Answer of September 2003

Clinical History:

Sudden onset of dizziness, double vision, slurring of speech and unsteady gait.

    Figure 1. Axial T1 weighted image (day 3)

    Figure 2. Axial T2 weighted image (day 3)

            Figure 3. Axial ADC image (day 3)

Diagnosis:

Subacute brainstem infarct

Discussion:

There is a T1 hypointense (figure 1), T2 hyperintense lesion (figure 2) in the midbrain with decreased ADC value (figure 3) typical of an acute or subacute brainstem infarct. Subacute haemorrhage (day 3) show hyperintensity in T1 weighted image due to methaemoglobin. Chronic midbrain infarct, multiple sclerosis and acute osmotic myelinolysis show elevated ADC values.