Methods
Setting
The study was conducted in our 22-bed intensive care unit of Habib Bourguiba University
Hospital in Sfax, Tunisia. Patients admitted in our unit came from Sfax (1.2 million
inhabitants) and other cities of southern Tunisia.
Study Population
Medical records of children (age range, 1-15 years) who were admitted in our intensive care
unit in 2011 were retrospectively reviewed. The diagnosis of rubella encephalitis was
clinically suspected in febrile patients with impaired cerebral function (altered consciousness,
personality or behavioral changes lasting more than 24 hours) with a history of rubella
contact or a maculopapular rash. The diagnosis was definitively confirmed when serum
immunoglobulin (M) antibodies against the rubella virus were positive and/or cerebrospinal
fluid antirubella virus immunoglobulin (M) was also positive.
For all included patients, the following data were recorded:
Previous rubella vaccination: In Tunisia children can be vaccinated against rubella
mump and measles viruses at the age of 15 months only in the private sector.
Preventive measures have been conducted since 2005 to prevent congenital rubella
by vaccinating all young girls aged between 13 and 18 years and nonimmunized
women during the postpartum period.
Body temperature, the presence of a maculopapular rash, lymphadenopathy, and/or
arthralgia.
Systolic and diastolic blood pressure, heart rate, and respiratory rate.
Clinical severity was assessed by the Pediatric Risk of Mortality score calculated
within the first 24 hours of intensive care unit stay.8
Neurologic examination: consciousness status, meningeal syndrome, seizures,
papillary or ocular abnormalities, cranial nerve dysfunction, and motor or sensitive
deficit.
Neurovegetative disorders were defined by a wide hemodynamic variation
(hypertension/hypotension or bradycardia/tachycardia) because of cerebral insults
without other evident causes.
Neuroimaging findings: All our patients underwent either cerebral computed
tomography or brain magnetic resonance imaging (MRI) on admission. Magnetic
resonance imaging was not performed for all the included patients because of either
medical contraindication or logistic difficulties. It was performed using a 1-T machine.
The images were obtained using T1-weighted, T2-weighted, and fluid-attenuated
inversion recovery sequences in the sagittal, axial, and coronal planes.
Routine laboratory tests.
Cerebrospinal fluid samples were systematically investigated by polymerase chain
reaction for herpes simplex virus type 1 and 2. Enzyme-linked immunosorbent assay
detecting antirubella immunoglobulin (M) (normal range below 1.2 UI/mL) was
performed for all our patients. We also recorded glucose and albumin levels in the
cerebrospinal fluid as well as the results of bacterial cultures.
Electrophysiological tests: Electroencephalography (EEG) was performed if seizures
or subtle status epilepticus was suspected. Moreover, subtle status epilepticus was
suspected in patients with minor motor phenomena such as rhythmical twitching of
facial or ocular muscles or distal extremities. The diagnosis was considered if the EEG
showed epileptic discharges without motor convulsive activity. Electrophysiological
tests were also performed in patients with consciousness recovery delay to assess the
severity of brain damage.
Management
Our patients received corticosteroids (dexamethasone with a daily dose at 0.15 mg/kg every
6 hours during 5 consecutive days). Mannitol was administrated if neuroimaging tests
showed cerebral edema and/or herniation. The dose given was 1.5 g/kg/d with a progressive
decrease for a predicted duration of 5 days. Hypertonic saline is not used in our practice.
Anticonvulsants (phenobarbital) were used only if seizure was diagnosed either clinically or
according to electrophysiological tests. All our patients received cefotaxime (300 mg/kg/d)
and acyclovir (15 mg/kg every 8 hours) since their admission until obtaining the definitive
results of cerebrospinal fluid sample tests. Intubation and mechanical ventilation were
performed in cases with severe consciousness impairment (Glasgow Coma Scale score