How does encephalitis manifest after a tick bite? - briefly
Severe headache, high fever, neck stiffness, altered consciousness, seizures, and focal neurological deficits are typical signs of encephalitis following a tick bite. These manifestations usually emerge days to weeks after exposure, often together with a rash or flu‑like symptoms.
How does encephalitis manifest after a tick bite? - in detail
Tick‑borne encephalitis develops after the bite of an infected Ixodes tick. The virus enters the bloodstream during the feeding period, and after an incubation of 7‑14 days systemic symptoms appear. Early signs often include sudden fever, malaise and a sore throat. Within a few days, the disease may progress to a neurological phase characterized by meningeal irritation and cerebral inflammation.
Typical neurological manifestations are:
- Severe headache, often described as “pressing” or “throbbing”.
- Neck stiffness and photophobia indicating meningeal involvement.
- Altered mental status ranging from confusion to stupor.
- Focal neurological deficits such as weakness, dysarthria or visual field loss.
- Seizures, both generalized and focal, occurring in up to one‑third of patients.
- Ataxia and gait instability reflecting cerebellar involvement.
- Tremor, myoclonus or dystonia as movement‑disorder presentations.
- Cranial nerve palsies, most frequently affecting the facial nerve.
Laboratory findings support the clinical picture. Cerebrospinal fluid analysis shows pleocytosis with a lymphocytic predominance, elevated protein and normal or slightly reduced glucose. Magnetic resonance imaging may reveal hyperintense lesions in the basal ganglia, thalamus or cerebellum, consistent with inflammatory edema.
The disease course can be biphasic. After an initial febrile period, a symptom‑free interval may precede the neurological phase. Recovery varies; many patients improve within weeks, yet up to 30 % experience persistent deficits such as chronic fatigue, memory impairment or motor dysfunction. Early diagnosis and supportive care, including antipyretics, antiviral agents where indicated and seizure control, reduce morbidity and improve outcomes.