disorder without structural lesion detectable on CT.

Dynamic CT of micro- and macroangiopathic states of the cerebrum

Dynamic computed tomography utilizing intravenous contrast agents affords a unique opportunity to evaluate pathologic vascular states of the cerebrum in cross-section with an imaging system which is more contrast-sensitive than either conventional film-screen or digital subtraction angiography. Dynamic scanning therefore routinely allows the non-invasive detection of pathologic vascularity in-vivo in lesions that could previously only be detected reliably primarily with in-vitro techniques. The first section of this two part report examines the microscopic vascularity observed in active demyelination, inflammatory states, trauma, infarction and other forms of acquired cerebral disease. In the second section, the ability of intravenous dynamic cranial computed tomography to detect macroscopic pathologic vascularity is reviewed. The diagnostic principles of conventional angiography apply in this technique except that the lesion is viewed in cross-section, rather than in-toto with all structures superimposed. The method therefore yields a true tomographic angiogram. Abnormal vascular states associated with malignancies, vascular malformations, aneurysms, and vascular occlusions are simply evaluated and correlate precisely with the aberrant vascular patterns revealed angiographically.

Angiographic changes in a case of herpes simplex encephalitis

A case of herpes encephalitis predominating in the right temporal lobe with unusual angiographic changes is reported. Carotid angiography revealed a right temporal mass with vascular blush and early venous filling through irregular veins. Early venous filling and vascular blush have been known for a long time with cerebral inflammatory disease, but venous drainage through irregular veins is unusual.

Treatment of mycotic intracranial aneurysms

Two patients with mycotic intracranial aneurysms were successfully treated with only antibiotic therapy. One patient, who had subacute bacterial endocarditis, rheumatic valvular disease, and an abscessed tooth, sustained a subarachnoid hemorrhage from a ruptured right middle cerebral artery trifurcation aneurysm. The other patient, who had Turner's syndrome and probable congenital aortic stenosis, developed multiple neurological findings during an ipisode of acute bacterial endocarditis precipitated by an infected ingrown toenail; a false aneurysm of the distal left middle cerebral artery and two lesions involving the left superior cerebellar artery were found. A study of the literature shows that only 45 patients with mycotic intracranial aneurysms have received adequate antibiotic therapy and angiographic documentation. Statistically, there does not appear to be a clear-cut advantage to antibiotic plus surgical therpy over antibiotic alone. In fact, in 21 patients who underwent serial angiography, lesions were smaller in six and not visualized in 11. In four patients the aneurysms increased in size; in two others fresh lesions formed. The author proposes the following diagnostic and therapeutic regimen: 1) earliest possible diagnosis of the underlying disorder; 2) appropriate antibiotic therapy; 3) early four-vessel cerebral angiography and follow-up studies every 2 to 3 weeks; study; 5) definitive operation upon completion of antibiotic therapy if the lesion is larger or the same size; and 6) postoperative angiography to evaluate the effectiveness of treatment and to search for interim lesions.

Angiographic findings with an intracranial gumma

The case of a syphilitic gumma in the cerebellopontine angle is reported. The angiographic appearance of neurosyphilis is similar to that of cerebral inflammatory processes of all varieties. The hypervascularity of the blush shown on angiography is due to hyperemia surrounding the focal necrosis. Vasoconstriction and dilatation may be seen with meningovascular syphilis and gummata. This case showed a focal hypervascularized lesion unlike the avascular lesions described in the textbooks.

Tuberculose meningo-encefalica na infância: estudo anatomo-patologico de 10 casos

Estudo anátomo-patológico de 10 casos de tuberculose do SNC em crianças, com idade inferior a 10 anos. São enfatizadas as alterações macro e microscópicas produzidas pela tuberculose nas meninges, parênquima nervoso e vasos. Os achados clínicos e patológicos são discutidos e correlacionados com a literatura. Os autores concluem que: 1) a lesão, em crianças com tuberculose do SNC, é geralmente uma meningoencefalite proliferativa; 2) o parênquima nervoso pode ser afetado por propagação contígua do processo tuberculoso ou por alterações circulatórias secundárias a lesões arteriais; 3) por causa da localização dos vasos endocranianos no espaço sub-aracnóideo, eles são geralmente lesados pelo processo inflamatório, que determina uma endarterite obliterante, a qual pode ser observada por angiografia carotídea.

Central nervous system tuberculosis: a persistent disease

✓ The authors report their experience with four recent cases of tuberculosis affecting the central nervous system (CNS), including tuberculous meningitis and tuberculomas of both the cerebrum and the cerebellum. They emphasize that antituberculous drugs have given the neurosurgeon a role of increased importance and effectiveness in the management of CNS tuberculosis. Shunts, radical excisions, and fusion have new significance. Angiography and brain scans may reveal operable lesions. The authors believe that CNS tuberculosis should always include triple therapy with INH, PAS, and streptomycin plus corticosteroids to control cerebral edema and help to minimize basilar adhesions and hydrocephalus in tuberculous meningitis.