Meningitis in children

Classification principles

The disease is notable for the diversity of its forms. For an accurate diagnosis, meningitis is divided into groups according to several key criteria:

1. By the nature of the exudate: inflammation of the meninges can be purulent or serous.
2. By clinical course: acute, subacute, and chronic variants of the disease development are distinguished.
3. By origin:
4. Primary meningitis develops immediately as an independent nosological entity.
5. Secondary meningitis develops as a severe complication against the background of an already existing primary inflammatory focus in the body. The risk of such a scenario directly depends on the patient's premorbid background.
6. By etiology: the disease is polyetiological. A wide variety of agents can act as triggers: viruses, bacteria, fungi, or protozoa.

Topographic classification of nervous tissue lesions

The inflammatory process is far from always limited only to the meninges. Depending on which specific structures of the central nervous system are involved, the following specific forms are distinguished:

• Leukoencephalitis: the pathology affects exclusively the white matter of the brain (i.e., neural pathways and nerve fibers are damaged).
• Polioencephalitis: the grey matter of the brain (directly the neuronal cell bodies) is affected in isolation.
• Poliomyelitis: inflammation is localized in the grey matter (neuronal cells) of the spinal cord.
• Panencephalitis: a severe total lesion in which both white and grey matter are involved in the pathological process.
• Meningoencephalitis: combined inflammation encompassing both the meninges themselves and the brain parenchyma.

Clinical presentation: syndromic approach

In pediatric practice, the clinical presentation of meningitis is based on a triad of basic syndromes. This triad is always present, regardless of which specific microorganism caused the inflammation.

The classical triad includes:

1. Infectious syndrome (also known as infectious toxicosis syndrome).
2. Cerebral syndrome.
3. Meningeal syndrome.

The key link at the initial stage is the infectious syndrome. It manifests with prominent signs of systemic intoxication and autonomic nervous system dysfunction.

It is characterized by:

• Severe fever (persistent elevation of body temperature).
• Pathological changes in the emotional background and the central nervous system as a whole. The child may develop either severe psychomotor agitation or deep depression of consciousness.
• Autonomic disruptions: tachycardia (pathological acceleration of the heart rate), tachypnea (rapid breathing), marked pallor of the skin, and anorexia (complete refusal to eat).

Class and exam questions

What else to study on this topic

• Detailed characteristics of cerebral syndrome in meningitis
• Specific symptoms of meningeal syndrome in children
• The influence of the premorbid background on the risk of developing secondary meningitis
• Differential diagnosis of purulent and serous exudate

Other topics from the section «Chapter 12. Infectious and parasitic diseases»

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.