Clinical diagnosis of syncopes (including so-called breath-holding spells) without electroencephalography or ocular compression.
A recent article in this journal suggested that ocular compression during electroencephalography was useful in distinguishing "breath-holding spells and syncope" from epileptic seizures. The method proposed involved measurement of the RR interval on the simultaneously recorded electrocardiographic trace and determining both the absolute RR lengthening and the change in RR interval as compared with the baseline value. It is argued by the present author that this is not an appropriate way to come to a diagnosis in episodic loss of consciousness in children. It is pointed out that so-called "breath-holding spells" are reflex syncopes and that the diagnosis of reflex syncopes should be by clinical history, even if this means delaying the diagnosis until a future consultation. Published evidence on the nature and clinical diagnosis of reflex syncopes in infants and children is reviewed in depth. It is concluded that routine electroencephalography is not an appropriate investigation when the diagnosis of episodic loss of consciousness is in doubt and has the implicit danger of false positive "abnormality". Aside from scientific exploration of the developing autonomic nervous system, the only current indication for diagnostic ocular compression is to induce a syncope so that its nature may be better understood. Such a circumstance might be a history of an apparent reflex syncope but with atypical features, including prolonged post-syncopal unconsciousness such as might indicate epileptic absence status. Several additional investigations of a primarily cardiological nature may be indicated in some cases, but a wait-and-see policy is usually to be preferred.
Stephenson
John B P
JB
D003937:Diagnosis, Differential; D004562:Electrocardiography; D004569:Electroencephalography; D004827:Epilepsy / Q000503:physiopathology*; D005123:Eye / Q000503:physiopathology*; D006801:Humans; D012119:Respiration; D013575:Syncope / Q000175:diagnosis* / Q000503:physiopathology*