Birth hypoxia is detrimental to neuronal function. In this study, its effect on spinal monosynaptic reflex was investigated on two different age groups of human newborn babies using few non-invasive electrophysiological parameters. A total of 57 newborns (25 hypoxic + 32 non-hypoxic) were the study subject. Out of which, 31 newborns (11 hypoxic + 20 non-hypoxic) were examined within 48 hours of birth, and the rest 26 (14 hypoxic + 12 non-hypoxic) were examined between 48h and 120h (five days) of birth. H-reflex latency (HRL), distal motor latency (DL), and H-reflex conduction velocity (HRCV), were estimated for understanding the transmission of impulse in the monosynaptic reflex pathway. Moreover, Hmax, Mmax, and H/M ratio were observed for studying the spinal motor neuronal excitability. The injurious effect of hypoxia was detected on HRL, HRCV, Hmax and H/M ratio in babies who were examined within 48h of birth. The HRL was significantly increased and other parameters were significantly reduced. In the older group of babies, however, Hmax was the only parameter affected by hypoxia. The relatively older babies of hypoxic or non-hypoxic group had higher Hmax and H/M ratio compared to younger ones of their own group.

Action Potentials↗

PubMedDate not supplied

Electrophysiological studies in newborns with reference to gestation and anthropometry.

Fourteen full term appropriate for gestational age (FT-AGA) and 11 preterm appropriate for gestational age (PT-AGA) newborns and their mothers constituted study subjects. The mothers were subjected to hemoglobin and serum albumin estimations. Offsprings were subjected to measurements of weight, crown heel length and head circumference along with motor nerve conduction velocity (MNCV) and H-reflex latency (H-RL) at right median nerve. The MNCV was found to be significantly lower and H-RL significantly higher in PT-AGA babies compared to FT-AGA babies. The gestation, crown heel length of baby and maternal serum albumin status were found to be significant independent variables. Multiple regression equations have been derived using these parameters as determinative variables. These equations explained much higher per cent variation than explained by simple regression equations.

Action Potentials↗

PubMedDate not supplied

Electrophysiological studies in children with paralytic poliomyelitis.

Ten healthy children (Group I), twenty children with acute spinal poliomyelitis (Group II and III) and twenty children of post-polio residual paralysis (Group IV) between the age group of 9 months to 4 years were the study subjects. The motor nerve conduction velocity (MNCV), standardized distal motor latency (SDML) and motor latency (M-RL) were similar in all the groups studied No H-reflex could be elicited in children with acute spinal poliomyelitis seen within one week of onset of paralysis (Group II). The H-max from 4-6 week group (III) improved with time in 9-12 month (Group IV) but did not attain the control (Group I) value. The H-reflex latency (H-RL) which was prolonged in Group III children returned back to normal value in children with residual paralysis (Group IV). The M-max which was significantly reduced in Group II children further decreased in Group III children before showing a significant rise in children with residual paralysis (Group IV). The M-max showed a significant correlation to duration of paralysis during the first week of onset of the disease process and with the muscle power assessed clinically in children with residual paralysis (Group IV). The H/M ratio of children with acute paralysis (Group III) was similar to control while that of residual paralysis was significantly lower in comparison to controls. However, the corrected H/M ratio of children with acute paralysis (Group III) and residual paralysis (Group IV) was significantly lower than the controls. There was significant increase in corrected H/M ratio in group IV children compared to group III.

Child, Preschool↗