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Despite increasing awareness of the high prevalence of functional neurological symptoms, there has been only one recent clinical evaluation of functional eye movement disorders, but this study reported only functional (psychogenic) oculogyric crises, opsoclonus and flutter.1 The aim of this retrospective study was to examine the clinical phenotype and range of functional eye movement disorders, and to report their prevalence across two neuro-otology outpatient clinics.
We performed a systematic retrospective search of the hospital's electronic patient database for patients attending a neurologist-led (AMB) neuro-otology outpatient clinic at Charing Cross Hospital, London, from August 2013 to August 2015 (Clinic 1), and at the National Hospital for Neurology and Neurosurgery, London, from August 2014 to August 2015 (Clinic 2). The terms ‘functional’ or ‘non-organic’ or ‘psychogenic’ or ‘psychosomatic’ or ‘somatoform’ or ‘conversion’ and ‘ocular’ or ‘eyes’ or ‘accommodation’ or ‘near reflex’ or ‘voluntary nystagmus’ or ‘convergence spasm’ or ‘convergent spasm’ or ‘spasm of the near reflex’ or ‘convergence’ were searched for.
From those clinic letters identified from the above searches, patients were included in the study when clinical signs on eye movement examination were deemed to be functional (psychogenic) by the senior clinician (AMB), using chart and video reviews. Table 1 shows the diagnostic categories used.