124 Epochs of Anosmia and Ageusia in Multiple Sclerosis: Chemosensory Uhthoff’s Phenomenon

Abstract

Study Objective

To reveal that while long duration of anosmia and ageusia has been seen with Multiple Sclerosis (MS) [Doty 1997], repetitive shorter epochs ofanosmia and ageusia has not heretofore been presented.

Methods

Case Study: A 39 year old right-handed male, with a history of MS, presents with six years MS concurrent with epochs of anosmia and ageusia. The anosmia andageusia present concurrently, preventing him from smelling and tasting his meal. At baseline, he is able to smell and taste coffee, peppermint, gum, sweet and salty foods, rating his smell and taste at 70% normal. However, during the epochal events, he reports the inability to smell and taste white rice, shrimp, meat, butter, carrots, onions, spinach, and sour foods. He states that these episodes occur approximately ten times a week, last for two hours, and rates his smell and taste from 0-10% during these events.

Results

Abnormalities Neurological Examination: Cranial Nerve (CN) Examination: CN II: bilateral pale discs. CN III, IV, VI: bilateral ptosis. CN IX, X: decreased gag reflex bilaterally. Motor Examination: Drift Test: positive left pronator drift, with right adductor digiti minimi sign and right cerebellar spooning. Sensory Examination: Ipswich Touch Test: decreased in left lower extremity. Temperature: decreased in left lower extremity. Rydel-Seiffer Vibratory Test: bilateral upper extremities 5 and bilateral lower extremities 3. Tandem Gait: unstable. Cerebellar Examination: Holmes Rebound Phenomena: positive with left greater than right. Reflexes: 1+ bilateral upper extremities, absent bilateral lower extremities. Neuropsychiatric Examination: Animal Fluency Test: 15 (abnormal). Clock Drawing Test: 3 (abnormal). Center for Neurologic Study Lability Scale: 16 (pseudobulbar affect).

Conclusion

Primary olfactory dysfunction with secondary inhibition of retronasal smell and perceived taste [Gruss 2015] can be an etiology. Such an olfactory dysfunction may reflect variation in nasal mucosal engorgement due to normal variability of the olfactory cycle [Eccles 1978]. This phenomenon is an unlikely due to the short duration ofepochs.

The cause of anosmia and ageusia in this patient suggests a central lesion involved in the processing of both smell and taste. Transient rapid symptoms associated with temperature change, as in Uhthoff’s phenomenon seen in MS, can manifest with deficiency in special senses including visual field loss [Davis 2010]. Such also may be the origin for the chemosensory loss seen here. While this phenomenon may be induced by hot baths, more subtle temperature changes may also induce such symptoms [Romani 2000]. Given that olfactory threshold changes have been demonstrated in acute inflammatory changes in MS, such a temperature related etiology is more likely to manifest [Lutterotti 2011]. MS patients should be screened for chemosensory dysfunction, and those with chemosensory dysfunction should be assessed for demyelinating disease.

Funding Acknowledgements

Smell and Taste Treatment and Research Foundation