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Refractory periods in SUNCT

Dear Sir,

The article by Paliwal et al. [1] brings to mind the importance of assessing the presence/absence of refractory periods in the differential diagnosis of short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), primarily because trigeminal neuralgia attacks are systematically followed by refractory periods, contrary to what is frequent in SUNCT.

Since the first communication of SUNCT [2], it has been known that post-attack refractory periods may be only relative or completely absent. Moreover, we reported that SUNCT paroxysms could be triggered during the “descrescendo” phase of an ongoing attack [3], and that occasionally, the usual stimuli seemed totally ineffective, even when applied for a prolonged time [4]. The sensitivity, or threshold, for attack generation, may therefore, differ from time to time. Later, we documented these findings [5] in a patient in whom many SUNCT attacks could be modulated by lengthening of the trigger stimuli.

Indeed, we first described the four patterns of the temporal profile of solitary SUNCT attacks: “plateau-like”, “saw-tooth like”, “repetitive”, and “plateau-like plus exacerbations” [4]. A repetitive pattern of sharp or spike-like paroxysms, without reaching the baseline in between the solitary peaks, inherently carried important pathophysiological implications, as spontaneous or triggered attacks overlapped each other, thus substantiating our observations that SUNCT attacks may lack refractory periods.

Available knowledge regarding both quantitative and qualitative temporal aspects of SUNCT attacks has been extensively reported by our group [25]. Unfortunately, Paliwal et al. [1] did not mention our early findings and mistakenly referenced the absence of refractory periods in SUNCT to an article by Cohen et al. [6]. For the sake of accuracy it should be noted that, in regards to this subject, Cohen et al. simply replicated our findings, many years later.

References

  1. 1.

    Paliwal VK, Singh P, Kumar A, Rahi SK, Gupta RK (2012) Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) with preserved refractory period: report of three cases. J Headache Pain 13:167–169, 22227716, 10.1007/s10194-011-0412-7

    PubMed Central  Article  PubMed  Google Scholar 

  2. 2.

    Sjaastad O, Saunte C, Salvesen R et al (1989) Shortlasting, unilateral, neuralgiform headache attacks with conjunctival injection, tearing, sweating and rhinorrhea. Cephalalgia 9:147–156, 2743414, 1:STN:280:DyaL1MzgsVSrsQ%3D%3D

    Article  CAS  PubMed  Google Scholar 

  3. 3.

    Pareja JA, Pareja J, Palomo T, Caballero V, Pamo M (1994) SUNCT syndrome. Repetitive and overlapping attacks. Headache 34:114–116, 8163367, 10.1111/j.1526-4610.1994.hed3402114.x, 1:STN:280:DyaK2c3hs1Wiug%3D%3D

    Article  CAS  PubMed  Google Scholar 

  4. 4.

    Pareja JA, Sjaastad O (1994) SUNCT syndrome in the female. Headache 34:217–220, 8014038, 10.1111/j.1526-4610.1994.hed3404217.x, 1:STN:280:DyaK2c3osVSkug%3D%3D

    Article  CAS  PubMed  Google Scholar 

  5. 5.

    Laín AH, Caminero AB, Pareja JA (2000) SUNCT syndrome. Absence of refractory periods and modulation of attack duration by lengthening of the trigger stimuli. Cephalalgia 20:671–673, 11128827, 10.1111/j.1468-2982.2000.00081.x

    Article  PubMed  Google Scholar 

  6. 6.

    Cohen AS, Matharu MS, Goadsby PJ (2006) Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) or cranial autonomic features (SUNA)—a prospective clinical study of SUNCT and SUNA. Brain 129:2746–2760, 16905753, 10.1093/brain/awl202

    Article  PubMed  Google Scholar 

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Correspondence to Juan A. Pareja.

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Open Access This article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Pareja, J.A., Álvarez, M. & Montojo, T. Refractory periods in SUNCT. J Headache Pain 13, 501 (2012). https://doi.org/10.1007/s10194-012-0463-4

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Keywords

  • Public Health
  • Internal Medicine
  • Differential Diagnosis
  • Temporal Profile
  • Trigeminal Neuralgia