Figure 5.

Distribution of DWI lesions in patients with acute limbic encephalitis showing a preferential affection of the lateral hippocampus corresponding to the CA1 region. The time course of the ratio of apparent diffusion coefficient (rADC) in CA1 of the affected hippocampal cornu ammonis shows a reduction from days 1 to 3 and an increase to values >1 after a few weeks. Pairwise comparison shows a significantly different rADC in each of the initial four time points (1 to 14 days) with an increase in the later stages of the disease. Pat 5 shows highly selective involvement of both hippocampi in autoimmune limbic encephalitis (coronal FLAIR) with bilateral swelling and edema. Follow-up imaging 6 months after the encephalitis showed a prominent degeneration and atrophy of both hippocampi, which corresponded to profound memory deficits in this patient as a functional sequel of the hippocampal damage. Post hoc comparisons (t-test) of ADC between time periods show that during all time points in the acute and subacute phase (days 1 to 14) ADC was significantly reduced compared with the time points in the normalization phase starting around day 28. *P<0.05. Pat, patient.