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PAEDIATRIC ALTERED
CONSCIOUS LEVEL GUIDELINE |
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DELPHI PROCESS
Round two
12. Intracranial
infections
Herpes simplex encephalitis
12b (ii) Herpes simplex encephalitis should be suspected clinically in a child with a reduced conscious level (and therefore aciclovir started) if:
(a) the child has had a prolonged convulsion with no other known precipitating cause
|
Position |
Comment |
|
Renal |
Are we ranking all children in the same group here, or excluding those within the febrile convulsion age group? |
|
Micro |
Do we have any information as to how common HSV Encephalitis is in children in the UK? From either laboratory or BPSU data, if so it would give us some idea about how many children would have to be given ACV to treat one case of HSE. It is worth noting that HSE is more common in adults |
|
Neuro |
depends on the age of the child. If in febrile convulsion age range no, but if older yes |
|
PICU |
Children with febrile fit previously well and clear fever not suitable, if sliding encephalopathy then fit Yes - always |
|
Agreed |
Neither agree nor disagree |
Disagreed |
|
65% |
23% |
12% |
(b) the child has focal neurological signs
|
Position |
Comment |
|
Paed |
acyclovir, only in those children, where we are able to rule out a intracranial abscess as a cause of the symptoms and seizures. |
|
Endo |
Depends on CT findings i.e. if no structural abnormality |
|
Paed |
Yes if fever also / history suggestive |
|
PICU |
and CT doesn’t give alternative diagnosis |
|
Agreed |
Neither agree nor disagree |
Disagreed |
|
73% |
27% |
0 |
(c) the child has had a fluctuating conscious level for 6 hours or more
|
Agreed |
Neither agree nor disagree |
Disagreed |
|
74% |
22% |
4% |
(d) the child has, or has been in contact with, herpetic lesions
|
Position |
Comment |
|
Virology |
This is a rather
too broad a question. The answer is yes
if there were maternal genital lesions at or just prior to birth or maternal
lesions on the skin or mucous membranes elsewhere whilst feeding or nursing
the child, or in a close family contact at home. Not a casual contact (e.g. visitor) with a
labial lesion or indeed members of the nursing staff, provided strict
infection control measures were observed. |
|
Micro |
Except neonates |
Agreed |
Neither agree nor disagree |
Disagreed |
|
84% |
8% |
8% |
(e) Aciclovir should be started when the following clinical features are present (please comment) :
|
Position |
Comment |
|
Virology |
Once again this is a very broad question and the answer will be different for a neonate or an adolescent. Perhaps it would be better to address the question on recognition (see later). |
|
Neuro |
Focal lesions on MRI scan or EEG |
|
PICU |
FOCAL SIGNS,FOCAL SEIZURES,SUSPICIOUS SKIN LESIONS,CONTACT WITH HSV |
|
Neuro |
Seizures, fever, focal signs, white
cells in CSF, focal abnormality on MRI |
|
Renal |
As stated above, it is a diagnosis of exclusion and the
threshold for starting acyclovir should be low. Any unexplained case of
reduced consciousness would warrant acyclovir |
|
Paed |
Prolonged or focal convulsions in the absence of other cause (eg known epilepsy) and ongoing altered level of consciousness ( ie exclude post ictal) Focal neurological signs Fluctuating level of consciousness in absence of other recognised cause ( head injury) If LP is contraindicated and no obvious alternative diagnosis, aciclovir should be commenced together with broad spectrum antibiotics |
|
Paed |
Unexplained, prolonged seizures in the absence of any other clinical / chemical features supporting alternative cause |
|
Endo |
Prolonged or recurrent convulsions without full recovery of conscious level or associated disorientation |
|
ED |
sick child, sepsis, decreased conscious level, cause unknown |
12b (v) The clinical suspicion of herpes simplex encephalitis can be strengthened by:
(a) a magnetic resonance image scan with non-specific features of herpes simplex encephalitis
|
Position |
Comment |
|
Virology |
Very many conditions could result in non-specific features by MRI |
|
PICU |
Improbable that one would get an emergency MRI – contrast
CT much more likely. |
|
Endo |
but not sure many units can get urgent MRI in sedated/ventilated child |
Agreed |
Neither agree nor disagree |
Disagreed |
|
86% |
14% |
0 |
(b) an abnormal EEG with non-specific features of herpes simplex encephalitis
|
Position |
Comment |
|
Virology |
It would be unwise to ignore such findings if, for example, there was no other obvious cause for reduced consciousness. Nevertheless, for HSV encephalitis one would expect evidence of some "lateralisation". |
|
Neuro |
I suspect we treat too early to
see EEG abnormality nowadays |
Agreed |
Neither agree nor disagree |
Disagreed |
|
76% |
24% |
0 |
(c) a positive CSF result for herpes simplex virus DNA in PCR of CSF
|
Position |
Comment |
|
Virology |
False positives may
occur due to contamination at some stage of the procedure. If in doubt, the laboratory should repeat
the procedure, although not necessarily on an additional CSF specimen. AGREE PCR results may be
negative in the early stages (3 days or less) or after 14 days. HSV antibody comes in later 10-14 days, sometimes even longer,
depending on the assay used.
Furthermore it is essential to conduct antibody assays to ensure that
synthesis is within the CNS. |
|
Metab |
Not a full 9 here, because we find rather a high number of false positives |
|
Paed |
Results take days to retirn |
Agreed |
Neither agree nor disagree |
Disagreed |
|
100% |
|
|
(vi) Intravenous acyclovir can be stopped before 14 days of treatment if there is no ongoing clinical suspicion of herpes simplex encephalitis.
|
Position |
Comment |
|
Virology |
It is now generally
advised to continue aciclovir for three weeks, perhaps even longer and in
larger doses. This is because there
is increasing evidence of reactivation with further damage over a prolonged
period. A case can be made out for
examining the CSF by PCR say at 2 weeks, and 3 weeks, and even after that if
there has been inadequate clinical improvement. |
|
Neuro |
Particularly if PCR is negative |
|
PICU |
SHOULD AWAIT PCR RESULT |
|
Renal |
If another cause has been clearly identified |
|
Paed |
Especially if an alternative diagnosis has been confirmed |
|
Renal |
HSV PCR usually back within 14 days and should be checked if emabarking on acyclovir. |
|
Metab |
I have done this myself, but worry about this approach, because of the risk of under treatment, and the effects of a resurgent infection if treatment is withdrawn. On the other hand a balance to what would otherwise be gross over treatment of a rare infection |
|
Paed |
This is not relevant for the acute guideline |
|
Micro |
We have had a small number of patients who are HSV PCR positive in whom the ACV has been stopped and the patient has been at home, I would be interested to know if there is any consensus as to how such cases should be managed. Currently we give them oral ACV. |
|
Endo |
If prompt recovery and no supporting features e.g. after prolonged convulsion, but complete recovery in 24hrs, I would not persist with acyclovir |
|
Neuro |
I would say 10 days |
Agreed |
Neither agree nor disagree |
Disagreed |
|
79% |
13% |
8% |
Intracranial abscess
12c (i) An intracranial abscess should be suspected in a child with a reduced conscious level if:
(a) there are clinical signs of sepsis and no other detectable source
|
Agreed |
Neither agree nor disagree |
Disagreed |
|
70% |
19% |
11% |
(b) there are clinical signs of sepsis and focal neurological signs
Agreed |
Neither agree nor disagree |
Disagreed |
|
100% |
|
|
(c) there are focal neurological signs
|
Position |
Comment |
|
Radiol |
Not without evidence of sepsis or predisposition eg cardiac or SCID. Focal neurology = CT anyway |
|
Paed |
Yes but much less common than other possible diagnoses in this circumstance |
|
Paed |
only if the signs are new onset and not due to already known cranial pathology i.e. cerebral palsy |
Agreed |
Neither agree nor disagree |
Disagreed |
|
88% |
12% |
0 |
(d) there are signs of raised intracranial pressure
|
Position |
Comment |
|
Radiol |
Not without sepsis as above Raised ICP = CT anyway |
|
Neuro |
And no other cause can be found |
|
Neuro |
Also ?context e.g. congenital heart disease |
|
Paed |
Yes but much less common than other possible diagnoses in this circumstance |
Agreed |
Neither agree nor disagree |
Disagreed |
|
81% |
19% |
0 |
Tuberculous meningitis
12d (i) Tuberculous meningitis should be suspected in a child with reduced conscious level if:
(a) there are clinical
features of meningitis (already defined)
|
Position |
Comment |
|
Paed |
But except in certain high risk groups other forms of meningitis much more common |
|
Micro |
In particular if there is a chronic history or clinical failure to respond to antibiotic therapy |
|
Paed |
It would have to be more than just features of meningitis as the incidence of TB locally is extremely low |
Agreed |
Neither agree nor disagree |
Disagreed |
|
78% |
15% |
7% |
(b) there has been contact with a case of pulmonary tuberculosis
|
Position |
Comment |
|
Paed |
Yes, but most such children will be screened promptly and treated if appropriate. Surely more common for the child with TBM to be the index case, so the absence of known contact shouldn’t dissuade one from considering the diagnosis, especially in high risk groups |
|
Metab |
or if X-ray features + |
Agreed |
Neither agree nor disagree |
Disagreed |
|
96% |
4% |
0 |