Page 133 - TBE_Book_V2_2019

Chapter 6: TBE in children

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Long-term consequences diagnosed. The occurrence of residual
symptoms in childhood TBE was later
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The occurrence of long-term neurologic and confirmed by Engman et al. Children
neuro-psychologic sequelae in approximately followed-up 1 year after their acute disease
one third of adults after TBE infection is well- (recruited from a previous prospective study)
known. 2,28 However, the literature is reported significantly more fatigue, headache,
inconsistent when it comes to the risk for long and irritability than did children after
-term residua of childhood TBE. For many neuroborreliosis or control subjects.
years, but also recently, some studies have
concluded that pediatric TBE has a more Additionally, children were screened for neuro
favorable outcome. 16,17,19 However, consider- -developmental problems (e.g., executive
ing what is judged to be a complication of TBE function, memory, motor skills, behavior, etc.)
is important. If only looking at the gross using a validated questionnaire. Children who
neurologic status and superficial assessment had TBE had significantly more difficulties (5
of health and cognitive functioning, it is easy out of 7), mainly with memory, executive
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to conclude that childhood TBE is not a long- function, and perception.
term problem for most patients. But emerging
data support the premise that pediatric TBE In a larger study by Fowler et al., the findings
carries a risk of incomplete recovery, of residual symptoms and neurodevelop-
especially in terms of well-being and cognitive mental/cognitive problems in childhood TBE
function. were consolidated. Of note, the severity of the
acute phase of disease did not influence risk of
One of the first studies addressing the issue of long-term disease burden. More than 3
incomplete neurocognitive recovery was residual symptoms (e.g., headache, fatigue,
published in 2005 by Schmolck et al. Over a memory problems, irritability, concentration
mean of 3.2 years (range 6 months–11 years) problems, etc.) were seen in approximately
after acute TBE illness, 19 pediatric subjects 70% of the children in the long-term after
with TBE were evaluated in comparison with acute disease. Clinically significant problems
healthy controls. Children who had suffered with executive functioning were noted in
from TBE displayed lower scores in a approximately 40% of the children.
structured neurologic examination and had Additionally, a significant decrease in working
significantly impaired attention and psycho- memory index, but not global IQ, was seen
motor speed. Additionally, only one child in using the Wechsler Intelligence Scale for
the TBE group had a normal EEG, whereas the Children-IV when testing children after a
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remaining children were found to display diagnosis of TBE. Prominent deficit in
pathologic symptoms (mainly background working memory capacity and increased task-
20
slowing) without clinical disease. related functional MRI signal in working
memory-related cortical areas during working
Later, in a Swiss study, researchers concluded memory testing have been shown in pediatric
that permanent residua (i.e., severe mental patients after TBE. These functional MRI
and physical handicap) after pediatric TBE was abnormalities suggest diffuse neuronal
rare (1 child out of 55, approximately 2%), but damage behind the development of neuro-
no specific assessment of cognitive functions developmental/cognitive problems seen in
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19
was performed. By administering validated childhood TBE. Krbkova et al. have also
questionnaires, Fowler et al. showed that 4 described cognitive problems (memory prob-
out of 6 children had residual symptoms, not lems and lowered school grades) in a large
always obvious, several years after TBE was study; however, they found such deficits to a

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