From initial information received on 1/21/06 from a literature report. A report of three cases, it was reported that three pts were evaluated at the neuromuscular clinic from 2001 to 2005, All pts underwent detailed history, general and neurological examinations, electro diagnostic and lab studies, including spinal fluid, complete blood count, metabolic panel, serology for autoimmune disorders, Lyme serology, VDRL, serum immune fixation, thyroid studies glucose and HBA1C, and MRI for brain and spine. The other two pts from this literature report are reported in cases 200603299 and 200603300.   A healthy 46 year old man had received a dose of Influenza vaccine sometime in 2001 to 2005. The date of vaccination was not specified. The trade name, manufacturer, lot number, route and site of administration were not reported. The pt did not have any acute illness or systemic infections prior to the vaccination. He did not have any history of diabetes mellitus, alcohol abuse, exposure to any known neurotoxins, and there was no family history of neuropathy. Seven days after receiving the influenza vaccine the pt experienced sensation of burning, tingling, and itching over the trunk. Over the next 10 days he developed difficulty chewing, bilateral facial weakness and diplopia, along with tingling and numbness in feet and hands, mild weakness in limbs, and gait difficulty, all tendon reflexes were absent. Sensation were normal. Spinal fluid protein was 142 mg/dl with 2 lymphocytes and normal glucose. Electro diagnostic studies were unremarkable except for mild impersistence of median nerve F waves (4 to 10) with normal latencies. Needle EMG testing of distal lower extremity muscles was unremarkable. Blink reflex showed absent R1 and R2 responses bilaterally and normal response with direct facial stimulation, suggesting a proximal conduction block. Cranial MRI showed subtle enhancement of facial nerves. Pt was treated with a 5 day course of IVIG 0.4 g/kg per day and improved. Four weeks later, the pt noted increasing numbness in toes and hands as well as increasing weakness in ankles with decreased balance and gait difficulty. Examination showed weakness with grade 4 MRC strength in intrinsic hand muscles, hip flexors, and ankle dorsiflexion. Muscle stretch reflexes were diminished in the arms and absent at knees and ankles, vibration and pin sensation were diminished in feet with preserved proprioception. Electrodiagnostic studied showed widespread abnormalities, indicating a demyelinating polyneuropathy, median and ulnar sensory potentials were absent, and sural sensory potentials were preserved. The pt was treated with IVIG 1g/kg monthly for four months and improved promptly. He experienced another relapse, which responded to pulse IV methylprednisolone 1000 mg/wk, and developed gastrointestinal side effects. There after he was treated with monthly IVIG and oral mycophenolate was added 1g twice a day. Th pt has not required IVIG for one year and remains free of relapses. The pts status at the last follow up showed that he had no deficits. The authors conclusion is that this pt , who was other wise health, developed CIDP with rapid onset in close proximity to influenza vaccinations, suggesting a plausible relationship between the immunization and the induction of CIDP. It is possible that antecedent events such as immunization are more likely in such pts,  but has not been systemically evaluated. In contrast to GBS, which is a monophasic illness, how a single event such as immunization may trigger induction of a relapsing or chronic immune mediated disorder such as CIDP is not known. The reporter for this case is the same as for cases 200603299, and 200603300.