Kembara Xtra - Medicine - Viral Meningitis

Kembara Xtra - Medicine - Viral Meningitis 
A clinical condition in which there is a fever and signs or symptoms of acute meningeal inflammation (such as headache, photophobia, stiff neck, and/or nausea/vomiting, among others) The most frequent cause of aseptic (nonbacterial) meningitis is viral meningitis (VM).
Nervous system(s) affected

Epidemiology 
Incidence - Peaks from summer to fall in temperate areas (but is present year-round in subtropical or tropical climates) - Estimated 75,000 VM cases caused by enterovirus annually in the United States - Viral meningitis is most commonly caused by non-polio enteroviruses.


Pathophysiology and Etiology 
VM is a rare side effect of an acute viral infection such gastroenteritis, mumps, HSV, VZV, and arthropod-borne viruses in immunocompetent hosts.
- Case reports in the literature suggest that SARS-CoV-2 can occasionally result in VM. CMV and EBV are examples of viral pathogens that may exist in immunocompromised hosts.
Non-polio human enteroviruses are the root cause of between 23-61% of VM cases. The fecal-oral pathway is frequently used to spread these viruses.
West Nile, Zika, chikungunya, dengue, St. Louis encephalitis virus, and Eastern horse encephalitis virus are among the viruses spread by mosquitoes. The Powassan virus, Colorado tick fever virus, and tickborne encephalitis virus are all transmitted by ticks.
HSV-2 is typically linked to recurrent benign lymphocytic (Mollaret) meningitis (80% of cases).
Genetics
no identifiable

Risk Elements 

Close associates of VM patients may contract the main viral illness but are less likely to develop VM themselves.
Age (most prevalent in children under the age of 5): Severe disease is more likely to affect infants under the age of one month.
 Immunocompromised host, which makes patients more vulnerable to CMV, HSV, and EBV Aspects of Geriatrics
The most prevalent causes of VM in the elderly are VZV and HSV; other diagnoses to be taken into account include malignancy and medication-induced aseptic meningitis.

Prevention 

 Use proper hand washing and hygiene techniques.
 Refrain from sharing food, drink, and utensils with others, especially the sick.
 Recommend wearing suitable clothing, DEET, and mosquito nets if you must be outside to avoid being bitten by mosquitoes and ticks.


Accompanying Conditions 
Meningoencephalitis, myopericarditis, neonatal enteroviral sepsis, flaccid paralysis, and encephalitis

History: Acute onset (within hours to days) of the following adult symptoms is the most common. - Fever (incidence varies by virus; enterovirus: 65-83%; mumps: 54-98%; HSV: 6-52%);
- A headache, a key early sign.
- Photophobia (mostly associated with enterovirus in 79–85% of cases, 33-64% with HSV, and 7% with mumps) 
- Myalgias/arthralgias (88 percent enterovirus, 50 percent HSV, and 14 to 21 percent mumps)- Vomiting and nausea, fatigue
- Nuchal stiffness (55–69% for enterovirus, 22%–71% with HSV, and 8–85% for mumps).Alterations in mental state, seizures, or focal neurologic impairments should make other diagnoses a priority.
Infants are more likely to experience nonspecific symptoms, such as poor feeding, vomiting, lethargy, fever, and irritability.
 Further historical details:
- Historical travel and outdoor pursuits
- Sexual history, including HSV and HIV
- Immunocompromised host, including HIV (CMV, HSV, adenovirus) and solid organ transplant - Previous VZV infection
- Immunization history (VZV, influenza, and mumps)

clinical assessment 

 Fever, tachycardia, tachypnea, and hypotension are the vital signs.Neurologic: Absence of changes in mental status (if any, seek alternate diagnoses) - A fear of light
Meningeal symptoms
Nuchal stiffness
In patients with meningitis, the Brudzinski sign (neck flexion causes involuntary hip and knee flexion in the supine patient) and the Kernig sign (resistance to knee extension following hip flexion to 90 degrees) are only marginally responsive (5%).Jolt accentuation test: quick horizontal head rotation emphasizes headache (poor sensitivity and specificity, uncertain value in meningitis diagnosis).- West Nile virus infection results in asymmetric flaccid paralysis.
HEENT: Parotitis (in cases of measles infection)
- Coxsackievirus A-related Herpangina
- Bulging fontanelle in young children
Dermatology: - Vesicular rash of hand, foot, and mouth disease (coxsackievirus) - Generalized lymphadenopathy (EBV, HIV)
The presence of a palpable petechial or purpuric rash should raise the possibility of bacterial meningitis. Abdomen: - Splenomegaly (in EBV).
- Stomach ache


Multiple Diagnoses 

Meningitis due to bacteria (BM)
 Fungal meningitis (avoid in immunocompromised individuals; agents include Coccidioides and Cryptococcus neoformans)
Other contagious diseases include amebiasis, ehrlichiosis, leptospirosis, syphilis, TB, and lyme disease.
Infections of the parameninges, such as subdural empyema Leukemia, lymphoma, or another neoplastic condition (including metastasis) Leukemia, lymphoma, or other viral syndrome
Acute metabolic encephalopathy; migraine/tension headache; postoperative aseptic meningitis; drug-induced (chemical) meningitis (NSAIDs, TMP/SMX, amoxicillin, TNF-inhibitors, lamotrigine, IVIG, and monoclonal antibodies); brain/epidural abscess; and inflammatory diseases (such as Behçet's disease, sarcoidosis, and SLE).

Initial tests for a laboratory investigation (lab, imaging)

 Blood cultures, procalcitonin/C-reactive protein, CBC, BMP, and serum laboratories - Normal or slightly increased WBC on CBC
- BMP: Plasma and CSF glucose levels should be compared.
- Procalcitonin/C-reactive protein: Should be normal in VM (when serum PCT is high in adults, investigate bacterial meningitis) - Blood cultures: in VM, they should be negative
Lumbar puncture: - LP is the primary diagnostic method for determining if a patient has VM or BM.
In the event that bacterial meningitis is suspected, start empiric antibiotics very away. Consider using a clinical decision-making tool that has been proven effective, such as the Bacterial Meningitis Score (BMS), when determining a child's risk of bacterial meningitis.
- Risks and contraindications:
 Signs or symptoms of elevated intracranial pressure (focal neurologic findings, papilledema, altered mental status, new-onset seizures), impaired cellular immunity, local infection over a potential LP site, suspected epidural abscess, use of anticoagulants or a possible coagulopathy, and the potential for cardiorespiratory compromise as a result of the positioning of the patient during the procedure If there is clinical concern for elevated intracranial pressure, consider CT.
The hazards of the procedure include bleeding, infection, discomfort, cerebral herniation, and post-LP headache.
- CSF evaluation
 Normal opening pressure should be present.
 Cell differential/count:
Lymphocyte predominance (in early infection, PMN predominance may occur) RBCs suggest traumatic tap but may be found in HSV meningitis/encephalitis CSF glucose: typically normal (may have moderate drop in mumps or HIV) 100-1,000 WBC/L (may be higher in enteroviral meningitis)
CSF lactate is normal. If it is elevated >4.2 mmol/L, it is highly suggestive of bacterial meningitis. If it is elevated, the differential diagnosis also includes TB, seizures, hemorrhage, and ischemia. Lactate levels are less reliable if antibiotics have been started prior to LP. The gold standard for bacterial meningitis diagnosis is CSF culture, which should be negative for bacterial pathogens in VM. PCR/NAAT (4)[C]: - Becoming more widespread as sensitivity/specificity levels improve
Utilizable for the quick detection of numerous potential diseases (bacteria, viruses, and fungi), subject to institutional availabilityCSF IgM antibodies for arboviruses; sensitivity for infections varies by test; may allow early termination of empiric therapy 

Tests in the Future & Special Considerations
maladies that could change lab results:
Diabetes: Take current blood sugar levels into account as a possible indicator of CSF glucose levels.
 Neurologic conditions (such as demyelinating illness, an intracranial tumor, or a history of a stroke or transient ischemic attack)

Management consists of supportive therapy (such as pain relief and intravenous fluids) as well as low-threshold empiric antibiotics for BM pending test results. 


First Line of Medicine

 Analgesics and antipyretics (Adult doses are given; increase doses as needed for pain relief.) - Acetaminophen (Tylenol) 500 to 1,000 mg PO every eight hours; 325 to 650 mg PR every four hours (maximum 3 g/24 hours) - Naproxen 550 mg PO BID - Ibuprofen 400 to 800 mg PO every eight hours
- If pain is unbearable, think about taking short-term opioids.
Antiemetics: Promethazine (Phenergan) 12.5 to 25 mg PO/PR/IM/IV q4-6h; Ondansetron (Zofran) 4 to 8 mg IV every eight hours (maximum dose: 50 mg/24 hours to reduce side effects). Antiviral medications (1), (3)[C]
- Empiric administration of acyclovir at a dose of 10 mg/kg IV every eight hours (adult dose) to patients with CSF pleocytosis, negative Gram stain results, and suspicion of HSV while awaiting the results of conclusive (such as HSV or VZV PCR) testing HSV meningitis in immunocompetent patients improves with or without antiviral medication and can be managed with only supportive care.
Antibiotics (directed at the most likely pathogen) are not recommended for the treatment of VM.
- Reasonable empiric treatment that excludes BM.
Start the subsequent blood cultures and, if possible, LP.
Remember to take into account patients who are elderly, have had antibiotics previously, are ill-appearing, or are immunocompromised.
 If there is a very low chance of BM, treat symptoms and monitor patients in an inpatient environment while awaiting test results.
 Corticosteroids: Not advised in VM (advised as an adjuvant therapy in BM)


Referral 

An urgent referral to neurosurgery is necessary for patients with known CSF shunts or drains, recent neurosurgery or trauma, or intrathecal pumps in the case of potential VM or BM.


Admission 
Initial inpatient care may involve the following: - Pain management and empirical treatments (waiting lab findings)
- intravenous fluids (depending on clinical presentation and hydration state)
- Neurologic surveillance for altered mental state, fever, stiff neck, and headache Discharge is dependent on clinical factors (dehydration, emesis, pain control, functional level, social conditions, and ability to follow up), including contact restrictions and private room until BM is ruled out. In stable patients, VM can be managed outside of the hospital.


Close follow-up is necessary to make sure that all symptoms have disappeared. - A small percentage of adult patients develop cognitive morbidities after VM, with the severity of the handicap depending on the virus that caused it.
 Developmental monitoring following VM in children because illness consequences in children are more likely to be severe.
Monitoring the patient to look out for relapses or symptoms getting worse.
 Keep an eye out for neurological issues: - Seizures, mental changes, and newly developed weakness
- Examine the patient's ability to have a companion track changes in their mental or neurological condition after discharge.

Diet 
Move liquids. eat in moderation
Discuss the extremely low likelihood of transmission to close contacts with the patient. Promote cleaning your hands.
Over the course of two to three weeks, headache, myalgia, and weakening recurrence are probable.


Prognosis: Most patients recover within 7 to 10 days, but in a few, quality of life may not return to normal for months, and headaches and other neurologic symptoms may sporadically last for weeks to months.
Very young children and some adults experience long-term cognitive deficits as a result of VM, despite the condition's low mortality rate.

Complications include: muscle weakness, impatience, and exhaustion; rare complications include cognitive issues and developmental delay.

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