Answer: Lyme Disease can be very difficult to diagnose. The disease should at least be considered in anyone residing in or having visited an endemic region during tick season. In most cases there are clear systemic signs of Lyme infection before any neurological symptoms occur. These signs include a characteristic rash called erythema chronicum migraines (ECM) with a spreading red ring with a clear center. Those will or without the rash often develop systemic symptoms 7 to 14 days later including fever, chills, headaches, malaise and joint pain.
Neurological symptoms usually occur in the second stage of Lyme Disease and easiest to identify when there are signs of meningitis, nerve root irritation or cranial nerve palsies, all uncommon in MS. But Lyme can be elusive and less commonly will create neurological symptoms difficult to separate from MS.
The diagnosis of Lyme is never made by MRI; instead the diagnosis requires the correct demographics, clinical history and serological studies of both the blood and spinal fluid. When in doubt we will often treat individuals with oral doxycycline. The duration of required therapy is unclear but there is little evidence to support more than 2-3 weeks of therapy, depending on the circumstances. The main controversy with lyme disease is whether post treatment Lyme or chronic Lyme Disease exists. This has been written about extensively and I will leave that to other authors.