Functional outcomes of infants with Narakas grade 1 birth-related brachial plexus palsy undergoing neurotization compared with infants who did not require surgery.

PURPOSE: This study aimed to investigate the functional outcomes of infants who underwent neurotization for shoulder abduction and elbow flexion in Narakas grade 1 birth-related brachial plexus palsy (BRBPP) and compare this cohort to children who progressed past the point of needing intervention. METHODS: A cohort study was conducted at a single center between 1999 and 2010. Two-hundred and eight infants were identified with BRBPP that presented for neurosurgical care as infants. Of those, 38 (18 %) received neurosurgical intervention with approximate 2-year follow-up. Only infants undergoing cranial nerve XI to suprascapular nerve neurotization for shoulder abduction (SA) weakness and medial pectoral nerve to musculocutaneous nerve neurotization for elbow flexion (EF) weakness were included. In addition, 30 infants who improved past the need for surgical intervention and had been followed for close to 24 months were identified for comparison. Descriptive statistics and exploratory analysis were performed using SAS 9.2 and JMP 9.0.2. RESULTS: Shoulder abduction For SA, there were no differences in age at presentation between the operative (6-9 months) and non-operative (5-9 months) groups (p = 0.99). Infants in the operative cohort had significantly worse initial function (p = 0.008). At 2-year follow-up, the two groups had become similar (p = 1.0). Elbow flexion For EF, there were no differences in age at presentation between the operative (6-8 months) and non-operative (5-8.5 months) groups (p = 0.98). Infants in the operative cohort had significantly worse initial function (p = 0.002). At 2-year follow-up, those two groups had become similar (p = 0.26). CONCLUSIONS: Infants undergoing neurotization for Narakas grade 1 brachial plexus injury had similar long-term function to those who had improved and never required surgery. The preoperative exam findings were significantly different between the intervened and non-intervened groups, while the postoperative exam findings were not.

Halobacteriovorax, an underestimated predator on bacteria: potential impact relative to viruses on bacterial mortality.

Predation on bacteria and accompanying mortality are important mechanisms in controlling bacterial populations and recycling of nutrients through the microbial loop. The agents most investigated and seen as responsible for bacterial mortality are viruses and protists. However, a body of evidence suggests that predatory bacteria such as the Halobacteriovorax (formerly Bacteriovorax), a Bdellovibrio-like organism, contribute substantially to bacterial death. Until now, conclusive evidence has been lacking. The goal of this study was to better understand the contributors to bacterial mortality by addressing the poorly understood role of Halobacteriovorax and how their role compares with that of viruses. The results revealed that when a concentrated suspension of Vibrio parahaemolyticus was added into microcosms of estuarine waters, the native Halobacteriovorax were the predators that responded first and most rapidly. Their numbers increased by four orders of magnitude, whereas V. parahaemolyticus prey numbers decreased by three orders of magnitude. In contrast, the extant virus population showed little increase and produced little change in the prey density. An independent experiment with stable isotope probing confirmed that Halobacteriovorax were the predators primarily responsible for the mortality of the V. parahaemolyticus. The results show that Halobacteriovorax have the potential to be significant contributors to bacterial mortality, and in such cases, predation by Halobacteriovorax may be an important mechanism of nutrient recycling. These conclusions add another dimension to bacterial mortality and the recycling of nutrients.

Draft genome sequences for the obligate bacterial predators Bacteriovorax spp. of four phylogenetic clusters.

Bacteriovorax is the halophilic genus of the obligate bacterial predators, Bdellovibrio and like organisms. The predators are known for their unique biphasic life style in which they search for and attack their prey in the free living phase; penetrate, grow, multiply and lyse the prey in the intraperiplasmic phase. Bacteriovorax isolates representing four phylogenetic clusters were selected for genomic sequencing. Only one type strain genome has been published so far from the genus Bacteriovorax. We report the genomes from non-type strains isolated from aquatic environments. Here we describe and compare the genomic features of the four strains, together with the classification and annotation.

Differences in bacterial community structure on Hydrilla verticillata and Vallisneria americana in a freshwater spring.

The phylogenetic composition of the epiphytic bacterial community of an invasive aquatic plant (Hydrilla verticillata) and a native species (Vallisneria americana [eelgrass]) of the Wakulla Spring (Florida) was investigated, along with the water column bacterial composition, using clone libraries of the 16S rRNA genes. The bacterial clones from three clone libraries were classified into 182 operational taxonomic units (OTUs), most of which were affiliated with bacterial divisions commonly found in freshwater ecosystems. Based on the identified classes, the bacterial communities on eelgrass and Hydrilla were distinct, such that Planctomycetes, Cyanobacteria, Bacilli and Actinobacteria were found on eelgrass and in the water column but not on Hydrilla. On the other hand, Deltaproteobacteria and Verrucomicrobiae were found on Hydrilla and in the water column but not on eelgrass. Further distinctions observed were that Armatimonadia and Deinococci were found only on Hydrilla while Gemmatimonadetes was found only on eelgrass. Our results indicated differences between the epiphytic bacterial community on the two plants and the water column at the species level, but an even representation of the most abundant phylogenetic taxa (classes) in all three libraries was revealed. Statistical comparison of the retrieved sequences confirmed that the three libraries did not differ significantly at the community level (LIBSHUFF, p <0.05).

Radial to axillary nerve neurotization for brachial plexus injury in children: a combined case series.

OBJECT: Axillary nerve palsy, isolated or as part of a more complex brachial plexus injury, can have profound effects on upper-extremity function. Radial to axillary nerve neurotization is a useful technique for regaining shoulder abduction with little compromise of other neurological function. A combined experience of this procedure used in children is reviewed. METHODS: A retrospective review of the authors' experience across 3 tertiary care centers with brachial plexus and peripheral nerve injury in children (younger than 18 years) revealed 7 cases involving patients with axillary nerve injury as part of an overall brachial plexus injury with persistent shoulder abduction deficits. Two surgical approaches to the region were used. RESULTS: Four infants (ages 0.6, 0.8, 0.8, and 0.6 years) and 3 older children (ages 8, 15, and 17 years) underwent surgical intervention. No patient had significant shoulder abduction past 15° preoperatively. In 3 cases, additional neurotization was performed in conjunction with the procedure of interest. Two surgical approaches were used: posterior and transaxillary. All patients displayed improvement in shoulder abduction. All were able to activate their deltoid muscle to raise their arm against gravity and 4 of 7 were able to abduct against resistance. The median duration of follow-up was 15 months (range 8 months to 5.9 years). CONCLUSIONS: Radial to axillary nerve neurotization improved shoulder abduction in this series of patients treated at 3 institutions. While rarely used in children, this neurotization procedure is an excellent option to restore deltoid function in children with brachial plexus injury due to birth or accidental trauma.

Involvement of the brachial plexus and its branches by cystic hygromas.

Lymphatic malformations that involve the nervous system are uncommon. The authors review their experience with involvement of the brachial plexus and its branches by cystic hygromas. A retrospective review of the authors' experience with pathology of the pediatric brachial plexus revealed 4 cases involving patients with compression of this structure and its branches due to cystic hygroma. Although such cases are apparently rare, the neurosurgeon should consider malformations of the lymphatic system in the differential diagnosis of masses involving the brachial plexus and its branches.

Medial pectoral nerve to musculocutaneous nerve neurotization for the treatment of persistent birth-related brachial plexus palsy: an 11-year institutional experience.

OBJECT: Medial pectoral nerve (MPN) to musculocutaneous nerve (MCN) neurotization for recovery of elbow flexion by biceps reinnervation is a valid option following traumatic injury to the upper brachial plexus. A major criticism of the application of this technique in infants is the smaller size of the MPN and mismatch of viable axons. We describe our institutional experience utilizing this procedure and critically examine functional outcomes. METHODS: Office charts and hospital records of children from over an 11-year period beginning January 1997 were reviewed. Of the 53 children of various ages undergoing brachial plexus exploration for traumatic injury of any nature, 20 underwent MPN to MCN neurotization as a part of an overall procedure in the first year of life to treat birth-related brachial plexus palsy and had at least 9 months' follow-up. Medial pectoral nerve to MCN neurotization was chosen if the results of clinical examination and intraoperative electrophysiological evidence were consistent with medial cord function. Functional recovery was defined as the ability of the child to bring their hand to their mouth. RESULTS: Sixteen patients (80%) gained functional recovery. The median age at surgery was 7 months. Median time to first clinic visit documenting recovery was 11.5 months and median overall follow up was 21.5 months. Preoperative hand function was a useful predictor of recovery of elbow flexion. CONCLUSIONS: Medial pectoral nerve to MCN neurotization is a valid surgical option for the reinnervation of the biceps muscle for birth-related brachial plexus palsy when the hand is functional preoperatively. Useful elbow flexion can be expected in the majority of these children.