Description |
A 68-year-old woman presented to the clinic complaining of "bouncing" vision when waking up at night for one month. Two years ago, she experienced discrete episodes of spinning for seconds provoked by head movements, which resolved spontaneously. Her ocular motor and vestibular exams were normal aside from apogeotropic nystagmus (brought on by roll more than Dix-Hallpike testing), most intense in right roll test (Figure 1). The general neurological examination was unremarkable except for mild difficulty in tandem gait. She was diagnosed with apogeotropic horizontal canal (HC) benign aroxysmal positional vertigo (BPPV) and underwent treatment with repositioning maneuvers and head-shaking in the clinic and with vestibular PT, although there was no change in symptoms or nystagmus. Given refractory positional nystagmus, contrast-enhanced MRI of the brain was ordered and was unremarkable. Over the next several weeks, balance worsened, positional symptoms persisted, and dizziness was experienced constantly without provocation. Examination was now notable for gazeevoked with rebound nystagmus, saccadic smooth pursuit and VOR suppression, horizontal head shaking induced downbeat nystagmus and ataxic gait. Positional apogeotropic nystagmus was still present. Paraneoplastic panel was unrevealing (ANNA-1/2/3, PCA-1/2/Tr, Amphiphysin, CRMP-5, VGKC, VGCC, GAD-65, Ma/Ta and ZIC4), as was CT chest, abdomen and pelvis and other labs to investigate a; progressive cerebellopathy (negative/normal CRP, ESR, Vitamins B1/B12/ E, Cu, celiac panel, anti-TPO, HIV and +ANA titer of 1:320, which was a chronic finding). Given continued deterioration, she was admitted for expeditious LP and PET scan. Repeat contrast-enhanced brain MRI was normal. Lumbar puncture demonstrated normal WBC, protein and glucose levels. Extensive CSF studies were negative including: gram stain, Cryptococcus, VDRL, HSV/CMV/VZV PCR, WNV-IgG, Mycobacteria/Whipple's PCR, Oligoclonal IgG, Autoimmune panel, Cytology and Flow cytometry. She underwent whole-body FDG-PET that was notable for symmetric cerebellar hypometabolism (Figure 2). Further diagnostic testing was performed. |