A 57-year-old patient had known Crohn disease for several years, which was eventually treated by extensive colectomy in 1998 with no further relapse. Since 2000, she has complained of abnormal olfactory symptoms characterized by the occurrence of brief, repeated, and stereotyped episodes of strong smell sensations without substrate. Odorant perceptions were difficult to describe precisely and did not correspond to known odors. When prompted, she compared them to perfumes, to a “rainy day,” or even to a “wet dog,” ascribing them a pleasant aspect. Episodes usually lasted a few seconds up to minutes and could occur many times per day in an unpredictable fashion. Conversely, known odors were perfectly identified, and she denied any subjective smell loss. She never had epileptic seizures, and electroencephalographic results were normal. Brain computed tomography failed to show any structural abnormality in particular in the temporal lobe, olfactory bulbs, or tracts. In 2003, while the frequency of olfactory hallucinations was decreasing, she developed a resting tremor of the right hand that progressively evolved into full-blown, asymmetrical, levodopa-responsive parkinsonism typical of PD. Iodine I 123–labeled ioflupane single-photon emission computed tomography (DaTSCAN; GE Healthcare Bio-Sciences, Little Chalfont, England) showed a severe reduction of radiotracer uptake in both striatum more marked in the putamen and on the left side. In 2005, while the patient was being successfully treated daily with pramipexole, 1.5 mg; amantadine hydrochloride, 200 mg; and a combination of levodopa, 200 mg, carbidopa, 50 mg, and entacapone, 400 mg, abnormal odors disappeared completely and never recurred. The results of a detailed rhinologic examination were unremarkable, and olfactometric testing showed mild hyposmia (normal score, ≥ 31; TDI score, 26.5 points; the TDI test is performed using the Sniffin’ Sticks, which is a validated test battery with normative data available10 that is routinely performed in our institution and assesses the 3 major components of smell, including odor threshold [7-10 items], discrimination [12-16 items], and identification [12-16 items] of common odors; the TDI score is obtained by summing the 3 subscores). Hyposmia detected by the test was subjectively unnoticed by the patient.