Tricks of the Neuro Exam

malingerers and mimics

Malingering

•  ..the intentional production of false or grossly exaggerated physical or psychological symptoms, motivated by external incentives

•  not considered a mental illness

DSM-IV-TR, 2000

Conversion Disorder •  Alteration or loss of a physical function

suggestive of a physical disorder

•  The expression of an underlying psychological conflict or need.

•  Somatoform disorder

DSM-IV-TR, 2000

Conversion diagnosis •  Symptoms or deficits are present that affect voluntary motor or sensory

function

•  Psychologic factors are judged to be associated with the symptom or deficit

•  The symptom or deficit is not intentionally produced or feigned (as in factitious disorder or malingering).

•  The symptom or deficit, after appropriate investigation, cannot be explained fully by a general medical condition, the direct effects of a substance, or as a culturally sanctioned behavior or experience.

•  The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.

DSM-IV-TR, 2000

How common?

•  Functional paralysis - 5/100,000

• Non-epileptic attacks

•  10-20% of epilepsy clinic

•  up to 50% of status epilepticus admits

27 yo man with minor fall, can’t move his legs

•  A friend recently was in an MVA and had a C4 injury

• His exam reveals flaccid paralysis of both legs

•  Sensation is absent

• What should you test next?

Signs

Complemental Opposition���

aka Hoover’s sign

Stone, et al, J Neurol Neurosurg Pscyh, 2005

La Belle Indifférence

•  Little utility

Collapsing/Give way weakness

•  try irregular resistance

•  valid?

Arm drop?

•  look for slow/jerky descent of arm

•  occasionally arm remains elevated

Functional gait • Dramatic slowness

• Dragging limb “as a log” •  Falling to/away from doctor

• Uneconomic posture/requiring balance

•  Sudden knee buckling, esp without falls

• Dramatic recovery

Keane, Neurology, 1989

Stone et al, BMJ & Lempert et al

Dragging monoplegia Uneconomic posture

Pseudoataxia Walking on ice

Functional Gait Disorders

27 yo man with conversion disorder

•  FES

•  TMS

•  A good conclusion

Two true cases, one long night

•  27 yo drug abuser arrives in ER, says he can’t see

•  32 yo brought in by friends, says she can’t hear anything

Blindness

•  should be able to... sign name, bring fingers together in front of eyes

• Mirror test

• Menace test

• Do they walk into things?

•  Two money tests

Tubular field deficit

Monocular diplopia/polyopia

•  can be due to ocular issues

Auditory

37 yo man says he can’t feel the right side of his

face • Get an MRI

• Get a CT

• Consider tPA

• Get all neuro with your exam

Sensory exam

•  if in doubt...

Sensory exam

•  clues: shape of glove/sock

•  sharp border

•  not cross midline

Hemisensory

• midline splitting

•  splitting at limbs

•  vibratory splitting - not clearly valuable

Sensory clues

37 yo man says he can’t feel the right side of his

face • Get an MRI

• Get a CT

• Consider tPA

• Get all neuro with your exam

criteria for further testing

•  if uncertain about exam

•  if a patient needs an exam instead of

•  reassurance

•  a certain opinion

•  if there is any doubt and there are significant ramifications

Conclusion

•  Recognize malingering vs. conversion

• Do a detailed exam

•  Benefit of the doubt