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Postinfectious cerebellitis (PIC) is a rare complication of Epstein-Barr virus (EBV) infection. Whereas its course is usually regarded as self-limited, it can be prolonged and produce considerable residual disability. We report two adults with persistent PIC after EBV infection who demonstrated complete and rapid recovery with a course of plasmapheresis (total plasma exchange [TPE]).Case reports. Case 1. A 20-year-old woman (Case 15 in reference 1) developed fever and myalgia, followed 2 weeks later by onset over 3 days of slurred speech, gait instability, and difficulty judging distances. Examination revealed hypermetric saccadic eye movements, cerebellar dysarthria, dysmetria, dysdiadochokinesis, and ataxic gait. She had flattened affect, decreased verbal output and phonemic fluency, perseveration, and poor visual-spatial planning. Results of strength, reflex, and sensory testing were normal. Gadolinium-enhanced brain MRI and EEG were normal. CSF revealed three lymphocytes, normal protein, and glucose. Heterophile antibody was positive; serum EBV titer was 1:896; EBV viral capsid was 1:1280; restricted immunoglobulin (Ig) G was 1:320; and EBV nuclear antigen (EBNA) was 1:20, diagnostic of chronic or recurrent EBV infection. CSF viral capsid, diffuse and restricted IgG, and EBNA were normal. The persistence of motor and cognitive symptoms at 1 month prompted treatment with plasmapheresis. There was marked improvement in a stepwise fashion the day after each of six sessions of TPE. One week after treatment, the examination was only minimally abnormal, and 1 month after treatment, all cerebellar motor tests and neuropsychological tests had returned to normal, except for tests of complex and unstructured list learning.Case 2. A 28-year-old man developed fever, myalgia, and pharyngitis. Two to 3 weeks later he had vertigo, ataxia, dysarthria, untidy handwriting, and incoordination of his limbs. He had difficulty concentrating and making quick decisions, and his family noted a flattened affect. Brain MRI and EEG were normal. EBV IgG titer was 1:640; IgM was elevated (1/10); and EBNA was negative, consistent with primary infection Ͻ6 weeks previously. Symptoms persisted, and examination 3 months after the onset of the illness revealed hypermetric saccades, cerebellar dysarthria, upper extremity rebound, dysmetria and dysdiadochokinesis, widened stance, and ataxic gait. Strength, reflexes, and sensation were normal. Attention, declarative learning, and phonemic fluency were reduced; thinking was concrete; and he perseverated on the Luria diagram. This lack of recovery prompted treatment with plasmapheresis. During the course of five TPE sessions, the cerebellar motor syndrome abruptly improved, and thinking and personality reverted to the premorbid state. Three months after TPE, the examination was normal.Discussion. Acute cerebellar meningoencephalitis from EBV infection is rare, occurring more commonly in children than in adults. It is characterized by an acute pancerebellar syndrome sometimes with brainstem signs or...

Optimal choice of beam energy in radiation therapy is easy in many well‐documented cases, but less obvious in some others. Low‐energy beams may provide better conformity around the target than their high‐energy counterparts due to reduced lateral scatter, but they also contribute to overdosage of peripheral normal tissue. Beam energy was added as an optimization parameter in an automatic aperture‐based inverse planning system. We have investigated a total of six cases for two sites (prostate and lung), representative of deep‐seated and moderately deep‐seated tumors. For one case for each site, different numbers of beam incidences were considered. The other cases for each site were optimized using a fixed number of incidences. Four types of plans were optimized: 6 MV, 23 MV, and mixed energy plans with one or two energies per incidence. Each plan was scored with a dose‐volume cost function. Cost function values, number of segments, monitor units, dose‐volume parameters, and isodose distributions were compared. For the prostate and lung cases, energy mixing improved plans in terms of cost function values, with a more important reduction for a small number of beam incidences. Use of high energy allowed better peripheral tissue sparing, while keeping similar target coverage and sensitive structures avoidance. Low energy contribution to monitor units usually increased with the number of beam incidences. Thus, for deep‐seated and moderately deep‐seated tumors, energy optimization can produce interesting plans with less peripheral dose and monitor units than for low energy alone.PACS numbers: 87.55.de, 87.55.dk, 87.56.N‐