Abstract
A 40-year-old man presented with a 25-year history of cramps affecting the abdomen, neck, and limbs. Examination revealed fasciculation in the forearms, abdomen, and chin (video on the Neurology® Web site at Neurology.org). There was shoulder girdle wasting with bilateral mastectomy scars (figure, B and C). Creatine kinase (CK) was 1,650 U/L (normal < 310 U/L). Electrodiagnostic studies revealed sensory neuronopathy with neurogenic changes on EMG. Genetic testing demonstrated excess CAG repeats in the androgen receptor gene, confirming Kennedy disease.1 This X-linked disorder is the most common adult-onset spinal muscular atrophy. CK can be markedly raised.2 Gynecomastia results from androgen insufficiency and can precede the development of neurologic symptoms.
A 40-year-old man presented with a 25-year history of cramps affecting the abdomen, neck, and limbs. Examination revealed fasciculation in the forearms, abdomen, and chin (video on the Neurology® Web site at Neurology.org). There was shoulder girdle wasting with bilateral mastectomy scars (figure, B and C). Creatine kinase (CK) was 1,650 U/L (normal < 310 U/L). Electrodiagnostic studies revealed sensory neuronopathy with neurogenic changes on EMG. Genetic testing demonstrated excess CAG repeats in the androgen receptor gene, confirming Kennedy disease.1 This X-linked disorder is the most common adult-onset spinal muscular atrophy. CK can be markedly raised.2 Gynecomastia results from androgen insufficiency and can precede the development of neurologic symptoms.
Figure. Relevant examination findings.
(A) Perioral fasciculation and grouped motor unit discharges in a patient with Kennedy disease (video). (B) Shoulder girdle weakness and wasting with bilateral scapular winging. (C) Scars from bilateral mastectomies performed at age 15 for gynecomastia.
Supplementary Material
Footnotes
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AUTHOR CONTRIBUTIONS
Dr. Whittaker: design/conceptualization of the study, analysis/interpretation of neurophysiology data, drafting/revising the manuscript. Prof. Chinnery: drafting/revising the manuscript. Dr. Miller: drafting/revising the manuscript.
STUDY FUNDING
No targeted funding reported.
DISCLOSURE
R. Whittaker receives funding from the National Institute of Health Research, EPSRC, and Wellcome Trust. P. Chinnery is a Wellcome Trust Senior Fellow in Clinical Science (101876/Z/13/Z) and a UK NIHR Senior Investigator. P.F.C. receives additional support from the Wellcome Trust Centre for Mitochondrial Research (096919Z/11/Z), the Medical Research Council (UK) Centre for Translational Muscle Disease Research (G0601943), EU FP7 TIRCON, and the National Institute for Health Research (NIHR) Newcastle Biomedical Research Centre based at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health. J. Miller reports no disclosures relevant to the manuscript. Go to Neurology.org for full disclosures.
REFERENCES
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