'Cryptogenic Drop Attacks' revisited: evidence of overlap with functional neurological disorder

Drop attacks: a practical guide

'Drop attacks' encompass both falls and transient loss of consciousness, but the term is not clearly defined. We offer our definition and explore the differential diagnoses. The most common causes are cardiovascular. We discuss clinical and electrographic criteria that suggest underlying arrhythmia or other serious cardiac disorders that require further investigation, and the potential diagnoses that may underlie these 'worrying syncopes'. Vestibular dysfunction also commonly causes collapses, sometimes without typical vertigo. These two common conditions may coexist especially in the elderly. Falls in elderly people often require assessment through a lens of frailty and multifactorial risk factors, rather than seeking a unitary diagnosis. Some drop attacks may be due to longstanding epilepsy and we discuss how to approach these cases. Functional neurological disorder is a common cause in younger people, for which there may also be clinical clues. We review the rarer causes of collapse that may be described as drop attacks, including cataplexy and hydrocephalic attacks.

Drop attacks as a subtype of FND: A cognitive behavioural model using grounded theory

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A grounded theory approach explored idiopathic drop attacks.

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Our proposed model is consistent with current cognitive behavioural models of FND.

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A main precipitating factor of a fall related to another cause was identified.

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External triggers, anxiety, rumination and dissociation are maintaining factors.

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For many, idiopathic drop attacks may be best understood as a form of FND.

Idiopathic drop attacks are falls to the floor, without warning, and without loss of consciousness, for which the cause is uncertain. They are poorly studied but recent research suggests that many idiopathic drop attacks may be usefully considered within the spectrum of functional neurological disorder (FND).

The aim of this study was to test a cognitive behavioural model of idiopathic drop attacks, in order to inform formulation and treatment. Interviews and diaries were completed by seven individuals experiencing drop attacks, and were analysed using a grounded theory qualitative data approach.

Through the coding and synthesis of data into themes, a proposed cognitive behavioural model was identified, with a main precipitating event in all cases being a fall related to another cause, such as a mechanical fall or a fall due to medical reasons. Additional precipitating factors identified included situational triggers, high levels of stress, and dissociation. A maintaining cycle of thoughts, emotion and behaviour is outlined.

Our proposed theory is consistent with current cognitive behavioural models of FND. A cognitive behavioural understanding of drop attacks when considered part of FND aids formulation in clinical practice, and suggests that cognitive behavioural therapy interventions for FND may also be applicable in this population.