The Neurologic Examination. John W. Engstrom, M.D. University of California San Francisco School of Medicine

Transcription

1 The Neurologic Examination John W. Engstrom, M.D. University of California San Francisco School of Medicine

2 Overview The Neurologic Examination Mental status demonstration/questions Cranial nerves demonstration/questions Motor exam demonstration/questions Sensory exam demonstration and questions Top Ten Suggestions for a Better Neurologic Examination

3 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 1. If the patient can give a completely coherent history, then the mental status examination is probably normal

4 Mental Status Assessment and the Medical History Typical lucid history establishes normal orientation, attention, recent recall, speech If history suggests a cognitive problem, then a methodical mental status exam is necessary

5 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 1. If the patient can give a completely coherent history, then the mental status examination is probably normal 2. The neurologist says the encephalopathy is metabolic and is almost always correct

6 Delerium- Common Causes and Evaluation Metabolic Causes Hyponatremia, hypernatremia Renal failure Hypoxia, ischemia Hypoglycemia, hyperglycemia Hypothyroidism, hyperthyroidism Recreational drugs Alcohol intoxication / withdrawal Other drugs Hypercalcemia, hypermagnesia Hyperphosphatemia Laboratory Studies Na BUN, Cr PO2 Glucose Thyroid function tests Toxicology screen Alcohol level, osmolarity Review medications Calcium, magnesium Phosphate

7 Delerium Common Causes and Evaluation Infectious Causes Sepsis Meningitis Neurologic Causes Subarachnoid hemorrhage Cerebral infarction Seizures, post-ictal state Laboratory Studies Cultures, CBC, Chest X-Ray, UA Lumbar puncture (LP), Cultures, CBC Brain CT, LP Brain CT or MRI Consider brain CT/MRI, EEG

8 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 1. If the patient can give a completely coherent history, then the mental status examination is probably normal 2. The neurologist says the encephalopathy is metabolic and is almost always correct 3. Dementia the lights are on but nobody is home; Delerium the lights are flickering on and off.

9 Dementia vs. Delerium Delerium fluctuating levels of consciousness and inattentiveness General exam accompaniments: fever, tachycardia, tremor, asterixis, myoclonus Neurologic exam: poor and fluctuating attention

10 Dementia vs. Delerium Dementia poor intellectual or cognitive function with no disturbance of consciousness Always establish cognitive baseline prior to acute illness from family, friends, coworkers In the elderly, beware of the delerious and demented inpatient! If chronic, best assessed as an outpatient Ask about changes in functional cognitive activities (i.e. balancing checkbook, paying bills)

11 Establishment/Levels of Coma Inability to interact voluntarily with the environment Levels of coma Thalamic-localizes painful stimulus Upper brainstem-pupillary abnormalities Middle brainstem-corneal responses Lower brainstem-respiration, cardiovascular

12 Exam of the Uncooperative Patient Encephalopathy signs -tachycardia, fever, meningismus, tremor, asterixis, myoclonus CN-nystagmus (vertical=structural), facial asymmetry, dysarthria, brainstem reflexes Motor-grade best movement (e.g.-against gravity, ability to walk or stand) Sensory- Symmetry of withdrawal to pain

13 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 4. After establishing new-onset coma, the pupillary examination is the most important initial neurologic examination test

14 Fixed Pupils and Coma Dilated (7-9 mm) Early brain herniation Mid-position (3-5 mm) Late herniation? Drug effect? Adequacy of light stimulus

15 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 4. After establishing new-onset coma, the pupillary examination is the most important initial neurologic examination test 5. Visual field testing is highly informative and underutilized by the non-neurologist

16 Screening for Visual Field Deficits Cooperative patient-move examiner finger in the center of each quadrant with patient gaze fixed Test each eye by covering the opposite eye, present stimulus in all 4 quadrants Use a single digit to suddenly approach each half of the visual fields; normally elicits a blink Avoid using entire hand-elicits corneal reflex Report as Does/Does not blink to threat

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19 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 4. After establishing new-onset coma, the pupillary examination is the most important initial neurologic examination test 5. Visual field testing is highly informative and underutilized by the non-neurologist 6. There are only two types of headaches, old and new

20 Old Headaches vs. New Headaches Severity or location of headaches rarely helpful with diagnosis Historical risk factors: New-onset elderly, immunosuppressed Focal neurologic signs Postural supine or standing Fever, rash, stiff neck Sudden onset over 1-2 seconds

21 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 4. After establishing new-onset coma, the pupillary examination is the most important initial neurologic examination test 5. There are only two kinds of headaches-old headaches and new headaches. 6. Visual field testing is highly informative and underutilized by the non-neurologist 7. Weakness is either neurologic or non-neurologic

22 The Weak Patient: Breakaway Weakness DEFINITION: Variable resistance by the patient during muscle power testing ASSOCIATED WITH PAIN: Cannot determine if underlying weakness present UNASSOCIATED WITH PAIN: Poor effort

23 The Weak Patient: History and Examination NEUROLOGIC NON-NEUROLOGIC UPPER MOTOR NEURON LOWER MOTOR NEURON FATIGUE BREAKAWAY ANTERIOR HORN CELL NERVE ROOT NERVE- NMJ Axonal OR Demyelination MUSCLE PAIN POOR EFFORT

24 From: Medical Research Council, Aids to the Examination of the Peripheral Nervous System. W.B. Saunders, Philadelphia, 1986.

25 From: Medical Research Council, Aids to the Examination of the Peripheral Nervous System. W.B. Saunders, Philadelphia, 1986.

26 The Weak Patient: Central Weakness I Power - distal > proximal extensors > flexors in arms dorsiflexors > plantar flexors in legs Bulk - Normal Tone - spastic; Babinski signs present Reflexes - Sensation - Normal or

27 The Weak Patient: Central Weakness II Spasticity-velocity-dependent increase in tone to passive stretch of a limb Rapid, repetitive movements are slow-fingers and feet Pronator drift

28 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 8. The presence of diminished sensation is more helpful in defining a neurologic deficit than positive sensory phenomena (i.e.-paresthesias or pain).

29 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 8. The presence of diminished sensation is more helpful in defining a neurologic deficit than positive sensory phenomena (i.e.-paresthesias or pain). 9. Use the history to determine which parts of the neurologic examination need to be performed in detail.

30 The High-Yield Neurologic Examination: Top Ten Suggestions for a Better Neurologic Examination 8. The presence of diminished sensation is more helpful in defining a neurologic deficit than positive sensory phenomena (i.e.-paresthesias or pain). 9. Use the history to determine which parts of the neurologic examination need to be performed in detail. 10. Symmetry, or lack thereof, is a powerful diagnostic observation on the cranial nerve, motor, sensory, coordination, and reflex examinations.

31 Conclusions A good screening neurologic exam can be performed in minutes Subsequent neurologic exam will be dictated by the history and initial examination findings The pattern of neurologic findings is the most helpful, rather than a single finding