How do symptoms of an encephalitis tick appear? - briefly
Typical early signs are fever, headache, and malaise, followed by neurological manifestations such as confusion, neck stiffness, seizures, and occasionally paralysis.
How do symptoms of an encephalitis tick appear? - in detail
Tick‑borne encephalitis (TBE) manifests in two distinct phases after an infected bite. The incubation period ranges from 7 to 14 days, after which the first phase presents with systemic, flu‑like signs. Common manifestations include sudden fever, intense headache, muscle aches, and malaise. Nausea, vomiting, and abdominal discomfort may accompany these symptoms. Some patients develop a rash at the bite site, though this is not universal.
After a brief remission lasting from a few days up to a week, the second phase begins, characterized by neurological involvement. Typical central nervous system signs are:
- High fever persisting beyond the initial phase
- Severe, persistent headache, often described as frontal or occipital
- Neck stiffness and photophobia, indicating meningeal irritation
- Altered mental status ranging from confusion and disorientation to lethargy
- Cognitive deficits such as impaired concentration and short‑term memory loss
- Motor abnormalities, including tremor, ataxia, and loss of coordination
- Cranial nerve dysfunction, most frequently facial nerve palsy, leading to unilateral facial weakness
- Seizures, which may be focal or generalized, especially in severe cases
- Sensory disturbances, such as paresthesia or hypoesthesia in limbs
In pediatric patients, the disease may present with irritability, vomiting, and a higher propensity for seizures. Elderly individuals often exhibit a more subdued febrile response but experience rapid progression to encephalitic symptoms.
Laboratory findings support clinical diagnosis. Cerebrospinal fluid analysis typically shows pleocytosis with a predominance of lymphocytes, elevated protein concentration, and normal or slightly reduced glucose levels. Serologic testing for specific IgM antibodies confirms recent infection, while polymerase chain reaction (PCR) may detect viral RNA in early stages.
Complications arise when inflammation extends to the spinal cord, resulting in myelitis. Symptoms then include limb weakness, urinary retention, and bowel dysfunction. Persistent neurological deficits, such as chronic ataxia or cognitive impairment, may remain after acute recovery.
Early recognition of the biphasic pattern and neurological signs enables prompt supportive care and reduces the risk of long‑term sequelae. Vaccination remains the primary preventive measure for individuals residing in or traveling to endemic regions.