AAHS ASPN ASRM - 2013 Annual Meeting - American Association ...

Metastatic Breast Cancer Recurrence to the Brachial Plexus - MRI Imaging Characteristics
Institution where the work was prepared: Mayo Clinic, Rochester, MN, USA
Helena Gerhardt Summers, MD; Kimberly Amrami; Robert Spinner; Mayo Clinic
Abstract:
The brachial plexus is a complex and difficult structure to image, especially in patients with previous surgical and radiation treatment to nearby structures in
the breast and axilla. We reviewed twenty one patients with a history of breast cancer and symptoms of brachial plexopathy, including sensory deficits, weakness,
and pain, with MRI imaging and positive EMG findings. The majority of these patients had been “disease free” for many years (range 0-26 years, average
14 years) with insidious onset of symptoms. 18 of 21 patients underwent surgical biopsy of the brachial plexus, chest wall, or supraclavicular lymph nodes.
The 3 patients without surgical biopsies were treated presumptively for recurrent cancer based on imaging findings. 9 patients had PET scans. Only 9 of the
21 patients had a correct prospective diagnosis by imaging. On retrospective review the majority of cases had MRI evidence of recurrent disease including signal
abnormalities, abnormal enhancement, and masses. Many of the interpretations were revised after repeat examinations with intravenous gadolinium or at
higher field strength (3T). This study attempts to better characterize the imaging characteristics of the brachial plexus in patients with breast cancer, with a
focused goal to evaluate false positive results and, thus, eliminate unwarranted and potentially harmful surgery. By correlating imaging features with pathologically
proven cases of recurrent tumor, we also aim to accurately identify patients with breast cancer recurrence of the brachial plexus. By distinguishing true
positive results from radiation fibrosis or other causes of brachial plexopathy, appropriate and earlier treatment is possible. The role of PET scanning for improving
sensitivity will also be evaluated.
Outcome Measures in Brachial Plexus Reconstruction
Institution where the work was prepared: Mayo Clinic, Rochester, MN, USA
Keith A. Bengtson; Brian Kotajarvi, PT; Allen Bishop, MD; Robert Spinner, MD; Alexander Shin, MD; Mayo Clinic
A comprehensive review of the literature on brachial plexus reconstruction reveals a paucity of detailed measures of outcome. Motor return is generally measured
using manual muscle testing (MMT) with the British Medical Research Council (BMRC) scale of M0-M5. Function is measured in descriptive and fairly
insensitive terms. The insensitivity of the BMRC scale is greatest at the upper and lower extremes between M0 and M2, as well as between M4 and M5. MMT,
especially when performed by various examiners from several medical centers, results in a high variability of measures. Higher variability requires larger number
of patient to prove efficacy of treatment.
One way to reduce variability is to use isometric motor testing with force plate gauges which are highly sensitive to small variations in strength. Various isometric
strength testing devices already exist for the shoulder and elbow motions. Unfortunately, these machines do not eliminate the effect of gravity. Therefore,
early recovery, when the muscle is not strong enough to overcome gravity, is not detected. Our group has developed specific, reproducible testing of muscle
strength using standardized placement of force plates in such a way as to eliminate the effects of gravity. These techniques measure the isometric force generated
by a muscle group in a standardized fashion. Specifically, force is measured in shoulder flexion, extension, abduction, internal rotation, and external
rotation. Elbow flexion and extension, and forearm pronation is also measured. We hope to establish standards of measurement that will aid in future research
on the success of brachial plexus reconstruction. These protocols will be described as they pertain to specific types of brachial plexus reconstruction. We will
also present preliminary results from illustrative cases.
A Long Segmental Nerve Trunk Crush Injury Induces Increased Sprouting but does not Impair Peripheral Nerve
Regeneration
Institution where the work was prepared: University of Calgary, Calgary, Canada
Qing Gui Xu; Rajiv Midha, MD; Douglas Zochodne; University of Calgary
Background:
Nerve crush is a well established rodent model of a Sunderland Grade II nerve injury. We hypothesized that a long segmental peripheral nerve trunk crush injury
would impede axonal regeneration as compared to a short focal crush injury.
Methods:
In Sprague–Dawley rats (n=8-10/group), the mid-thigh sciatic nerve was exposed and then crushed for 30 seconds, using either a plastic-tipped jewelers forceps
(crush zone 2 mm) or a modified snap, lined with smooth 2 cm long reciprocal plastic resin cassettes, which upon closing caused a long zone (20mm)
crush injury. Two weeks following injury, nerve samples were harvested 5 and 15mm distal to the proximal injury level. Toluidine blue stained semithin sections
were evaluated by an observer blinded to treatment groups for myelinated axon counts. Semi-quantitative RT-PCR for a number of expressed genes,
including GAP-43/B50, was also performed on the injured nerve. In another set of rats (3/group), retrogradely labelled (using flurogold) neurons were counted
from the lumbar spinal cord and L5 DRG.
Results:
Both short and long crush produced regenerative sprouting, with myelinated axon densities significantly (p