Brain abscess

A brain abscess is a localised infection inside the brain in which micro-organisms — most commonly bacteria — form a pus-filled cavity encapsulated within its own membranous wall. The expanding abscess raises intracranial pressure and can cause severe neurological damage if not treated urgently.

**Routes of infection:** 1. Spread from an infection elsewhere in the body (most common) — including chronic middle ear or sinus infections, dental or jaw infections, face or scalp infections 2. Blood-borne spread from the lungs or chest 3. Direct entry through an open head wound, skull fracture, or neurosurgical procedure

**Risk factors include:** congenital heart disease, meningitis, shunt infections, chronic ear/sinus disease, head trauma, and immunocompromised states.

**Symptoms differ by age:**

*Infants and young children:* fever, bulging fontanelle (soft spot on top of the head), unusual sleepiness or reduced alertness, increased irritability, high-pitched cry, poor feeding, projectile vomiting, seizures.

*Older children and adults:* fever, severe headache, nausea and vomiting, personality or behaviour changes, speech changes, difficulty walking, limb spasticity, seizures.

**Treatment** must begin immediately upon diagnosis: - Hospitalisation with close neurological monitoring - High-dose intravenous antibiotics (or antifungals, depending on organism) - Surgical drainage — aspiration or excision of the abscess to reduce intracranial pressure and obtain samples for culture - Anticonvulsants and steroids as needed - Ventilatory support in severe cases

After the acute phase resolves, rehabilitation is often needed to recover function lost during the illness.