Establishing consensus on Paroxysmal Sympathetic Hyperactivity after acquired brain injury A syndrome of paroxysmal, episodic sympathetic and motor hyperactivity following acquired brain injury has been identified for almost 60 years. While research has increased, the field remains hampered by confused nomenclature (at least 31 eponyms in the literature) 1 , and multiple, overlapping sets of diagnostic criteria. The history of the various diagnostic sets are outlined in the following figure. The consensus group recommended that ‘paroxysmal sympathetic hyperactivity’ (PSH) replace previous terms to describe the: “syndrome, recognised in a subgroup of survivors of severe acquired brain injury, of simultaneous, paroxysmal transient increases in sympathetic [elevated heart rate, blood pressure, respiratory rate, temperature, sweating] and motor [posturing] activity”. It is hoped that the consensus position will represent an important foundation from which to standardise PSH research and management. Five of the original 16 criteria failed to reach the criterion for scale retention and were dropped (see Table 1 below). The VAS scores for the remaining 11 features yielded an acceptable Cronbach’s Alpha of 0.8. These were used to develop an 11-point probabilistic diagnostic scale, with agreed definitions for each of these diagnostic features being produced. These items were combined with a symptom severity index to produce a diagnostic tool for use with adults (the Paroxysmal Sympathetic Hyperactivity assessment measure (PSH-AM)). Members of the PSH Consensus Process were: Steering Committee. Ian J Baguley MBBS PHD Brain Injury Rehabilitation Service, Westmead Hospital, University of Sydney, Sydney, Australia Iain E Perkes MD Department of Psychiatry, Royal Prince Alfred Hospital, Sydney, Australia Juan-Francisco Fernandez-Ortega MD PHD Department of Intensive Care, Hospital Regional Universitario Carlos Haya, Malaga, Spain Alejandro A Rabinstein MD Department of Neurology, Mayo Clinic, Minnesota, USA Giuliano Dolce MD S. Anna Institute – Research in Advanced Neurorehabilitation, Crotone, Italy Henk T Hendricks MD PHD Rehabilitation Centre Groot Klimmendaal, Arnhem, The Netherlands Working Group (alphabetical order). Emelio J Alted Lopéz MD Trauma Care Unit, Hospital Universitario 12 de Octubre, Madrid, Spain P David Adelson MD Barrow Neurological Institute at Phoenix Children’s Hospital, Arizona, USA Geoffrey C Booth MD Department of Rehabilitation Medicine, Bone & Joint Institute, Newcastle, Australia José Manuel Borrallo-Pérez MD Intensive Care Unit, Hospital Universitario de Guadalajara, Spain Dennis E Bullard MD Department of Neurosurgery, Duke University Medical Centre, North Carolina, USA Emmanuel Cuny MD Department of Neurosurgery, CHU Hôpitaux de Bordeaux, France Antonio De Tanti MD Cardinal Ferrari Rehabilitation Centre, Parma, Italy José-Maria Dominguéz-Roldan MD Neurointensive Care Unit, Hospital Universitario Virgen del Rocío UCI-HRT, Seville, Spain Michael R Fearnside MBMS Department of Neurosurgery, Western Medical School, University of Sydney, Australia Gerard E Francisco MD Department of PM&R at The University of Texas Health Science Center at Houston, Texas, USA Holly E Hinson MD Department of Neurology and Neurocritical Care, Oregon Health & Science University, USA Darryl L Kaelin MD Division of Physical Medicine and Rehabilitation, University of Louisville, Kentucky, USA Linda E Krach MD Department of Physical and Rehabilitation Medicine, University of Minnesota Medical School, USA Peter AC Lim MBBS Postgraduate Medical Institute, Singapore General Hospital, Singapore Lv Li-Quan MD Department of Neurosurgery, Shanghai Changzheng Hospital, Shanghai, China Lucia F Lucca MD S. Anna Institute – Research in Advanced Neurorehabilitation, Crotone, Italy Nilesh M Mehta MD Critical Care Medicine, Children’s Hospital Boston, Philadelphia, USA David K Menon Division of Anaesthesia, University of Cambridge, United Kingdom Denise M Niklasch (Lemke) DNP/ANP-BC Department of Neurology, Medical College of Wisconsin, USA Melissa T Nott PHD Lecturer, School of Community Health, Charles Sturt University, Australia Natalia Rodríguez Nieva MD Department of PM&R, Hospital Universitari Sant Joan de Déu, Barcelona, Spain Remo N Russo MBBS PHD Department of Rehabilitation Medicine, School of Medicine, Flinders University, Adelaide, Australia Adam M Scheinberg MBBS MMed Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, Australia John Whyte MD PHD Moss Rehabilitation Research Institute, Einstein Healthcare Network, Philadelphia, USA Nathan D Zasler MD Department of PM&R, Virginia Commonwealth University, Virginia, USA The steering committee developed a questionnaire based on a systematic review of the literature. The resulting definition, nomenclature and an inclusive set of 16 diagnostic criteria derived from a recent review 2 (reproduced below) were forwarded to the expert group utilising a Delphi approach. The PSH-AM is designed to be used in different clinical settings (e.g., digital data collection in ICU versus paper records in subacute settings). Serial PSH-AM data allows clinical certainty to increase or decrease along with changes in the patient’s clinical status, for example, as alternative differential diagnoses are treated or excluded. All fields on the form are completed; unavailable information is scored as zero. In the CFS, a zero for sweating is taken as no visible sweating, mild sweating is where the skin is glistening or moist, moderate has visible beads of sweat and severe equals profuse sweating. For posturing, zero is absent hypertonicity during episodes. Mild posturing applies when hypertonicity increases during episodes, but the limb can be moved with modest force. Moderate posturing implies difficult to overcome hypertonicity and requires specific hypertonicity treatment. Severe posturing has unbreakable tone during episodes despite treatment. OBJECTIVE METHODS RESULTS CONCLUSIONS Acknowledgements Ian J Baguley, Iain E Perkes, Juan-Francisco Ferndandez-Ortega, Alejandro A Rabinstein, Giuliano Dolce, Henk T Hendricks for the Consensus Working Group REFERENCES 1. Baguley, I.J. (2008). Autonomic complications following central nervous system injury. Seminars in Neurology 28, 716-725. 2. Perkes, I.E., Menon, D.K., Nott, M.T. and Baguley, I.J. (2011). Paroxysmal Sympathetic Hyperactivity after acquired brain injury: a review of diagnostic criteria. Brain Injury 25, 925- 932. METHODS 31 people, including eight of the nine authors of previously published PSH diagnostic criteria (detailed in Figure1 below) 2 , joined the consensus process. The group was designed to have representation from major medical specialities dealing with the syndrome including intensive care, neurology, neurosurgery, and rehabilitation medicine, along with nursing and Allied Health perspectives. The group were chosen from 8 countries including Australia, the USA, and countries within Asia and Europe. From Perkes et al, Brain Injury 2011 From Perkes et al, Brain Injury 2011 Clinical Feature Scale (CFS) 0 1 2 3 Score heart rate < 100 100 - 119 120 - 139 140 respiratory rate < 18 18 - 23 24 - 29 30 systolic blood pressure < 140 140 - 159 160 - 179 180 temperature < 37 37 - 37.9 38 - 38.9 39.0 sweating nil mild moderate severe posturing during episodes nil mild moderate severe CFS Subtotal Severity of Clinical Features nil 0 mild 1 - 6 moderate 7 - 12 severe 13 Diagnosis Likelihood Tool (DLT) clinical features occur simultaneously episodes are paroxysmal in nature sympathetic over-reactivity to normally non-painful stimuli features persist 3 consecutive days features persist 2 weeks post brain injury features persist despite treatment of alternative differential diagnoses medication administered to decrease sympathetic features 2 episodes daily absence of parasympathetic features during episodes absence of other presumed cause of features antecedent acquired brain injury (Score 1 point for each feature present) DLT subtotal Combined total (CFS + DLT) PSH Diagnostic Likelihood unlikely < 8 possible 8 - 16 probable > 17 Moderately severe sweating and extensor posturing in a patient with PSH Participants were asked to rate their opinion of the relative importance of each diagnostic item using an unnumbered, 10 centimetre Visual Analogue Scale (VAS), with one end representing “completely unimportant” and the other “extremely important”. Participants’ data were scored out of 100 by measuring in mm from the left hand side of the line. Diagnostic criteria were dropped if group consensus failed to agree on their relative importance, proceduralised by removing those items with a median VAS <6. The remaining diagnostic system was tested using Cronbach’s Alpha, with a goal of reaching 0.8 (suitable for research purposes). The criteria were then combined into an assessment measure for use in clinical and research settings. Table 1. Clinical features of PSH: Consensus agreed: • simultaneity of clinical features • clinical features are paroxysmal in nature • sympathetic over-reactivity to normally non-painful stimuli • absence of intra-paroxysmal parasympathetic features during episodes • features persist  3 consecutive days • features persist  2 weeks post injury • features persist despite treatment of alternative differential diagnoses • medication administered to decrease sympathetic features •  2 episodes daily • lack of alternative explanations • antecedent acquired brain injury Consensus not agreed: • weight loss  25% of body weight • episodes lasting <120 minutes • heterotopic ossification • other sympathetic features present, eg, piloerection • prolonged sedation due to sympathetic features Figure 1. The PSH Assessment Measure (PSH-AM) Poster 0380