Bone Health and Endocrine Care of Boys with Duchenne Muscular Dystrophy: Data from the MD STARnet.

BACKGROUND: Patients with Duchenne muscular dystrophy (DMD) are at high risk of endocrine and bone health complications resulting from the high glucocorticoid (GC) doses used to treat this condition. There are limited data characterizing the clinical management of these complications. OBJECTIVE: To determine the frequency of bone health screening, endocrinologist evaluation, and use of endocrine and bone health pharmacotherapy in the clinical care of males with DMD. METHODS: A population based cohort study using data from the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) was conducted. Clinical data was abstracted from the medical records of 683 males with DMD at five surveillance sites across the US. RESULTS: A DXA scan had been documented in 24% of cases; the percentage of cases with DXA varied across surveillance sites from 13% to 43%, p < 0.001. History of fracture and greater disease duration were associated with greater odds of having a DXA. Only 4.7% of cases had documentation of an endocrinologist evaluation. The frequency of documented endocrine and bone health pharmacotherapy use included calcium (42.8%), vitamin D (36.6%), bisphosphonates (13.3%), growth hormone (1.9%), testosterone (1.7%), insulin (1.2%), and metformin (0.3%)Conclusions:A low percentage of DMD males had record of DXA scan, endocrinologist evaluation, or treatment with endocrine or bone health pharmacotherapy. Endocrine and bone health care may represent an unmet need in the DMD population.

Comparison study of branch versus main trunk repetitive nerve stimulation of facial nerve in normal subjects.

PURPOSE: Repetitive stimulation of the facial nerve is performed in neuromuscular junction disorders. Main nerve stimulation is currently used. There is more discomfort and artifact than stimulation of a branch. We stimulated the temporal branch of the facial nerve to the frontalis and compared the responses with that of main trunk stimulation. We compared the amplitudes and the corresponding amperage. METHODS: Eleven normal volunteers between 18 and 65 years of age were studied. Repetitive nerve stimulation of both the main trunk and the temporal branch to the frontalis muscle was performed at a frequency of 3 Hz, and waveforms were recorded from the frontalis muscle using adhesive surface electrodes. The amplitudes and corresponding amperages were compared. RESULTS: The amplitude comparison between the main trunk and that of the temporal branch to the frontalis yielded a paired two-tail P-value of 0.33. The comparison of corresponding stimulus intensities used yielded a paired two-tail P-value of 4.2 × 10. CONCLUSIONS: We concluded that the stimulus intensity required to achieve similar amplitudes in small branch stimulation is much lower than that required in main trunk stimulation.

Skin biopsy in complex regional pain syndrome: case series and literature review.

BACKGROUND: Accumulating experimental and clinical evidence supports the hypothesis that complex regional pain syndrome type I (CRPS-I) may be a small fiber neuropathy. OBJECTIVES: To evaluate the use of commercially available standard biopsy methods to detect intradermal axon pathology in CRPS-I, and to ascertain if these structural changes can explain quantitative sensory testing (QST) findings in CRPS-I. STUDY DESIGN: Retrospective review of charts and laboratory data. SETTING: Outpatient clinic METHODS: Skin biopsies from 43 patients with CRPS-I were stained with PGP 9.5, and epidermal nerve fiber density, sweat gland nerve fiber density and morphological abnormalities were evaluated. Thirty-five patients had quantitative sensory testing. RESULTS: Alterations in skin innervation were seen in approximately 20% of CRPS-I patients with commercial processing. There were no patient characteristics, including duration of disease, that predicted a decreased epidermal nerve fiber density (ENFD). There was no consistent relationship between QST changes and ENFD measured by standard commercial skin biopsy evaluation procedures. LIMITATIONS: Commercial processing of tissue does not utilize stereologic quantitative analysis of nerve fiber density. Biopsy material is utilized from a proximal and distal source only, and differences in denervation of a partial nerve territory may be missed. The functional attributes of small fibers cannot be assessed. CONCLUSIONS: The negative results indicate that CRPS-I may be associated with changes in the ultramicroscopic small fiber structure that cannot be visualized with commercially available techniques. Alternatively, functional rather than structural alterations of small fibers or pathological changes at a more proximal site such as the spinal cord or brain may be responsible for the syndrome.

Intramuscular botulinum toxin in complex regional pain syndrome: case series and literature review.

BACKGROUND: Pain associated with Complex Regional Pain Syndrome (CRPS) is frequently excruciating and intractable. The use of botulinum toxin for relief of CRPS-associated pain has not been well described. OBJECTIVES: To assess whether intramuscular botulinum toxin injections cause relief of pain caused by CRPS, and to assess the risks of this treatment. STUDY DESIGN: Retrospective chart review. SETTING: Outpatient clinic. METHODS: 37 patients with spasm/dystonia in the neck and/or upper limb girdle muscles. INTERVENTION: EMG-guided injection of Botulinum Toxin - A (BtxA), 10-20 units per muscle. Total dose used was 100 units in each patient. Local pain score was measured on an 11-point Likert scale, 4 weeks after BtxA injections. RESULTS: Mean pain score decreased by 43% (8.2 ± 0.8 to 4.5 ± 1.1, P < 0.001). 97% patients had significant pain relief. One patient had transient neck drop after the injections. LIMITATIONS: This is a retrospective study, it lacks a control group and hence the placebo effect cannot be eliminated. This study does not provide information on the efficacy of this treatment after 4 weeks. CONCLUSIONS: Intramuscular injection of botulinum toxin in the upper limb girdle muscles was beneficial for short term relief of pain caused by CRPS. The incidence of complications was low (2.7%).