Can Migraines Cause Amnesia?
Yes, migraines can cause transient amnesia, most notably through a condition called transient global amnesia (TGA), which occurs significantly more often in migraine patients than in the general population.
The Evidence for Migraine-Associated Amnesia
Transient Global Amnesia (TGA)
The strongest evidence comes from a large population-based cohort study showing that migraine patients have a 2.48-fold increased risk of developing TGA compared to non-migraine individuals 1. This risk is particularly pronounced in female migraine patients aged 40-60 years, who show a 3.18-fold increased risk 1. A meta-analysis confirmed this association across multiple studies 2.
TGA presents as:
- Acute onset of anterograde amnesia (inability to form new memories)
- Repetitive questioning characteristic of the confused state
- Duration of 4-24 hours with complete resolution
- Preservation of personal identity (patients remain oriented to self)
When TGA Occurs with Migraine
TGA can occur during a migraine attack itself, though this is rare 3. Key patterns include:
- TGA typically begins after the migraine headache starts
- Always occurs during severe migraine attacks
- Vomiting or vomiting efforts consistently precede the TGA episode 3
- In some cases, classic migrainous phenomena (aura) accompany the amnesia 4
The proposed mechanism involves venous congestion in the mesial temporal lobes—forceful vomiting creates a Valsalva maneuver that blocks venous return, transmitting high venous pressure to the cerebral venous system and causing temporary venous ischemia to memory structures 3.
Other Cognitive Dysfunction in Migraine
Beyond TGA, migraines cause broader cognitive dysfunction 5:
During attacks (ictal):
- Difficulty with receptive and expressive language
- Impaired attention
- Memory problems
Between attacks (interictal):
- Persistent memory-related deficits
- Altered subcortical activity affecting the hippocampus (memory center)
Red Flags to Exclude Secondary Causes
When evaluating amnesia in a migraine patient, the guidelines emphasize ruling out more serious conditions 6:
- Thunderclap headache → subarachnoid hemorrhage
- Atypical aura → stroke, TIA, or seizure
- Progressive headache with memory changes → intracranial mass
- Focal neurological symptoms → secondary headache disorder
- Altered consciousness or personality changes → suggests secondary cause
- New onset after age 50 → consider temporal arteritis
Clinical Implications
For diagnosis: TGA in migraine patients is a clinical diagnosis after excluding stroke and TIA. Neuroimaging is only indicated when secondary headache disorders are suspected 6.
For treatment: While acute and preventive migraine treatments may help reduce cognitive symptoms 5, limited specific data exists for migraine-related amnesia. Standard migraine management applies 6, 7.
Important caveat: One case report suggests that the combination of triptans (rizatriptan) and benzodiazepines (temazepam) may predispose to TGA 8, though this requires further validation.
The association between migraine and amnesia is well-established, particularly for TGA, but the underlying mechanisms remain incompletely understood 2.