In questioning the diagnosis of a What is it? case (l), Quinn and Hardie (2) state that in their experience linear streaks of increased signal in the putamen on magnetic resonance imaging (MRI) are not seen in Huntington's disease but were seen in four of their cases of neuroacanthocytosis (3). In their response (4) Kang and Fahn stressed that the finding of linear streaks of increased signal in the putamen is rather nonspecific but they cite no evidence to support their contention.
In a series of patients with juvenile Huntington's disease Strada et al. (5) described hyperintensity in the putamen on MRI on intermediate and T,-weighted images. They felt, however, that this hyperintensity was not seen or was only minimal in adult onset Huntington's disease. I agree with Kang and Fahn that the linear streaks on MRI are nonspecific as evidenced by the following case of adult onset Huntington's disease.
A seventy-year-old woman presented with 20 years history of involuntary movements and slowly progressive dementia. Her mother died of a similar illness at the age of 70 years. On examination she had generalized nonrepetitive arrhythmic quick jerky movements and gait disturbance. Repeated fresh blood films were negative for acanthocytes. MRI scan (1.5 tesla magnet, T,-weighted images, TR 2000, TE 80 ms) revealed generalized cortical and caudate atrophy, and there were linear streaks of increased signal in both putamina (Fig. 1).
Linear streaks in putamen on MRI T,-weighted images is a nonspecific finding that may indicate gliosis (5) or increased water content.