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

Abstract

Study Objective: To reveal that while longduration of anosmia and ageusia has been seen withMultiple Sclerosis (MS) [Doty 1997], repetitive shorterepochs ofanosmia and ageusia has not heretofore beenpresented.METHODS: Case Study: A 39 year old right-handed male,with a history of MS, presents with six years MSconcurrent with epochs of anosmia and ageusia. Theanosmia andageusia present concurrently, preventinghim from smelling and tasting his meal. At baseline, he isable to smell and taste coffee, peppermint, gum, sweetand salty foods, rating his smell and taste at 70% normal.However, during the epochal events, he reports theinability to smell and taste white rice, shrimp, meat,butter, carrots, onions, spinach, and sour foods. Hestates that these episodes occur approximately ten timesa week, last for two hours, and rates his smell and tastefrom 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 gagreflex bilaterally. Motor Examination: Drift Test: positiveleft pronator drift, with right adductor digiti minimi signand right cerebellar spooning. Sensory Examination:Ipswich Touch Test: decreased in left lower extremity.Temperature: decreased in left lower extremity. RydelSeiffer Vibratory Test: bilateral upper extremities 5 andbilateral 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 FluencyTest: 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 olfactorydysfunction may reflect variation in nasal mucosalengorgement due to normal variability of the olfactorycycle [Eccles 1978]. This phenomenon is an unlikely dueto the short duration ofepochs.The cause of anosmia and ageusia in this patientsuggests a central lesion involved in the processingof both smell and taste. Transient rapid symptomsassociated with temperature change, as in Uhthoff'sphenomenon seen in MS, can manifest with deficiencyin special senses including visual field loss [Davis2010]. Such also may be the origin for the chemosensory loss seen here. While this phenomenon maybe induced by hot baths, more subtle temperaturechanges may also induce such symptoms [Romani2000]. Given that olfactory threshold changes have beendemonstrated in acute inflammatory changes in MS,such a temperature related etiology is more likely tomanifest [Lutterotti 2011]. MS patients should bescreened for chemosensory dysfunction, and those withchemosensory dysfunction should be assessed for demyelinating disease.