An evaluation of the role of environmental factors in the disease penetrance of cervical dystonia

Abstract

Cervical dystonia patients had a history, prior to symptom onset, of significantly more frequent episodes of surgery and of car accidents with hospital attendance than their age-matched unaffected siblings. Soft tissue trauma appears to increase risk of development of cervical dystonia in genetically predetermined individuals.

Sun exposure is an environmental factor for the development of blepharospasm

“…Environmental risk factors for cervical dystonia include trauma,7 10 but no relationship has been found between head trauma and blepharospasm or other cranial phenotypes 39. Similarly, scoliosis, which has been associated with cervical dystonia,40 has been shown not to be a risk for blepharospasm 41.…”

“…Environmental factors may influence disease penetrance and phenotype expression 7–9. Patients with cervical dystonia, compared with their unaffected siblings, have a history of more frequent car accidents with hospital attendance;10 anterior segment eye disease has been suggested to be a risk factor for blepharospasm,11 whereas coffee drinking appears protective 12. Cervical dystonia appears to be the most frequent phenotype in northern Europe, whereas blepharospasm seems more frequent in southern Europe.…”

Understanding dystonia: diagnostic issues and how to overcome them

“…It seems to be the resulting force of a complex network of genetic, epigenetic and environmental vectors. Penetrance is the result of adding individual vectors 6,27,28,29,30 . Sensory abnormalities may drive dystonia, as well as somatosensory receptive fields being abnormally enlarged and disorganized in patients, with sensitive stimuli modulating dystonic movement.…”

“…The etiology of primary dystonia is assumed to be a complex combination of intrinsic metabolic properties, environmental and genetic factors 27,28 .…”

“…Scoliosis and soft tissue trauma appear to increase the risk of cervical dystonia in genetically predetermined individuals 28,29 . Sunlight exposure has been linked to a higher risk factor for the development of blepharospasm.…”