Solvent Abuse Brain

This 22 year-old patient presented with abnormal behaviour, nystagmus and truncal ataxia. The axial T2-weighted MR shows reduced signal in the thalami, and increased signal in the posterior limbs of the internal capsules. Cortical grey-white differentiation is reduced. Other images show increased signal elsewhere in the corticospinal tracts, in the middle cerebellar peduncles and in the pontine crossing fibres. The dentate nuclei are of low signal.
The MR changes are consistent with heavy solvent abuse, of which the patient has a long history.
MR changes in toluene abuse by inhalation have been described. White matter lesions (focal and diffuse) are seen in 46%, cerebral atrophy in 27%, and thalamic hypointensity in 20%. White matter changes and thalamic hypointensity are associated with abuse for longer than 4 years. The mechanism of thalamic hypointensity may be iron deposition and axonal loss.
Other causes of thalamic hypointensity include metabolic disorders such as caeruloplasmin deficiency and lysosomal storage disorders.
References:
1. Aydin K, et al. Cranial MR Findings in Chronic Toluene Abuse by Inhalation. Am J Neuroradiol 23:1173-1179, August 2002
2. Autti T , Joensuu R and Åberg L. Decreased T2 signal in the thalami may be a sign of lysosomal storage disease. Neuroradiology 49:571-578, 2007
Credit: Dr Laughlin Dawes, Dr Constantine Phatouros