Basement membrane thickness of the vocal cord in cases of sudden infant death.

In 1991, 1994 and 1997 Shatz et al. reported on a specific and pathognomonic basement membrane (BM) thickening of the vocal cord in cases of sudden infant death syndrome (SIDS). In 40 cases of sudden and unexpected infant death the histological examination of the larynx was performed to identify possible differences between SID (n=26) and non-SID (n=14) cases. The dissection technique of Hohmann (1963) and Maxeiner (1986) was modified for the infant's larynx. Since the normal range of the BM thickness of the vocal cord for the age group younger than 1 year had not yet been exactly defined, a reference interval had to be established (0.5 microm-2.0 microm). In 2 SID and 1 non-SID cases a mean BM thickness (BMT) of more than 2.0 microm could be estimated (2.38 microm-2.95 microm). The BMT in these cases appeared to be highly variable and not harmonically thickened. None of the investigated regions of the BM (cranial to caudal thirds, ventral to dorsal areas) seemed to be preferred thickened. There was no statistically significant difference between the two groups. A specific thickening of the BM of the vocal cord in SID cases could not be confirmed. Therefore, BMT cannot be used as a diagnostic postmortem marker for SID.