Progressive leftsided cerebellar atrophy and intermittend CSWS-like EEG. Is it Rasmussen Encephalitis?

Objective: Is there more than coincidence of developmental delay, CSWS-like episodes in EEG and progressive unilateral cerebellar atrophy?

Method: A severly mentally retarded 18 years old boy, with developmental delay from birth, shows epilepsy with predominantly petit mal seizures and rare grand mal since the age of 4 to 6 years. The EEG is fluctuating all over the years with CSWS-status like episodes and multiregional epileptic activity over the parieto-occipital regions. Additionally there is progressive leftsided cerebellar atrophy.

Results: Until know we have no explanation for this coincidence of developmental delay, CSWS-like episodes and progressive cerebellar atrophy. Could it be a process similar to Rasmussen encephalitis? Biopsy was not yet done.