Neurological Assessment Part 1

Transcription

1 Neurological Assessment Part 1 MOTOR EXAMINATION: Look at bulk, contour and symmetry of individual muscles: muscles of face upper arm arm thigh lower leg Look for atrophy--may help to localize the site of atrophy producing lesion 1. Disuse atrophy--usually seen in patients that have been immobilized for a period of time. Muscle stretch reflex preserved. 2. Denervation atrophy--usually the result of damage to lower motor neurons or their axons that interrupts conducting nerve impulses to skeletal muscles. No muscle tone or muscle stretch reflexes. CRANIAL NERVE EVALUATION OLFACTORY NERVE (I) Olfactory nerve function is tested by presenting non-noxious odorants such as coffee, soap, tobacco, or orange separately to each nostril. Ask patient to occlude one nostril with a finger and ask if he/she smells something when the odorant is placed beneath the un-occluded nostril. Use what is available in lab. Check box if positive for that smell. R L Coffee Soap Tobacco Orange Inability to detect a smell is referred to as anosmia. If anosmia is present, note whether it is bilateral or unilateral.

2 OPTIC NERVE (II) The visual pathways begin at the retina and ends in the cortex of the occipital lobe. Visually inspect the eyes and eyelids for any asymmetries or abnormalities. Observe the globes of the eye for size and location within the orbit. Examine the upper eyelids to see if one or both droops, a condition called ptosis. The levator palpebrae superioris muscle is a skeletal muscle of the upper eyelid involved in keeping the eye open and is innervated by the oculomotor nerve (III). See if globes of the eye protrude or bulge out of the orbits, a condition called proptosis (exophthalmos). Test for light reflex. If possible go to a darkened room with the examiner sitting to one side of the patient. The patient is instructed to look straight ahead and focus on some distant point. The examiner brings the bright light from the side of the patient s head into one eye. Pupillary reactions in both eyes should be examined and recorded. Normally, the pupils of both eyes should promptly constrict. Iridoplegia is a term used to describe lack of constriction of the pupil. Check box if positive: Right eye Left eye Constricted OCULOMOTOR, TROCHLEAR, AND ABDUCENS NERVES (III, IV, VI) These nerves innervate the ocular motor muscles of the eye. In addition, the oculomotor nerve innervates the elevator of the upper eyelid (levator palpebrae superioris), superior rectus, inferior rectus, medial rectus, inferior oblique and regulates pupil size and lens shape for accommodation. The trochlear nerve innervated the superior oblique while the abducens innervates the lateral rectus (remember SO 4 LR 6 ). Have patient hold his/her head steady while the examiner asks the patient to follow a finger as it is moved into different positions in front of the patient. Do the following in this order for right/left eye. Note any deviations of each eye and indicate the nerve involved: Lateral rectus - abduction Superior rectus - finger up (superiorly) Inferior rectus - finger down (inferiorly) Medial rectus- adduction (finger towards and across midline) Inferior oblique - finger up (superiorly) Superior oblique - finger down (inferiorly) Comments

3 TRIGEMINAL NERVE (V) This nerve is a mixed nerve carrying sensory information (pain, temperature, touch) from the face, oral and nasal cavities as well as the cornea. Motor fibers of this nerve innervates the muscles of mastication (temporalis, masseter, medial and lateral pterygoids), and tensor tympani. Sensory testing of the face can be performed with a safety pin so that touch stimuli can be applied. We will not open the pin. Touch the following areas: 1. Forehead on both sides in succession, asking the patient whether the two stimuli feel the same or different (innervated by ophthalmic nerve). 2. Cheeks over maxillary prominence (innervated by maxillary nerve). 3. Chin on both sides near midline near mental foramen (innervated by mandibular nerve). Check box if normal: Forehead Cheeks Chin R L Comments: Muscles of mastication: open jaw - lateral pterygoid close jaw - temporalis, masseter, medial pterygoid protrude jaw with mouth slightly open - lateral pterygoid FACIAL NERVE (VII) This nerve is a mixed nerve with both sensory and motor functions. Motor fibers innervate the muscles of facial expression, including the platysma. Sensory fibers transmit taste from the anterior two thirds of tongue. Observe the patient s f ace, paying particular attention to lower eyelids, nasolabial folds, and corners of the mouth. The face should appear symmetrical in intact persons. Clinical things to look for: slight drooping of the lower eyelid, possibly with tears appearing on the cheek, drooping of the corner of the mouth on the affected sides. Saliva may dribble from the corner of the mouth. Speech may be slurred. Also, eye on the affected side may not fully close with blinking.

4 Do the following tests: Ask patient to hold head steady, look upward and raise the eyebrows. Contraction of the frontalis muscle should produce wrinkles in the forehead. Damage to the facial nerve may cause the eyebrow on the affected side to not elevate, with no wrinkles on that side. Look at eyelids--in patients with facial nerve dysfunction, the upper and lower eyelids will not appear equal. Ask patient to smile and show the teeth. Damage to the facial nerve in the involved side will cause the smile to be asymmetric. Purse lips as if attempting to whistle or kiss. We will not assess taste from the anterior two-thirds of the tongue. Explain what Bell s palsy represents and how you would test for it? VESTIBULOCOCHLEAR NERVE (VIII) Cochlear division is concerned with hearing. Vestibular division is concerned with equilibrium or more specifically, monitoring the position of the head in space while we are stationary and in motion. Cochlear Nerve Do you have difficulty hearing conversations? Yes No Do you favor one ear over the other when talking on the telephone? Yes No Finger rub some distance lateral to the patient s ear out of hearing range. Then move fingers closer to ear, asking the patient when sound is first heard. Repeat on the other side. Left Right Which ear heard the sounds closer to the ear? The Rinne test is used on patients who perform poorly on the above test. All of you will perform the test anyway. The Rinne test is useful in distinguishing conduction deficits from nerve deficits. Conduction deficits include obstruction of the external ear canal or disease of the middle ear that restricts the movement of the auditory ossicles.

5 Do the following: Strike the tuning fork gently against your palm and place it against the base of the mastoid process. The patient is asked to indicate when the tone is no longer heard. At that moment, the tines of the tuning fork are brought close to the external auditory meatus, and the patient is asked if the tone is heard again. For normal hearing, the tone will be heard again about 2x long as bone conduction. In patients with sensorineural hearing loss (damage to cochlear nerve), they will hear the tone again but duration of time will be reduced. In patients with conduction disorders, the tone will not return when the tines are brought close to the ear. The Rinne test in this case would be considered negative. Rinne test results: Right ear Left ear Positive Negative Positive Negative Weber test: Place a vibrating tuning fork on the vertex of the skull (center of forehead). The patient is asked to indicate on which side, if either, the tone is louder. Normal hearing - tone is equally heard on both sides. Sensorineural hearing loss - tone is louder in normal ear (or good ear). Record the results for Weber test: Right ear Left ear Positive Negative Positive Negative Conduction deafness - tone is louder on the diseased side - tone is heard better on the diseased side or bad ear. Hearing loss with aging is presbycusis. Tinnitus - hissing, roaring, whistling or humming in the ear - found in patients with otosclerosis - spongy bone formation in front of the foot plate of stapes resulting in conduction hearing loss.

6 Vestibular nerve - some clinically important functions of the vestibular nerve: nystagmus- involuntary, rapid, rhythmic movement of the eyeball vertigo - illusion of movement, i.e., room spinning vomiting falling nausea Do Past-pointing test by asking patient to alternately touch his nose and reach toward examiner s finger. Do three or four times with eyes open, then with eyes closed. Keep the examiner s finger beyond reach of patient s reach. Patients with vestibular disease when reaching forward with eyes closed will drift away from examiner s finger toward the side of vestibular disease. Past-pointing test: Right hand Left hand Drift No drift Drift No drift Do marching-in-place test - used to evaluate vestibular function Have patient march in place with eyes open and then closed. Normal patients continue to face in the same direction whether their eyes are open or closed. Patients with vestibular disease tend to rotate to one side when eyes are closed, toward the diseased side. Marching test - check box if o.k. Eyes open Eyes closed GLOSSOPHARYNGEAL NERVE (IX) This is a mixed nerve and will be tested with vagus (X) Vagus - mixed nerve Clinical - difficulty swallowing because these two nerves innervate the muscles of the pharynx used for swallowing. Inspect uvula and soft palate - normally, uvula is symmetrical and located in the midline. Vagal nerve lesions can cause the uvula to deviate to one side. Say ah. the soft palate will elevate with ah. Lesion of vagus will not elevate the soft palate on the affected side. Hoarseness - may indicate damage to the vagus (innervates larynx and vocal folds).

7 SPINAL ACCESSORY (XI) Innervates sternocleidomastoid and trapezius Elevate or shrug shoulders and have examiner push down on both shoulders simultaneously. HYPOGLOSSAL (XII) Motor to muscles of tongue Examine tongue. Stick out your tongue and observe if tongue stays in midline or deviates to one side. In patients with lesions to hypoglossal nerve, tongue will deviate to affected side. Ask patient to say la la la, tee tee tee, or dee dee dee. These will be difficult to do in patients with lesions of this nerve because of difficulty in moving tongue against hard palate. Stick out tongue again and examine if one side is atrophied or undergoes fasciculations--a characteristic of lesions to the nerve on one side. Record your results: Deviation to one side R L La, la, la (lingual sounds) difficulty normal Atrophy Fasciculation