Neurophysiological tests and neuroimaging procedures in non‐acute headache: guidelines and recommendations

Abstract

The use of instrumental examinations in headache patients varies widely. In order to evaluate their usefulness, the most common instrumental procedures were evaluated, on the basis of evidence from the literature, by an EFNS Task Force (TF) on neurophysiological tests and imaging procedures in non‐acute headache patients. The conclusions of the TF regarding each technique are expressed in the following guidelines for clinical use. Interictal electroencephalography (EEG) is not routinely indicated in the diagnostic evaluation of headache patients. Interictal EEG is, however, indicated if the clinical history suggests a possible diagnosis of epilepsy (differential diagnosis). Ictal EEG could be useful in certain patients suffering from hemiplegic and basilar migraine. Recording of evoked potentials is not recommended for the diagnosis of headache disorders. There is no evidence to justify the recommendation of autonomic tests for the routine clinical examination of headache patients. Manual palpation of pericranial muscles, with standardized palpation pressure, can be recommended for subdividing patient groups but not for diagnosis. Pressure algometry and electromyography (EMG) cannot be recommended as clinical diagnostic tests. In adult and paediatric patients with migraine, with no recent change in attack pattern, no history of seizures, and no other focal neurological signs or symptoms, the routine use of neuroimaging is not warranted. In patients with atypical headache patterns, a history of seizures and/or focal neurological signs or symptoms, magnetic resonance imaging (MRI) may be indicated. If attacks can be fully accounted for by the standard headache classification [International Headache Society (IHS)], a positron emission tomography (PET) or single‐photon emission computerized tomography (SPECT) and scan will generally be of no further diagnostic value. Nuclear medicine examinations of the cerebral circulation and metabolism can be carried out in subgroups of headache patients for diagnosis and evaluation of complications, when patients experience unusually severe attacks, or when the quality or severity of attacks has changed. Transcranial Doppler examination is not helpful in headache diagnosis. Although many of the examinations described are of little or no value in the clinical setting, most of the tools have a vast potential for further exploring the pathophysiology of headaches and the effects of pharmacological treatment.

The role of imaging in the pathophysiology and diagnosis of headache

“…in headache patients varies widely. Recently, a EFNS Task Force evaluated (among other instrumental examination tools) the usefulness of imaging procedures in non-acute headache patients on the basis of evidence from the literature [16 ]. Following these recommendations, in adult and paediatric patients with migraine with no recent change in attack pattern, no history of seizures and no other focal neurological signs or symptoms, the routine use of neuroimaging is not warranted.…”

Electrophysiological response patterns of primary sensory cortices in migraine

“…During the last decade almost every modality of stimulation has been used to study evoked responses in migraine. Various interictal and ictal abnormalities have been reported in migraine, although as yet there are no findings that can be used as a diagnostic tool [7]. We will review the available published data, discuss their findings and examine the possible neurobiological bases of the reported abnormalities.…”

Imaging patients with suspected brain tumour: guidance for primary care

“…Previous secondary care studies of consecutive non-acute isolated headache quoted abnormalities for migraine as 0-3.1% and unspecified headache 0-6.7%. 10 A secondary care prospective study suggested that headache without the development of additional signs or symptoms for longer than 11 weeks after initial presentation will only be due to a tumour in exceptional cases. 38 In primary care, if a tumour is present and a headache diagnosis cannot be made at presentation, 74% of tumours will have presented by 3 months, and 90% by 6 months.…”