Differential diagnosis of mesiotemporal lesions: case report of neurosyphilis

Abstract

Sir, The September issue of Neuroradiology contained an interesting article by Vieira Santos et al. entitled “Differential diagnosis of mesiotemporal lesions: case report of neurosyphilis” [1]. Coincidentally, a paper by us on the same subject (the differential diagnosis of neuroradiologically apparent medial temporal lobe abnormalities [2]) was published in the September issue of the Journal of Neurology. As an author of the latter paper, I would like to make some remarks on the case report by Vieira Santos et al. [1]. The authors state that medial temporal lobe involvement in neurosyphilis had previously been described in only four patients. However, this statement is incorrect. First, the cited article by Kanamalla et al. does not include such a finding in the context of neurosyphilis. Second, as we document [2], although medial temporal lobe involvement in neurosyphilis can still be regarded as rare, it is not as rare as the authors suggest. In addition to the case report of Vieira Santos et al., as well as a report that was recently published in Neurology [3], at least 16 patients with this neuroimaging pattern can be found in the literature. With respect to its pathogenesis, we have already pointed out that the assumption of a meningovascular origin is questionable [2]. We would like to pose the questions: how do the authors interpret the discordant results of the serologic and CSF tests in syphilis and, as a result, which stage of syphilis do they see in their patient? Finally, the differential diagnosis of the clinical signs and symptoms of the patient include Lyme neuroborreliosis. Borrelia burgdorferi is well known as a confounder of serologic tests in syphilis [4]. As penicillin G may be a satisfactory treatment alternative in neuroborreliosis [5], the response to this kind of treatment cannot be regarded as a sufficient criterion of differentiation. We therefore ask whether the authors ruled out Lyme neuroborreliosis in this patient.