Focal retrograde amnesia associated with vascular headache

Area of Science:

• Neuroscience
• Neurology
• Cognitive Psychology

Background:

• Retrograde amnesia is a complex memory disorder affecting past experiences.
• While often associated with brain injury or disease, less common causes are continually being investigated.
• Headache disorders, particularly migraine, have been anecdotally linked to certain non-classical amnesias.

Observation:

• A 42-year-old man presented with recurrent headaches and severe retrograde amnesia, affecting personal and public events over 15-20 years.
• Neuropsychological testing revealed deficits in retrograde memory but preserved anterograde memory and learning.
• Neurological examination showed focal electroencephalogram (EEG) abnormalities in the left fronto-temporal region, with normal CT, MRI, and SPECT scans.

Findings:

• Despite no recovery of retrograde memory after five years, positron emission tomography (PET) scans were normal, and subsequent neuropsychological tests showed no deficits.
• This case represents the first documented instance of selective retrograde amnesia in a patient whose primary neurological diagnosis was headache.
• The findings suggest a potential, albeit rare, link between primary headache disorders and profound retrograde memory impairment.

Implications:

• This case expands the understanding of amnesia's diverse etiologies, suggesting primary headache disorders as a potential, though uncommon, cause.
• It underscores the importance of considering a broad differential diagnosis in patients presenting with amnesia, even in the absence of typical brain imaging findings.
• Further research into the neurobiological mechanisms connecting headache and selective memory deficits may offer new insights into both conditions.