Cluster headache as a manifestation of a stroke-like episode in a carrier of the MT-ND3 variant m.10158T>C.

In a recent article Fu et al reported about a 52 years old female with a mitochondrial disorder due to the variant m.10158T>C in the mtDNA located gene MT-ND3. The study has a number of shortcomings. The study would particularly profit from providing more data about multisystem disease, from providing the current medication, the cerebro-spinal fluid findings, the detailed phenotypic presentation, and the genotype of first-degree relatives. Since the index patient had experienced recurrent seizures it is crucial to know the current and previous anti-seizure medication as it may strongly determine the outcome. Some of them are mitochondrion-toxic and particularly valproic acid may exhibit fatal side effects. The outcome may also depend on the degree of multisystem involvement why it is crucial to prospectively investigate the patient for subclinical involvement of organs not obviously affected. Additionally, the outcome of the stroke-like lesions on imaging would be interesting to see. Stroke-like lesions may completely disappear or may end up as white matter lesion, laminar cortical necrosis, focal atrophy, cyst, or as the so-called toenail sign. There is also a need of discussing more profoundly the imaging findings and their diagnostic significance and to investigate first degree relatives of the index patient clinically and genetically. Though highly interesting, the presentation of this case of a mitochondrial disorder lacks clinical and genetic data of the patient and his relatives. Outcome parameters, such as severity of disease, degree of progression, drugs, pathogenicity of the mutation, and multisystem involvement require a profound discussion.