TY - JOUR
T1 - Research priorities in limb and task-specific dystonias
AU - Richardson, Sarah Pirio
AU - Altenmüller, Eckart
AU - Alter, Katharine
AU - Alterman, Ron L.
AU - Chen, Robert
AU - Frucht, Steven
AU - Furuya, Shinichi
AU - Jankovic, Joseph
AU - Jinnah, H. A.
AU - Kimberley, Teresa J.
AU - Lungu, Codrin
AU - Perlmutter, Joel S.
AU - Prudente, Cecília N.
AU - Hallett, Mark
N1 - Publisher Copyright:
© 2017 Pirio Richardson, Altenmüller, Alter, Alterman, Chen, Frucht, Furuya, Jankovic, Jinnah, Kimberley, Lungu, Perlmutter, Prudente and Hallett.
PY - 2017/5/3
Y1 - 2017/5/3
N2 - Dystonia, which causes intermittent or sustained abnormal postures and movements, can present in a focal or a generalized manner. In the limbs, focal dystonia can occur in either the upper or lower limbs and may be task-specific causing abnormal motor performance for only a specific task, such as in writer's cramp, runner's dystonia, or musician's dystonia. Focal limb dystonia can be non-task-specific and may, in some circumstances, be associated with parkinsonian disorders. The true prevalence of focal limb dystonia is not known and is likely currently underestimated, leaving a knowledge gap and an opportunity for future research. The pathophysiology of focal limb dystonia shares some commonalities with other dystonias with a loss of inhibition in the central nervous system and a loss of the normal regulation of plasticity, called homeostatic plasticity. Functional imaging studies revealed abnormalities in several anatomical networks that involve the cortex, basal ganglia, and cerebellum. Further studies should focus on distinguishing cause from effect in both physiology and imaging studies to permit focus on most relevant biological correlates of dystonia. There is no specific therapy for the treatment of limb dystonia given the variability in presentation, but off-label botulinum toxin therapy is often applied to focal limb and task-specific dystonia. Various rehabilitation techniques have been applied and rehabilitation interventions may improve outcomes, but small sample size and lack of direct comparisons between methods to evaluate comparative efficacy limit conclusions. Finally, non-invasive and invasive therapeutic modalities have been explored in small studies with design limitations that do not yet clearly provide direction for larger clinical trials that could support new clinical therapies. Given these gaps in our clinical, pathophysiologic, and therapeutic knowledge, we have identified priorities for future research including: the development of diagnostic criteria for limb dystonia, more precise phenotypic characterization and innovative clinical trial design that considers clinical heterogeneity, and limited available number of participants.
AB - Dystonia, which causes intermittent or sustained abnormal postures and movements, can present in a focal or a generalized manner. In the limbs, focal dystonia can occur in either the upper or lower limbs and may be task-specific causing abnormal motor performance for only a specific task, such as in writer's cramp, runner's dystonia, or musician's dystonia. Focal limb dystonia can be non-task-specific and may, in some circumstances, be associated with parkinsonian disorders. The true prevalence of focal limb dystonia is not known and is likely currently underestimated, leaving a knowledge gap and an opportunity for future research. The pathophysiology of focal limb dystonia shares some commonalities with other dystonias with a loss of inhibition in the central nervous system and a loss of the normal regulation of plasticity, called homeostatic plasticity. Functional imaging studies revealed abnormalities in several anatomical networks that involve the cortex, basal ganglia, and cerebellum. Further studies should focus on distinguishing cause from effect in both physiology and imaging studies to permit focus on most relevant biological correlates of dystonia. There is no specific therapy for the treatment of limb dystonia given the variability in presentation, but off-label botulinum toxin therapy is often applied to focal limb and task-specific dystonia. Various rehabilitation techniques have been applied and rehabilitation interventions may improve outcomes, but small sample size and lack of direct comparisons between methods to evaluate comparative efficacy limit conclusions. Finally, non-invasive and invasive therapeutic modalities have been explored in small studies with design limitations that do not yet clearly provide direction for larger clinical trials that could support new clinical therapies. Given these gaps in our clinical, pathophysiologic, and therapeutic knowledge, we have identified priorities for future research including: the development of diagnostic criteria for limb dystonia, more precise phenotypic characterization and innovative clinical trial design that considers clinical heterogeneity, and limited available number of participants.
KW - Botulinum toxin
KW - Deep brain stimulation
KW - Dystonia
KW - Inhibition
KW - Limb
KW - Research priorities
KW - Task-specific
UR - http://www.scopus.com/inward/record.url?scp=85019953133&partnerID=8YFLogxK
U2 - 10.3389/fneur.2017.00170
DO - 10.3389/fneur.2017.00170
M3 - Review article
C2 - 28515706
AN - SCOPUS:85019953133
SN - 1664-2295
VL - 8
JO - Frontiers in Neurology
JF - Frontiers in Neurology
IS - MAY
M1 - 170
ER -