Table 3.

Differential diagnosis of leukoencephalopathy involving the corticospinal tracts.

Diagnosis	MRI findings	Clinical issues
Capecitabine induced leukoencephalopathy	- Restricted diffusion and/or increased T2W/FLAIR signal in the cerebral white matter - Involvement of the course of the bilateral corticospinal tracts, as well as of the corpus callosum, has been described	Excellent recovery upon cessation of Capecitabine with no or minimal residual deficit
Amyotrophic lateral sclerosis (ALS)	- Bilateral hyperintensities along the corticospinal tracts extending from the corona radiata to the brainstem seen on T2WI and FLAIR, reduced diffusion on DWI.	- Mixed upper and lower motor neuron signs - Mean age of onset: 62 years
Primary lateral sclerosis (PLS)	- Bilateral hyperintensities along corticospinal tracts on T2WI and reduced diffusion on DWI	- Upper motor neuron without lower motor neuron signs
X-linked Adrenoleukodystrophy (XAD)	- Symmetrical, confluent demyelination in the peritrigonal region T1W: reduced signal of involved white matter, enhancement present T2W/FLAIR: Increased signal of involved white matter Bilateral corticospinal tract involvement described	- Spectrum of phenotypes: childhood cerebral forms, adrenomyeloneuropathy, isolated adrenal insufficiency
Hypoglycaemic coma	- Parietal/occipital lobe, amygdala, basal ganglia involvement T1W: Gyral swelling, sulcal effacement T2W: Parieto-occipital infarcts, tends to spare cerebral white matter DWI: reduced diffusion along bilateral corticospinal tracts	- Altered mental state - Associated with hypoglycaemic state from Diabetes medications without adequate glucose intake or glucose utilization
Wilson disease	T1W: Reduced in basal ganglia T2W: Bilateral symmetrical hyperintensity in putamina, thalami, caudate nuclei, globus pallidi Bilateral corticospinal tract involvement described	- Inherited copper metabolism disorder - Autosomal recessive - Hepatic, neurological and psychiatric manifestations
Adult onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP)	White matter lesions that are hyperintense on T2W/FLAIR and hypointense on T1W are seen. Bilateral corticospinal tract involvement has been described.	- Autosomal dominant - Range: early adulthood to 8th decade of life - Supportive management