title: Retrospective study of a TTR FAP cohort to modify NIS+7 for therapeutic trials.
abstract: Protein stabilization and oligonucleotide therapies are being tested in transthyretin amyloid polyneuropathy (TTR FAP) trials. From retrospective analysis of 97 untreated TTR FAP patients, we test the adequacy of Neuropathy Impairment Score+7 tests (NIS+7) and modifications to comprehensively score impairments for use in such therapeutic trials. Our data confirms that TTR FAP usually is a sensorimotor polyneuropathy with autonomic features which usually is symmetric, length dependent, lower limb predominant and progressive. NIS+7 adequately assesses weakness and muscle stretch reflexes without ceiling effects but not sensation loss, autonomic dysfunction or nerve conduction abnormalities. Three modifications of NIS+7 are suggested: 1) use of Smart Somatotopic Quantitative Sensation Testing (S ST QSTing); 2) choice of new autonomic assessments, e.g., sudomotor testing of distributed anatomical sites; and 3) use of only compound muscle action potential amplitudes (of ulnar, peroneal and tibial nerves) and sensory nerve action potentials of ulnar and sural nerve - than the previously recommended attributes suggested for the sensitive detection of diabetic sensorimotor polyneuropathy. These modifications of NIS+7 if used in therapeutic trials should improve characterization and quantification of sensation and autonomic impairment in TTR FAP and provide better nerve conduction tests.
authors.affiliation: Peripheral Neuropathy Research Laboratory, Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: N
authors.initials: N
authors.lastname: Suanprasert
authors.affiliation: Amyloidosis Center, Department of Neurology, Boston University School of Medicine, 72 East Concord Street, K504, Boston, MA 02118, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Berk
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Benson
authors.affiliation: Peripheral Neuropathy Research Laboratory, Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: P J B
authors.initials: PJ
authors.lastname: Dyck
authors.affiliation: Peripheral Neuropathy Research Laboratory, Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Klein
authors.affiliation: Alnylam Pharmaceuticals, 300 Third Street, Cambridge, MA 02142, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Gollob
authors.affiliation: Alnylam Pharmaceuticals, 300 Third Street, Cambridge, MA 02142, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Bettencourt
authors.affiliation: Alnylam Pharmaceuticals, 300 Third Street, Cambridge, MA 02142, USA.
authors.forename: V
authors.initials: V
authors.lastname: Karsten
authors.affiliation: Peripheral Neuropathy Research Laboratory, Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. Electronic address: dyck.peter@mayo.edu.
authors.forename: P J
authors.initials: PJ
authors.lastname: Dyck
mesh_terms: D000328:Adult; D000368:Aged; D028227:Amyloid Neuropathies, Familial / Q000175:diagnosis* / Q000503:physiopathology; D017776:Autonomic Pathways / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D009460:Neurologic Examination; D009482:Neurophysiology; D055815:Young Adult
keywords: Ceiling effects; Modified NIS+7; Neuropathy Impairment Score (NIS); Polyneuropathy signs and tests; Smart Somatotopic QSTing; Transthyretin amyloidosis polyneuropathy (TTR FAP)