How to recognize encephalitis after a tick bite? - briefly
Watch for rapid onset of fever, intense headache, neck rigidity, confusion, or seizures within weeks of a tick bite; these neurological symptoms indicate possible encephalitis and require urgent medical assessment.
How to recognize encephalitis after a tick bite? - in detail
Tick bites can transmit the virus that causes tick‑borne encephalitis (TBE). Early detection relies on recognizing a specific pattern of symptoms that evolves from the initial bite to neurological involvement.
Within 7‑14 days after exposure, many patients experience a nonspecific febrile illness: high temperature, malaise, headache, and muscle aches. These signs often mimic other viral infections, making clinical suspicion essential when a recent tick attachment is confirmed.
The second phase, when the central nervous system becomes involved, presents distinct neurological features:
- Severe headache that does not respond to analgesics
- Neck stiffness or photophobia suggesting meningeal irritation
- Confusion, disorientation, or altered consciousness
- Focal neurological deficits such as weakness, ataxia, or cranial nerve palsy
- Seizures, particularly in severe cases
- Tremor, dysarthria, or abnormal movements indicating basal ganglia involvement
Laboratory evaluation should include:
- Cerebrospinal fluid (CSF) analysis: elevated white‑cell count with lymphocytic predominance, increased protein, normal or slightly reduced glucose
- Serology: detection of specific IgM and IgG antibodies against TBE virus in serum or CSF
- Polymerase chain reaction (PCR) when available, to identify viral RNA in CSF
Imaging studies, primarily magnetic resonance imaging (MRI), may reveal hyperintense lesions in the thalamus, basal ganglia, cerebellum, or brainstem, supporting the diagnosis.
Prompt medical attention is warranted if any of the neurological signs appear after a tick bite, especially when accompanied by fever. Early antiviral supportive care and close monitoring reduce the risk of permanent deficits. Vaccination remains the most effective preventive measure for individuals in endemic regions.