Patient with Progressive Loss of Function & Bulbar Signs

I wonder if you kindly share your opinion and experience regarding HRN who is a four years old boy with progressive loss of function and marked bulbar signs. The first symptoms began about one month ago with fever, drooling, dysphagia and dysarthria. He had also several convulsions as left sided facial twitching and loss of consciousness lasting only for few seconds. There was a history of upper respiratory tract infection one week prior to these symptoms. He has been admitted in a provincial hospital for 20 days and in our hospital since 10 days ago. On the first days of his admission he had a lumbar puncture which revealed 8 WBC, 50 RBC, protein of 19mg/dl and a glucose of 40mg/dl. The CSF culture was negative for bacterial pathogens. The brain MRI revealed (please click on pictures to enlarge):

He has been on Acyclovir (10mg/kg/dose 3 times a day) for one week. The first impression was Herpetic encephalitis or ADEM. HRN has been admitted to our ward about 10 days ago when he still had low grade fever with somehow deteriorated bulbar signs such as drooling, nasal speech, dysphagia, hypo-reflexive gag response and uvula at the midline. During past 10 days his condition has been worsened with agitation and motor restlessness with deepend dysphagia and dysarthria, but fever has gone. Now he could not walk and is quite bed-ridden with hypotonia and brisk deep tendon reflexes. His consciousness is cloudy and he is not well oriented but wakeful. He is totally fed by nasogastric tube and has a blunt face with apparent bilateral facial weakness:

During past 20 days we had three LPs. The 1st one of 9th November showed; 7000 RBCs- 35 WBCs (95% lymphs)- Protein 49mg/dl- Sugar 53mg/dl. The LP of 14th November revealed; 5 RBCs- 12 WBCs (90% lymphs)- protein 135mg/dl- sugar 58mg/dl. And the last LP of 19th November showed; no RBC- 6 WBCs- protein 60mg/dl- sugar 83mg/dl. The PCR for Herpes virus was NEGATIVE.

The recent brain MRI was as below:

At our center HRN received a dose of methyl prednisolone pulse as well as IVIG 1gr/Kg for two days with a little or any response. He is now on his third day of acyclovir 20mg/kg/dose three times a day.

1. What is your diagnosis?

2. Is the symptoms and signs more in the favor of presylvian syndrome or ADEM?

3. If a type of acquired opercular syndrome, what is the cause?

4. What should we do next for this patient?

Please kindly email your replies to: mahmoh365@yahoo.com or mohamadi@tums.ac.ir.

Thanks for your attention and cooperation.

M. Mohammadi MD, Pediatric Neurologist