*6.3.3. Encephalitis with normal CSF cell counts*

whereas only one (1.8%) had an isolated initial phase of the disease [51, 53]. In the Russian publications, this clinical manifestation is named "fever form" and is reported to represent up to 50% of all clinical presentations of TBE [54]. Abortive form of TBE most frequently presents itself by a moderate fever, headache, fatigue, and other nonspecific symptoms of the initial phase of the disease. The fever usually subsides in a few days and the disease does not have

28 Meningoencephalitis - Disease Which Requires Optimal Approach in Emergency Manner

Meningitis is characterized by fever, headache, nausea, vomiting, and meningeal signs. These symptoms and signs are present in the majority but not in all the patients. In a study encompassing 448 adult patients with TBE from Slovenia, almost all reported headache and had fever, more than 50% suffered from nausea and/or vomiting, and 70% had clearly expressed meningeal signs [33]. Encephalitis may manifest by a variety of neurological symptoms and signs, most often with tremor (especially of the fingers of the upper extremities and tongue), sometimes with nystagmus, speech disorder, ataxia and movement disorders, occasionally with seizures, and very rarely with brain stem symptoms and/or cranial nerve abnormalities. Impaired consciousness, ranging from mild to severe, insomnia, and concentration and cognitive function disturbances are rather frequent. Mental disorders including amnesia, behavioral changes, psychosis, and delirium may also occur. Patients may have sensory impairment. Myelitis is virtually always associated with meningoencephalitis, and as a rule manifests with flaccid paralyses that are occasionally preceded by severe pain in the affected muscle groups. The involvement is usually asymmetrical. Most often extremities are affected, more frequently the upper than the lower limbs, and more often the proximal segments of the extremities than the distal ones. Patients with pareses of respiratory muscles usually require

According to rather limited data, involvement of cranial nerves is rare, mostly asymmetrical, typically associated with severe acute illness, and usually has a favorable outcome [46, 47, 58]. Ocular, facial, and pharyngeal muscles are most often affected, but hearing and vestibular

In a series of 1218 adult patients diagnosed with TBE at a single center, 11 (0.9%) developed peripheral facial palsy (2 bilateral, 9 unilateral); however, 3 out of 11 patients had associated borrelial infection. The latter finding suggests that in patients who develop peripheral facial palsy in the course of TBE, and who had been exposed to ticks in the region where both TBE and Lyme borreliosis are endemic, coexistent infection with Lyme borreliae have to be taken

Occasionally, autonomic nervous system disorders are present in patients with TBE [60].

long-term consequences [55, 56].

**6.2. Meningitis, encephalitis, and myelitis**

artificial ventilatory support [12, 32, 57].

*6.3.1. Involvement of cranial nerves*

defects are also encountered [42].

into account [59].

*6.3.2. Autonomic disorders*

**6.3. Other manifestations in the acute phase of illness**

Literature review revealed some reports on a serologically confirmed TBEV infection in patient with encephalitis but without CSF pleocytosis [61, 62]. This disagrees with the large series of serologically proven TBE patients, in which CSF pleocytosis was found in all the cases [12, 42, 43, 47]. However, the latter finding might be the result of a selection bias because in the studies CSF pleocytosis was one of the essential inclusion criteria for the diagnosis of TBE.
