Meningismus

Meningismus, also known as meningism, refers to a set of signs and symptoms that mimic meningitis but are not caused by inflammation of the meninges, the membranes surrounding the brain and spinal cord. The hallmark symptom is nuchal rigidity, or stiffness of the neck, which makes it difficult or painful to flex the neck forward. Other signs can include headache, photophobia (sensitivity to light), and fever.

This condition is typically a reactive phenomenon to an underlying illness that is not infectious in nature. Common causes include dehydration, especially in infants and young children, where fluid loss can lead to meningeal irritation. Electrolyte imbalances, such as hyponatremia (low sodium levels), can also trigger meningismus. Certain gastrointestinal infections, even without direct meningeal involvement, can sometimes present with these symptoms. Additionally, severe pain from other sources, like significant muscle strain or even certain types of headaches, can on occasion manifest as meningeal signs.

Diagnosis relies on ruling out true meningitis. This often involves a thorough medical history and physical examination, paying close attention to the absence of other signs of infection like altered mental status or focal neurological deficits. Laboratory tests may be performed to assess hydration status, electrolyte levels, and rule out infection. If meningitis is suspected, a lumbar puncture (spinal tap) would be performed to analyze cerebrospinal fluid. Treatment for meningismus focuses on addressing the underlying cause, such as rehydration for dehydration or correcting electrolyte imbalances.