1.2.3.1.1 Familial hemiplegic migraine type 1 (FHM1)

A 51-year-old librarian describes neurological attacks, at least six such attacks over her adult life. Each begins with an odd forewarning sensation that spreads gradually across more than five minutes: first a general clumsiness of movement on one side, then slurred, effortful speech, and finally a definite weakness of the affected limb, the features clearly rolling in one after another rather than arriving simultaneously. The warning phase and the weakness together last around 40 minutes before settling. She has never developed a significant headache with these events, and she reports no associated confusion or memory loss afterwards. Her aunt experienced strikingly similar attacks and was thoroughly assessed by a specialist team who confirmed she met the same diagnostic pattern, and testing has come back confirming a CACNA1A gene mutation.