Abstract
Purpose: :
Dravet Syndrome, also known as Severe Myoclonic Epilepsy in Infancy (SMEI), is a rare but devastating seizure disorder with onset of the disease usually in the first year of life. It has been linked to genetic mutations in the SCN1 gene encoding the alpha-1 subunit of a neuronal voltage-gated sodium channel, and up to 80% of SMEI patients have this mutation. Up to 40% of cases involve a photosensitivity component, in which light triggers the epileptic response making this disease unique among the epilepsies. Little is known about the precise mechanism for this finding, but there is some speculation that it is due to the presence of these abnormal channels present in retinal ganglion cells. These seizures are poorly responsive to medications.
Methods: :
We present a case of one patient with SMEI whose photosensitive seizures were unsuccessfully controlled with anti-convulsive medications. Treatment was initiated using a unilateral occluding eye patch applied for six hours at a time in an alternating pattern.
Results: :
This treatment was successful in reducing the number of seizures by 40% (20 episodes in 2007 to 12 in 2008), allowing the patient to tolerate dim lighting and an ocular examination without an epileptic response.
Conclusions: :
The effectiveness of monocular alternating occlusion therapy in this patient is novel and has not been previously reported. It is a possible adjunctive therapy to the traditional treatment options of anti-seizure medications for SMEI.
Keywords: ion channels • photoreceptors • visual development: infancy and childhood