title: Relative preservation of finger flexion in amyotrophic lateral sclerosis.
abstract: A characteristic pattern of intrinsic hand muscle involvement--known as the split hand sign--is typical of ALS; differential involvement of forearm muscles has not been examined systematically. After observing that finger-flexion was often preserved in ALS, despite severe weakness of finger-extension, we assessed the relative involvement of these two muscle groups in a cohort of patients with ALS. We found finger-flexion to be relatively preserved, when compared with finger-extension, in patients with ALS. In many cases finger-flexion is only minimally affected, even when finger-extension is totally paralyzed. The reasons for this predilection are unclear, but may be similar to those underlying the split-hand sign. Nevertheless, the discrepancy may provide another useful clinical clue in patients presenting with distal upper-limb weakness.
authors.affiliation: Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah-Hebrew University Medical Center, Israel.
authors.forename: Ari
authors.initials: A
authors.lastname: Shemesh
authors.affiliation: Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah-Hebrew University Medical Center, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Arkadir
authors.affiliation: Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Hadassah-Hebrew University Medical Center, Israel. Electronic address: marc@gotkine.com.
authors.forename: Marc
authors.initials: M
authors.lastname: Gotkine
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D005385:Fingers / Q000503:physiopathology*; D006801:Humans; D053580:Muscle Strength / Q000502:physiology*; D018908:Muscle Weakness / Q000503:physiopathology*
keywords: ALS; Clinical neurology; Clinical sign; Finger extension; Finger flexion; Motor neuron disease; Neuromuscular; Upper-limb weakness