Outcome of chronic idiopathic meningitis

Diagnostic and therapeutic approach to chronic meningitis in Brazil: a narrative review

BACKGROUND

Chronic meningitis (CM) is characterized by neurological symptoms associated with the evidence of cerebrospinal fluid pleocytosis lasting > 4 weeks. Studies on the management of CM in Brazil are scarce.

OBJECTIVE

To critically review the literature on CM and propose a rational approach in the Brazilian scenario.

METHODS

Narrative literature review discussing the epidemiology, clinical evaluation, basic and advanced diagnostic testing, and empirical and targeted therapy for the most relevant causes of CM. The present review was contextualized with the local experience of the authors. In addition, we propose an algorithm for the management of CM in Brazil.

RESULTS

In Brazil, tuberculosis and cryptococcosis are endemic and should always be considered in CM patients. In addition to these diseases, neurosyphilis and other endemic conditions should be included in the differential diagnosis, including neurocysticercosis, Baggio-Yoshinari syndrome, and endemic mycosis. After infectious etiologies, meningeal carcinomatosis and autoimmune diseases should be considered. Unbiased and targeted methods should be used based on availability and clinical and epidemiological data.

CONCLUSION

We propose a rational approach to CM in Brazil, considering the epidemiological scenario, systematizing the etiological investigation, and evaluating the timely use of empirical therapies.

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

Evaluation of the epidemiologic, clinical, radiologic, and treatment methods of patients with subacute and chronic meningitis

Background

Meningitis is known as a meningeal inflammation accompanied by pleocytosis in the cerebrospinal fluid (CSF), and can be classified into acute, subacute, and chronic meningitis based on symptoms duration of ≤ 5 days, ≥ 5 days and ≥ 4 weeks, respectively. Subacute and chronic meningitis are caused mainly by indolent infectious agents and noninfectious causes such as autoimmune, and neoplastic. In this study, we investigated the characteristics, diagnosis, and treatment of subacute and chronic meningitis.

Methods

We extracted the medical records of patients with chronic and subacute meningitis who were referred to three tertiary centers from Jun 2011 to Jun 2021. Initially, 2050 cases of meningitis were screened, and then 79 patients were included in the study.

Results

Headache (87.3%), nausea and vomiting (74.7%), fever (56.4%), and visual impairments (55.7%) were the most prevalent symptoms. The most common signs were nuchal rigidity (45.3%), altered mental status (26.9%), and papillary edema (37.5%). Brain computed tomography (CT) was normal in 68.6% of the patients while 22.9% of the cases had hydrocephalus. Brain magnetic resonance imaging (MRI) was normal in 60.0% of the patients. The most common abnormal MRI findings were leptomeningeal enhancement (16.0%) and hydrocephalus (16.0%). We had a 44.3% definite diagnosis with bacterial (n:25, 31.6%) and neoplastic (n:8, 10.1%) being the most prevalent etiologies. Mycobacterium tuberculosis (60%) and Brucella spp. (12%) were the most prevalent bacterial pathogens.

Conclusions

The most common etiologies include infectious, neoplastic, and immunologic. Due to insidious presentation and uncommon etiologies, establishing a proper diagnosis, and providing timely targeted treatment for patients with subacute and chronic meningitis remains a challenge for clinicians.

Chronic Meningitis

PURPOSE OF REVIEW

This article describes the clinical presentation, diagnostic approach (including the use of novel diagnostic platforms), and treatment of select infectious and noninfectious etiologies of chronic meningitis.

RECENT FINDINGS

Identification of the etiology of chronic meningitis remains challenging, with no cause identified in at least one-third of cases. Often, several serologic, CSF, and neuroimaging studies are indicated, although novel diagnostic platforms including metagenomic deep sequencing may hold promise for identifying organisms. Infectious etiologies are more common in those at risk for disseminated disease, specifically those who are immunocompromised because of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), transplantation, or immunosuppressant medications. An important step in identifying the etiology of chronic meningitis is assembling a multidisciplinary team of individuals, including those with specialized expertise in ophthalmology, dermatology, rheumatology, and infectious diseases, to provide guidance regarding diagnostic procedures.

SUMMARY

Chronic meningitis is defined as inflammation involving the meninges that lasts at least 4 weeks and is associated with a CSF pleocytosis. Chronic meningitis has numerous possible infectious and noninfectious etiologies, making it challenging to definitively diagnose patients. Therefore, a multifaceted approach that combines history, physical examination, neuroimaging, and laboratory analysis, including novel diagnostic platforms, is needed. This article focuses on key aspects of the evaluation of and approach to patients with chronic meningitis. Specific infectious etiologies and differential diagnoses of subacute and chronic meningitis, including noninfectious etiologies, are addressed.

Diagnostic Value and Safety of Brain Biopsy in Patients With Cryptogenic Neurological Disease: A Systematic Review and Meta-analysis of 831 Cases

BACKGROUND

The role of brain biopsy in patients with cryptogenic neurological disease is uncertain.

OBJECTIVE

To determine the risks and benefits of diagnostic brain biopsy for nonneoplastic indications in immunocompetent patients.

METHODS

Appropriate studies were identified by searching electronic databases.

RESULTS

We screened 3645 abstracts and included 20 studies with a total of 831 patients. Indications for biopsy were: (1a) severe neurological disease of unknown etiology in adults (n = 7) and (1b) in children (n = 2); (2) suspected primary angiitis of the central nervous system (PACNS) (n = 3); (3) chronic meningitis of unknown cause (n = 3); (4) atypical dementia (n = 4); and (5) nonneoplastic disease (n = 1). Diagnostic success rates calculated for subgroups were 51.3% (34.5-68.1) for 1a, 53.8% (42.9-64.5) for 1b, 74.7% (64.0-84.1) for 2, 30.3% (17.2-45.4) for 3, and 60.8% (41.2-78.8) for 4. Clinical impact rates were 30.5% (13.6-50.6) for 1a (n = 6), 67.1% (42.8-87.3) for 1b (n = 2), 8.3% (2.3-20.0) for 3 (n = 1), and 14.2% (6.5-24.3) for 4 (n = 2). Lymphoma (n = 32) and Creutzfeldt-Jakob disease (n = 30) were the most common diagnoses on the final histopathology reports of positive brain biopsies in 1a. In 1b, encephalitis (n = 7), PACNS (n = 6), and demyelination (n = 6) were the most common. The odds ratio for achieving a diagnostic biopsy when there was a radiological target was 3.70 (P = .014, 95% confidence interval, 1.31-10.42).

CONCLUSION

Brain biopsy in cryptogenic neurological disease was associated with the highest diagnostic yield in patients with suspected PACNS. The greatest clinical impact was seen in children with cryptogenic neurological disease. The presence of a radiological target was associated with a higher diagnostic yield.

Evaluation and treatment of chronic meningitis

Chronic meningitis is defined as an inflammatory cerebrospinal fluid (CSF) profile that persists for at least 1 month. The presentation often includes headache, nausea, vomiting, cranial neuropathies, symptoms of elevated intracranial pressure, or focal neurologic deficits. The most common etiologies of chronic meningitis fall into 3 broad categories: infectious, autoimmune, and neoplastic. Evaluation of the patient with suspected chronic meningitis should include a detailed history and physical examination as well as repeated CSF diagnostics, serologic studies, and biopsy of the brain or other abnormal tissue (eg, lymph node or lung), when indicated. Early identification of the etiology and rapid treatment are crucial for improving morbidity and mortality, but potential infectious and neoplastic conditions should be excluded prior to empirically starting steroids or immunosuppressive medications.

Open biopsy in patients with acute progressive neurologic decline and absence of mass lesion

OBJECTIVE

Patients with acute to subacute neurologic decline undergo a battery of imaging and laboratory tests to determine a diagnosis and treatment plan. Often, after an extensive evaluation, a brain biopsy is recommended as yet another tool to assist in determining the diagnosis. The goal of this retrospective cohort analysis is to measure the sensitivity of open brain biopsy in this patient population, compare these results with the preoperative presumed diagnosis, and evaluate if the biopsy result significantly alters treatment.

METHODS

The authors reviewed the medical records of 135 consecutive patients who underwent open brain biopsies for acute to subacute progressive neurologic decline between January 1999 and September 2008 at a single institution. All patients with mass lesions, with HIV/AIDS, and who were younger than 20 years of age were excluded from the study. Fifty-one patients met these criteria and all preoperative tests, imaging, and treatment plans were examined and compared with postbiopsy interventions to determine the impact of the biopsy on patient outcome.

RESULTS

The sensitivity of open brain biopsy at our institution was 35%. The most common preoperative presumed diagnosis was vasculitis and the most common postoperative finding was Creutzfeldt-Jakob disease, followed by amyloid angiopathy. Postbiopsy hemorrhage was a complication in 4% of patients. Treatment plans changed as a direct result of the biopsy in 8% of patients, and in only 4% did the biopsy findings make a difference in disease course.

CONCLUSION

In patients with progressive neurologic decline without a radiographic mass lesion or immunodeficiency, open brain biopsy often fails to provide a diagnosis and even more rarely does it significantly alter treatment.

Chronic meningitis

Chronic meningitis is a syndrome commonly defined by the presence of continuously persistent meningeal inflammation for at least 4 weeks. Presenting neurologic features are often nonspecific, and the list of differential diagnoses is broad. Despite the development of modern molecular diagnostic methods, establishing a specific cause may challenge the acumen of the treating neurologist with clues to the diagnosis residing outside the nervous system and requiring focused investigation. This review discusses selected etiologies illustrating issues in diagnosis and etiologic categories to be considered in the evaluation of this challenging syndrome.

[Chronic meningitis: aetiologies, diagnosis and treatment]

PURPOSE

Chronic meningitis are very uncommon and account for less than 10% of all meningitis cases. Their symptoms are uncunth and there outcome is insidious. Therefore, they remain often unknown. There are only a few published reports on this disease, so diagnosis and therapeutic approachs are difficult.

CURRENT KNOWLEDGE AND KEY POINTS

Positive chronic meningitis diagnosis is easy. However, determining the cause of chronic meningitis remains dilemma, as many infectious and noninfectious processes (including inflammatory, neoplastic or autoimmune aetiologies or as a result of a chemical exposure) can result in the chronic meningitis syndrome. In order to institute a pertinent treatment, sometimes urgently needed, diagnostic approach must be extremely rigourous and accutely orientated. Nevertheless, although extensive investigations, 30% of the aetiologies remain undetermined. Only two choices are left for the medical physician: an aggressive attitude based on complementary investigations or a contemplated therapy with a close clinical and biological control. On the other hand, when the patient's condition is quickly deterioring without a clear and proved aetiology, it is sometimes necessary to institute an empirical treatment, not always properly determined and sometimes contreversial. Besides, few reports on prognosis and outcome od idiopathic chronic meningitis have been published.

FUTURE PROSPECTS AND PROJECTS

After a review of aetiologies and diagnostic investigations chronic meningitis, we propose a practical experience attitude about management and treatment of chronic meningitis. Thus, large-scale studies about the follow up chronic meningitis in long term, in particular those without aetiology, treated or no, should improve the outcome of this chronic syndrome.

Chronic meningitis presenting with acute obstructive hydrocephalus

A previously healthy 24-year-old woman presented to the Emergency Department unresponsive with a Glasgow Coma Scale score of 4 and evidence of brainstem herniation. She was intubated and hyperventilated. Computed axial tomography scan of the brain demonstrated four-chamber hydrocephalus. Continued hyperventilation and mannitol diuresis were sufficient to arrest the impending herniation while emergent ventriculostomy was arranged. The patient recovered without sequelae and ultimately received a diagnosis of chronic idiopathic meningitis. This case highlights a rarely diagnosed disorder that presented with an acutely life threatening condition.

Chronic Meningitis

Treatment of chronic meningitis depends on the underlying cause. Once a specific cause has been established, appropriate targeted therapy is initiated. When the cause is unknown, a decision must be made whether to employ empiric therapy while the diagnostic evaluation is ongoing. This decision is based on three factors: 1) the clinical status of the patient; 2) the most likely cause based on demographic, historical, examination, and initial laboratory data; and 3) the risk-to-benefit ratio of the proposed treatment regimen. Initial efforts focus on deciding whether the meningitis is infectious or noninfectious. When a decision is made to start empiric therapy, antituberculous treatment is generally given for several weeks to judge therapeutic response. Patients who do not respond to antituberculous therapy are next treated with broad-spectrum antibiotics for unusual bacterial pathogens such as Actinomyces (penicillin), the Lyme disease spirochete Borrelia burgdorferi (ceftriaxone), Brucella (doxycycline plus rifampin), or Francisella tularensis (streptomycin plus gentamicin). Antifungal therapy is generally reserved for patients who are at particular risk for mycotic infection (owing to underlying immunosuppression or an extraneural infection site). Finally, empiric glucocorticoids are generally reserved for patients with consistently negative culture results and a probable noninfectious cause.

Overview of acute and chronic meningitis

Meningitis can be subdivided based on time course of onset and duration, cerebrospinal fluid (CSF) profile, and underlying origins into acute aseptic and septic meningitis, recurrent meningitis, and chronic meningitis. These are distinct syndromes that require different management strategies. Most cases of meningitis are caused by infection. The causal agent is generally predictable based on the type of meningitis, host factors, and clues from the history and examination. CSF examination remains the critical diagnostic test.

Idiopathic steroid responsive chronic lymphocytic meningitis--clinical features and long-term outcome in 17 patients

BACKGROUND

Some patients with chronic lymphocytic meningitis appear to respond to corticosteroid treatment, but investigations fail to identify the cause. The use of corticosteroids in patients with chronic meningitis is controversial and the long-term outcome is unclear.

AIM

To review the long-term outcome in 17 patients with the syndrome of idiopathic steroid responsive chronic lymphocytic meningitis.

METHODS

Review of patients' records and examination of surviving patients 1.5 to 17.5 years (median 8.8 years) after presentation.

RESULTS

The cause of the steroid responsive chronic meningitis was found during follow up in two of the 17 patients: Wegener's granulomatosis and multiple sclerosis in one patient each. A cause was not found in the other 15 patients. Seven of these patients eventually recovered and corticosteroids were withdrawn after six weeks to six years without a recurrence of symptoms. Four patients improved transiently, but died six months to 26 years after starting treatment; in two, steroids were withdrawn a few weeks before death. Four patients had active chronic meningitis and reduction in the dose of corticosteroids was associated with a recurrence of symptoms. Leptomeningeal and brain biopsy in eight patients showed non-specific abnormalities which were not helpful in the diagnosis.

CONCLUSIONS

A subgroup of patients with idiopathic chronic lymphocytic meningitis responds to corticosteroids. Leptomeningeal biopsy and long-term follow up seldom identify the underlying cause in these patients. Steroid treatment must be undertaken with caution, even after infective causes of chronic meningitis have been excluded.

A 67-year-old woman with polymyalgia rheumatica and left hemispatial neglect

A 67-year-old woman with a diagnosis of polymyalgia rheumatica presented initially with periods of confusion and incontinence. A CT scan of the brain was normal and she was treated with tapering doses of corticosteroids and clinical improvement. After a brief period off steroids, the patient presented with a progressive dementia, left-sided clumsiness, gait disturbances and left hemispatial neglect. An MRI at this time demonstrated a large area of edema over the right parietal lobe and intense cortical enhancement. A chest CT demonstrated multiple nodules. Biopsies of the lung and brain failed to identify any infectious organisms or malignant tissue. The leptomeningeal biopsy revealed multiple granulomatous areas with central necrosis and hystiocytic cells consistent with idiopathic hypertrophic pachy-meningitis.

Diagnostic yield of brain biopsy in neurodegenerative disorders

OBJECTIVE

The diagnostic yield and therapeutic implications of brain biopsy were determined in a series of 50 consecutive brain biopsies that were performed in 48 patients between 1990 and 1995 at The Johns Hopkins Hospital to assess progressive neurodegenerative disorders of unclear origin.

METHODS

Severely immunocompromised patients and patients undergoing biopsies for suspected neoplastic lesions were excluded from this analysis. Before surgery, the patients had undergone extensive laboratory and radiographic tests, including lumbar puncture (all 48 patients), electroencephalography (26 of 48 patients), magnetic resonance imaging (all 48 patients), and angiography (17 of 48 patients). Despite the results of these studies, diagnoses could not be established, and thus, brain biopsies were undertaken.

RESULTS

Only 10 of the 50 biopsies (44 open procedures and 6 stereotactic procedures) led to diagnoses, resulting in a diagnostic yield of 20%. An additional three biopsies (6%) were only suggestive of diagnoses. The results of 33 biopsies (66%) were abnormal but nonspecific, and the results of 4 (8%) were normal. Minor complications associated with biopsy occurred in five cases (10%), and there were no deaths. Of the 10 patients whose biopsies were diagnostic, only 4 underwent meaningful therapeutic intervention as a result of the procedure, resulting in an overall therapeutic benefit in only 8% of all the cases. An analysis of patient subgroups to elucidate a correlation with diagnostic biopsy revealed that patients with focal magnetic resonance imaging findings had the highest likelihood of a diagnostic biopsy (odds ratio, 4.00). Electroencephalography and laboratory abnormalities were not predictive of a diagnostic biopsy.

CONCLUSION

We conclude that the current diagnostic yield (20%) of brain biopsy for progressive neurodegenerative disorders is lower than that of earlier reports and that the therapeutic benefits of the procedure are limited.