A 38-year-old woman was presented to a headache clinic
with a 12-year history of headaches. Patient already fulfilled the whole
diagnostic criteria for migraine without aura. She reported the headaches were
pulsated, localized to the right front temporal region, at a frequency of 1-2
episodes per month, with mild to moderate intensity and lasted 4-72 hours. She
also complained of severe osmophobia during and between headache attacks. In
the pain free period, she had extreme intolerance to any odors. She could not
tolerate odorants such as perfume, cleaning products, paints, pesticides,
cigarette smoke etc. as odors triggered nausea. There were no cranial autonomic
symptoms such as lacrimation, conjunctival injection, nasal congestion,
rhinorrhea, forehead/facial sweating, ptosis or meiosis. Migraine prophylaxis
had been administered daily for the past two years.
The most likely diagnosis of this presentation is:
There is significant association between odors and
primary headaches, particularly to migraine with or without aura and
tension-type headache. The
literature of its occurrence in secondary headaches is very scarce. In
migraine patients, prevalence of osmophobia during the headache attacks ranges
from 20.0% to 81.7% and in the period between headache attacks, this prevalence
ranges from 24.0% to 53.3%. According to the patient, osmophobia caused great
impact on her quality of life, more than headache. She would like to treat only
her osmophobia.
A female patient diagnosed with migraine without aura
complained of severe osmophobia. Phenytoin administered as a prophylactic
treatment was effective in resolving osmophobia within 90 days.
The patient had a 12-year history of headaches that
fulfilled all the diagnostic criteria for migraine without aura.
Her general medical and neurological examinations were normal.
Patients brain MRI and CT were normal. Results were normal of routine blood
tests like biochemical, hematological liver, kidney and metabolic
investigations. After administration of drugs such as beta-adrenergic blockers,
tricyclic antidepressants, calcium channel blockers, serotonergic antagonist
and anti-epileptics, there were marked improvement in the frequency and
intensity of headache attacks but osmophobia remain unchanged. However,
phenytoin, an anti-epileptic drug not used in migraine prophylaxis, has been
suggested to treat the central and autonomic disturbances of migraine, such as
osmophobia, hyperosmia, pain in the limbs and motion sickness that occur in the
pain-free period.
The treatment was aimed to cure and maintain osmophobia. A
prophylactic treatment with phenytoin was started to osmophobia, at a dose of
100 mg, once a day. Her improvement was accompanied through an osmophobia diary
which was filled out by patient herself during the treatment period. There was
reduction in the frequency and intensity of osmophobia in the first two months
of treatment, with disappearance of this symptom within 90 days. Phenytoin was maintained
for another three months.
Patient met the diagnostic criteria for migraine without
aura, according to International Classification of Headache Disorders, third
edition, beta version (ICHD-3β), but her main complaint was a severe
osmophobia. Although osmophobia is not a diagnostic criterion for migraine, but
many studies show that this symptom is highly prevalent and is useful to
differentiate migraine from tension-type headache. Like headache, osmophobia
affects the quality of life of migraine patients and hinders the performance of
their professional activities, especially in those who work in environments
with strong odors, such as in perfumery, gas station and the selling of
insecticide or beauty products. Many drugs are used to prevent headache
attacks, but unfortunately, there is no specific treatment for osmophobia.
There is a study published in 1986 that suggests treating the central and
autonomic disturbances of migraine that occur in pain-free period, such as
osmophobia, hyperosmia, limb pain and motion sickness. Phenytoin is suggested
in the treatment of osmophobia.
Phenytoin is an antiepileptic drug that is primarily used
for controlling partial seizures, tonic-clonic or clonic-generalized. However,
it is also used to treat idiopathic trigeminal neuralgia and vestibular
paroxysmia. During the follow-up
of this patient, scores 1, 2, 3 and 4 were assigned, respectively, for mild,
moderate, severe and very severe intensities during the treatment period with
phenytoin. Then we multiplied the four intensity groups by its respective
scores and the sum of these products was called osmophobia index (OI). The
reduction of this index indicates an improvement in the intensity of
osmophobia.
In the present case, the approach to prevent osmophobia is
fulfilled. From the experience in this case, phenytoin should be considered as
possible prophylactic treatment for osmophobia between headache attacks in
migraine patients.
J Clin Case Rep 6:749. doi:10.4172/2165-7920.1000749
Phenytoin in the Treatment of Osmophobia in Migraine Patient: A Case Report
Raimundo Pereira Silva-Néto
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