Lectures: Diagnostic Criteria
General Diagnostic Criteria
Multiple Sclerosis can be difficult to diagnose. Although no neurological symptoms or findings are pathognomonic for MS, certain important clues can be found during history and/or physical exam that will lead to the correct diagnosis.
Intranuclear ophthalmoplegia is rarely found in young adults in diseases other than MS. Altered color vision in one eye, optic pallor and/or Marcus-Gunn pupil (relative afferent pupillary defect) may all be signs of optic neuritis and can provide information on subclinical or resolved optic neuritis. Many different types of nystagmus are common findings in patients with MS.
A mild intention tremor can be another early sign of MS. Slight motor weakness and spasticity may be found. Positive Romberg's sign, decreased vibratory and proprioceptive sense in lower extremities may also be seen in early MS
A middle-aged or young adult presenting with Lhermitte's sign should undergo a very careful neurologic examination to rule out possible MS. (Lhermitte's sign is present if a patient complains of paresthesia or electric shock-like sensation which radiates down long the length of the spine or up through the head upon flexing the neck.)
Diagnosis by Exclusion
It is important to remember that no neurological abnormality should not be used as a criterion for MS if it can be explained by other medical problems of the patients. In this regard, MS is traditionally considered a "diagnosis by exclusion."
Standard Criteria for Diagnosis
At present there are no tests in which an abnormality is specific for MS. Nonetheless, clinical examinations and diagnostic testing including MRI, lumbar puncture and evoked potentials are very helpful. The following standard diagnostic criteria developed by Poser et al., are commonly used:
Criteria for Diagnosis Diagnostic Categories History of two attacks with positive oligoclonal bands or increased IgG in CSF; no clinical or para clinical evidence of a disease Probable MS with laboratory support History of two attacks without laboratory abnormalities Clinically probable MS History of two attacks with clinical and para clinical evidence of one lesion; Oligoclonal bands or increased IgG present in CSF Laboratory-supported definite MS History of at least two attacks; Clinical evidence of at least one lesion and clinical or para clinical evidence of another lesion Clinically-definite MS