Here, we describe two congenitally deaf male siblings with the same compound heterozygotic, likely pathogenic mutations in the FGF3 gene, associated with the labyrinthine aplasia, microtia and microdontia (LAMM) syndrome. Both children had bilateral cochleovestibular aplasia, precluding cochlear implantation. The elder brother received an auditory brainstem implant (ABI) with very limited auditory responses. During the ABI-surgery of the younger subject, it was discovered that excellent auditory responses could be obtained when the electrode array was placed considerably more caudally and more medially than standard. It was observed that the foramen of Luschka, the entrance to the lateral recess of the fourth ventricle was located more caudally. In view of this observation the good auditory development of the latter child, it was decided to give the older child a contralateral ABI. Again, it turned out that the anatomy of the brainstem was abnormal with a more caudal location of the foramen of Luschka and the cochlear nucleus, and this child is showing good progress with his auditory development. It is concluded that one should be aware of the anatomical differences at the level of the brainstem when placing an ABI in children with this genetic disorder (and most likely also in the LAMM syndrome). This also underpins the need of a multidisciplinary approach with closely collaborating team members and good family guidance when diagnosing and treating children with rare deafness.

We suggest short range stiffness (SRS) at the elbow joint as an alternative diagnostic for EMG to assess cocontraction.Elbow SRS is compared between obstetric brachial plexus lesion (OBPL) patients and healthy subjects (cross-sectional study design). Seven controls (median 28. years) and five patients (median 31. years) isometrically flexed and extended the elbow at rest and three additional torques [2.1,. 4.3,. 6.4. N. m] while a fast stretch stimulus was applied. SRS was estimated in silico using a neuromechanical elbow model simulating the torque response from the imposed elbow angle.SRS was higher in patients (250. ±. 36. N. m/rad) than in controls (150. ±. 21. N. m/rad, p = 0.014), except for the rest condition. Higher elbow SRS suggested greater cocontraction in patients compared to controls. SRS is a promising mechanical alternative to assess cocontraction, which is a frequently encountered clinical problem in OBPL due to axonal misrouting.

PLEXUS is an expert system which has been designed to advise physicians on the complex subject of brachial plexus injuries. Patient history information and results of neurological, neurophysiological and neuroradiological examinations are entered into the computer by the physician. Computer output consists of the localization of the injury, indication of the severity of the injury, and a treatment plan. PLEXUS was validated in cooperation with four international experts and was tested clinically in four hospitals. The independent validation showed that PLEXUS has a good performance. Features which must be improved include the extension of the functionality of the system to facilitate a more direct communication, and enhancement of the system's ability to assist in data gathering and entry. This study highlights the importance of thorough validation for the development of these kinds of systems.