FREDERICTON—New Brunswick is redoubling its efforts to find the cause of a baffling neurological disease that has killed six and infected 48 others, announcing Thursday that an expert committee will lead the ongoing investigation. “The discovery of a potentially new and unknown syndrome is scary,” Health Minister Dorothy Shephard told a new conference. “I know that New Brunswickers are concerned and confused about this potential neurological syndrome.” Shephard also announced that health officials have drafted a new, comprehensive questionnaire for patients and their families. The questionnaires, which can take up to four hours to complete, will be filled out over the next six to eight weeks, and the new committee has a four−month schedule to complete a clinical review of every patient’s medical records. Part of the committee’s mandate is to provide second opinions and to rule out potential causes. “We have faith that this diligence will pay off,” Shephard …