A Case Report of Synesthesia and Migraines

Questions:

(1) Why? Why was this research conducted? What is the hypothesis? The paper I chose is titled, “Synesthesia and Migraine: Case Report”. The study was conducted to describe a single case report of a woman who experienced synesthesia along with migraine headaches. In this case, the synesthesia was acquired and was completely coincident with migraine headaches. There are two main hypotheses to synesthesia, (1) that cross-activation of the relevant perceptual areas is due to cross-wiring between perceptual areas of the brain that was not disconnected after birth, or (2) that cross-activation is due to abnormal processing in normally wired perceptual association areas. This case study was undertaken as it could give insight into which of these two models is active in synesthesia.

(2) Who? Whom are they studying? The study was of a 40-year-old graphic designer who suffers from bipolar disorder type II. She has reported suffering from migraines with and without visual aura since 2004 (6 years at the time this article was published). Before the start of her migraines, she had not experienced any form of synesthesia. When her migraines started, she reported a mixture of sensations during the visual aura phase.

(3) How? How did they do the research? This research was observational and relied heavily on self-reporting of the patient during medical consultation.

(4) What? What were the results of their study? What did they find out? The medical background includes a description of the pharmacological treatments she has been going through to try and relieve her migraine headaches. This was important information to exclude the possibility that one of the medications contributed to her synesthesia symptoms. In other cases, it has been shown that hallucinogenic drugs can enhance perceptions and possibly cause synesthesia. This possibility was ruled as unlikely based on the types of drugs administered. She characterized her experience as surrealistic, never lasting between 30 minutes and 2 hours. The experience almost always was followed by a migraine headache within 1 hour. She experienced flickering and sparkling near the rim of the upper visual field. If she heard a loud and high-pitched sound, she would see a grayish area in her field of vision. She also reported a strong lemon taste with saliva if she stared at a bright light. This was especially true if she looked at fluorescent tube lights in a ceiling. She reported no other illusions, hallucinations, or any other psychotic symptom. She tested normally in a standard neurological examination.

(5) What? What did they think these results mean? What are the implications for practical application, or for further research? This case was unusual in that there are very few examples of acquired synesthesia, meaning that most people with synesthesia are born with it. The woman in this case study did not develop synesthesia until she was in her 30s and its onset corresponded to the onset of migraine headaches. The fact that she did not develop synesthesia until she was into middle age suggests to the authors that this case was not caused by the failure of neural circuits to be wired correctly during development. The authors believe that this case supports a model in which synesthesia is caused by abnormal processing rather than the physical “wiring” of the neural circuits. They make several arguments that the synesthesia symptoms are unlikely to be linked to the medication she is taking, the bipolar disorder she suffers from, or other explanations such as epilepsy. While there is not a lot in the way of experiments and controls in this study, the authors make good use of one of nature’s own experiments, a woman with synesthesia and migraine headaches to gain evidence to support one hypothesis of synesthesia.

Reference

Alstadhaug, K, B, & Benjaminsen, E. (2010). Synesthesia and migraine: Case report. BMC Neurology 10, 121-124.