CACNA1A and familial hemiplegic migraine: Patients of familial hemiplegic migraine (FHM) with CACNA1A gene mutation may develop progressive cerebellar signs, and MRI revealed predominant cerebellar vermis atrophy [26] while proton MR spectroscopy (1H–MRS) found reduced NAA, Glu and elevated ml in the superior cerebellar vermis indicating regionally distinct neuronal impairment [27].