Neurology - Motor/Sensory Exam and Assessment of Mental Status


LSU Physician Champion - Dr. Jesus Lovera


Mental Status

Level of consciousness: Examine the baseline level of awakeness. If the patient is drowsy or asleep stimulate them and see if they can maintain arousal.
Attention: Determine if the patient attends to your voice and commands. Delirious patients will have fluctuating attention.
WORLD: Have the patient spell the word world forwards and backwards. People with normal attention can do this task.
Number repetition: Explain that you are going to say several numbers outloud. Ask the patient to listen for the numbers you are going to say and repeat them after you have finished. Give the patient a list of random numbers one digit every second. Start with three digits and increase one digit per trial until the patient consistently makes mistakes.
Now ask the patient to repeat the digits backwards. Start with three digits and increase by one digit per trial. Most people can repeat 5 digits.

Language

Fluency: As you observe the patient estimate how many words per minute they produce while talking. People with expressive aphasias will have effortful speech with only few words per minute

Paraphasias: Determine if the patient makes any errors during speech where words or syllables are produced. With semantic paraphasias a related word is substituted. A neologism is a completely non-sensical word. Phonelogical paraphasias result in some of the syllables being wrong but more than half of the word is correct. Semantic are common in Wernicke’s(fluent-aphasia) while phonemic are common in non-fluent (Brocca’s) aphasias.

Naming: Have the patient name different objects. Shirt, tie, lapelle, shoe, nail, cuticle, watch are good examples. The NIH stroke scale has standard pictures for naming. You should include high and low frequency words.
If the patient can’t name have them point at the objects you name. This will sort out whether the concept of the word is lost or not. People with expressive aphasias may correctly point out objects they can’t name while people with receptive aphasias are more likely not to be able to do this

Repetition: Have the patient repeat a sentence. Also have them repeat sensical and non-sensical words. NIH stroke scale has handy standarized phrases.

Language comprehension: Give the patient simple commands to follow. Do not use midline commands such as stick your tongue or close your eyes because people with impaired comprehension may still be able to follow these commands. Start with one step commands such as “point to the ceiling” “point to the floor”. Increase the number of steps “point to me then point to you”. Increase the grammar complexity: “Point to me, after you point to the door.” Watch your body language to make sure you are not giving non-verbal cues such as pointing or touching.



Memory

  Give the patient three unrelated words, ask them to repeat them and remind them that you will ask them to remember them in 5 min. Proceed to other parts of the exam as distraction and then ask the patient to remember the three words.
A more sensitive procedure uses 5 words with two learning trials where the patient is asked to repeat the words and then the correct words are repeated back to him/her.

Praxis

  Apraxia is the inability to performed learned motor acts that is not due to weakness. Ask the patient to do the following: “use a pair of scissors”, “use a screwdriver”, “pretend you are hammering a nail onto the wall”, “wave bye-bye”, “signal to stop a care”, “signal come here”.

Calculations, Right left confusion, finger agnosia

 
Ask the patient to do simple digit arithmetic.
Ask the patient to show you their thumb, then their index, then their pinky finger.
Ask the patient to show you their left hand, their right hand, their left ear, their right ear.
Calculations, R-L confusion, finger agnosia, agraphia comprise Gertsmann’s syndrome.

Neglect

 
Anosognosia (unawareness of the deficits): ask the patient what is wrong with their affected side.
Extinction to double stimulation: Ask the patient to tell close their eyes and tell you where you touch them. Touch them on the right and left sides of their body then on both sides. Alternate trials and see if they can correctly answer left, right both. Patients with neglect will extinguish the affected side thus when both sides are touch they will report only the left side being touched.
A similar procedure can be done with visual and auditory stimuli by asking the patient to point or tell you on which side your fingers are wiggling. Wiggle your fingers the left, right and both sides. For auditory extinction, rub your fingers on the left, right and both sides.

Line bisection: Use a standard letter size paper in landscape orientation and draw a horizontal line on most of the paper. Ask the patient to bisect the line. Fold the paper matching the endpoints of the line. Most normal people will bisect the line within 1-2 millimeters from the midline.
Neglect may be also obvious in construction tasks such as drawing the clock. In these cases the patient may draw only half a clock or more commonly place all the numbers on the right side.

Frontal lobe tasks:

Fist, side, palm: Ask the patient to tap on their hand or their table with their, fist then the side and then the palm of their hand. Show them the sequence several times and then ask them to perform it. Patients with frontal lobe deficits will get stuck in one of the components of the sequence. Go no-go: ask the patient to show you one finger when you show two fingers and two fingers when you show one finger. Start with one finger and repeat a few times until they get it correctly. Then do two fingers several times until they do it correctly. Then start alternating randomly between one or two fingers and observe how many errors they make.


Luria loops: Draw three of these and ask the patient to copy them multiple times. Patients with frontal lobe problems will draw more than 3 loops in each loop.


Motor Exam

Observe muscles for fasciculations and atrophy

 
Tapping the muscles can trigger fasciculations or myotonia.

Palpate the muscles

 
Atrophied muscles have a “rubbery” consistency.

Assess spasticity

 
With the patient prone move the joint from fully flexed to fully extended over a second time (one one thousand). Note any catch or marked resistance to movement. If you are testing for this do it prior to strength testing as strength, testing may make spasticity more pronounced.

Assess for tone and rigidity

 
Here you will perform similar movements but at a lower speed as when assessing spasticity.
When testing for decreased tone it is useful to look for pendular movements of the knee and excessive flapping of the arm with rapid alternating rotation of the trunk. Rigidity will be more evident when the patient is asked to tap ther fingers on the contralateral upper extremity.

Strength

 
Evaluate strength against resistance for flexion, extension, abduction, adduction of the upper and lower extremities. Basic exam will include deltoids, rotator cuff, biceps, triceps, wrist, extension and finger extension, intrinsic hand muscles. Hip flexion and extension, adductors, abductors, knee flexion and extension, ankle dorsiflexion, plantiflexion, inversion eversion.

When testing the lower extremities functional testing may be more useful than confrontation testing. Hip flexor weakness is evident during walking. Quadriceps, and gluteus major weakness is evident when getting out of a chair or doing a squat. Gastrocnemius weakness is evident asking the patient to stand on their toes similarly, dorsiflexion weakness is evident when having patients walk on their heels.
Have the patient tap their thumb and finger as fast as they can. Rapid finger tapping and rapid foot tapping may be the only findings in subtle upper motor neuron lesions.

Strength is graded:
5: full strength
4: can be overcome
3: can be overcome with minimal effort but overcomes gravity
2: can’t overcome gravity
1: muscle contraction but no movement.
0: no contraction

Pronator drift is tested as part of strength exam

 
Have the patient hold both upper extremities at 90 degrees from the trunk and observe the upper extremity for downward drift and pronation. Closing the eyes and tapping on the hands makes this phenomenon more evident but may be confounded by proprioception loss. Upward drift can occur with parietal lesions. This is a test of strength but also proprioception.


Tips

 
Involve only one joint in your testing. For example when testing the biceps, hold the arm and have the patient flex the elbow. This will help prevent confusing more distal weakness when there is proximal weakness.

Coach the patient to give you full effort. If they have pain coach them to give you the best effort just once. True weakness should not give away (where there is decent effort initially followed by loss of effort).

Tailor your effort to the size of the patient. Using only two fingers to push on the extremity may give you an idea of whether they are really weak. ⅘ muscles can usually be overcome with 2 fingers.

Test the same muscle alternating between extremities. For example test the right deltoids, then the left deltoid.

Go in order from the upper to the lower extremities and work from proximal to distal.

Tailor your exam to what your hypothesis is. For example if you think that the radial nerve is involved then it’s important to test muscles innervated by this nerve and muscles not innervated by this nerve.

If you suspect an upper motor neuron lesion then it’s very important to compare search for the pattern of upper motor neuron weakness (weak deltoids, triceps, wrist and finger extension and preserved biceps, wrist and finger flexion).