Alzheimer’s disease – a case for the laser dentist?

By Jan Tunér

It is well known that laser phototherapy (LPT) is effective in treating Herpes Simples type 1 (HSV-1). There are several methods to treat HSV-1, primarily various prescription and non-prescription topical medications. These are effective but generally less effective than LPT. And they do not have the great advantage of LPT in that LPT seems to be able to prolong the periods of recurrence [1, 2, 3]. Two recent Swedish studies have observed the connection between the herpes simplex virus and Alzheimer’s disease (4, 5]. It is interesting the read the abstract of these two studies:

Herpes simplex virus (HSV) is thought to play an etiological role in the development of Alzheimer’s disease (AD). Plasma samples from 360 AD cases (75.3% women, mean age 61.2 years) and 360 age- and sex-matched dementia-free controls, taken on average 9.6 years before AD diagnosis, were analyzed for anti-HSV antibodies (immunoglobulin G, IgG, and immunoglobulin M, IgM) by enzyme-linked immunosorbent assays. In the complete sample group, the presence of anti-HSV IgG and IgM antibodies did not increase the risk of AD significantly (odds ratio (OR) 1.636, P = .069 and OR 1.368, P = .299, respectively). In cases with 6.6 years or more between plasma sampling and AD diagnosis (n = 270), there was a significant association between presence of anti-HSV IgG antibodies and AD (OR 2.250, P = .019). Among persons with a follow-up time of 6.6 years or more, HSV infection was significantly associated with AD.

Previous studies have suggested a link between herpes simplex virus (HSV) type 1 and the development of Alzheimer’s disease (AD). The present analysis included 3432 persons (53.9% women, mean age at inclusion 62.7 ± 14.4 years) with a mean follow-up time of 11.3 years. The number of incident AD cases was 245. Serum samples were analyzed for anti-HSV antibodies (immunoglobulin (Ig)G and IgM) by enzyme-linked immunosorbent assays. The presence of anti-HSV IgG antibodies was not associated with an increased risk for AD, controlled for age and sex (hazard ratio, HR, 0.993, P = .979). However, the presence of anti-HSV IgM at baseline was associated with an increased risk of developing AD (HR 1.959, P = .012). Positivity for anti-HSV IgM, a sign of reactivated infection, was found to almost double the risk for AD, whereas the presence of anti-HSV IgG antibodies did not affect the risk.

When reading the above articles, it seems possible that prolonging the intervals of recurrence in these patients is valuable. And it appears that if the attacks are treated at each recurrence, the virus will in the end be inactivated. Whether or not this means that the virus is completely inactivated or just not expressing itself clinically is still unknown.

What does this mean for dentistry? It is obvious that dentists see patients with HSV-1 regularly and, so far, more dentist than medical doctors have an access to a therapeutic laser. With the above information in mind, it seems more important than ever for dentists to pay attention to patients with HSV-1 and in particular with those with a history of recurrence. These patients should be informed to contact the dental office as soon as the prodromal symptoms re-appear. In the paper by Schindl [1] the patients were even treated in the silent, in-between periods and this was also effective. This would further suggest that a known HSV-1 patient at a regular check-up could be laser treated to advantage.

LPT for HSV-1 is then not a method of treating the actual pathology, but there is growing evidence of the possibility to use LPT in a more direct way [6, 7, 8], but then, this is not dentistry any longer.



[1] Schindl A, Neuman R. Low-intensity laser therapy is an effective treatment for recurrent herpes simplex infection. Results from a randomized double-blind placebo controlled study. J Investigative Dermatology. 1999; 113 (2): 221-223.

[2] de Paula Eduardo C, Aranha AC, Simões A, Bello-Silva MS, Ramalho KM, Esteves-Oliveira M, de Freitas PM, Marotti J, Tunér J. Laser treatment of recurrent herpes labialis: a literature review. Lasers Med Sci. 2014; 29 (4): 1517-1529.

[3] Muñoz Sanchez P J, Capote Femenías J L, Díaz Tejeda A, Tunér J. The effect of 670-nm low laser therapy on herpes simplex type 1. Photomed Laser Surg. 2012; 30 (1): 37-40.

[4] Lövheim H, Gilthorpe J, Johansson A, Eriksson S, Hallmans G, Elgh F. Herpes simplex infection and the risk of Alzheimer’s disease-A nested case-control study. Alzheimers Dement. 2014 Oct 7. pii: S1552-5260(14)02770-8. doi: 10.1016/j.jalz.2014.07.157. [Epub ahead of print]

[5] Lövheim H, Gilthorpe J, Adolfsson R, Nilsson LG, Elgh F. Reactivated herpes simplex infection increases the risk of Alzheimer’s disease. Alzheimers Dement. 2014 Jul 17. pii: S1552-5260(14)02421-2. doi: 10.1016/j.jalz.2014.04.522. [Epub ahead of print]

[6] Rojas J C, Bruchey A K, Gonzalez-Lima F. Low-level light therapy improves cortical metabolic capacity and memory retention. J Alzheimers Dis. 2012; 1; 32 (3): 741-752.

[7] Meng C, He Z, Xing D. Low-Level Laser Therapy Rescues Dendrite Atrophy via Upregulating BDNF Expression: Implications for Alzheimer’s Disease. J Neurosci. 2013. 14; 33 (33): 13505-13517.

[8] Farfara D, Tuby H, Trudler D, Doron-Mandel E, Maltz L, Vassar RJ, Frenkel D, Oron U. Low-Level Laser Therapy Ameliorates Disease Progression in a Mouse Model of Alzheimer’s Disease. J Mol Neurosci. 2014 [Epub ahead of print]