Podcast
Questions and Answers
A patient reports a loss of smell following a head injury. Which cranial nerve is MOST likely affected?
A patient reports a loss of smell following a head injury. Which cranial nerve is MOST likely affected?
- Vagus nerve
- Olfactory nerve (correct)
- Facial nerve
- Optic nerve
During an eye exam, a patient is unable to see objects in the temporal fields of both eyes. This visual field defect is MOST likely caused by a lesion at which location?
During an eye exam, a patient is unable to see objects in the temporal fields of both eyes. This visual field defect is MOST likely caused by a lesion at which location?
- Optic tract
- Optic chiasm (correct)
- Visual cortex
- Optic nerve
A patient presents with ptosis, mydriasis, and a ‘down and out’ gaze of the right eye. Which cranial nerve is MOST likely affected?
A patient presents with ptosis, mydriasis, and a ‘down and out’ gaze of the right eye. Which cranial nerve is MOST likely affected?
- Trochlear nerve
- Facial nerve
- Abducens nerve
- Oculomotor nerve (correct)
A patient is asked to look inward and downward, and you observe a deficit in this movement. Which cranial nerve is MOST likely affected?
A patient is asked to look inward and downward, and you observe a deficit in this movement. Which cranial nerve is MOST likely affected?
A patient has difficulty chewing and reports a loss of sensation in the forehead and cheek. Which cranial nerve is MOST likely affected?
A patient has difficulty chewing and reports a loss of sensation in the forehead and cheek. Which cranial nerve is MOST likely affected?
A person cannot abduct their eye. Which nerve is MOST likely affected?
A person cannot abduct their eye. Which nerve is MOST likely affected?
A patient has paralysis of the upper and lower face on the same side of their face. This is MOST likely caused by damage to what?
A patient has paralysis of the upper and lower face on the same side of their face. This is MOST likely caused by damage to what?
A patient experiences a loss of taste on the anterior two-thirds of the tongue and has difficulty with facial expressions. Which cranial nerve is MOST likely affected?
A patient experiences a loss of taste on the anterior two-thirds of the tongue and has difficulty with facial expressions. Which cranial nerve is MOST likely affected?
During a neurological examination, a patient demonstrates a positive Weber test, with lateralization to the left ear. Rinne's test is normal in both ears. Where is the MOST likely location of the lesion?
During a neurological examination, a patient demonstrates a positive Weber test, with lateralization to the left ear. Rinne's test is normal in both ears. Where is the MOST likely location of the lesion?
A patient complains of vertigo. You extend patient's neck and sustain for 10 sec then rotate neck to right and ask the patient about their feeling. Patient reports vertigo. After the patient has recovered you stand the patient up and get them to sit on a rotatory chair, and fix the patient's head. You then get the patient to rotate their trunk fully to the right/or left side for 5 seconds .The patient reports no vertigo. What is the MOST likely cause of the patient's vertigo?
A patient complains of vertigo. You extend patient's neck and sustain for 10 sec then rotate neck to right and ask the patient about their feeling. Patient reports vertigo. After the patient has recovered you stand the patient up and get them to sit on a rotatory chair, and fix the patient's head. You then get the patient to rotate their trunk fully to the right/or left side for 5 seconds .The patient reports no vertigo. What is the MOST likely cause of the patient's vertigo?
A patient has diminished saliva production, difficulty swallowing, and a loss of taste sensation on the posterior one-third of the tongue. Which cranial nerve is MOST likely affected?
A patient has diminished saliva production, difficulty swallowing, and a loss of taste sensation on the posterior one-third of the tongue. Which cranial nerve is MOST likely affected?
A patient has difficulty swallowing, hoarseness, and impaired gag reflex. Which cranial nerve is MOST likely affected?
A patient has difficulty swallowing, hoarseness, and impaired gag reflex. Which cranial nerve is MOST likely affected?
A patient presents with weakness in shrugging the shoulders and turning the head to the opposite side. Which cranial nerve is MOST likely affected?
A patient presents with weakness in shrugging the shoulders and turning the head to the opposite side. Which cranial nerve is MOST likely affected?
Your patient is unable to stick their tongue straight out of their mouth. The tongue deviates to one side when the patient attempts to protrude it. Which cranial nerve is MOST likely affected?
Your patient is unable to stick their tongue straight out of their mouth. The tongue deviates to one side when the patient attempts to protrude it. Which cranial nerve is MOST likely affected?
Which of the following cranial nerves is NOT purely sensory?
Which of the following cranial nerves is NOT purely sensory?
Unilateral upper motor neuron lesions of cranial nerves do not cause apparent manifestations except for which of the following cranial nerves?
Unilateral upper motor neuron lesions of cranial nerves do not cause apparent manifestations except for which of the following cranial nerves?
When testing the acuity of vision, and the patient can not count your fingers at 30cm, what is the next step?
When testing the acuity of vision, and the patient can not count your fingers at 30cm, what is the next step?
What is the name for a lesion that is caused by lesion involving right perichiasmal area?
What is the name for a lesion that is caused by lesion involving right perichiasmal area?
What muscles does the oculomotor nerve supply?
What muscles does the oculomotor nerve supply?
The light reflex involves which cranial nerves?
The light reflex involves which cranial nerves?
When testing accommodation assess for which of the following?
When testing accommodation assess for which of the following?
A patient looks the the affected eye looks outwards and has diplopia only when the patient looks outwards toward the paralyzed side. Which nerve is MOST likely affected?
A patient looks the the affected eye looks outwards and has diplopia only when the patient looks outwards toward the paralyzed side. Which nerve is MOST likely affected?
A positive test for External ophthalmoplegia involves which of the following?
A positive test for External ophthalmoplegia involves which of the following?
A patient has abnormal face sensation. Which part of the trigeminal nerve supplies this symptom?
A patient has abnormal face sensation. Which part of the trigeminal nerve supplies this symptom?
Why should you ask the patient to look upwards and inwards when testing the corneal and conjunctival reflexes?
Why should you ask the patient to look upwards and inwards when testing the corneal and conjunctival reflexes?
What does and absence of blinking on both sides while testing the corneal and conjunctival reflexes indicate?
What does and absence of blinking on both sides while testing the corneal and conjunctival reflexes indicate?
When testing the motor part of the trigeminal nerve, and you ask the patient to open their mouth, what should you expect?
When testing the motor part of the trigeminal nerve, and you ask the patient to open their mouth, what should you expect?
An exaggerated jaw jerk reflex, shown by closure of the jaws, denotes a bilateral U.M.N.L. above the motor nucleus of which cranial nerve
An exaggerated jaw jerk reflex, shown by closure of the jaws, denotes a bilateral U.M.N.L. above the motor nucleus of which cranial nerve
If the patient laughs and improve asymmetry, the facial nerve lesion is where?
If the patient laughs and improve asymmetry, the facial nerve lesion is where?
When testing the acoustic nerve, what is the first step?
When testing the acoustic nerve, what is the first step?
A patient presents with a spinal accessory nerve lesion, which of the following may be observed?
A patient presents with a spinal accessory nerve lesion, which of the following may be observed?
What does Fasciculation indicate when inspecting the tongue?
What does Fasciculation indicate when inspecting the tongue?
Which of the following is a pure motor cranial nerve?
Which of the following is a pure motor cranial nerve?
Which cranial nerve is responsible for muscles of expression of the face, posterior belly of digastrics,Platysma, Stapedius and Stylohyoid?
Which cranial nerve is responsible for muscles of expression of the face, posterior belly of digastrics,Platysma, Stapedius and Stylohyoid?
In cases of ptosis, what can be done to determine whether the ptosis is partial or complete?
In cases of ptosis, what can be done to determine whether the ptosis is partial or complete?
Which cranial nerves contain parasympathetic fibers?
Which cranial nerves contain parasympathetic fibers?
A patient presents with diplopia that is exacerbated when descending stairs. Which cranial nerve is MOST likely affected?
A patient presents with diplopia that is exacerbated when descending stairs. Which cranial nerve is MOST likely affected?
During a neurological exam, a patient's eye is noted to be adducted (turned inward) at rest. Which cranial nerve is MOST likely affected, and what is the likely muscle imbalance?
During a neurological exam, a patient's eye is noted to be adducted (turned inward) at rest. Which cranial nerve is MOST likely affected, and what is the likely muscle imbalance?
A patient is being evaluated for vestibular function. During the Dix-Hallpike maneuver, the therapist observes nystagmus and reports of intense vertigo. After the symptoms subside, the therapist has the patient sit in a rotating chair and rotates the patient's trunk while the head is fixed. The patient reports no vertigo. What is the MOST likely origin of the patient's vertigo?
A patient is being evaluated for vestibular function. During the Dix-Hallpike maneuver, the therapist observes nystagmus and reports of intense vertigo. After the symptoms subside, the therapist has the patient sit in a rotating chair and rotates the patient's trunk while the head is fixed. The patient reports no vertigo. What is the MOST likely origin of the patient's vertigo?
A patient presents with a unilateral lesion affecting the hypoglossal nerve (XII). Which of the following tongue deviations would be expected upon protrusion, and why?
A patient presents with a unilateral lesion affecting the hypoglossal nerve (XII). Which of the following tongue deviations would be expected upon protrusion, and why?
A patient is diagnosed with damage to the chorda tympani nerve. Which sensory deficit would MOST likely result from this condition?
A patient is diagnosed with damage to the chorda tympani nerve. Which sensory deficit would MOST likely result from this condition?
A patient reports a sudden loss of smell after experiencing a viral upper respiratory infection. Although there is no structural damage visualized, the patient continues to have anosmia. What is the MOST likely underlying cause?
A patient reports a sudden loss of smell after experiencing a viral upper respiratory infection. Although there is no structural damage visualized, the patient continues to have anosmia. What is the MOST likely underlying cause?
During an examination, a patient exhibits a positive glabellar reflex, characterized by sustained blinking with repetitive tapping on the glabella. This finding is MOST indicative of:
During an examination, a patient exhibits a positive glabellar reflex, characterized by sustained blinking with repetitive tapping on the glabella. This finding is MOST indicative of:
A patient has suffered a stroke affecting the motor cortex responsible for facial movement. Which of the following clinical presentations would MOST likely differentiate an upper motor neuron lesion from a lower motor neuron lesion of the facial nerve?
A patient has suffered a stroke affecting the motor cortex responsible for facial movement. Which of the following clinical presentations would MOST likely differentiate an upper motor neuron lesion from a lower motor neuron lesion of the facial nerve?
A patient presents with dysphagia, loss of gag reflex, and hoarseness. Which combination of cranial nerve impairments BEST explains these findings?
A patient presents with dysphagia, loss of gag reflex, and hoarseness. Which combination of cranial nerve impairments BEST explains these findings?
A patient is being tested for accommodation. What specific triad of events should the examiner observe in a normal response?
A patient is being tested for accommodation. What specific triad of events should the examiner observe in a normal response?
During a neurological examination, you note that a patient has difficulty with fine motor movements of the tongue and exhibits fasciculations. This MOST likely suggests:
During a neurological examination, you note that a patient has difficulty with fine motor movements of the tongue and exhibits fasciculations. This MOST likely suggests:
A ptotic eyelid with associated miosis, enophthalmos, and anhidrosis is indicative of:
A ptotic eyelid with associated miosis, enophthalmos, and anhidrosis is indicative of:
A patient with a suspected cranial nerve lesion reports that food tastes 'off' or metallic. When testing with different solutions, they can correctly identify salty and sour tastes but not sweet or bitter on the anterior tongue. This pattern suggests damage to which cranial nerve branch?
A patient with a suspected cranial nerve lesion reports that food tastes 'off' or metallic. When testing with different solutions, they can correctly identify salty and sour tastes but not sweet or bitter on the anterior tongue. This pattern suggests damage to which cranial nerve branch?
A concert musician reports increasing difficulty playing the flute, specifically with precise lip movements and control of air pressure inside the mouth. Which cranial nerve and associated muscle group are MOST likely affected?
A concert musician reports increasing difficulty playing the flute, specifically with precise lip movements and control of air pressure inside the mouth. Which cranial nerve and associated muscle group are MOST likely affected?
During a cranial nerve examination, a physical therapist notes that a patient has significant asymmetry in their smile. When asked to smile spontaneously, the asymmetry is more pronounced than when the patient is asked to smile on command. What does this suggest about the location of the lesion?
During a cranial nerve examination, a physical therapist notes that a patient has significant asymmetry in their smile. When asked to smile spontaneously, the asymmetry is more pronounced than when the patient is asked to smile on command. What does this suggest about the location of the lesion?
A patient reports experiencing parosmia following a traumatic brain injury. How would you BEST explain this symptom to the patient?
A patient reports experiencing parosmia following a traumatic brain injury. How would you BEST explain this symptom to the patient?
A patient is observed to have gaze-evoked nystagmus during smooth pursuit eye movements. This finding is MOST likely indicative of:
A patient is observed to have gaze-evoked nystagmus during smooth pursuit eye movements. This finding is MOST likely indicative of:
During a cranial nerve exam, you observe the patient's uvula deviates to the right when they say "ah." Which cranial nerve is MOST likely affected and on which side?
During a cranial nerve exam, you observe the patient's uvula deviates to the right when they say "ah." Which cranial nerve is MOST likely affected and on which side?
A patient presents with bilateral tongue weakness but no fasciculations. They also report being unable to wrinkle their forehead. What is the MOST likely location of the lesion?
A patient presents with bilateral tongue weakness but no fasciculations. They also report being unable to wrinkle their forehead. What is the MOST likely location of the lesion?
A patient reports experiencing vertigo along with hearing loss and tinnitus. Which of the following is MOST likely affected?
A patient reports experiencing vertigo along with hearing loss and tinnitus. Which of the following is MOST likely affected?
A patient is undergoing hearing tests. Air conduction is better than bone conduction in both ears. According to Weber's test, the vibrations are heard in the middle of the forehead. What does this indicate?
A patient is undergoing hearing tests. Air conduction is better than bone conduction in both ears. According to Weber's test, the vibrations are heard in the middle of the forehead. What does this indicate?
Which cranial nerve is assessed by testing the ability to shrug the shoulders against resistance?
Which cranial nerve is assessed by testing the ability to shrug the shoulders against resistance?
A patient cannot feel pain or light touch on the left side of their face, but motor control of chewing is intact. Where is the MOST likely location of the lesion?
A patient cannot feel pain or light touch on the left side of their face, but motor control of chewing is intact. Where is the MOST likely location of the lesion?
A patient presents with diplopia, ptosis, and a dilated pupil in their right eye. They exhibit an 'down and out' gaze when asked to look straight ahead. Which of the following BEST explains the underlying cause?
A patient presents with diplopia, ptosis, and a dilated pupil in their right eye. They exhibit an 'down and out' gaze when asked to look straight ahead. Which of the following BEST explains the underlying cause?
A patient has difficulty turning their head to the left against resistance, but shoulder elevation is normal. Which portion of the accessory nerve is MOST likely affected?
A patient has difficulty turning their head to the left against resistance, but shoulder elevation is normal. Which portion of the accessory nerve is MOST likely affected?
When performing a visual field test by confrontation, the patient is instructed to:
When performing a visual field test by confrontation, the patient is instructed to:
A patient develops a lesion that selectively damages the superior oblique muscle of the right eye. What specific movement deficit would you expect to observe when testing extraocular movements?
A patient develops a lesion that selectively damages the superior oblique muscle of the right eye. What specific movement deficit would you expect to observe when testing extraocular movements?
A patient exhibits a complete loss of vision in the right eye. This is MOST likely due to damage to which of the following?
A patient exhibits a complete loss of vision in the right eye. This is MOST likely due to damage to which of the following?
A patient is noted to have intact pupillary light reflexes, but impaired accommodation. This MOST strongly suggests a lesion affecting which structure?
A patient is noted to have intact pupillary light reflexes, but impaired accommodation. This MOST strongly suggests a lesion affecting which structure?
A lesion of the optic tract will cause...
A lesion of the optic tract will cause...
Which of the following cranial nerves does NOT have a nucleus in the brainstem?
Which of the following cranial nerves does NOT have a nucleus in the brainstem?
If a patient displays a positive Trendelenburg sign on the right during gait, and also is unable to shrug their right shoulder against resistance, what cranial nerve is MOST likely involved?
If a patient displays a positive Trendelenburg sign on the right during gait, and also is unable to shrug their right shoulder against resistance, what cranial nerve is MOST likely involved?
Where will the tongue deviate if the patient presents with a lower motor neuron lesion of the hypoglossal nerver?
Where will the tongue deviate if the patient presents with a lower motor neuron lesion of the hypoglossal nerver?
If the patient shows improvement in facial asymmetry during a joke or smiling, the facial nerve lesion is...
If the patient shows improvement in facial asymmetry during a joke or smiling, the facial nerve lesion is...
When inspecting the tongue and Fasciculation is noted, this indicate...
When inspecting the tongue and Fasciculation is noted, this indicate...
When a patient have difficulties with precise lip movements and control of air pressure inside the mouth when playing musical instrument. what cranial nerve and associated muscle group are MOST likely affected?
When a patient have difficulties with precise lip movements and control of air pressure inside the mouth when playing musical instrument. what cranial nerve and associated muscle group are MOST likely affected?
If the patient can correctly identify salty and sour tastes but not sweet or bitter on the anterior tongue? This pattern suggests damage to which cranial nerve branch?
If the patient can correctly identify salty and sour tastes but not sweet or bitter on the anterior tongue? This pattern suggests damage to which cranial nerve branch?
A patient says tongue feels different. how do we test the patient?
A patient says tongue feels different. how do we test the patient?
A patient with difficulties in his lower face, The therapist ask the patient to wrinkle his forehead but unable because he also have absence of wrinkles of the forehead. Where is the lesion?
A patient with difficulties in his lower face, The therapist ask the patient to wrinkle his forehead but unable because he also have absence of wrinkles of the forehead. Where is the lesion?
If patient complains from Vertigo during neck rotation and in rotatory chair. What is your diagnosis?
If patient complains from Vertigo during neck rotation and in rotatory chair. What is your diagnosis?
Which Autonomic fibres are included within IX & X cranial nerve?
Which Autonomic fibres are included within IX & X cranial nerve?
A previously healthy patient reports a persistent altered sense of smell after recovering from a bout of influenza. Imaging reveals no structural abnormalities. Which of the following mechanisms BEST explains this patient's condition?
A previously healthy patient reports a persistent altered sense of smell after recovering from a bout of influenza. Imaging reveals no structural abnormalities. Which of the following mechanisms BEST explains this patient's condition?
Following a stroke, a patient demonstrates intact pupillary light reflexes in both eyes, but is unable to accommodate when focusing on a near object. Pharmacological testing with dilute pilocarpine shows no pupillary constriction. Which of the following is the MOST probable location of the lesion?
Following a stroke, a patient demonstrates intact pupillary light reflexes in both eyes, but is unable to accommodate when focusing on a near object. Pharmacological testing with dilute pilocarpine shows no pupillary constriction. Which of the following is the MOST probable location of the lesion?
Following a traumatic brain injury, a patient reports persistent difficulty with balance and coordination. During the vestibular exam, the therapist performs the head thrust test, which is positive for the left horizontal canal. Which of the following compensatory strategies is the MOST likely adaptation occurring in the brain?
Following a traumatic brain injury, a patient reports persistent difficulty with balance and coordination. During the vestibular exam, the therapist performs the head thrust test, which is positive for the left horizontal canal. Which of the following compensatory strategies is the MOST likely adaptation occurring in the brain?
A patient presents with a constellation of signs including ipsilateral ptosis, miosis, and anhidrosis. However, the patient's ability to blink and wrinkle their forehead remains intact. Which of the following pathways is MOST likely affected?
A patient presents with a constellation of signs including ipsilateral ptosis, miosis, and anhidrosis. However, the patient's ability to blink and wrinkle their forehead remains intact. Which of the following pathways is MOST likely affected?
A patient exhibits a resting tremor, rigidity, postural instability, and difficulty initiating movements; also exhibiting a reduced blink rate and decreased facial expression. Which of the following best explains the cranial nerve related to this condition?
A patient exhibits a resting tremor, rigidity, postural instability, and difficulty initiating movements; also exhibiting a reduced blink rate and decreased facial expression. Which of the following best explains the cranial nerve related to this condition?
A patient reports blurred vision and difficulty reading small print. An examination reveals that the patient has an impaired pupillary constriction response during accommodation, but normal pupillary light reflexes. Knowing that accommodation involves the ciliary muscle and pupillary constrictor, where is the MOST likely location of the lesion?
A patient reports blurred vision and difficulty reading small print. An examination reveals that the patient has an impaired pupillary constriction response during accommodation, but normal pupillary light reflexes. Knowing that accommodation involves the ciliary muscle and pupillary constrictor, where is the MOST likely location of the lesion?
A patient with a history of recurrent sinusitis presents with anosmia. Examination reveals no nasal obstruction or inflammation. The most appropriate next step in managing this patient is to FIRST:
A patient with a history of recurrent sinusitis presents with anosmia. Examination reveals no nasal obstruction or inflammation. The most appropriate next step in managing this patient is to FIRST:
A patient reports experiencing double vision when descending stairs. Neurological examination reveals normal ocular movements in all directions except for impaired depression and intorsion of the left eye. Which of the following is the MOST likely lesion?
A patient reports experiencing double vision when descending stairs. Neurological examination reveals normal ocular movements in all directions except for impaired depression and intorsion of the left eye. Which of the following is the MOST likely lesion?
During a neurological examination, a patient is asked to protrude their tongue. The tongue deviates to the right. The patient also exhibits fasciculations and atrophy of the right side of the tongue. These findings suggest a lesion of which cranial nerve?
During a neurological examination, a patient is asked to protrude their tongue. The tongue deviates to the right. The patient also exhibits fasciculations and atrophy of the right side of the tongue. These findings suggest a lesion of which cranial nerve?
A patient is diagnosed with Bell's palsy affecting the right side of their face. Electrophysiological studies reveals significant axonal degeneration. The therapist wants to use electrical stimulation to prevent atrophy and facilitate the recovery of facial muscles. Which is the MOST appropriate parameters?
A patient is diagnosed with Bell's palsy affecting the right side of their face. Electrophysiological studies reveals significant axonal degeneration. The therapist wants to use electrical stimulation to prevent atrophy and facilitate the recovery of facial muscles. Which is the MOST appropriate parameters?
Flashcards
Olfactory Nerve (I)
Olfactory Nerve (I)
Responsible for the sense of smell. Damage can lead to anosmia (loss of smell).
Optic Nerve (II)
Optic Nerve (II)
Responsible for vision. Tested using visual acuity charts and confrontation tests for visual fields.
Oculomotor Nerve (III)
Oculomotor Nerve (III)
Controls most eye movements, pupil constriction, and eyelid elevation. Damage leads to ptosis and/or diplopia.
Trochlear Nerve (IV)
Trochlear Nerve (IV)
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Trigeminal Nerve (V)
Trigeminal Nerve (V)
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Abducent Nerve (VI)
Abducent Nerve (VI)
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Facial Nerve (VII)
Facial Nerve (VII)
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Vestibulocochlear Nerve (VIII)
Vestibulocochlear Nerve (VIII)
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Glossopharyngeal Nerve (IX)
Glossopharyngeal Nerve (IX)
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Vagus Nerve (X)
Vagus Nerve (X)
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Accessory Nerve (XI)
Accessory Nerve (XI)
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Hypoglossal Nerve (XII)
Hypoglossal Nerve (XII)
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Olfactory Nerve Lesion
Olfactory Nerve Lesion
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Optic Nerve Lesion
Optic Nerve Lesion
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Ptosis
Ptosis
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Diplopia
Diplopia
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Convergent Squint
Convergent Squint
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Unilateral Pterygoid Paralysis
Unilateral Pterygoid Paralysis
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Cochlear Part Lesion
Cochlear Part Lesion
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Mixed Cranial Nerves
Mixed Cranial Nerves
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Sensory Cranial Nerves
Sensory Cranial Nerves
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Motor Cranial Nerves
Motor Cranial Nerves
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Study Notes
- There are 12 pairs of cranial nerves
- The nucleus of cranial nerves are bilaterally supplied from the pyramidal tracts of both sides, except for the lower part of the facial nucleus and the hypoglossal nucleus
- Unilateral upper motor neuron lesions of the cranial nerves don't cause apparent manifestations except for lower facial and hypoglossal nerves
Name and Classification of Cranial Nerves
- I Olfactory nerve
- II Optic nerve
- III Oculomotor nerve
- IV Trochlear nerve
- V Trigeminal nerve
- VI Abducent nerve
- VII Facial nerve
- VIII Vestibulocochlear nerve
- IX Glossopharyngeal nerve
- X Vagus nerve
- XI Accessory nerve
- XII Hypoglossal nerve
- Sensory cranial nerves contain only afferent (sensory) fibers, including I, II, and VIII
- Motor cranial nerves contain only efferent (motor) fibers including III, IV, VI, XI, and XII
- Mixed nerves contain both sensory and motor fibers including V, VII, IX, and X
I: Olfactory Nerve
- The olfactory nerve is purely sensory
- The function is smell
- To test, use a familial, non-irritant substance such as coffee grounds and test each nostril by itself
- Lesions can cause anosmia, parosmia, and olfactory hallucinations
II: Optic Nerve
- The optic nerve is purely sensory providing acuity and field of vision
Acuity of Vision Test
- Use a Snellen's chart or finger counting at a distance of 6 meters
- Repeat with a shorter distance should the patient fail to count fingers at the first distance
- At 30 cm, if the patient still fails to count the fingers, use hand movements
- If the patient cannot see movements, test for light perception using a torch
- Blindness can be considered if there is no light perception
- Each eye should be examined separately
- A lesion will decrease acuity of vision
Visual Field Confrontation Test
- The examination must use a confrontation test
- Sit in front of the patient at a distance of 60-100 cm and tell the patient to keep their eyes level with yours
- The patient should close one eye, and you close the opposite eye
- Insist that the patient looks into your eye and nowhere else
- Examine for the field of vision of the patient's open eye by bringing your finger slowly from the periphery inward
- Test the whole field by bringing your finger from above, below, left, and right
- Lesions of the optic nerve will result in the visual field defects
- Visual field defects at different sites of the optic nerve will result in different deficits
- Optic Nerve section = Total loss of vision in ipsilateral eye
- Optic Chiasm Section = Bitemporal hemianopia
- Optic Tract Section = Contralateral hemianopia
- Lower Optic Radiation section = Upper quadrantic anopia
- Upper Optic Radiation section = Lower quadrantic anopia
- Visual cortex Section = Contralateral homonymous hemianopia
III, IV, & VI: Oculomotor, Trochlear, and Abducent Nerves
- Oculomotor, Trochlear, and Abducent Nerves are purely motor
- The function of all three is to supply the extraocular muscles
Muscles each serves:
- Oculomotor serves the medial, superior, and inferior recti, inferior oblique, and levator palpebrae superioris
- Trochlear serves the superior oblique
- Abducent serves the lateral rectus
- The Oculomotor nerve also supplies intraocular muscles such as the constrictor pupillae muscle of the iris, and ciliary muscle of the lens
Extra Ocular Movement Tests
- To test the abducent nerve, ask the patient to look laterally to test the Lateral Rectus
- To test the trochlear nerve, ask the patient to look inwards & downwards (looking toward the opposite shoulder) to test the Superior Oblique
- To test the oculomotor nerve, ask the patient to look in all other directions (especially looking upward and looking medially) to test the superior medial and inferior rectus and the inferior oblique muscles.
- Complete the tests separately, on each eye
- If there are normal results, ocular nerves are intact
Performing with both eyes
- Then repeat tests on both eyes simultaneously for conjugate movement
- If normal, then the centers for conjugate movements present in the brain stem, and in the frontal and occipital lobe cortex are intact.
Ptosis
- Ptosis (dropping of the eyelid) can be due to oculomotor nerve palsies with complete ptosis, mydriasis and divergent squint, or sympathetic paralysis (Horner's Syndrome).
- Horner's Syndrome has partial ptosis, miosis, enophthalmos and anhydrosis
- Determine whether the ptosis is partial or complete by abolishing the action of the frontalis muscle by pressing a finger over the superior orbital margin, then ask the patient to open his eye
- If able to open, then ptosis is partial
- If unable to open, ptosis is complete
Pupils Examination
- Pupils should be equal, round and reactive to light, and accommodation
- The light reflex uses afferent cranial nerve (Cr) 2 and efferent Cr 3
- If one eye is exposed to light, while shading the other, there occurs constriction of the pupil of the exposed eye (direct reaction) as well as of the other eye (consensual reaction)
- Pupillary abnormalities can indicate cranial nerve lesions
- No constriction of the pupil in one eye indicates a lesion of the oculomotor nerve of that eye
- No constriction of the pupil in both eyes indicates lesions of the optic nerve or both oculomotor nerves
Accommodation Reflex
- When the patient is asked to follow a point moving towards them from far away, the following triad normally occurs
- Convergence of the eyes due to contraction of both medial recti muscles
- Miosis constriction of pupils due to contraction of constrictor pupillae muscles
- Accommodation (increased refractive power of the lens) due to contraction of ciliary muscles
Lesion
- Trochlear lesions only occur only when the patient looks downwards e.g. when descending the stairs or reading, and limit movement inwards and downwards
- An abducent nerve lesion will present as diplopia only when the patient looks outwards toward the paralyzed side, limiting movement on the affected eye outwards, and creating a convergent squint where the eye looks inward.
- Oculomotor Lesions are called external ophthalmoplegia and will have ptosis (drooping eyelid), divergent paralytic squint, diplopia on passive elevation of the eyelid, and limited movement
- Internal ophthalmoplegia involves an ipsilateral dilated fixed pupil (mydriasis), with affection of the light reflex while the consensual reflex is preserved.
(V) Trigeminal Nerve
- The trigeminal nerve is a mixed nerve
Function
- Its sensory part conducts sensations from the face (except the angle of the mandible supplied by C2), the general sensation from the anterior 2/3 of the tongue and the buccal cavity
- Its motor part supplies the muscles of mastication (Temporalis, Masseter and Lateral and Medial Pterygoids), anterior belly of the digastric, mylohyoid and tensor palate
Sensory examination
- Test for sensations including pain (using a pin) and touch (using a piece of cotton) over the face, and compare between:
- Both sides of the face
- The ophthalmic, maxillary and mandibular division on each side
- The inner and outer parts of the face.
- The patient's eyes should be closed and symmetry should be checked, both center and periphery of the face.
- Corneal & Conjunctival reflexes (afferent is the ophthalmic division Cr 5, efferent is Cr 7 bilaterally) can be assessed by asking the patient to look upwards and inwards and touching the corneo-conjunctival junction from the lateral side to avoid direct photic stimulation, using a thin piece of cotton.
- Stimulation of one eye should result in blinking of both eyes
- Absence of blinking on one side is facial paralysis of that side.
- Absence of blinking on both sides indicates:
- Sensory trigeminal affection of the stimulated side
- Bilateral facial paralysis or organic causes (coma)
Motor examination
- The power of the muscles of mastication must be tested include:
- Temporalis muscle: ask the patient to clench teeth and put their hand over the temples to palpate the muscle
- Masseters: clench teeth and palpate muscle, holding its ant. & post Borders.
- Pterygoids: Fix head; ask the patient to open the mouth; normally there is no deviation
- Unilateral pterygoid paralysis will deviate the jaw to the affected side
- Bilateral pterygoid paralysis will cause inability to open the mouth
- It can be tested when the patient opens the mouth against resistance, to assess muscle power
- Jaw reflex uses: afferent Cr 5 and an efferent Cr 5
- While the mouth is slightly open, place your index finger on the lower jaw, and then tap it from above downwards.
- Normally the reflex is absent
- An exaggerated reflex is shown when the jaws close, indicating a bilateral U.M.N.L. above the motor nucleus of the 5th cranial nerve above the pons as in pseudobulbar palsy.
Lesions
- Lesions of the sensory portion will lead to abnormal face sensation such as trigeminal neuralgia
- Lesions of the motor portion will lead to difficult mastication.
(VII) Facial Nerve
- The facial nerve is mixed nerve
Function
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Its sensory portion receives taste sensation from the 2/3 of the tongue and the buccal cavity
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Its motor portion supplies muscles of expression of the face as well as the posterior belly of digastrics, Platysma, Stapedius and Stylohyoid
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The autonomic portion supplies the lacrimal gland as well as the submaxillary and sublingual salivary glands
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The face should be observed face for asymmetry and involuntary movements
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Wrinkle the forehead and bare teeth to tighten and screw eyes shut and blow out cheeks
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Testing this way can reveal more subtle effects of the facial nerve
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The upper half of face is innervated by both cerebral hemispheres so upper motor neuron lesions can still wrinkle the forehead
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There are several classifications of the innervation of muscles that will define a specific action
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Frontalis Temporal Elevation of eyebrows
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Curregator Temporal and Zygomaticus Corrugation of eyebrows (Frowning)
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Procerus Temporal , Zygomaticus and Buccal Elevation of nose
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Orbicularis Occuli Temporal and Zygomaticus Palpebral :Light closure of eye Orbital: Firm closure of eye Lacrimal : For lacrymation
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Dilator Nasalis Buccal and Zygomaticus Dilatation of nostril compression of nostril
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Compressor Nasalis Buccal and Zygomaticus
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Risoreus Buccal and Zygomaticus Smiling (mouth closed)
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Levators Buccal and Zygomaticus Elevation of lip
- Labii Alaeque Nasi: Medial border
- Labii Superioris: In lateral direction
- Zygomaticus Buccal and Zygomatic Major: Smiling (show teeth) Minor: Upper lip protrusion
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Orbicularis Oris Buccal ,Zygomaticus and Mandibular Kissing
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Depressors Depressors Buccal and Mandibular Anguli Oris: Drawing the corners of the mouth down. Labii inferioris: Protrusion of lower lip.
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Mentalis Mandibular Make chin up
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Buccinator Mandibular and Buccal Blowing of cheek
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Platysma Cervical Drawing the corners of
| | U.M.N.L | L.M.N.L | | ----------- | ---------------------------------------- | ------------------------------------------ | | 1 | Affecting Ʌ tract above facial nucleus | Affecting the facial motor nucleus or the | | | | nerve itself | | 2 | Paralysis of the muscles of the lower half | Paralysis of the muscles of the upper & | | | of the face on the opposite side of the | lower halves of the face on the same side | | | lesion (supplied from the opposite Ʌ tract | of the lesion | | | only) | | | 3 | Paralysis involves the voluntary movement; | Paralysis affects voluntary, emotional & | | | it spares the emotional & associative | associative movements | | | movements | | | 4 | Paralysis is associated with hypertonia & | Paralysis is associated with hypotonia & | | | hyperreflexia | hyporeflexia | | 5 | There is associated hemiplegia on the | If there is hemiplegia, it is on the opposite | | | same side of the facial paralysis | side of the facial paralysis (crossed | | | | hemiplegia) |
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To differentiate clinically between U M N and L M N facial paralysis, ask the patient to close their eye on the affected side
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The patient CAN close (UMNL) and the patient CANNOT close (LMNL)
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A glabellar reflex can also be tested.
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A joke.If the patient laughs and improve asymmetry then it is UMNL. If not, then it is LMNL.
(VIII) Vestibulocochlear Nerve
- The vestibulocochlear nerve is purely sensory, divided into two parts:
- The cochlear part carries impulses for hearing and its lesion can decrease the acuity of hearing and tinnitus
- The vestibular part carries impulses for equilibrium and its lesion leads to vertigo.
Testing Cochlear Portion
- Check patient acuity of hearing.
- The Watch test: If there is diminution of the patient's hearing
- -Using the vibrating tuning fork, compare air conduction (fork placed in
- front of patient's ear) with bone conduction (fork placed on patient's mastoid process).
- Place the tuning fork in the middle of the forehead.
Testing Vestibular Portion - For patients with no history of vertigo:
- From sitting and/ or supine lying. Supine lying gives great ROM, especially if pain is present.
- The therapist extends the patient's neck and sustains for 10 sec, then rotates the neck to the right/left side, sustaining for 10 sec (for each side)
- Observe the patient's facial expression and ask the patient about his feeling
- Report positive result if the patient complains from vertigo
(VIII) Vestibulocochlear Nerve - For patients WITH history of vertigo:
- tests are used that help differentiate between vertigo due to VBI or inner ear disease such as labrynthinitis with some assistance to rotate chair, fix the patient's head by both of the therapist's hands from patient's face sides (do not touch patient's ears),
- Then ask the patient to rotate the trunk fully to the right or left side for 5 seconds for each side while the patient's head is maintained in neutral position
- Ask the patient about their felling
- Patients with Vertigo in both above will have VBI
- If patients have Vertigo only in first test, it is indicative of some inner ear (vestibular) disease, typically labrynthinitis
Glossopharyngeal Nerve
- Mixed Nerve -Motor portion will control muscle of the pharynx called stylopharyngeus -Sensory control from posterior portion of tongue and pharynx -Autonomic control will involve the parotid gland
Vagus Nerve
Mixed Nerve
-
Will share motor, sensory, and autonomic role -Specifically, will involve soft pallate, pharynx, larynx, skin over auditory meatus, thoracic regions
- Autonomic portion will focus on inhibiting, the heart secretory regions along bronchial tree
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Lesions of IX &/or X will result in:
- Dysphagia, Dysarthria, H oarseness o voice, N asal regurgitation
XI Accessory Nerve
- Is purely Motor Nerve
- Has roles for BOTH cranial and spinal portion
- Cranial-innervates muscle portions of: -Palate, & PHARYNX
- Spinal controls control of: -Sternomastoid , -Trapezius
- Testing methods require use by either raising shoulders (against resistance.) And or rotation of the head
- Key factor to know, is that SCM means flexion with side bending
- Key findings of testing=Weakness of SCM & trapezius muscle.
VII-HYPOGLOSSAL
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A purely motor based nerve! And it has high control regions of Tongue!!
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A upper motor neuron Lesion will impact the deviation & and make it towards the opposite part of lesion
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A lower motor neuron lesion- this also may impact deviation region. However. it has same side Lesion
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Key: UMNL won't show fasciculation/or signs of wasting
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But LOWER does Testing Requires visual assessment via movement(deviation ), testing of power or presence of wasting -You also look at tongue color or dimpling signs on tongues.
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