How do symptoms of encephalitis tick appear after a bite? - briefly
Symptoms usually develop 1–3 weeks after the bite, starting with fever, headache, and fatigue and advancing to confusion, neck stiffness, seizures, or other neurological deficits. Early signs such as altered mental status or focal weakness may appear quickly, requiring prompt medical assessment.
How do symptoms of encephalitis tick appear after a bite? - in detail
Tick‑borne encephalitis (TBE) typically follows a bite from an infected Ixodes tick. After an incubation period of 7–14 days, patients enter a prodromal phase marked by nonspecific signs such as fever, headache, malaise, myalgia, and gastrointestinal upset. These symptoms often resemble a viral flu and may last 1–5 days before neurological involvement begins.
The second phase presents with central nervous system disturbance. Common manifestations include:
- Severe, persistent headache, often described as frontal or occipital.
- High fever that may exceed 39 °C.
- Neck stiffness and photophobia, indicating meningeal irritation.
- Cognitive deficits: confusion, disorientation, difficulty concentrating.
- Motor abnormalities: weakness, ataxia, tremor, or loss of coordination.
- Sensory disturbances: paresthesia, numbness, or dysesthesia.
- Cranial nerve involvement: facial palsy, double vision, or hearing loss.
- Seizures, which can be focal or generalized.
- Altered consciousness ranging from lethargy to coma in fulminant cases.
Laboratory findings typically reveal pleocytosis in cerebrospinal fluid, elevated protein, and sometimes a modest increase in lymphocytes. Serologic testing shows rising IgM and IgG titers against TBE virus. Magnetic resonance imaging may demonstrate hyperintense lesions in the thalamus, basal ganglia, or brainstem.
Early recognition of these clinical patterns is essential for supportive care, as no specific antiviral therapy exists. Monitoring respiratory function, managing intracranial pressure, and preventing secondary infections improve outcomes. Recovery may be incomplete; residual neurological deficits such as chronic fatigue, gait disturbance, or memory impairment occur in a proportion of survivors.