The "spray can" sign: Validation of a clinical observation in chronic inflammatory demyelinating polyneuropathy

Sean J. Pittock, Dara Meldrum, Orla Hardiman

Research output: Contribution to journalArticlepeer-review


Background: The presentation of chronic inflammatory neuropathies is variable. The decision regarding when to intervene with treatment is ideally determined by identifying early markers of loss of function. Objective: To test the hypothesis that an observation of functional impairment, defined by a patient with demyelinating neuropathy, can be used as a reproducible and reliable measure of improvement with intravenous immune globulin. Design: A 28-year-old woman presented with a chronic inflammatory demyelinating polyneuropathy. Her first complaint was the inability to use her deodorant spray because of hand weakness. A calibrated pincer gauge fixed on top of her usual spray can was used to objectively test finger flexion. Tip grip and lateral pinch were also measured. A calibrated dynamometer was used to measure grip strength. Results: Power and precision grip force were reproducible in normal control subjects by means of the spray can test. This test proved to be a reliable indicator of reduced muscle strength in the patient and improved after treatment with intravenous immune globulin. Conclusions: The spray can test objectively quantified the daily function, nominated by the patient, of operating an aerosol can. This measurement, drawn from a functional loss observed by the patient, proved to be a portable and reliable indicator of decline and recovery in chronic inflammatory demyelinating polyneuropathy.

Original languageEnglish (US)
Pages (from-to)1637-1640
Number of pages4
JournalArchives of neurology
Issue number10
StatePublished - Oct 1 2002

ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Clinical Neurology


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