What is meningitis?

From the Guidelines

Meningitis is a serious and potentially life-threatening infection of the meninges, the protective layers around the brain and spinal cord, characterized by symptoms such as fever, headache, neck stiffness, and altered consciousness. The clinical features of meningitis can vary depending on the age of the patient and the causative agent, but common symptoms include fever, vomiting, headache, and neck stiffness 1. In adults, the "classic triad" of neck stiffness, fever, and altered consciousness is present in less than 50% of cases, and other symptoms such as seizures, focal neurological symptoms, and a reduced conscious level may also occur 1. Some key points to consider when diagnosing meningitis include:

• The clinical features are often not clear-cut, and concern from healthcare providers is necessary to ensure prompt diagnosis and treatment 1
• Age can be an indicator of the likely causative agent, with Listeria or pneumococcal disease more common in older people, and meningococcal infection more common in adolescents and young adults 1
• A rash may be present in some cases of meningitis, particularly those caused by Neisseria meningitidis, but its absence does not rule out the diagnosis 1
• Kernig's and Brudzinski's signs are not helpful in the clinical diagnosis of suspected meningitis due to their low sensitivity 1 In children, the symptoms of bacterial meningitis can be more subtle and atypical, particularly in younger infants, and may include fever, chills, vomiting, photophobia, and severe headache 1. It is essential to consider meningitis in the differential diagnosis of any patient presenting with symptoms such as fever, headache, and neck stiffness, and to perform further testing, such as lumbar puncture and imaging, to confirm the diagnosis and guide treatment.

From the Research

Definition and Symptoms of Meningitis

• Meningitis is a serious infection that causes inflammation of the meninges, the protective membranes surrounding the brain and spinal cord 2, 3, 4, 5.
• The symptoms of meningitis include neck stiffness, fever, vomiting, photophobia, positive Kernig and Brudzinski's sign, and lethargy 2, 3, 4, 5.
• Neck stiffness is the most important sign of meningitis, caused by the stretching of inflamed nerve roots and meninges in the cervical region 2.

Clinical Examination and Diagnosis

• The clinical examination is crucial in diagnosing meningitis, with the absence of fever, neck stiffness, and altered mental status effectively eliminating meningitis 5.
• The presence of jolt accentuation of headache is a useful adjunctive maneuver in diagnosing meningitis, with a sensitivity of 100% and specificity of 54% 5.
• Kernig sign and Brudzinski sign are classic signs of meningeal irritation, but their accuracy in diagnosing meningitis has been inadequately studied 2, 5.

Types and Complications of Meningitis

• Meningococcal meningitis is a devastating disease that can cause severe neurologic sequelae if not diagnosed early and treated appropriately 4.
• Waterhouse-Friderichsen Syndrome is a rare and feared complication of severe meningococcal disease, carrying a high mortality rate of 20% 4.
• Aseptic meningitis associated with leptomeningeal enhancement may be an atypical phenotype of MOG-EM, a type of inflammatory demyelinating disease 3.