Postnatal maturation of phrenic nerve in children

Contributions of Larry E. Becker to Neuropathologic Research in the Sudden Infant Death Syndrome: A Tribute

“…At the outset of this work, essentially nothing was known about the developmental profile of the vagus and phrenic nerves in early life, particularly in the first year of life, i.e., the period of risk for SIDS. A major strength of Larry and his group was that they understood the importance of gaining baseline (normative) information in preparation for SIDS analysis [15,16]. A major example of this approach was the analysis of the postnatal maturation of the phrenic nerve [15].…”

“…A major strength of Larry and his group was that they understood the importance of gaining baseline (normative) information in preparation for SIDS analysis [15,16]. A major example of this approach was the analysis of the postnatal maturation of the phrenic nerve [15]. They systematically examined this nerve at a standard (pericardial) level in 17 (control) children from 3 postnatal days until 8 years [15].…”

“…A major example of this approach was the analysis of the postnatal maturation of the phrenic nerve [15]. They systematically examined this nerve at a standard (pericardial) level in 17 (control) children from 3 postnatal days until 8 years [15]. Analysis was performed with computer-based morphometrics in 1-lm-thick, glutaraldehydefixed, toluidine blue-stained, cross-sections of nerve.…”

Conduction velocity of the human phrenic nerve in the neck

“…The phrenic nerve is a mixed nerve, comprising mainly large diameter myelinated fibers, and to a lesser degree, small diameter non-myelinated fibers carrying afferent signals from the diaphragm (Duron, 1981;Heinbecker et al, 1936;Teixeira et al, 1992). This composition is roughly similar to that of the upper limb motor nerves and thus similar motor conduction velocities are expected (between 52 and 74 m s À1 ) (Delisa et al, 1994).…”

Clinico-Pathologic Conference: Congenital Hypomyelinating Neuropathy in Two Infants of a Triplet Birth

“…All nerves examined from these patients show a g ratio consistently higher than 0.8, with unobtainable values in the sympathetic chain. A normative graph for phrenic nerves was devised in 1992 [11]; for ages 3^6 months the g ratio ranged from 0.45 to 0.80 with a mean of 0.7, somewhat paralleling those obtained from sural nerves. The same group also developed a normative graph for vagus nerves with similar results [12].…”