title: The Ultrasound pattern sum score - UPSS. A new method to differentiate acute and subacute neuropathies using ultrasound of the peripheral nerves.
abstract: OBJECTIVE
  Ultrasound differentiation of neuropathies is a great challenge. We, therefore, suggest a standardized score to operationalize differentiation between several acute and subacute onset neuropathies.
  
  
  METHODS
  We retrospectively analyzed the ultrasound data of 61 patients with acute or subacute neuropathies, e.g. chronic immune-mediated neuropathies, Guillain-Barré syndrome (GBS), and axonal/vasculitic neuropathies. We compared these data to 28 healthy controls. Based on these results an ultrasound pattern sum score (UPSS) with three sub-scores (UPS-A for the sensorimotor nerves, UPS-B for the cervical roots and the vagal nerve and UPS-C for the sural nerve) was developed. Afterwards, the applicability of the score was prospectively validated in 10 patients with chronic neuropathies and in 14 patients with unknown acute and subacute PNP before performing additional tests.
  
  
  RESULTS
  UPS-A and UPSS were significantly higher in CIDP than in other neuropathies and controls (p<0.001). UPS-B was significantly more often pathologic in GBS than in CIDP and other neuropathies (p<0.001). Using receiver operation characteristics curve analysis boundary values for each score were defined. Positive predictive value (PPV) of these scores for CIDP and GBS was >85%. Vasculitic neuropathies showed an intermediate type of UPSS compared to other axonal neuropathies (p<0.001). In the prospective application the pattern score could be used with good accuracy in several types of neuropathy.
  
  
  CONCLUSIONS
  UPS-A and UPSS operationalize to diagnose acute and subacute-onset CIDP and its variants with high sensitivity, specificity, and PPV. An increased UPS-B with normal UPSS and other sub scores may point to the diagnosis of GBS with high PPV and enables the differentiation from CIDP.
  
  
  CONCLUSIONS
  Using the UPSS and its sub-scores gives a new diagnostic power to the method of the peripheral nerve ultrasound.
authors.affiliation: Department of Neurology, Basel University Hospital, Basel, Switzerland. Electronic address: alexander.grimm@usb.ch.
authors.forename: Alexander
authors.initials: A
authors.lastname: Grimm
authors.affiliation: Department of Neurology, Basel University Hospital, Basel, Switzerland.
authors.forename: Bernhard F
authors.initials: BF
authors.lastname: Décard
authors.affiliation: Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany.
authors.forename: Hubertus
authors.initials: H
authors.lastname: Axer
authors.affiliation: Department of Neurology, Basel University Hospital, Basel, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Fuhr
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010525:Peripheral Nerves / Q000000981:diagnostic imaging*; D010523:Peripheral Nervous System Diseases / Q000145:classification / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D011115:Polyneuropathies / Q000145:classification / Q000175:diagnosis / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography / Q000379:methods*
keywords: Inflammatory neuropathy; Nerve enlargement; Nerve ultrasound; Polyneuropathy; Ultrasound pattern; Ultrasound score