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Objective: There are currently no effective treatments to halt the muscle breakdown in Duchenne muscular dystrophy (DMD), although genetic-based clinical trials are being piloted. Most of these trials have as an endpoint the restoration of dystrophin in muscle fibers, hence requiring sufficiently well-preserved muscle of recruited patients. The choice of the muscles to be studied and the role of noninvasive methods to assess muscle preservation therefore require further evaluation. Methods:We studied the degree of muscle involvement in the lower leg muscles of 34 patients with DMD Ͼ8 years, using muscle MRI. In a subgroup of 15 patients we correlated the muscle MRI findings with the histology of open extensor digitorum brevis (EDB) muscle biopsies. Muscle MRI involvement was assigned using a scale 0-4 (normal-severe). Results:In all patients we documented a gradient of involvement of the lower leg muscles: the posterior compartment (gastrocnemius Ͼ soleus) was most severely affected; the anterior compartment (tibialis anterior/posterior, popliteus, extensor digitorum longus) least affected. Muscle MRI showed EDB involvement that correlated with the patient's age (p ϭ 0.055). We show a correlation between the MRI and EDB histopathologic changes, with MRI 3-4 grades associated with a more severe fibro-adipose tissue replacement. The EDB was sufficiently preserved for bulk and signal intensity in 18/22 wheelchair users aged 10-16.6 years. Conclusion:This study provides a detailed correlation between muscle histology and MRI changes in DMD and demonstrates the value of this imaging technique as a reliable tool for the selection of muscles in patients recruited into clinical trials. Neurology ® 2011;76:346-353 GLOSSARY AO ϭ antisense oligonucleotide; DMD ϭ Duchenne muscular dystrophy; EDB ϭ extensor digitorum brevis; KAFO ϭ knee-ankle-foot orthosis; NSA ϭ number of signal averages; TE ϭ echo time; TR ϭ repetition time.The progressive loss of muscle fibers and their replacement by fat and connective tissue is part of the disease course of DMD.1 Despite several exhaustive natural history studies on the clinical course of DMD, the progression of pathology in individual muscle groups is poorly defined. 2Information on muscle pathology in DMD is limited to the muscles that are biopsied at the time of diagnosis (often quadriceps femoris), 2 the mean age at diagnosis being ϳ4.5 years. 3,4 There are now early clinical trials using novel genetic-based techniques in boys with DMD with the aim to restore dystrophin expression. These include the drug PTC124, 5 which allows

Epidemiologic data on chronic inflammatory demyelinating polyneuropathy (CIDP) is limited, and previous studies have shown variable results. The frequencies of CIDP subtypes remain unknown. Variations due to use of different diagnostic criteria have not been studied. We examined the prevalence and incidence of CIDP in Leicestershire and Rutland, UK (population 963,600). Prevalence day was 1 May 2008. The prevalence of CIDP fulfilling the 2006 clinical and electrophysiologic European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria was 4.77 per 100,000 (95% confidence interval [CI] 3.49-6.37). Using the 1991 American Academy of Neurology (AAN) criteria, the prevalence was 1.97 per 100,000 in this population (95% CI 1.19-3.08). Lewis-Sumner syndrome was diagnosed in 15.2% of patients, and 23.9% had pure sensory onset. Over 40% required no immunotherapy, and 84.6% of those treated responded. More than 80% of the AAN criteria-negative but EFNS/PNS criteria-positive patients were responsive to treatment. Both sets of criteria were equally likely to identify patients who required therapy. The mean annual incidence rate over the 3 years preceding the prevalence day was 0.70 per 100,000/year using EFNS/PNS criteria (95% CI 0.43-1.08), and 0.35 per 100,000/year using AAN criteria (95% CI 0.17-0.64). We conclude that the AAN criteria may underestimate prevalence and incidence of the disease. The EFNS/PNS criteria provide higher diagnostic sensitivity and are of greater clinical relevance, and they also offer a useful breakdown of the epidemiologic data for CIDP subtypes.

Our results confirm the efficacy and tolerability of LEV in children with refractory epilepsies and demonstrate good response and retention rates at 12 months. It represents the largest cohort of paediatric patients published so far on LEV with a 1-year follow-up.