Isolated small-vessel angiitis of the central nervous system

Central nervous system vasculitis in the intensive care unit

Intensivists are sometimes faced with unexplained neurologic defects in ICU patients. A subacute presentation over weeks or months characterized by headache and mental status change with focal deficits in the absence of evidence of secondary vasculitis or other diseases mentioned in the differential diagnosis should arouse suspicion of PACNS. Delay in diagnosis of this rare condition may lead to additional morbidity and prolong ICU stay. There is also a risk of permanent cognitive dysfunction with untreated PACNS. A reactive CSF picture, ischemic changes on MR imaging, and alterations in vessel caliber on cerebral angiography are not diagnostic but strengthen the evidence for PACNS. A brain biopsy may be required to confirm the diagnosis. High-dose steroid therapy with a prolonged course and gradual taper controls the disease in most cases. Additional immunosuppressive therapy is needed in some patients.

Reliability of normal findings on MR imaging for excluding the diagnosis of vasculitis of the central nervous system

OBJECTIVE

We attempt to determine whether angiography is indicated in patients with suspected central nervous system (CNS) vasculitis who present with negative findings on MR imaging studies.

CONCLUSION

MR imaging findings may be negative in the setting of CNS vasculitis confirmed on angiography, indicating that advanced imaging techniques tailored to detect infarction (i.e., fluid-attenuated inversion recovery, diffusion-weighted, and perfusion imaging) may be necessary to enhance the sensitivity of an MR study and that despite the high sensitivity of MR imaging for CNS vasculitis, angiography may still be required to render an accurate diagnosis.

[Angiitis of the central nervous system in systemic diseases]

PURPOSE

This review is aimed at presenting classification and diagnosis criteria of isolated central nervous system (CNS) angiitis, and at proposing guidelines for diagnosis and management of this disease.

CURRENT KNOWLEDGE AND KEY POINTS

Isolated CNS angiitis are rare and most information has been provided by studies of very small series. Angiitis can be primitive or secondary to infectious, neoplastic diseases, or toxics. Clinical manifestations and radiologic abnormalities are not specific. A brain biopsy is therefore often required to confirm the diagnosis, as numerous non-inflammatory vascular diseases can mimic both clinically and radiologically isolated CNS angiitis.

PERSPECTIVES AND PROJECTS

To help guide the diagnosis and therapeutical management of patients with CNS angiitis, strict classification criteria should be used: 1) rule out the various diseases that can mimic clinical and radiological CNS aspects related to isolated angiitis and differentiate "isolated CNS angiitis" from "CNS angiitis associated with systemic diseases"; 2) search for factors associated with the development of a "secondary CNS angiitis"; 3) check presumed mechanism at the origin of the cerebral vascular disease: "angiitis" versus "angiopathy"; 4) if the diagnosis of "primary CNS angiitis" is still suspected, it seems reasonable to perform cerebral and leptomeningeal biopsies. Treatment is still unknown and has to be discussed on a case by case basis according to the severity and progression of symptoms.

Pathogen-free granulomatous diseases of the central nervous system

Pathogen-free granulomatous diseases (PFGD) of the central nervous system (CNS) are a group of disorders with protean clinical and pathological findings. Failure to identify a causative organism leads to considerable diagnostic difficulty. The neuropathology records between 1985 and 1995 were retrospectively reviewed, and the medical records of all patients in whom a diagnosis of PFGD of the CNS was made were retrieved. Patients in whom an infective agent was shown either by culture, special staining techniques, or by immunohistochemical methods were excluded. We identified 11 patients (eight male, three female) who fulfilled the pathological criteria for this condition. Average age at diagnosis was 38.7 years (range, 17 to 78). Neurological symptoms were the presenting feature in nine patients. Neuroimaging findings included hydrocephalus (54.5%), meningeal enhancement (45.5%), and mass lesions (45.5%). Seven patients had antemortem CNS biopsies (brain/meninges [n = 6], spinal [n = 1]), which showed noncaseating granulomas. Eight patients died (mortality rate: 72.7%). Postmortem examination showed granulomatous involvement of the leptomeninges and cerebral parenchyma in all cases with systemic involvement in 50%, chiefly in the form of noncaseating granulomas of the hilar nodes. Six patients fulfilled the clinical, radiological, and pathological diagnostic criteria for neurosarcoidosis. The remaining five patients had an unclassifiable pathogen-free granulomatous disease of the CNS. PFGD of the CNS are associated with a poor prognosis. Although neurosarcoidosis may account for some of the cases, there remains an unclassifiable subgroup that continues to be a diagnostic and management challenge.

Isolated angiitis of central nervous system with pleocytosis in the cerebrospinal fluid

We report the case of a 32-year-old woman with isolated angiitis of the central nervous system. This case shows that high levels of pleocytosis may not rule out isolated angiitis of the central nervous system if this diagnosis can be considered on clinical grounds.

Primary angiitis of the central nervous system: report of two cases and review of the literature

Two cases of primary angiitis of the central nervous system with subarachnoid hemorrhage are reported. One patient was admitted with very thin and localized sulcal subarachnoid hemorrhage, followed by the development of multiple parenchymal edema. Although the first angiography showed only a mild narrowing of an artery, the second angiography demonstrated multiple segmental narrowings of arteries. An open biopsy failed to show histological changes. The second patient suffered from sylvian subarachnoid hemorrhage along with multiple intracerebral hemorrhages, with angiography that was diagnostic for angiitis. In both cases, predonine was initiated and further angiography clearly demonstrated a resolution of the angiitis. The usefulness of serial angiography for diagnosis in comparison with surgical biopsy and for monitoring the treatment of this disease is discussed. The occurrence of subarachnoid hemorrhage in this disease is also reviewed.

Cerebrospinal fluid and therapy of isolated angiitis of the central nervous system

BACKGROUND

Serial cerebral angiograms, computed tomography, and magnetic resonance imaging are among the proposed methods for monitoring disease activity and response to therapy in isolated angiitis of the central nervous system. Cerebrospinal fluid has not proved to be useful in monitoring clinical course.

CASE DESCRIPTION

We describe a 45-year-old man with histological diagnosis of isolated angiitis of the central nervous system that was treated with prednisone plus azathioprine and monitored for 2 years. Samples of the cerebrospinal fluid were obtained for cytological and routine chemical examination, as well as albumin and immunoglobulin content. Before treatment, cerebrospinal fluid showed marked plasmatic transudation of albumin and intrathecal synthesis of immunoglobulins. During the first year of immunosuppression no events were noticed, and the previously abnormal aspects of the cerebrospinal fluid showed improvement. During the weaning of azathioprine, a new stroke occurred in conjunction with a marked deterioration of cerebrospinal fluid parameters. Immunosuppression was resumed at previous levels, and during the following year no further events occurred. Once again, abnormal cerebrospinal fluid values improved significantly.

CONCLUSIONS

We report a case of isolated angiitis of the central nervous system in which the serial cerebrospinal fluid examinations (albumin and immunoglobulin content) showed a close correlation with clinical course. This method may be useful in monitoring response to therapy.

Clinical recognition of granulomatous angiitis of the brain. Novel magnetic resonance image

Granulomatous angiitis of the brain is a rare form of vasculitis affecting small and medium-size blood vessels. The most common initial symptoms include headache and confusion after age 45. The cerebrospinal fluid is almost always abnormal with lymphocytic pleocytosis and protein content over 100 micrograms/dl. Diagnosis may be supported by contrast-enhanced magnetic resonance imaging findings of a hypointense granuloma surrounding a hyperintense blood vessel. Described herein is a previously unrecorded magnetic resonance image in an autopsied case of granulomatous angiitis of the brain.