From the Guidelines
Blepharospasms are primarily caused by abnormalities in the brain's basal ganglia, which controls movement, and can be triggered by fatigue and stress 1.
Possible Causes
- Unknown causes: The exact cause of blepharospasms is often unknown
- Brain abnormalities: Abnormalities in the brain's basal ganglia, which is the area responsible for controlling movement
- Conditions: Blepharospasms can be a symptom of a condition such as blepharospasm disorder, dystonia, or Parkinson's disease
- Medications: Certain medications like antipsychotics and anti-emetics can also cause blepharospasms as a side effect
Treatment
Treatment typically involves botulinum toxin injections, such as Botox, which can help relax the muscles and reduce spasms, as supported by the use of OnaBoNT-A and incoBoNT-A for treating blepharospasm 1. In some cases, medications like clonazepam or trihexyphenidyl may be prescribed to help manage symptoms. It's essential to consult a healthcare professional for proper diagnosis and treatment.
From the Research
Causes of Blepharospasm
- The exact cause of blepharospasm is not fully understood, but it is believed to be related to abnormal functioning of the brain's motor control systems 2.
- Research suggests that blepharospasm may be caused by a combination of factors, including abnormalities in the basal ganglia dopamine system, sensorimotor learning substrate, and patterns of increased blinking 2.
- Some studies suggest that blepharospasm may be related to vascular compression of cranial nerve VII (CN VII), leading to involuntary unilateral contractions of muscles used in facial expression 3.
- Other research suggests that blepharospasm may be caused by a dynamic circuit hypothesis, which incorporates the joint influence of motor cortical regions and direct descending projections from the substantia nigra pars reticulata on brainstem motor nuclei 2.
Pathophysiology of Blepharospasm
- Blepharospasm is characterized by excessive or continuous eye closure related to overactivity of the orbicularis oculi and adjacent muscles bilaterally 4, 3.
- The disorder can also involve involuntary movements of the lower face and neck muscles, as well as dystonic, uncontrolled movements in areas outside the facial nerve distribution 4.
- Abnormal eye movements, including saccadic intrusions and extraocular muscle dystonia, can also occur in patients with blepharospasm 5.
- The pathogenesis of blepharospasm is believed to involve abnormalities in the basal ganglia, brainstem structures, and sensorimotor learning substrate 2, 5.