Evaluation of the Nervous System

One of the major things of the neurological exam is to be aware of the subdivisions. If someone comes into you as a new patient, CCHR, PIM, components of the exam that are relative to the history and also when you come to your review of systems. If you have the list in front of you, you are less likely to omit an exam.

Divisions:

• Mentation and Speech

• Cranial Nerves- most neurologists don’t do cranial nerve one.

• Motor- with several subdivisions. usually is the most important and the most robust. So when you are involved with patients that are lathergic or noncompliant or can’t cooperate it can give you important information/ good results when other divisions do not.

• Reflexes- lot of them in the book.

• Cerebellar- good coordination is dependent on good strength. Poor control versus poor cerebellar function

• Central Exam- more subject to a variety of error, be aware of the component

• Meningial Irritation- just keep in mind this is a part of the examination

How do you differentiate Cerebellar problems from those of the 8^th CN?

Presence or absence of Nystagmus (vestibular system problem when nystagmus is present) 90% seperation

Mentation- diagnosing the mental status

1. Level of consciousness. Descrease level on conciousness affects everyting else. Comatose- very little that you can do. You can grade them on a Glaslo carma (?) scale or just a description of how well they react. Do you have to arouse them? How much response do you get? Intellectual impairment and dementia diagnosis are also an element of the mental status- Alzheimer’s. To evaluate the intellectual function Minimetal status exam- came in 1974, many people use it worldwide- formalized to say what you do and don’t do. In terms of the evaluating the intellectual function, we find the information very important. A health brain in the US knows the president and the mayor, maybe the vice president- all important components of the healthy fund of information. Loss off long-term memory is involved in the fund of information (name, hometown)- in general more hard wired in. When diseases set in, these things will stay more then other things. Remote fund of information- its components are very wide.

2. Digit Span Random digit- immediate recall. Give the patient a string of 7 number and have them say it back to them. The average person can usually remember 7 digit in a span. One of the many things in the examination that are anxiety sensitive. Anxiety- non anxious patients will do better then those that are anxious. Many things are also culturally dependent (prior exposure needed)- ex. president of US. Someone in another culture may not know this. Usually you do a battery of tests.

3. Recent Memory- tell them a group of number or names and then come back in two minutes and ask you what those were. Requires you to remember store and recall information. More reliable then the immediate memory or the remote memory. For each test and the entire examination, you need practice and some grasp of the normal.

4. Orientation- for person, place and time- ex. what’s your name? some people call that orientation to person (adequate), or ask him what is it that I do- doctor, professor. What is the name of this place?- Howard University. Time is less stabile.

Speech

The biggest part is to know if the person has any phagia, and/or any significant dysfunction. Usually you can just talk to the person and you actually know if they have normal speech. What are the components of speech that you should be aware of:

1. Ability of a patient to follow commands. First order (open your eyes, raise your hand) monitors comprehension. #1 parameter concerning prognosis and communication. If the comprehension survives then it is a better prognosis (brain damage)

2. Speech production- do they produce loud volume of speech, is it fluent, or is it broken. Look for a lot of hesitation. Disturbance in speech flow is associated Broca’s Area- anterior aphagia Reduction in speech flow, fluency and amount produced. In the Broca’s aphagia, temporal and parietal lobes involved, but among the problems is with comprehension.

3. Naming

4. Repetition- Mary had a little lamb, count to 10.

You should also have the patient read and write. Core of speech evaluation

Motor Examination

1. Strength- Observe the patient. If you have a patient with a hemiplegia then you should look to see how much they move on the left and then on the right. The same with a hemiperesis. Look for differential movement. Tell the patient to do something, close the eyes and hold out hand. Weak arm will drop down. Compared one side to the other (left and right biceps)-very important. Test deltoid and dorsal wrist flexion (proximal vs. distal strength also). Hip flexors, knee extensor. Write it down based on which joint is doing what. When you test the individual muscles you want to see if there was weakness, (direction). Ex. there was weakness in the lower limbs, but not in the upper limbs (paraparesis), weakness on the left side but not on the right side (left-sided hemiparesis), proximal weakness but not distally (muscle dysfunction). Peripheral neuropathy- weakness distally but nor proximally

2. Tone- passive range of movement, look for equal resistance in either direction or any resistance. Increased tone with UMN lesions and basal ganglia disorders. Exam elbows, knees and wrists. Decreased tone with LMN lesions

3. Inspection- Look for wasting, differential, proximal or distal LMN lesion. Fasciculation LMN lesion

Tell patient to elevate the limbs, weaker side won’t go as high. Test them against resistance.

Walk the patient to determine the gait, very important. (cerebellum examination) If you do not walk a patient then your examination is incomplete.

Reflexes

Always want to compare R and L, upper and lower, proximal and distal. Biceps jerk, tricep jerk, knee jerk, ankle jerk, and the superficial reflexes (abdominal and cremasteric). Babinski reflux (normally the big toe will go down)- upper motor neuron lesion. But some may not have the sign.

No ankle jerk LMN lesions, clinically, peripheral neuropathies- worse in lower limbs then in the upper limb. Slipped disk  loss of ankle jerk (was very important)

Cerebellum

• You want them to tandom walk, one foot in front of the other. If you can’t walk the patient, you can’t say the cerebellum is normal. Tandom walking requires more cerebellar involvement. It is the more demanding task that uses the cerebellum in the lower limb.

• Heel-shin test- some people can’t dorsal flex so they can’t give you full cooperation.

• Alcoholic Cerebellum Degeneration (perenkymal cerebellum degeneration)- alcohol has short term effects on the cerebellum. Heavy drinking and malnutrition combined give you the ACD- long term and chronic ( Audio was bad at this point)

• Upper limb finger nose test- past pointing, intentional tremor, overshooting. You have to practice, especially on people with pathology.

• Other test of the cerebellum influenced by strength and can be misleading. So if you have you strength intact you can overcome some of the cerebellar problems.

• Normal cerebellum and muscle weakness on the left non-coordination

Sensory Test- many parameters

Pain and Temperature

HIV- pain was done with a pin, but it is done far less now because of AIDS and HIV. It is still a valuable parameter. They should tell you if it is sharp or dull, compare right with left in the face and the limbs. Compare the upper limbs with the lower limbs- to see if you have a spinal cord lesion leading to paraparesis. Can you feel it proximally or distally? Proximal will be better then distal in different neuropathies (ex. diabetic neuropathy). Wood pin is not as reliable as the safety pin.

Temperature- tested less often. The way around it is to use the tuning fork and ask them if the metal feels cold. Make sue to measure, proximal vs. distal, etc. Pain and temperature is carried in the Spinothalamic tract (tells you about the lateral column). Joint position test- Take the finger and tell if it is up or down. Can tell you if there is a proprioception problem

Romberg sign- people argue about it in the literature. Can you stand with your feet together and your eyes closed, need good proprioception and a good cerebellar system. Many people with cerebellar system dysfunctions tend to separate their heels. Small amount of triangle makes it a better base.

Vibration/Tuning forks- compare right with left, upper and lower, and compare the proximal and distal. Relatively subjective- a lot depends on how hard you strike the tuning fork. Hitting it hard can give them a very forceful sensation that they can pick up. You should be able to just detect it in their fingers- objective only if you (as the normal) can only feel it in your fingers.

Signs of Meningial Irritation- relatively simple, (couldn’t understand what he was saying) get the patient to relax- when you flex the neck reflex flexion of the patient’s head Brazinski sign. Nextitin (?)

Curinate sign- Flex the hip and attempt to extend the knee (normal person should be able to completely extend the knee). Meningial irritation limited extention or pain in the proximal thigh. Meningial irritation is found in meningitis (bacterial, viral, chronic, and subacute) and with subarachnoid hemorrhage (aneurysm ruptures).

Cranial Nerves

CN2- visual pathway- need to be aware of it. Visual acuity- Rosenbaum chart, should be 14 inches away from the face with bright light. 20/200-legally blind, 20/20 is considered normal. Highest on the chart is 20/800. Should do each eye separately. Confrontation of visual field. Should test each eye separately. Each eye has four quadrants and you should be able to demonstarate vision in each field. Small stationary is more useful the a large moving object.

Right hemiparesis- can be caused by a lesion in left internal capsule lesion. Damage of fibers going to the left occipital cortex- cover vision from the right side of the face and started from the left side of the retina. They will also have a right-homonomous hemianopsia. Most common visual problem. Quadrantanopsia is also a problem.

Bitemporal hemianopsia associated with pituitary adenoma. Damage to the medial fibers in the optic chiasm, dealing with vision from the temporal field.

Papillary Light reflex- CN2 and CN3. Both pupils should constrict when light is shined into one eye- consensual and direct light reflex. Should look at the charts and you should be able to determine the size of the pupil (need to write down how big the pupil was and if both pupils responded to light), may want to look at accommodation.

CN3, CN4, CN6- all concerned with eye movements. You can test the eyes separate or togther, but you have to test for conjugate gaze. Lateral and Medical Rectus- horizontal gaze. Look to right and up- superior rectus. To the right and down- infereior rectus. Medially and up- superior oblique. Medially and down- inferior oblique

Is there conjugate gaze? If they are not, then which muscle is it?

Double vision- diploplia. Double vision only on lateral gaze (left lateral or left medial rectus is not performing properly). Nystagmus- says that something is probably a problem in the vetibular system.

CN7- Moves the facial musculature (is the smile line different on each side), taste to anterior 2/3 of the tongue. Can not open the eyes or raise the eyebrows if there is a problem. If the eye is widely open CN7 problem/weakness (Audio was bad here)

CN8- observe for nystagmus- very valuable, tells you there is vestibular dysfunction. Auditory acuity on one side versus the other. Ask the patient what they hear with their eyes closed. Weber test- put tuning fork in the middle of the forehead. Rienne (sp?)test, put tuning fort on the mastoid process and then put it at the external ear and ask the patient which one is louder. Air conduction is usually louder.

CN 9, CN10, CN11, CN12-

CN12- innervates the tongue. The tongue deviates if one side is weak. Deviates towards the affected side of the tongue.

Fasiculations of the tongue- LMN lesion associated with hematotrophic lateral sclerosis

Corticobulbar lesion will give you a contralateral sign. Lower Motor Neuron lesion will give you an ipsilateral sign.

Category: Neurology notes