Abstract Background A 75year old male presented to a Movement Disorder Service with complex multimorbidity including: chronic pain, type 2 diabetes mellitus, hypoventilatory obesity syndrome, biliary calculus, moderate aortic stenosis, marked orthostatic hypotension, pulmonary hypertension, coronary artery bypass grafting, permanent pacemaker for complete atrioventricular block, carpal tunnel release bilaterally, polypharmacy and bilateral cataracts. History elucidated a distal to proximal sensory loss over 20years and neuropathic pain without nerve conduction confirmation; and progressively ataxic gait over several years. He also complained of hypophonia, bruxism, excessive daytime somnolence, passages, transitions, visual agnosia, textural illusion, oscillopsia, irritability, inflexibility, hoarding, impulsivity, disorganisation, inattention, apathy, depression and aspontaneity. He was intolerant of nocturnal continuous positive airway pressure device. Epworth score was 21. Methods Examination demonstrated: marked orthostatic hypotension, preserved cognition, hypersomnolence, dyspraxic dysgraphia, palmar and antecubital agraphaesthesia, downbeat horizontal nystagmus at eccentric gaze positions, square wave jerks, bidirectionally impaired head impulse test, dysmetric saccades, asymmetric cerebellar signs in upper and lower limbs, rightward Pisa syndrome, kinesigenic dystonic axial posturing, rightward laterocollis and equivocal Babinski/Oppenheim reflexes. Gait assessment demonstrated sensory and cerebellar ataxic features with marked apraxia. No pes cavus. Results Computed tomography of brain had Fazekas 1 small vessel disease, Medial temporal atrophy score 1, Koedam 1 and age-commensurate cerebral and cerebellar atrophy. RFC1 gene testing confirmed biallelic intronic AAGGG repeat expansion disorder. Conclusion Cerebellar Ataxia Neuropathy and Vestibular Areflexia Syndrome (CANVAS) should be considered in patients with presentations from mid-life of progressive sensory ataxic neuropathy, altered vestibular ocular reflex, gaze evoked nystagmus and prominent dysautonomia. CANVAS is a rare autosomal recessive genetic disorder with a protean presentation. Referral to Genetics Services should be undertaken for family counselling. Keeping an open mind in complex, multimorbid patients to a potentially unifying diagnosis is important to guide prognostication. The rumble of hooves in the distance is not always that of horses.
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