Leg amyotrophic diplegia: Prevalence and pattern of weakness at us neuromuscular centers

Mazen M. Dimachkie, Iryna M. Muzyka, Jonathan S. Katz, Carlayne Jackson, Yunxia Wang, April L. McVey, Arthur Dick, Mamatha Pasnoor, M. Tahseen Mozaffar, Z. Xiao-Song, John T. Kissel, E. Ensrud, Jeffrey Rosenfeld, Richard J. Barohn

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Objective: To identify the frequency of leg amyotrophic diplegia (LAD) at a US academic center, describe the pattern of weakness, and provide comparative data from 8 additional major US academic institutions. BACKGROUND: LAD is a leg onset variant of progressive muscular atrophy (PMA). LAD weakness is confined to the legs for at least 2 years, and there are no upper motor neuron signs. DESIGN/Methods: We present a retrospective chart review of 24 patients with the LAD presentation from the University of Kansas Medical Center ( n = 8 cases) and from 8 US academic institutions (n = 16 cases). Results: Of the 318 subjects identified in the University of Kansas Medical Center Neuromuscular Research Database, 82% (260 subjects) had amyotrophic lateral sclerosis (ALS), 1.9% (6) had familial ALS, 6.6% (21) had primary lateral sclerosis, and 9.2% (29) had lower motor neuron (LMN) disease. Of these 29 cases, 16 had PMA, 5 had brachial amyotrophic diplegia, while 8 had LAD. The mean LAD age of onset was 58 years with a male/female ratio of 3/1. Onset was asymmetric in 7/8. We identified a pelviperoneal pattern of weakness (sparing of knee extension and/or ankle plantar flexion) in 4 cases and distal predominant weakness in 3 cases. All patients had electrodiagnostic findings consistent with motor neuron disease confined to the lower extremities. We present LAD disease duration and survival data from 8 major academic neuromuscular centers. At last follow-up, weakness progressed to involve the arms in 6/24 LAD cases and of these 6 cases, 2 patients died from progression to typical ALS. From onset of symptoms, mean survival in LAD is 87 months, with 92% of cases being alive. Conclusions/Relevance: The natural history of LAD differs from typical forms of ALS and PMA. LAD is a slowly progressive disorder that accounts for a fourth of LMN disease cases. An asymmetric pelviperoneal pattern of weakness should heighten the suspicion for LAD.

Original languageEnglish (US)
Pages (from-to)7-12
Number of pages6
JournalJournal of Clinical Neuromuscular Disease
Issue number1
StatePublished - 2013


  • amyotrophic lateral sclerosis
  • leg amyotrophic diplegia
  • progressive motor dysfunction
  • progressive muscular atrophy

ASJC Scopus subject areas

  • Clinical Neurology
  • Neurology


Dive into the research topics of 'Leg amyotrophic diplegia: Prevalence and pattern of weakness at us neuromuscular centers'. Together they form a unique fingerprint.

Cite this