The author has read with great interest the report of Leow and Ward
Platt (1), who accurately studied the incidence of sudden, unexpected and
unexplained early neonatal deaths in the North of England giving an
overall rate of 0.35/10,000 live births.
While several works have stressed the importance of post-mortem
examination in every case of suspected sudden infant death syndrome
(SIDS), little, if any, attention has been given to the mandatory need to
apply the same investigational protocol also in all cases of sudden
perinatal unexplained death, i.e., sudden neonatal unexplained death
(SNUD) and sudden intrauterine unexplained death (SIUD) (2-5).
First of all, it should be underlined that there is a clear continuum
between unexplained perinatal death and SIDS, as developmental
abnormalities have been detected to be common to both, particularly in the
cardiac conduction system and in the brainstem centers regulating vital
functions. From the analysis of the conducting tissue, the following
pathological findings emerged: accessory atrio-ventricular pathways,
mostly Mahaim fibers, cartilaginous hypermetaplasia, abnormal resorptive
degeneration, junctional islands, persistent fetal dispersion, hypoplasia
of the cardiac conduction system or of the central fibrous body, splitting
of the atrio-ventricular node or of the His bundle, and the Zahn node. All
of these cardiac conduction findings may be isolated incidents, but they
are frequently associated with autonomic nervous system alterations of the
brainstem (2-5).
There is evidence to hypothesize the presence of a preexisting damage
in the cardiac conduction system and brainstem of vulnerable subjects, not
only in infants - newborns 0-1 month-old and infants 1-12 month-old - but
also, and at a greater frequency, in fetuses(2-5). This preexisting
vulnerability, if associated to a supervening pathology, such as a
bronchus-pneumonic or a placental infection act as triggering phenomenon
in particularly vulnerable infants and fetuses. The SIUD/SNUD/SIDS event
would occur, in subjects with preexisting still quiescent and undetected
abnormality in the conducting tissue and/or brainstem, when a new
pathological event, itself not deadly, concurs.
REFERENCES
1. Leow JY, Ward Platt MP. Sudden, unexpected and unexplained early
neonatal deaths in the North of England. Arch Dis Child Fetal Neonatal Ed
2011 Mar 11. [Epub ahead of print]
2. Matturri L, Ottaviani G, Lavezzi AM. Guidelines for neuropathologic
diagnostics of perinatal unexpected loss and sudden infant death syndrome
(SIDS): a technical protocol. Virchows Arch 2008;452:19-25.
3. Ottaviani G. Crib death. Sudden unexplained death of infants: the
pathologist's viewpoint, Springer-Verlag, Berlin Heidelberg, Germany 2007.
4. Matturri L, Ottaviani G, Ramos SG, Rossi L. Sudden Infant Death
Syndrome (SIDS): a study of cardiac conduction system. Cardiovasc Pathol
2000;9:137-45.
5. Ottaviani G, Matturri L. Histopathology of the cardiac conduction
system in sudden intrauterine unexplained death. Cardiovasc Pathol
2008;17:146-55.
Conflict of Interest:
None declared
The author has read with great interest the report of Leow and Ward Platt (1), who accurately studied the incidence of sudden, unexpected and unexplained early neonatal deaths in the North of England giving an overall rate of 0.35/10,000 live births. While several works have stressed the importance of post-mortem examination in every case of suspected sudden infant death syndrome (SIDS), little, if any, attention has been given to the mandatory need to apply the same investigational protocol also in all cases of sudden perinatal unexplained death, i.e., sudden neonatal unexplained death (SNUD) and sudden intrauterine unexplained death (SIUD) (2-5). First of all, it should be underlined that there is a clear continuum between unexplained perinatal death and SIDS, as developmental abnormalities have been detected to be common to both, particularly in the cardiac conduction system and in the brainstem centers regulating vital functions. From the analysis of the conducting tissue, the following pathological findings emerged: accessory atrio-ventricular pathways, mostly Mahaim fibers, cartilaginous hypermetaplasia, abnormal resorptive degeneration, junctional islands, persistent fetal dispersion, hypoplasia of the cardiac conduction system or of the central fibrous body, splitting of the atrio-ventricular node or of the His bundle, and the Zahn node. All of these cardiac conduction findings may be isolated incidents, but they are frequently associated with autonomic nervous system alterations of the brainstem (2-5).
There is evidence to hypothesize the presence of a preexisting damage in the cardiac conduction system and brainstem of vulnerable subjects, not only in infants - newborns 0-1 month-old and infants 1-12 month-old - but also, and at a greater frequency, in fetuses(2-5). This preexisting vulnerability, if associated to a supervening pathology, such as a bronchus-pneumonic or a placental infection act as triggering phenomenon in particularly vulnerable infants and fetuses. The SIUD/SNUD/SIDS event would occur, in subjects with preexisting still quiescent and undetected abnormality in the conducting tissue and/or brainstem, when a new pathological event, itself not deadly, concurs.
REFERENCES
1. Leow JY, Ward Platt MP. Sudden, unexpected and unexplained early neonatal deaths in the North of England. Arch Dis Child Fetal Neonatal Ed 2011 Mar 11. [Epub ahead of print] 2. Matturri L, Ottaviani G, Lavezzi AM. Guidelines for neuropathologic diagnostics of perinatal unexpected loss and sudden infant death syndrome (SIDS): a technical protocol. Virchows Arch 2008;452:19-25. 3. Ottaviani G. Crib death. Sudden unexplained death of infants: the pathologist's viewpoint, Springer-Verlag, Berlin Heidelberg, Germany 2007. 4. Matturri L, Ottaviani G, Ramos SG, Rossi L. Sudden Infant Death Syndrome (SIDS): a study of cardiac conduction system. Cardiovasc Pathol 2000;9:137-45. 5. Ottaviani G, Matturri L. Histopathology of the cardiac conduction system in sudden intrauterine unexplained death. Cardiovasc Pathol 2008;17:146-55.
Conflict of Interest:
None declared