Environmental risk factors and clinical phenotype in familial and sporadic primary blepharospasm
- G. Defazio, MD, PhD,
- G. Abbruzzese, MD,
- M.S. Aniello, MD,
- M. Bloise, MD,
- C. Crisci, MD,
- R. Eleopra, MD,
- G. Fabbrini, MD,
- P. Girlanda, MD,
- R. Liguori, MD,
- A. Macerollo, MD,
- L. Marinelli, MD,
- D. Martino, MD, PhD,
- F. Morgante, MD, PhD,
- L. Santoro, MD,
- M. Tinazzi, MD and
- A. Berardelli, MD
- From the Department of Neurologic and Psychiatric Sciences and School of Motor Sciences (G.G., M.S.A., A.M., D.M.), “Aldo Moro” University of Bari, Bari; Department of Neurosciences, Ophthalmology and Genetics (G.A., L.M.), University of Genoa, Genoa; Department of Neurology and Psychiatry (Rome) and NEUROMED Institute (M.B., G.F., L.S., A.B.), Sapineza University of Rome, Rome; Department of Neurology (C.C.), Second University of Naples, Naples; Department of Neurology (R.E.), Udine Hospital, Udine; Department of Neurosciences, Psychiatry, and Anesthesiological Science (P.G., F.M.), University of Messina, Messina; Department of Neurosciences (R.L.), University of Bologna, Bologna; and Department of Neurological and Vision Sciences (M.T.), University of Verona, Verona, Italy.
- Address correspondence and reprint requests to Dr. G. Defazio, Department of Neurological and Psychiatric Sciences, “Aldo Moro” University of Bari, Policlinico, Piazza Giulio Cesare 1, I-70124 Bari, Italy gdefazio{at}neurol.uniba.it
Abstract
Background: Although environmental and genetic factors may contribute to the etiology of blepharospasm, their relative contribution in causing familial and sporadic blepharospasm is unknown.
Methods: First-degree relatives of 122 patients with primary blepharospasm were examined with a validated 2-step diagnostic procedure, including a screening questionnaire and examination of some relatives. Examiners were blinded to the questionnaire data for family history of probands. Data for demographic and clinical features, prior ophthalmologic complaints, and nondecaffeinated coffee intake were collected from probands before family investigation.
Results: Dystonia was diagnosed in 27 relatives from 23 families (20% rate of family history for dystonia). No significant differences were found between familial and sporadic cases in the frequency of coffee drinking and eye diseases or in sex, age at onset, or tendency to spread. Multivariable conditional logistic analysis testing of 67 case patients and 127 family-matched unaffected siblings yielded a significant positive association between blepharospasm and prior eye diseases (adjusted odds ratio [OR] 2.5; 95% confidence interval [CI] 1.1–6.1; p = 0.03) and a significant inverse association between case status and ever coffee drinking (adjusted OR 0.23; 95% CI 0.1–0.8; p = 0.02).
Conclusions: The new information from this large family-based study on primary blepharospasm strongly supports eye diseases and coffee as risk factors for blepharospasm. The finding that the 2 environmental exposures exerted a similar influence on familial and sporadic blepharospasm, together with the convergent phenotypic expression in familial and sporadic cases, implies that familial and sporadic blepharospasm probably share a common etiologic background.
GLOSSARY
- BSP=
- primary blepharospasm;
- CI=
- confidence interval;
- ICC=
- intraclass correlation coefficient
Footnotes
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Study funding: Funded by the Comitato Promotore Telethon, Italy (grant GGP05165).
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Editorial, page 616
- Received November 6, 2010.
- Accepted February 18, 2011.
- Copyright © 2011 by AAN Enterprises, Inc.
