Using imaging to help diagnose headaches

Patients with primary headache disorders will most likely have normal examinations, but when an abnormality is found, you should attempt to localize the abnormality in the nervous system and pinpoint its cause (e.g., disease process, etc.). In these circumstances, it is important to obtain neuroimaging studies.

This article reviews important abnormalities of the nervous system that can result in headaches.

Diplopia

Migraine phenomena can uncommonly affect extraocular movements, producing diplopia which may last for several minutes or even hours, and may culminate in an ophthalmoplegic migraine.

However, diplopia can also be a sign that cranial nerves II, III, IV, and VI are involved in the disruption of extraocular movements.

Diplopia should be examined by imaging if it’s a new finding for the patient, or if it has significantly changed from prior presentations. Imaging should also be done if the diplopia is no longer associated with a headache, when it always occurred with a headache previously. Magnetic resonance (MR) angiography can be used to exclude masses, strokes, aneurysms, and stenosis in the posterior circulation.

Facial paresthesia and facial muscle weakness

Facial paresthesia and facial muscle weakness, affecting cranial nerves V or VII, may be seen with some migraine auras. These symptoms can occur with the headache and may or may not precede the headache pain. There can be lid drooping, mild facial asymmetry, and / or positive sensory changes experienced in the face that are not usually present with a patient’s migraine.

Papilledema of the optic nerve

All patients should have a fundoscopic exam to look for papilledema of the optic nerve, or cranial nerve II, which suggests increased intracranial pressure. If papilledema is present, either a computed tomography (CT) scan or magnetic resonance imaging (MRI) is needed to differentiate an intracranial mass from pseudotumor cerebri. A mass could potentially lead to cerebral herniation. If it is confirmed that no mass is present, a lumbar puncture is needed to measure opening pressure and diagnose pseudotumor cerebri.

Is there evidence of Horner’s syndrome during a headache event? This includes ptosis, miosis, tearing, pain, nasal stuffiness, and discharge. This may be seen with cluster headaches or benign paroxysmal hemicrania. It can also be seen with carotid artery disease which can affect the sympathetic fibers on the outside of the carotid artery.

You may find some motor and sensory abnormalities when examining a patient with headache. For example, limb or body paresthesia with or without weakness can occur as an aura before or during a headache. However, focal abnormalities in the motor or sensory examination may indicate structural abnormalities in the nervous system.

Vertiginous migraine is controversial, but it has been identified in numerous circumstances. Originally it was thought to be primarily a pediatric phenomenon, but it has been increasingly recognized and possibly represents a basilar migraine type (i.e., a headache that originates in the brainstem). Patients with basilar migraines typically exhibit symptoms such as dizziness, nausea and vomiting, diplopia, ataxia, nystagmus, and diaphoresis.

It can be difficult to differentiate between a basilar migraine, benign paroxysmal positional vertigo, and stroke.

Symptoms may occur without headache, as a prodrome, with headache, or as a postdromal event. Patients will note symptoms in close temporal proximity to the headache in most cases.

Be sure to ask about photophobia and phonophobia. Vertigo may be part of the aura, or there may be other auras present before the vertigo phase.

To make the diagnosis of vertiginous migraine, posterior fossa tumors, seizures, and vestibular disorders must be excluded.

A consideration for managing vertiginous headaches

Patients will sometimes experience regular migraines and sometimes experience vertiginous migraines. We treat these patients with migraine prophylactic medications and trigger avoidance.

Triptan medication packages contain inserts which caution against the use of triptans in basilar migraine. There is controversy over the use of triptans, with many researchers suggesting that there is no credible evidence showing basilar vasospasm with triptan use.