Classification of Phenotype Characteristics in Adult-Onset Spinal Muscular Atrophy

Abstract

Background/Aims: Degenerative lower motor neuron diseases (LMND) encompass a group of rare clinically and genetically heterogeneous disorders with the hallmark of anterior horn cell degeneration in the spinal cord and brainstem. In a recently proposed classification, LMND were subdivided according to the clinical disease pattern and time course. This study was performed to investigate the clinical practicability of the classification. Methods: In 22 patients with adult LMND (mean disease duration, 24 years), the disease course and detailed clinical, electrophysiological, magnetic resonance imaging, laboratory, and genetic investigations were analyzed. Results: All patients could be assigned to the distinct disease subgroups, i.e. 11 patients to the slowly progressive generalized form (group 1), one to the distal form (group 2), 3 to the segmental distal form (group 3a), and seven to the segmental proximal form (group 3b). Conclusions: The proposed classification was confirmed to be a practicable tool, and additional implications for the classification of LMND could be drawn from the data in our patient sample.

Quantitative muscle ultrasound in neuromuscular disorders using the parameters ‘intensity’, ‘entropy’, and ‘fractal dimension’

“…However, this set of parameters was able to distinguish between affected and unaffected, healthy skeletal muscle in an easy and quick diagnostic setting. Remarkably, this set of parameter was also able to distinguish between diseases with a predominant proximal pattern of muscle involvement (LGMD, IM, and SMA) [24–26] and healthy controls by sole examination of distal, and clinically not involved muscles (for statistical analysis see Tables 2 and 3). The patient with IM (Fig.…”

Guideline “Motor neuron diseases” of the German Society of Neurology (Deutsche Gesellschaft für Neurologie)

“…Laryngospasms are frequent in SBMA but may also occur in ALS partients [ 20 ]. Patients should be informed that they are harmless and self limitating.…”

Spinale Muskelatrophien

“…Die adulte proximale SMA (Beginn ca. 30 bis 60 Jahre) oder SMA-Typ IV wird in der Literatur meist im Kontext der "lower motor neuron diseases" genannt und schließt eine heterogene Erkrankungsgruppe ein [3,4]. Mehrheitlich sind die proximalen Beinmuskeln betroffen, der Verlauf ist meist langsam progredient.…”