Introduction

About 10% of functional (psychogenic) movement disorders (also called conversion disorders) are related primarily to problems with standing and walking.1–6 They should be diagnosed by demonstrating internal inconsistency and incongruity with disease, but this process can be especially problematic for gait disorders reflected in a higher rate of misdiagnosis than other functional disorders.7 We report two cases of a particular subtype of functional gait disorder, astasia, which were detected because of the effect that iPhone use had on the presenting symptoms. We review previous literature in this area.

Case 1

A 16-year-old boy presented with a 3-day history of balance problems. This began after he fell against a wall after a 1 h period of standing. He had three subsequent falls to the ground with no dizziness, vertigo, weakness or sensory disturbance. If he concentrated hard, or focused intently on something else such as his iPhone, his balance and gait were normal but, ‘If I relax with my mind blank, I fall over.’ He reported chronic insomnia, intermittent low mood and episodes of depersonalisation. He and his family were anxious about a sinister cause.

As he entered the room he was texting on his phone with a normal gait. Neurological examination on the bed was normal. When …