CLINICAL NEUROLOGY AMINOFF PDF
Clinical Neurology, 10e. Roger P. Simon, Michael J. Aminoff, David A. Greenberg Appendix: Clinical Examination of Common Isolated Peripheral Nerve. Clinical Neurology is intended to introduce medical students and house officers to the field of Handbook of Clinical Neurology, Vol 90 (Series Eds: Aminoff. Note regarding print appearance: Because the Clinical Reasoning section appears almost exclusively .. ogy, and more—the practice of clinical neurology is.
|Language:||English, Spanish, Japanese|
|Genre:||Children & Youth|
|ePub File Size:||27.74 MB|
|PDF File Size:||17.12 MB|
|Distribution:||Free* [*Regsitration Required]|
Clinical Neurology NINTH EDITION. Michael J. Aminoff, MD, DSc, FRCP Distinguished Professor Department of Neurology School of Medicine University of. Edited by Michael J. Aminoff, François Boller, Dick F. Swaab Pages vii-viii: Download PDF Chapter 12 The anatomical foundations of clinical neurology. HANDBOOK OF CLINICAL. NEUROLOGY. Series Editors. MICHAEL J. AMINOFF , FRANCOIS BOLLER, AND DICK F. SWAAB. VOLUME ELSEVIER.
New made-up words. These patients are usually unaware of and therefore not disturbed by their aphasia. There are a variety of aphasia features of expressive and receptive aphasia—patients syndromes. Agraphesthesia is the inability to identify by touch a Motor Language speech area Arcuate comprehension number written on the hand. Clinical Neuroanatomy.
Astereognosis is the inability to identify by touch an object placed in the hand. Failure of two-point dis- Broca fasciculus area Wernicke crimination is the inability to differentiate between a single stimulus and two simultaneously applied. Other forms of aphasia include con- ing with a specific site of pathology Figure Lesions at the numbered fingertip and gradually separated until they are per- sites produce aphasias with different features: See also Table In receptive also called fluent.
Traditional view of brain areas involved cent but separated. Language anomic aphasia. Written language is similarly inco- York. Aphasia Syndromes. A speech disorder dys- arthria may be difficult to distinguish from aphasia. Patients with parietal lesions may exhibit various signs. The patient cannot See also Figure Global aphasia combines aphasia is suspected.
Allesthesia is misplaced typically tion aphasia. Tests for apraxia include asking the patient to Vein simulate the use of a key. Used with permission from Waxman SG. Olfactory I Nerve The olfactory nerve mediates the sense of smell olfaction and is tested by asking the patient to identify common scents.
Mydriatic sympathomimetic or anticholiner- 7 gic eye drops are sometimes used to enhance dilation. The patient was asked to fill in the numbers on the face of a clock A and to draw a flower B.
Irritants such as alcohol should not be used because they may be detected as noxious stimuli indepen- dent of olfactory receptors. Riordan-Eva P. Optic 5. Asbury nasal. General Ophthalmology. Ophthalmoscopy should be conducted in a dark room 6 to dilate the pupils. Constructional apraxia is the inability to draw accurate representations of external space. Each nostril is tested separately. Optic nerve function is 3 assessed separately for each eye and involves inspecting the 4 back of the eye optic fundus by direct ophthalmoscopy.
Normal function can be assumed if the patient detects the smell. A Unilateral apraxias are commonly caused by contralat- eral premotor frontal cortex lesions. Motor integration—Praxis is the application of motor Fovea disk learning. The normal optic disk Figure is a yellowish. Bilateral apraxias. Photo by retina. Anosognosia is unawareness of a neurologic deficit.
Unilateral left-sided neglect in a patient with a right parietal lesion. The diagram A shows The optic nerve transmits visual information from the landmarks corresponding to the photograph B. The normal fundus. In phy of the optic nerve. The margins of the disk and the blood vessels that edema.
A In early papilledema. Appearance of the fundus in papilledema. It can be seen in patients with neurologic patients. Papilledema is almost always bilateral. In fully developed papill- eye. C In fully developed papilledema. B Moderate papilledima with disk swelling. The disk margins become blurred. Photos used with permission from Nancy Newman.
Another the optic disk and can be visualized by having the abnormality—optic disk pallor—is produced by atro- patient look at the light from the ophthalmoscope. In early reactivity. The disk may be hyperemic with linear hemor.
D In chronic atrophic papilledema. Acuity is tested in each eye rhages at its borders. The macula. Visual acuity should be tested with refractive errors engorged and spontaneous venous pulsations are corrected. Using the index vision. The smallest line of print that can be read is finger of either hand to locate the peripheral limits of noted.
D Testing the inferior nasal quadrant. Red—green color vision is often dispro. Gross abnormalities can be detected in less Figure Subtle field defects may be detected by asking be tested using colored pens or hatpins or with color the patient to compare the brightness of colored vision plates. C Testing the superior temporal quadrant. Another perceive light. A The left eye of the patient and the right eye of the examiner are aligned.
B Testing the superior nasal quadrant. Confrontation testing of the visual field.
Visual fields are tested for each eye separately. E Testing the inferior tempo- ral quadrant. In some situ- closed or covered. Central scotoma caused by inflammation of the optic disk optic neuritis or optic nerve retrobulbar neuritis.
Common visual field abnormalities and their ana. Right homonymous hemianopia with macular sparing resulting from posterior cerebral artery occlusion. Right homonymous superior quadran- tanopia caused by partial involvement of the optic radiation by a lesion in the left temporal lobe Meyer loop.
These three nerves control the action of the intraocular tomic correlates are shown in Figure Right homonymous inferior quadrantanopia caused by partial involvement of the optic radiation by a lesion in the left parietal lobe.
A similar defect may also result from lesion 9. Right nasal hemianopia caused by a perichiasmal lesion eg. Total blindness of the right eye from a com- plete lesion of the right optic nerve. Trochlear IV. Common visual field defects and their anatomic bases. Right homonymous hemianopia from a lesion of the left optic tract.
Right homonymous hemianopia from a complete lesion of the left optic radiation. Bitemporal hemianopia caused by pressure exerted on the optic chiasm by a pituitary tumor. Oculomotor III.
Interruption of this pathway. Normal pupils constrict briskly in response to disrupted. Pupillary dilation is controlled by a rectus rectus three-neuron sympathetic relay.
The ptosis due to lesions of the levator palpebrae muscle adducted eye is elevated by the inferior oblique and or its oculomotor III or sympathetic nerve supply.
Pupillary constriction miosis is mediated through parasympa- thetic fibers that originate in the midbrain and travel Superior Inferior rectus oblique with the oculomotor nerve to the eye. Eye movements—Movement of the eyes is accom- ambient light and their responses to light and accom. The upper lid normally covers 1 to 2 mm of testing eye movement.
They should be round and regular in ward. Other common pupillary abnormali- ties are listed in Table When the eyes converge to the eyes are thus misaligned. When the function of an extraocular muscle is shape. Abnormal protrusion of the eye by the oculomotor III nerve except the superior from the orbit exophthalmos or proptosis is best oblique.
Normal pupils aver. The eye is adducted by the the iris. When illumination is removed. Common Pupillary Abnormalities. Pupils—The diameter and shape of the pupils in 3. The six cardinal positions of gaze for two eyes. All extraocular muscles are innervated Horner syndrome. A slow drift of the eyes tions can help to distinguish a disorder of the ocular away from the position of fixation indicated by the muscles per se from a disorder that affects a cranial broken arrow is corrected by a quick movement back nerve.
Nystagmus from the pri- a flashlight held in each of the cardinal positions of gaze mary position is more likely to be pathologic than that and observing whether the eyes move fully and in a from the end position.
The image displaced farther in the direction and by placing the cool surface of a tuning fork on both of gaze is always referable to the weak eye. A less common form of nystagmus is pendular nystagmus. Trigeminal V Nerve sible should be identified by having the patient gaze in the direction in which the separation of images is great. The Ophthalmic division most common form. The image to be identified.
Trigeminal V nerve sensory divisions. If nystagmus is observed. Limitations of eye move- ment and any disconjugacy should be noted. Ocular oscillations—Nystagmus. Each eye is then covered in turn and the patient is and motor fibers to the muscles of mastication. In other settings. Mandibular leftward-beating nystagmus is. Used with permission from yoked conjugate fashion in each direction. If the patient complains of diplopia.
To detect nystagmus. Facial asked to report which of the two near or far images touch and temperature sensation are tested by touching disappears. The extraocu- lar muscles are innervated by the oculomotor III. With nor- LeBlond RF. Clinical directions. Because of their differential innervation. Jerk nystagmus usually increases in amplitude with gaze in the direction of the fast phase Alexander law.
The trigeminal nerve conveys sensory fibers from the face est. The oculomotor III nerve innervates all the extraocular muscles except the superior oblique. The direction of jerk nystagmus eg. If nerve moor function.
If the patient is normally able to whistle. Again the If the patient complains of hearing loss or cannot hear examiner looks for symmetry or asymmetry.
Facial weakness may be unblinking side. Facial VII Nerve The acoustic nerve has two divisions—auditory and The facial nerve supplies the facial muscles and mediates vestibular—which are involved in hearing and equilibrium. It is tested for instead normal response. With a central base of a lightly vibrating. To perform the Rinne test Figure To test facial strength. A Central and peripheral motor innervation of the face. To test taste sensation. This discrepancy is the sound can no longer be heard.
The comparison between the two sides. Normal jaw the patient is asked to identify the taste. More subtle cotton-tipped applicators are dipped in sweet. Examination should include otoscopic inspec- tongue Figure The patient is Rinne tests performed with a Hz tuning fork. Facial VII nerve. The forehead receives motor projections from both hemispheres and the lower face eyes and below from the contralateral hemisphere only.
B Somatic afferent SA. Trigeminal motor function is tested by associated with dysarthria that is most pronounced for m observing the symmetry of opening and closing of the sounds.
Auditory asked to wrinkle the forehead. With strength is normal. With a the finger rub. To test the corneal reflex.
Clinical Neurology, 10e
The The motor examination includes evaluation of muscle patient is seated on a table with the head and eyes directed bulk. Reduced muscle bulk weakness. With conductive atrophy and twitching fasciculation. With conductive hearing loss.
Spinal Accessory XI Nerve The spinal accessory nerve innervates the sternocleido- mastoid and trapezius muscles. Tongue weakness also produces dysar- In patients with normal hearing or sensorineural hearing thria with prominent slurring of labial l sounds. Upper motor neurons arise in cerebral head.
The back of the tongue is stimulated on each side in turn using a tongue depressor or cotton-tipped applicator. Lower motor neurons project forward and is then quickly lowered to a supine position from brainstem and spinal cord.
Sternocleidomastoid weakness results in decreased ability to rotate the head away from the weak Rinne test Weber test muscle. In some cases. Conduction Localization I. In the Weber test see Figure The trapezius is tested by having the patient shrug the shoulders against resistance and noting any Hearing loss Rinne test Weber test asymmetry. With unilateral they are normal or decreased in bulk. They include projections from cortex to spinal cord corti- In patients who complain of positional vertigo.
The eyes are observed for nystagmus. Lesions of either upper or lower tal. Tests for hearing loss. As discussed later. Sensory function can be tested by the gag reflex. Patients with motor neuron spinal cord anterior horn cell or peripheral palatal weakness may also exhibit dysarthria. Atrophy orders. Abnormally decreased tone hypotonia or flaccidity may pronating. With normal tone. Tone ticity with diseases affecting the corticospinal tracts.
Rigidity is associ- ated classically with diseases of the basal ganglia and spas- B. The patient is seated on a table with the head and eyes directed forward A and is then quickly lowered to a supine position with the head over the table edge. Test for positional vertigo and nystagmus. Increased tone takes the form of rigidity.
Fine finger movements. Comparing the intensity of or thresh- emphasis should be on identifying differences from side old for sensation on the two sides of the body is useful for to side. Tone at the wrist is tested by grasping the forearm with one hand and flopping the wrist back and forth with the other.
Clinical Neurology, 10e
If the patient complains of sensory loss Figure Some tests of somatosensory together. Muscle strength. When sensory defi- muscle groups innervated by different nerves or nerve cits are more limited. The arm should move smoothly in all direc- tions. Tests of strength for selected indi- or a brushing motion of the fingertips—to the skin of a vidual muscles are illustrated in the Appendix. Sensory Disorders to determine muscles in the lower extremity.
Where possible. Technique for testing muscle strength. In the example shown biceps. Touch perception is tested by applying a light stimulus— whereas bilaterally symmetrical proximal weakness is such as a wisp of cotton. Light Touch metrical distal weakness is characteristic of polyneuropathy.
Strength is temperature sense by the small-fiber pathway. Because tested by having the patient execute a movement most sensory disorders affect distal more than proximal that involves a single muscle or muscle group and then sites. Bilaterally sym. The reported as normal.
What is the thalamus in the spinothalamic tracts. The examiner places one hand under the knee. Strength ment. Light touch normal strength for a young person cannot be expected sensation is conveyed by both pathways.
With increased tone. Tone in the legs is measured with the patient lying supine and relaxed. In pyramidal weakness due to lesions affecting limb or truncal segment. With the arms extended. With normal or reduced tone. The patient. Tests of somatosensory function. Limb Ataxia A disposable pin should be used to prick but not puncture Distal limb ataxia can be detected by asking the patient to the skin with enough force for the resulting sensation to be perform rapid alternating movements eg.
B Joint position sense. This can be tested using the flat side of a cold tuning fork C. Vibration mildly unpleasant. Temperature sensation is normal. Modified from LeBlond RF. The patient is asked whether the stimulus feels sharp. Depending on the cir- such as a joint. Testing begins distally. If a safety pin is used. Another test of lesions affecting the cerebellum or its connections. The patient is asked to from side to side. Some arms. If joint position sense is diminished distally.
Cold sensation is then compared on the distal phalanx of a finger or toe and slightly displaces the the two sides. Normal joint posi- tion sense is exquisitely sensitive. Position or another cold object. Tests of cerebellar function: C Vibration sense using Hz tuning fork. Pain A. A Touch using finger or dull end of safety pin and pain sharp end of safety pin. The snout reflex is elicited by gently tapping the lips and results in their protrusion. In the finger. This can be demonstrated by hav.
In the rooting reflex. When the patient may be accompanied by fanning of the toes. The commonly tested ten. Ataxia contraction of ipsilateral chin mentalis and perioral produces jerky and inaccurate movement. Ataxia of the lower flexion and adduction of the toes in response to stimula- limbs can be demonstrated by the heel-knee-shin test. With corticospi- ment. The glabellar reflex is elicited by repetitive tap- side of the bed or in a chair without lateral support.
The Choice: Embrace the Possible
Truncal Ataxia stimulation of the lips causes them to deviate toward the To detect truncal ataxia. Several when the arms. The palmar grasp reflex. The patient should be asked to stand with feet together and sively stretched by percussion on a tendon and depends on eyes open to detect instability from cerebellar ataxia.
The tion of the sole of the foot. The suck reflex consists of sible for the patient to keep the heel in contact with the shin. Superficial Reflexes other hand. The plantar grasp reflex consists of may cause the hand to strike the patient. The patient should then be observed walking affect any part of the reflex arc. The palmomental reflex is supine patient is asked to run the heel of the foot smoothly elicited by scratching the palm of the hand and results in up and down the opposite shin from ankle to knee.
The main goal of reflex testing is to detect absence or asymmetry. The superficial reflexes are elicited by stimulating the amplitude. Impaired ability to check the force of muscular con. Methods for eliciting these tendon 5. Extensor plantar reflex Babinski sign. Techniques for eliciting the quadriceps reflex in both seated and supine patients are shown. Methods to elicit the tendon reflexes.
The comatose patient cannot cooperate for a full neuro- DeGowin RL. Once started. The patient lordotic. Sensory function—Ask the patient to sketch out any area of perceived sensory deficit. Test the visual fields by confrontation. Central versus Peripheral Nervous System vibration sense in the feet and. Many symptoms and signs can be pro- upper limbs.
This means that a single. Where six cardinal directions of gaze. Gait abnormalities. Cranial nerves—Examine the optic disks for papill- edema. Reflexes—Compare the two sides for activity of the symptoms and signs are more definitive. Have the patient close Is the Lesion? Anatomic diagnosis takes advantage of neuroanatomic principles to localize a lesion in space.
Motor function—Compare the two sides with respect which localization can be achieved varies. Examination of the comatose patient is discussed at length Once the history and examination are completed. Left to right: The precision with 3. Test for orientation most likely to be correct.
Test light touch and A. The diagnostic process should always be guided by the law of 1. Mental status—Observe whether the patient is awake parsimony. Polyneuropathies produce distal.
The family history may point to a genetic disease. Preexisting diseases such as hypertension. Lesions of a cerebellar hemisphere produce ipsilat. Myopathies disorders of muscle ways above their crossing decussation in the medulla.
Once an anatomic diagnosis is reached. Hemispheric pathologic processes that cause disease in other organ sys- lesions are suggested by contralateral motor and sensory tems Table Thus a unilateral lesion in the pons can cause the horizontal plane. Valsalva Doctrine deficits affecting face.
Revisit the History in the limbs from interruption of the lateral spinothalamic tract. Anatomic patterns of involvement resulting from disorders affecting different sites in the nervous system. V nerve. Anatomic Patterns of Involvement Anatomic diagnosis of neurologic lesions can be facilitated B. Consider General Categories of Disease by recognizing patterns of involvement characteristic of Neurologic disease can be produced by the same kinds of disease at different sites Figure Filled areas are affected.
The relative involvement of upper motor Brainstem lesions can produce crossed deficits. This ment of the face on one side of the body and the arm and doctrine helps localize most focal cerebral lesions. Brainstem lesions should be Unilateral brain lesions typically produce symptoms and suspected with crossed deficits motor or sensory involve- signs on the opposite contralateral side of the body.
Numerous medica- so a cortical lesion can produce ipsilateral sternocleido. Etiologic Categories of Neurologic Disease. HIV-associated dementia. Arnold-Chiari malformation. Prevalence of selected neurologic diseases US. Etiologic Category Examples Degenerative Alzheimer disease.
Huntington disease. Samuels M. Parkinson disease. Time Course Is a Clue to Etiology rise to progressive. Neoplastic and degenerative processes. Data from Ropper A. Masdeu JC. Aids to the Examination of the Peripheral Nervous affects individuals of north European descent.
More often. Common Diseases Are Common undertaken to obtain additional diagnostic information. Brown D. It is helpful to 6th ed. Investigative Sometimes the anatomic syndrome is sufficiently distinc. Figure illustrates the rela. Sunija M.
After the history is taken. These investigations are addressed in Chapter 2. Brazis PW. In contrast to the pupillary constrictors, these muscles have nicotinic neuromuscular junctions and are therefore susceptible to neuromuscular junction blocking agents.
By following the pathways outlined in the figure, the consequences of lesions at various levels of the neuraxis can be deduced. Stimulation of fibers from the frontal gaze center of one cerebral hemisphere results in horizontal, conjugate eye movements to the contralateral side. If one frontal gaze center or its descending fiber tract is damaged, the eyes drift toward the involved cerebral hemisphere due to unopposed action of the remaining frontal gaze center.
For example, a destructive lesion in the right cerebral hemisphere, involving descending motor fibers and frontal gaze fibers, causes a left hemiplegia, with head and eyes deviated to the right. In other words, the eyes appear to look at a destructive hemispheric lesion and look away from the resulting hemiplegia. By contrast, a destructive left pontine lesion, for example, damages the left PPRF and surrounding region.
The eyes, therefore, cannot move to the left and tend to deviate to the right. Because descending pyramidal tract fibers cross the midline in the medulla, damage to the pyramidal tract fibers in the pons on the left results in a right hemiplegia.
Thus, the eyes appear to look away from a destructive pontine lesion but look toward the hemiplegia. If the abducens nerve or nucleus is destroyed, there is a loss of abduction of the ipsilateral eye cranial nerve VI palsy. With destruction of the tract of the medial longitudinal fasciculus, disconjugate gaze results, with loss of adduction of the ipsilateral eye same side as the tract of the MLF. Abduction of the contralateral eye is preserved, but there is nystagmus in the awake patient.
This type of disconjugate gaze abnormality is also termed internuclear ophthalmoplegia. The pathways for vertical eye movements are less well understood. Lower centers likely exist in the midbrain pretectal and tectal regions. If a patient cannot follow verbal commands, two useful tests are employed to determine brain stem integrity.
They activate the PPRF and subsequent pathways, not by cortical stimulation but rather by vestibular alterations. An oculocephalic or cervico-ocular or doll's eyes reflex is performed by turning the patient's head rapidly in the horizontal or vertical planes and by noting the movements or position of the eyes relative to the orbits.
This test obviously should not be performed if a cervical neck fracture is suspected.
If the pontine horizontal or midbrain vertical gaze centers are intact, the eyes should move in the orbits in the direction opposite to the rotating head. An abnormal response no eye movement on moving the head implies pontine or midbrain dysfunction and is characterized by no movement of the eyes relative to the orbits, or an asymmetry of movements.
Horizontal oculocephalic maneuvers are a relatively weak stimulus for horizontal eye movements. If a doll's eyes reflex is present, it is not necessary to continue with oculovestibular testing. If, however, the doll's eyes reflex is lacking, ice water calorics should be performed, because ice water is a stronger stimulus than oculocephalic maneuvers. Oculovestibular responses ice water calorics are reflex eye movements in response to irrigation of the external ear canals with cold water.
The head is raised to 30 degrees relative to the horizontal place, and the external canals are inspected for the presence of cerumen or a perforated tympanic membrane. Fifty to one hundred milliliters of cold water is instilled into the canal waiting 5 minutes between each ear , and the resulting eye movements are noted. Ice water produces a downward current in the horizontal semicircular canal and decreases tonic vestibular output to the contralateral PPRF.
Simplistically, one can think of this as an indirect means of stimulating the ipsilateral PPRF. Hence, after cold water instillation, there should be a slow, tonic, conjugate deviation of the eyes toward the irrigated ear if the brain stem is intact.
In a comatose patient, there is a loss of the past-phase nystagmus, and only tonic deviation of the eyes is seen if appropriate pontine-midbrain areas are intact. Thus, if nystagmus is noted in a seemingly unconscious patient, the patient is not truly comatose.
Thus, a lack of oculovestibular responses suggests pontine-midbrain dysfunction. Ice water calorics can help differentiate between the conjugate gaze weakness, or paralysis caused by either cortical cerebral hemisphere or brain stem pontine damage.
David L. Felten's fun, fast, and full-color Netter's Neuroscience Flash Cards.
Aminoffs Electrodiagnosis in Clinical Neurology
These portable, updated cards let you quiz yourself on anatomy, pathophysiology, and clinical presentation. They now include imaging content and offer increased clinical correlations Allam, and Richard A.
Baker uses visually rich Netter artwork to efficiently provide you with a concise overview of general neurology and its intersection with internal medicine, neurosurgery, ophthalmology, psychiatry, and orthopedics.
From stroke and epilepsy to dementia andPainful stimulation may produce no The approach to diagnosis of the comatose patient consists response or nonpurposeful reflex movements mediated first of emergency measures to stabilize the patient and through spinal cord or brainstem pathways. With destruction of the tract of the medial longitudinal fasciculus, disconjugate gaze results, with loss of adduction of the ipsilateral eye same side as the tract of the MLF.
Excessive consump- ease include hypertension. Some tests of somatosensory together. Movement Disorders. If a doll's eyes reflex is present, it is not necessary to continue with oculovestibular testing.