How do encephalitis symptoms manifest in humans after a tick bite? - briefly
After a tick bite, viral encephalitis usually starts with fever, headache, and neck stiffness, then progresses to confusion, seizures, or loss of consciousness. Additional signs may include photophobia, vomiting, and focal neurological deficits such as weakness or speech impairment.
How do encephalitis symptoms manifest in humans after a tick bite? - in detail
Tick bites that transmit the TBE virus initiate an incubation period of 7‑14 days, after which patients enter a prodromal stage. Early signs include abrupt fever (≥38.5 °C), intense headache, muscle aches, fatigue, and nausea. These systemic manifestations often precede neurological involvement by 1‑3 days.
The subsequent neurological phase presents with a spectrum of central‑nervous‑system symptoms:
- Meningeal irritation – neck stiffness, photophobia, and positive Kernig/Brudzinski signs.
- Encephalitic features – confusion, disorientation, impaired concentration, and agitation.
- Cerebellar dysfunction – ataxia, dysmetria, and gait instability.
- Cranial nerve deficits – facial palsy, diplopia, or hearing loss.
- Motor disturbances – generalized weakness, tremor, or focal paralysis.
- Seizure activity – focal or generalized tonic‑clonic seizures, sometimes progressing to status epilepticus.
- Autonomic instability – irregular heart rate, blood pressure fluctuations, and sweating abnormalities.
In severe cases, the disease may evolve into a prolonged convalescent stage marked by persistent cognitive deficits, chronic fatigue, and residual motor impairment. Laboratory testing typically reveals lymphocytic pleocytosis in cerebrospinal fluid, elevated protein, and specific IgM antibodies against the virus.
Rapid identification of these clinical patterns after a tick exposure is essential for timely antiviral therapy, supportive care, and prevention of long‑term neurologic sequelae.