A possible prevention of Obstetric Brachial Plexus Lesion (OBPL)

Shoulder dystocia is a severe complication during labour which means that the
child's shoulder gets stuck in the birth canal. This can be a traumatic
experience for the parents but it can also have serious consequences for the
child itself. Shoulder dystocia is the biggest risk factor for obstetric
brachial plexus lesion (OBPL). OBPL means that due to the difficult passage of
the shoulders during labour, the network of nerves on each side of the neck
leading to the arm can be damaged. In healthy subjects this connection between
the brains and the arm is responsible for the movement of various muscles and
the sensibility in different skin parts. These functions can be damaged in
varying gradaients in OBPL. When recovery of the nerves is unsufficient, the
development of essential muscles will fail such as bending of the elbow by the
biceps, which is necessary for everyday tasks as feeding, combing hair etc.
OBPL occurs in 1-3 per 1000 newborns from which 20 - 30 % keep permanent
damage. Nowadays the neurosurgeon can operate on the most severe cases, but
even then recovery of the arm function is less than can be observed on the
healthy side.

In this investigation we want to determine if stimulation of the nerve on each
side of the neck that leads to the muscles that make the shoudlers shrug is
possible in babies. This can possibly prevent a birth lesion of the barchial
plexus in the future (also called obstetric brachial plexus lesion -OBPL- or
Erbs palsy).

The investigation takes about half an hour. An experienced clinical
neurophysiologist determines the location for electrical stimulation of the
accessory nerve in the neck. In the first phase stimuli are applied to see if
the nerve reacts and then a train of stimuli is applied to see if the shoulders
stay shrugged. So two trains of stimuli are applied, each of which is half to
one second long, starting with a strength of the current as determined with
adults. The effect of nerve stimulation on the distance between the shoulders
is evaluated by the investigator and is also recorded on video.

Stimulating n. accesorius, which leads to the m. trapezius which shrugs the
shoulders and which is positioned on both sides of the neck close under the
skin.

Stimuli can be perceived as unpleasant, but are very safe due to the many years
of experience in children. We do not expect severe stimuli. When the load is
higher than expected, the legal representative can at any time withdraw the
child from participation. The time load is at most half an hour. Two stimuli
trains are applied where each stimulus is a half to one second, starting with
the low current strength as determined in adults and not experienced as
painful.