The role of VNS and surgery in Dravet syndrome is debatable, and neurologists have little data on effectiveness. One very small study reviewed the success rate of these surgeries at a particular institution (Dlouhy, et. al. 2016). Eight surgeries performed on seven patients with Dravet syndrome (one child had both a VNS implanted and, subsequently, a corpus callosotomy (CC)) showed decreased seizures in 5/6 of the VNS patients and 2/2 of the CC patients.
PCDH19 epilepsy is often misdiagnosed as Dravet syndrome (DS), especially in females where PCDH19 epilepsy is more prevalent. A recent study compared the clinical features of both and found that epilepsy onset was earlier in DS by an average of 6 months (Trivisano, et. al. 2016). The second seizure occurred after a longer period in the PCDH19 group, and seizures tended to cluster more in the PCDH19 group. Some symptoms, such as myoclonic seizures and photosensitivity, were only found in the DS group, while others, such as status epilepticus and intellectual disabilities, were found to occur equally in both groups.
Gait is a concern for patients with Dravet syndrome, though the causes of crouch gait remain unclear. One study examined 12 patients with Dravet syndrome (all of whom had SCN1A mutations) and found that all 12 (aged two years to 17 years) showed gait disturbance (Gitiaux, et. al. 2016). There were features of chronic denervation on EMG, and there was definite motor neuropathy in seven patients, with probable motor neuropathy in three patients.
While not specifically Dravet-related, a recent analysis of nearly 4,000 infants admitted to a NICU in Canada over a two year period identified 20 undiagnosed patients who were referred for metabolic or genetic screening. Of those 20, eight received a diagnosis based on next-gen sequencing, one of which was SCN1A-related encephalopathy syndrome. This highlights the potential benefits of early detection and screening on infants presenting to the NICU, as is often the case in the first year of life with Dravet syndrome.