Exploring hand and upper limb function in patients with inclusion body myositis (IBM)

Inclusion body myositis (IBM) is an inflammatory myopathy characterized by progressive weakness of knee extensors and finger flexors. Many patients lose independence with fine motor tasks; however, a gap remains as to how these deficits correlate with performance on functional outcome measures. We describe functional hand impairments as measured by performance-based outcome measures in a cross-sectional sample of 74 patients with IBM. Subjects completed a series of outcome measures (Functional Dexterity Test (FDT), Performance of the Upper Limb (PUL), and Sollerman Hand Function Test (SHFT)) alongside a collection of patient reported outcomes (PROs). Assessments were compared to standard IBM measurements, including grip strength and IBM Functional Rating Scale (IBMFRS). FDT and SHFT demonstrated significant correlations to grip (p<0.001; Spearman correlations r=0.48-0.70). Significant correlation was found between all functional outcome measures and IBMFRS (p<0.001; Spearman correlations r=0.51-0.77), as well as PRO Upper Extremity Scale for IBM (IBM-PRO) (p<0.05; Spearman correlations r=0.55-0.73). Non-ambulatory patients demonstrated significantly weaker grip (p<0.001), resulting in lower PUL scores and increased FDT completion times (p<0.001). Collectively, these assessments may provide insight to understanding functional limitations of the hands and potentially allow for more inclusive clinical trials with future validation of hand assessments in IBM.

Distal myopathy

Distal myopathies are a group of genetic, primary muscle diseases. Patients develop progressive weakness and atrophy of the muscles of forearm, hands, lower leg, or feet. Currently, over 20 different forms, presenting a variable age of onset, clinical presentation, disease progression, muscle involvement, and histological findings, are known. Some of them are dominant and some recessive. Different variants in the same gene are often associated with either dominant or recessive forms, although there is a lack of a comprehensive understanding of the genotype-phenotype correlations. This chapter provides a description of the clinicopathologic and genetic aspects of distal myopathies emphasizing known etiologic and pathophysiologic mechanisms.

Ischemic stroke cases presenting with hand weakness mimicking peripheral neuropathy

Pure motor monoparesis due to ischemic stroke involving a single extremity is a rare condition that can be easily misdiagnosed. Herein, we present three cases with isolated upper extremity monoparesis. All of our patients had weakness in the left hand. They were previously evaluated in other centers and were diagnosed with peripheral neuropathy by electromyography. When patients whose complaints did not resolve were admitted to our clinic, we performed electromyography again and observed that it was normal. Hereupon, we detected ischemic infarctions in cranial magnetic resonance imaging that would explain the patients' complaints. Isolated monoparesis mimicking peripheral neuropathy is a rare symptom in stroke patients. Pure motor monoparesis should be kept in mind in every patient presenting with acute-isolated monoparesis, and neuroradiological imaging should be performed.

A Confirmed Case in the United Kingdom of Hirayama Disease in a Young White Male Presenting with Hand Weakness

BACKGROUND

We present the first reported case of Hirayama disease in the United Kingdom. A literature review of Hirayama disease in the Western literature shows that this case is unique in being the first in the United Kingdom, constituting one of only a few cases in Europe with supporting magnetic resonance imaging and reported treatment outcome.

CASE DESCRIPTION

Our patient was a young Caucasian male who presented with progressive bilateral hand weakness, had confirmatory magnetic resonance imaging findings of Hirayama disease, and experienced improvement of symptoms with cervical collar immobilization.

CONCLUSIONS

This case lends further evidence to the flexion-induced myelopathy theory of Hirayama disease and supports the findings of other studies in which avoidance of neck flexion and cervical immobilization helped to attenuate disease progression in this patient group.

Sensorimotor modulation by botulinum toxin A in post-stroke arm spasticity: Passive hand movement

INTRODUCTION

In post-stroke spasticity, functional imaging may uncover modulation in the central sensorimotor networks associated with botulinum toxin type A (BoNT) therapy. Investigations were performed to localize brain activation changes in stroke patients treated with BoNT for upper limb spasticity using functional magnetic resonance imaging (fMRI).

METHODS

Seven ischemic stroke patients (4 females; mean age 58.86) with severe hand paralysis and notable spasticity were studied. Spasticity was scored according to the modified Ashworth scale (MAS). fMRI examination was performed 3 times: before (W0) and 4 (W4) and 11weeks (W11) after BoNT. The whole-brain fMRI data were acquired during paced repetitive passive movements of the plegic hand (flexion/extension at the wrist) alternating with rest. Voxel-by-voxel statistical analysis using the General Linear Model (GLM) implemented in FSL (v6.00)/FEAT yielded group session-wise statistical maps and paired between-session contrasts, thresholded at the corrected cluster-wise significance level of p<0.05.

RESULTS

As expected, BoNT transiently lowered MAS scores at W4. Across all the sessions, fMRI activation of the ipsilesional sensorimotor cortex (M1, S1, and SMA) dominated. At W4, additional clusters transiently emerged bilaterally in the cerebellum, in the contralesional sensorimotor cortex, and in the contralesional occipital cortex. Paired contrasts demonstrated significant differences W4>W0 (bilateral cerebellum and contralesional occipital cortex) and W4>W11 (ipsilesional cerebellum and SMA). The remaining paired contrast (W0>W11) showed activation decreases mainly in the ipsilesional sensorimotor cortex (M1, S1, and SMA).

CONCLUSIONS

The present study confirms the feasibility of using passive hand movements to map the cerebral sensorimotor networks in patients with post-stroke arm spasticity and demonstrates that BoNT-induced spasticity relief is associated with changes in task-induced central sensorimotor activation, likely mediated by an altered afferent drive from the spasticity-affected muscles.

Cortical activity modulation by botulinum toxin type A in patients with post-stroke arm spasticity: real and imagined hand movement

BACKGROUND

Our aim was to use functional magnetic resonance imaging (fMRI) to compare brain activation changes due to botulinum toxin A (BoNT) application between two chronic stroke patient groups with different degree of weakness treated for upper limb spasticity.

METHODS

Fourteen ischemic stroke patients with hand weakness and spasticity were studied. Spasticity was scored by modified Ashworth scale (MAS). FMRI was performed 3 times: before (W0) and 4 (W4) and 11 weeks (W11) after BoNT application. Group A: 7 patients (2 males, 5 females; mean age 59.14 years) with hand plegia, who imagined moving fingers. Group B: 7 age-matched patients (6 males, 1 female; mean age 59.57 years) able to perform sequential finger movement.

RESULTS

BoNT transiently lowered MAS in W4 in both groups. In group A, activation of the frontal premotor cortex dominated and persisted for all three fMRI sessions whereas the ipsilesional cerebellum and cortex bordering bilateral intraparietal sulcus activation changed over time. Between-session contrasts showed treatment-related activation decreases in the mesial occipitoparietal and lateral occipital cortex. In group B, brain activation was markedly reduced after BoNT (W4). Whereas some of these areas manifested only transient reduction and expanded again at W11, in others the reduction persisted.

CONCLUSION

Study of two age-matched groups with mild and severe weakness demonstrated different effects of BoNT-lowered spasticity on sensorimotor networks. Group A performing movement imagery manifested BoNT-induced reduction of activation in structures associated with visual imagery. Group B performing movement manifested reduced activation extent and reduced activation of structures outside classical motor system, suggestive of motor network normalization.