Table 1.

Summary of morphological abnormalities using MRI for the main forms of familial huntingtonism. Caudate atrophy is similar in HD, HDL2, and neuroacanthocytosis syndromes

Disease	Pattern of inheritance	Main findings	References
Huntington’s disease (HD)	AD	Progressive striatal atrophy antedating phenoconversion for years Variable degree of atrophy in cortical regions and white matter evident in the premanifest phase	Paulsen et al. [34] Aylward et al. [33••] Tabrizi et al. [32••]
C9orf72-related diseases	AD	Generalized atrophy seen C9orf72 huntingtonism but data is limited (6 patients)	Mahoney et al. [8], Hensman et al. [6•]
Huntington’s disease-like 1 (HDL1)/inherited prion diseases (IPD)	AD	Generalized cerebral and cerebellar atrophy	Xiang et al. [11] Mead et al. [51]
Huntington’s disease-like 2 (HDL2)	AD	Striatal atrophy in all reported cases, variable degree of cortical atrophy	Anderson et al. [14]
Spinocerebellar ataxia type 17 (SCA17)	AD	Generalized cerebral and cerebellar atrophy	Toyoshima and Takahashi [16]
Benign hereditary chorea (BHC)	AD	In general normal; cerebral and cerebellar atrophy and hypoplastic pallidum can occur in BLTa	Adam and Jankovic [54]
ADCY5-related dyskinesia	AD	Normal findings	Mencacci et al. [56]
Neuroacanthocytosis
Chorea-acanthocytosis (ChoAc)	AR	ChoAch: Vast majority displays striatal atrophy, striatal hyperintensities are common Striatal atrophy indistinguishable in both ChoAc and MLS, more prominent in the caudate head Progressive striatal atrophy demonstrated in MLS	Gradstein et al. [57] Walterfang et al. [58] Valko et al. [64]
McLeod syndrome (MLS)	XLR
NBIA
Neuroferritinopathy	AD	T2: Hypondense BG, cortex, red nucleus, and substantia nigra. Cavitations in caudate and putamen	McNeill et al. [66]
Aceruloplasminemia	AR	Iron accumulation in thalamus and caudate, absence of cavitations	Miyajima [68]

AD autosomal dominant, AR autosomal recessive, BG basal ganglia, BLT brain-lung-thyroid syndrome, XLR X-linked recessive