This paper was interesting because one doesn’t see too many reports focused on adult Dravet patients. It has been found that Parkinsonism is a motor condition that often develops in adults with Dravet syndrome. However, it is not well understood how Dravet syndrome, in particular dysfunction of the NaV1.1 sodium channel, is connected to the etiology of Parkinsonism. The current paper focuses on this issue, and it describes studies on a 19-year-old patient diagnosed with both conditions.
Loss of presynaptic dopaminergic cells is known to be a cause of Parkinsonism, but in the present case, based on dopamine transporter imaging, this mechanism was ruled out. Profiling of monoamine neurotransmitters in the cerebrospinal fluid was performed, and suggested that dopamine synthesis was impaired. Parkinsons patients with this etiology usually respond well to treatment with levodopa. This sounds hopeful, but unfortunately in the current case levodopa treatment was hampered by nausea, possibly caused by interactions with the multiple anti-seizure medications the patient was taking. Nevertheless, the authors have pinpointed a connection between sodium channel dysfunction and depressed monoamine neurotransmitter production, and they recommend that further studies investigate this link.