Electrical impedance myography discriminates congenital muscular dystrophy from controls.

INTRODUCTION: Electrical impedance myography (EIM) is an emerging non-invasive, highly reproducible electrophysiological technique that objectively characterizes muscle structure and composition by measuring bioimpedance. We assessed the ability of EIM ability to discriminate 2 forms of congenital muscular dystrophy (CMD), laminin α2 (LAMA2)-deficient CMD and collagen VI-deficient (COL6) CMD, from a group of healthy children. We also investigated correlations between subcutaneous fat thickness and EIM parameters. METHODS: Twenty-eight children with LAMA2 CMD (n = 12) or COL6 (n = 16) CMD and 18 normal children underwent EIM testing. RESULTS: The EIM 50-kHz phase was decreased in LAMA2 and COL6 CMD when compared with controls (P < 0.001). Reactance, however, was decreased in COL6 but not LAMA2 CMD compared with controls (P < 0.001). CONCLUSIONS: Our findings suggest that EIM may be useful in discriminating CMD from controls and may serve as a useful biomarker to follow disease progression in clinical trials.

Early onset and novel features in a spinal and bulbar muscular atrophy patient with a 68 CAG repeat.

Spinal and bulbar muscular atrophy (SBMA) is an X-linked neuromuscular disease caused by a trinucleotide (CAG) repeat expansion in the androgen receptor gene. Patients with SBMA have weakness, atrophy, and fasciculations in the bulbar and extremity muscles. Individuals with CAG repeat lengths greater than 62 have not previously been reported. We evaluated a 29year old SBMA patient with 68 CAGs who had unusually early onset and findings not seen in others with the disease. Analysis of the androgen receptor gene confirmed the repeat length of 68 CAGs in both peripheral blood and fibroblasts. Evaluation of muscle and sensory function showed deficits typical of SBMA, and in addition the patient had manifestations of autonomic dysfunction and abnormal sexual development. These findings extend the known phenotype associated with SBMA and shed new insight into the effects of the mutated androgen receptor.

Nummular headache update.

Nummular headache (NH) is a rare headache disorder characterized by focal and well-circumscribed pain fixed within a rounded or oval/elliptical-shaped area of the head, typically 2 to 6 cm in diameter (Grosberg et al. Curr Pain Headache Rep 11:310-2, 2007). The disorder most commonly affects the parietal region and is almost always unilateral and side-locked. The pain is typically characterized as pressure-like, sharp, or stabbing and is usually mild to moderate in intensity. Many patients experience superimposed exacerbations of pain, lasting from seconds to days (Grosberg et al. Curr Pain Headache Rep 11:310-2, 2007). Distortions of sensation including hyperesthesia, hypoesthesia, allodynia, and paresthesias are frequently reported in the affected area. The temporal pattern may be episodic or chronic. Rarely, the disorder may be bifocal or multifocal, affecting various regions of the head simultaneously or in sequence. Treatment with gabapentin, tricyclic antidepressants, or botulinum toxin may be helpful. In this review of the more than 250 cases now reported in the literature, the epidemiology, clinical features, pathogenesis, differential diagnosis, and management of this disorder are discussed.

Primary headache disorders and neuro-ophthalmologic manifestations.

Headache is an extraordinarily common complaint presenting to medical practitioners in all arenas and specialties, particularly primary care physicians, neurologists, and ophthalmologists. A wide variety of headache disorders may manifest with a myriad of neuro-ophthalmologic symptoms, including orbital pain, disturbances of vision, aura, photophobia, lacrimation, conjunctival injection, ptosis, and other manifestations. The differential diagnosis in these patients is broad and includes both secondary, or symptomatic, and primary headache disorders. Awareness of the headache patterns and associated symptoms of these various disorders is essential to achieve the correct diagnosis. This paper reviews the primary headache disorders that prominently feature neuro-ophthalmologic manifestations, including migraine, the trigeminal autonomic cephalalgias, and hemicrania continua. Migraine variants with prominent neuro-ophthalmologic symptoms including aura without headache, basilar-type migraine, retinal migraine, and ophthalmoplegic migraine are also reviewed. This paper focuses particularly on the symptomatology of these primary headache disorders, but also discusses their epidemiology, clinical features, and treatment.

A test of the role of two prefrontal/ subcortical networks in the "sequencing" of non-motor, visuo-spatial information.

There are a number of prefrontal/sub-cortical networks in the brain (e.g., cerebellar-thalamic-prefrontal or basal ganglia/supplementary motor cortex circuits) that despite having a clear role in motor function have been shown to be involved in non-motor tasks. In this project we test for the involvement of these networks in a dimensional judgment task that utilizes visual perceptual, visual spatial processing and requires the ordering of dimensional (height) information. Unlike previous studies examining non-motor sequencing, we directly compare both non-motor and motor versions of our dimensional judgment task. In addition, we examine activation uniquely associated with correct task responses. The findings provide evidence for the role of cortical not subcortical structures in the sequencing of visuo-spatial material apart from any motor output requirements. Our results suggest that the inferior parietal cortex (BA 7, 40) and medial frontal regions (BA 6, 8, 9 including the SMA) are instrumental to the task. Based on these results, we propose a prefrontal/parietal network plays a role in the implementation of a comparator mechanism that makes accurate comparisons along the dimension of interest, holds the information in working memory, and then (regardless of whether the information is correct or incorrect) generates a tag or abstract code that assigns the information a place in an ordered sequence. Most important, the information involved can be visual/symbolic and non-motor (not just motor) in nature.

The fungus does not transfer carbon to or between roots in an arbuscular mycorrhizal symbiosis.

• Carbon transfer from fungus to plant in the arbuscular mycorrhizal (AM) symbiosis has been reported, but its significance and even its existence have been called into question and the issue remains controversial. We investigated carbon movement from fungus to plant and from one mycorrhizal root system to another via a common AM fungal network in monoxenic cultures to avoid limitations of some previous studies. • 13 C and 14 C labeled substrates were supplied to functioning in vitro AM mycorrhizas between Ri T-DNA transformed carrot (Daucus carota) roots and Glomus intraradices to follow carbon movement into and between host and fungal metabolite pools. • Fungal triacylglycerol and trehalose were labeled when permeant substrates were supplied to the extraradical mycelium (ERM), but host-specific compounds in the roots did not become labeled. When labeled glucose was provided to a donor root system, label moved to recipient roots via a common AM fungal network but remained in fungal compounds. • We conclude that carbon flow in the AM symbiosis is normally unidirectional from plant to fungus and that while carbon is translocated by the fungus from one metabolically active root system to another, it remains within the intraradical mycelium (IRM).