Physical Examination for Multiple Sclerosis
Neurological Examination Components
The physical examination for MS must focus on detecting objective clinical evidence of CNS lesions, as symptoms alone are insufficient for diagnosis—objective neurological findings are mandatory. 1, 2
Essential Examination Elements
Cranial nerve assessment should evaluate for optic neuritis (decreased visual acuity, color desaturation, relative afferent pupillary defect), internuclear ophthalmoplegia, nystagmus, facial weakness, and trigeminal sensory loss 1, 3, 4
Motor examination must assess for weakness, spasticity, and upper motor neuron signs including hyperreflexia, clonus, and extensor plantar responses (Babinski sign) 3, 4
Sensory testing should document areas of decreased sensation to light touch, pinprick, vibration, and proprioception, as sensory disturbances are among the most common presenting symptoms 5, 3, 4
Cerebellar function requires assessment of coordination through finger-to-nose and heel-to-shin testing, evaluation of dysmetria, intention tremor, and ataxic gait 3, 4
Gait assessment should observe for ataxia, spasticity, foot drop, and impaired tandem walking 3, 4
Lhermitte sign should be elicited by neck flexion, which produces electric shock-like sensations radiating down the spine or into the limbs, indicating cervical spinal cord involvement 3
Critical Examination Principles
Objective clinical evidence means reproducible abnormalities on neurological examination that can be documented by the examining physician—historical accounts of symptoms without current objective findings are insufficient for establishing dissemination in space. 1, 2
An "attack" or relapse must last at least 24 hours and represent objective clinical findings, not just subjective symptoms 1
Multiple paroxysmal episodes occurring over 24 hours count as a single attack 1
Separate attacks must be separated by at least 30 days from onset to onset 1
Red Flags Suggesting Alternative Diagnoses
Certain examination findings should raise suspicion for MS mimics and warrant additional investigation:
Bilateral sudden hearing loss, gaze-evoked or downbeat nystagmus, and concurrent severe bilateral vestibular loss suggest non-MS pathology 1
Isolated cranial nerve involvement is rare in MS (10.4%), and isolated eighth nerve palsy is extremely rare (<1%) 6, 1
Focal neurologic symptoms including headache, confusion, diplopia, dysarthria, focal weakness, focal numbness, or facial weakness occurring together may indicate alternative diagnoses 6
Documentation Requirements
The examination must document the anatomical location of lesions to establish dissemination in space 1, 2, 5
Serial examinations are valuable for detecting new objective findings that establish dissemination in time 1
Normal neurological examination does not exclude MS, but persistent symptoms without any objective findings on repeated examinations make MS diagnosis highly unlikely 7
Common Pitfalls to Avoid
Never diagnose MS based on symptoms alone without objective examination findings—patients with persistent neurologic symptoms but consistently normal examinations, normal MRI, and normal CSF do not develop MS even after years of follow-up. 7
In one study of 143 patients with neurologic symptoms but normal initial examinations, MRI, and CSF, none developed MS after mean follow-up of 4.4 years 7
Costly serial investigations should be carefully reconsidered when the neurological examination remains normal at follow-up 7
Special caution is required in patients younger than 10 or older than 59 years, those with progressive onset, or unusual presentations such as dementia, epilepsy, or aphasia 1, 2, 8