Podcast
Questions and Answers
A patient presents with anosmia following a traumatic brain injury. Which cranial nerve is MOST likely affected?
A patient presents with anosmia following a traumatic brain injury. Which cranial nerve is MOST likely affected?
- Optic nerve (II)
- Facial nerve (VII)
- Trigeminal nerve (V)
- Olfactory nerve (I) (correct)
During a neurological examination, a patient is unable to perceive light in their left eye, but pupillary reflexes are normal in both eyes. This finding suggests a lesion located WHERE?
During a neurological examination, a patient is unable to perceive light in their left eye, but pupillary reflexes are normal in both eyes. This finding suggests a lesion located WHERE?
- Optic chiasm
- Visual cortex
- Left optic nerve (correct)
- Right optic tract
A patient presents with diplopia that is MOST pronounced when looking downwards and inwards. Which cranial nerve is MOST likely affected?
A patient presents with diplopia that is MOST pronounced when looking downwards and inwards. Which cranial nerve is MOST likely affected?
- Trochlear nerve (IV) (correct)
- Oculomotor nerve (III)
- Optic nerve (II)
- Abducens nerve (VI)
A patient demonstrates a right eye that is unable to abduct (move laterally). Additionally, they exhibit horizontal diplopia that worsens when looking to the right. Which cranial nerve is MOST likely involved?
A patient demonstrates a right eye that is unable to abduct (move laterally). Additionally, they exhibit horizontal diplopia that worsens when looking to the right. Which cranial nerve is MOST likely involved?
Following a stroke, a patient has difficulty chewing and reports numbness in the right cheek and temporal area. Which cranial nerve is MOST likely affected, and which specific branch?
Following a stroke, a patient has difficulty chewing and reports numbness in the right cheek and temporal area. Which cranial nerve is MOST likely affected, and which specific branch?
A patient presents with weakness in facial expression, but only on the lower left side of their face. The forehead muscles are spared. This pattern of weakness is MOST suggestive of a lesion in WHICH location?
A patient presents with weakness in facial expression, but only on the lower left side of their face. The forehead muscles are spared. This pattern of weakness is MOST suggestive of a lesion in WHICH location?
A patient reports a significant decrease in hearing acuity and constant ringing in their ears (tinnitus) following exposure to a loud explosion. Which cranial nerve and component is MOST likely affected?
A patient reports a significant decrease in hearing acuity and constant ringing in their ears (tinnitus) following exposure to a loud explosion. Which cranial nerve and component is MOST likely affected?
When testing the corneal reflex on a patient, stimulation of either eye fails to produce a blink in either eye. This finding suggests damage to WHICH pair of cranial nerves?
When testing the corneal reflex on a patient, stimulation of either eye fails to produce a blink in either eye. This finding suggests damage to WHICH pair of cranial nerves?
A patient having difficulty swallowing and also reports a change in their voice, now sounding hoarse. Examination reveals the uvula deviates to the right upon phonation. Which cranial nerve is MOST likely impaired?
A patient having difficulty swallowing and also reports a change in their voice, now sounding hoarse. Examination reveals the uvula deviates to the right upon phonation. Which cranial nerve is MOST likely impaired?
A patient has weakness when shrugging their right shoulder against resistance and also difficulty turning their head to the left against resistance. Which cranial nerve is MOST likely affected?
A patient has weakness when shrugging their right shoulder against resistance and also difficulty turning their head to the left against resistance. Which cranial nerve is MOST likely affected?
During a neurological examination, a patient protrudes their tongue, which deviates strongly to the right. This finding suggests a lesion of WHICH cranial nerve and on WHICH side?
During a neurological examination, a patient protrudes their tongue, which deviates strongly to the right. This finding suggests a lesion of WHICH cranial nerve and on WHICH side?
A patient presents with bilateral tongue weakness and fasciculations. They report progressive difficulty with speech and swallowing. This clinical picture is MOST suggestive of damage to WHICH cranial nerve and WHERE?
A patient presents with bilateral tongue weakness and fasciculations. They report progressive difficulty with speech and swallowing. This clinical picture is MOST suggestive of damage to WHICH cranial nerve and WHERE?
A patient with a known history of multiple sclerosis presents with sudden onset of painful vision loss in one eye, worsening with eye movement. This clinical presentation is MOST consistent with inflammation of which cranial nerve:
A patient with a known history of multiple sclerosis presents with sudden onset of painful vision loss in one eye, worsening with eye movement. This clinical presentation is MOST consistent with inflammation of which cranial nerve:
A patient presents with a decreased ability to taste sweet, sour and bitter flavors on the anterior two-thirds of the tongue. The remainder of the cranial nerve exam is unremarkable. The lesion is MOST likely affecting which cranial nerve segment:
A patient presents with a decreased ability to taste sweet, sour and bitter flavors on the anterior two-thirds of the tongue. The remainder of the cranial nerve exam is unremarkable. The lesion is MOST likely affecting which cranial nerve segment:
A patient who underwent a surgical procedure in the parotid region now presents with facial asymmetry, specifically an inability to close their right eye and drooping of the right corner of the mouth. The tongue and palatal sensation is normal. Which nerve was MOST likely damaged during the procedure?
A patient who underwent a surgical procedure in the parotid region now presents with facial asymmetry, specifically an inability to close their right eye and drooping of the right corner of the mouth. The tongue and palatal sensation is normal. Which nerve was MOST likely damaged during the procedure?
A patient reports experiencing vertigo, especially with changes in head position. The Dix-Hallpike maneuver elicits nystagmus. Which component of the vestibulocochlear nerve (VIII) is MOST likely implicated in this condition?
A patient reports experiencing vertigo, especially with changes in head position. The Dix-Hallpike maneuver elicits nystagmus. Which component of the vestibulocochlear nerve (VIII) is MOST likely implicated in this condition?
In a patient with a suspected stroke affecting the brainstem, which finding would be MOST indicative of damage to the lower part of the facial nucleus rather than to the upper part?
In a patient with a suspected stroke affecting the brainstem, which finding would be MOST indicative of damage to the lower part of the facial nucleus rather than to the upper part?
A patient complains of difficulty swallowing and loss of taste sensation in the posterior one-third of the tongue, accompanied by a diminished gag reflex. Which cranial nerve is MOST likely affected?
A patient complains of difficulty swallowing and loss of taste sensation in the posterior one-third of the tongue, accompanied by a diminished gag reflex. Which cranial nerve is MOST likely affected?
A patient who has recently undergone carotid endarterectomy presents with deviation of the tongue to the left upon protrusion. Which additional finding would MOST strongly suggest injury to the hypoglossal nerve during the surgery, rather than a more central UMN lesion?
A patient who has recently undergone carotid endarterectomy presents with deviation of the tongue to the left upon protrusion. Which additional finding would MOST strongly suggest injury to the hypoglossal nerve during the surgery, rather than a more central UMN lesion?
A patient undergoing treatment for cancer develops progressive hoarseness and difficulty swallowing. During examination, the left side of the palate droops, and the uvula is pulled to the right when the patient says "Ah". Which cranial nerve is MOST likely affected and on what side?
A patient undergoing treatment for cancer develops progressive hoarseness and difficulty swallowing. During examination, the left side of the palate droops, and the uvula is pulled to the right when the patient says "Ah". Which cranial nerve is MOST likely affected and on what side?
A patient presents with an inability to shrug their left shoulder and weakness in turning their chin to the right against resistance. The MOST likely site of lesion affecting the spinal accessory nerve (XI) is WHERE?
A patient presents with an inability to shrug their left shoulder and weakness in turning their chin to the right against resistance. The MOST likely site of lesion affecting the spinal accessory nerve (XI) is WHERE?
A patient is undergoing an exam for balance issues. During a Romberg Test with their eyes closed, the patient exhibits significant swaying and instability. This finding suggests MOST likely dysfunction of which component of the nervous system?
A patient is undergoing an exam for balance issues. During a Romberg Test with their eyes closed, the patient exhibits significant swaying and instability. This finding suggests MOST likely dysfunction of which component of the nervous system?
When evaluating the oculomotor nerve (CN III), which observation would MOST strongly suggest a compressive lesion, such as an aneurysm, rather than ischemic damage related to diabetes?
When evaluating the oculomotor nerve (CN III), which observation would MOST strongly suggest a compressive lesion, such as an aneurysm, rather than ischemic damage related to diabetes?
Following a traumatic injury, a patient exhibits weakness only in the muscles of facial expression on the right side of their face. Sensory testing and taste sensation are intact. Where is the lesion MOST likely located?
Following a traumatic injury, a patient exhibits weakness only in the muscles of facial expression on the right side of their face. Sensory testing and taste sensation are intact. Where is the lesion MOST likely located?
A patient presents with difficulty initiating swallowing, nasal regurgitation of fluids, and hoarseness with a bovine cough. Which cranial nerve is MOST likely affected and at what level is at least one lesion involved?
A patient presents with difficulty initiating swallowing, nasal regurgitation of fluids, and hoarseness with a bovine cough. Which cranial nerve is MOST likely affected and at what level is at least one lesion involved?
A patient reports experiencing episodic vertigo, tinnitus, and fluctuating hearing loss. These symptoms worsen with certain head movements. Which inner ear structure and, by extension, which branch of the vestibulocochlear nerve (VIII) is MOST likely involved?
A patient reports experiencing episodic vertigo, tinnitus, and fluctuating hearing loss. These symptoms worsen with certain head movements. Which inner ear structure and, by extension, which branch of the vestibulocochlear nerve (VIII) is MOST likely involved?
A patient presents with persistent dry eye and dry mouth following a head injury. If cranial nerve dysfunction is suspected, what combination of nerves could MOST plausibly explain these findings?
A patient presents with persistent dry eye and dry mouth following a head injury. If cranial nerve dysfunction is suspected, what combination of nerves could MOST plausibly explain these findings?
A patient exhibits complete loss of smell and reports diminished taste, stating that food tastes bland. While olfactory deficits are clear, HOW can a clinician BEST differentiate whether the altered taste is due to CN VII damage versus solely the loss of smell?
A patient exhibits complete loss of smell and reports diminished taste, stating that food tastes bland. While olfactory deficits are clear, HOW can a clinician BEST differentiate whether the altered taste is due to CN VII damage versus solely the loss of smell?
Following a lateral medullary stroke (Wallenberg syndrome), a patient demonstrates decreased pain and temperature sensation on the right side of their face and decreased pain and temperature sensation on the left side of their body. Which cranial nerve nucleus is MOST likely affected to cause the facial sensory loss?
Following a lateral medullary stroke (Wallenberg syndrome), a patient demonstrates decreased pain and temperature sensation on the right side of their face and decreased pain and temperature sensation on the left side of their body. Which cranial nerve nucleus is MOST likely affected to cause the facial sensory loss?
A patient presents with hearing loss in the right ear. The Weber test lateralizes to the left ear, and the Rinne test is negative in the right ear. What type of hearing loss is MOST likely?
A patient presents with hearing loss in the right ear. The Weber test lateralizes to the left ear, and the Rinne test is negative in the right ear. What type of hearing loss is MOST likely?
A patient reports that when they close their eyes, they feel as though they are being pushed to the left. The clinician performs the Head Thrust Test by rapidly moving the patient's head to the right, and the patients eyes momentarily saccade back to the center. This MOST likely indicates damage to WHICH component of the vestibulocochlear nerve (VIII)?
A patient reports that when they close their eyes, they feel as though they are being pushed to the left. The clinician performs the Head Thrust Test by rapidly moving the patient's head to the right, and the patients eyes momentarily saccade back to the center. This MOST likely indicates damage to WHICH component of the vestibulocochlear nerve (VIII)?
A patient who had surgery to remove a tumor near the jugular foramen now exhibits several cranial nerve deficits. Which combination of deficits would be MOST expected given the anatomical location?
A patient who had surgery to remove a tumor near the jugular foramen now exhibits several cranial nerve deficits. Which combination of deficits would be MOST expected given the anatomical location?
A patient with suspected Parkinson's disease is evaluated for upper motor neuron signs. Which response during the assessment of the Glabellar reflex would be MOST indicative of frontal lobe dysfunction?
A patient with suspected Parkinson's disease is evaluated for upper motor neuron signs. Which response during the assessment of the Glabellar reflex would be MOST indicative of frontal lobe dysfunction?
A patient presents with impaired taste sensation on the anterior two-thirds of the tongue. Which of the following actions would be MOST effective in differentiating between damage to the chorda tympani versus damage to the facial nerve proximal to the geniculate ganglion?
A patient presents with impaired taste sensation on the anterior two-thirds of the tongue. Which of the following actions would be MOST effective in differentiating between damage to the chorda tympani versus damage to the facial nerve proximal to the geniculate ganglion?
A patient develops internuclear ophthalmoplegia (INO) due to a lesion in the medial longitudinal fasciculus (MLF). During horizontal gaze testing, WHICH finding would be MOST characteristic of this condition?
A patient develops internuclear ophthalmoplegia (INO) due to a lesion in the medial longitudinal fasciculus (MLF). During horizontal gaze testing, WHICH finding would be MOST characteristic of this condition?
A patient presents with progressive atrophy and fasciculations of the tongue, accompanied by difficulty swallowing and speaking. Electromyography (EMG) confirms lower motor neuron involvement. What underlying pathology is MOST likely causing these cranial nerve deficits?
A patient presents with progressive atrophy and fasciculations of the tongue, accompanied by difficulty swallowing and speaking. Electromyography (EMG) confirms lower motor neuron involvement. What underlying pathology is MOST likely causing these cranial nerve deficits?
A patient exhibits complete bilateral loss of smell following a severe closed head injury. Imaging reveals damage to the cribriform plate. Which additional finding would MOST strongly support that the anosmia is due to direct trauma to the olfactory nerve (CN I) rather than a more central neurological issue?
A patient exhibits complete bilateral loss of smell following a severe closed head injury. Imaging reveals damage to the cribriform plate. Which additional finding would MOST strongly support that the anosmia is due to direct trauma to the olfactory nerve (CN I) rather than a more central neurological issue?
A patient presents with progressive vision loss. Examination reveals bilateral pallor of the optic discs and sluggish pupillary responses to light. Visual field testing demonstrates central scotomas in both eyes. Which of the following etiologies is MOST likely?
A patient presents with progressive vision loss. Examination reveals bilateral pallor of the optic discs and sluggish pupillary responses to light. Visual field testing demonstrates central scotomas in both eyes. Which of the following etiologies is MOST likely?
A patient presents with right-sided ptosis, mydriasis, and a 'down and out' gaze of the right eye. Pupillary light reflexes are absent on the right, but intact on the left. Which of the following is the MOST likely location of the lesion affecting the oculomotor nerve (CN III)?
A patient presents with right-sided ptosis, mydriasis, and a 'down and out' gaze of the right eye. Pupillary light reflexes are absent on the right, but intact on the left. Which of the following is the MOST likely location of the lesion affecting the oculomotor nerve (CN III)?
A patient presents with vertical diplopia that is MOST pronounced when reading a book held at close range. The patient compensates by tilting their head to the left. Which cranial nerve is MOST likely affected?
A patient presents with vertical diplopia that is MOST pronounced when reading a book held at close range. The patient compensates by tilting their head to the left. Which cranial nerve is MOST likely affected?
During an eye movement examination, a patient is unable to adduct the right eye past the midline. Convergence is intact. Where is the lesion MOST likely located?
During an eye movement examination, a patient is unable to adduct the right eye past the midline. Convergence is intact. Where is the lesion MOST likely located?
A patient reports numbness in the right forehead, cheek, and jaw. Corneal reflex is absent on the right but present on the left. Motor examination of mastication muscles is normal. Which is the MOST likely location of the lesion involving the trigeminal nerve (CN V)?
A patient reports numbness in the right forehead, cheek, and jaw. Corneal reflex is absent on the right but present on the left. Motor examination of mastication muscles is normal. Which is the MOST likely location of the lesion involving the trigeminal nerve (CN V)?
A patient exhibits weakness in the muscles of mastication and impaired sensation over the anterior two-thirds of the tongue. Reflex testing reveals an absent jaw jerk reflex. Where is the MOST likely location of a single lesion affecting the trigeminal nerve (CN V)?
A patient exhibits weakness in the muscles of mastication and impaired sensation over the anterior two-thirds of the tongue. Reflex testing reveals an absent jaw jerk reflex. Where is the MOST likely location of a single lesion affecting the trigeminal nerve (CN V)?
A patient develops sudden, severe, shock-like pain in the right cheek that is triggered by chewing and light touch. MRI is unremarkable except for mild compression of the trigeminal nerve (CN V) by a small blood vessel near the pons. Which medication is the MOST appropriate first-line treatment?
A patient develops sudden, severe, shock-like pain in the right cheek that is triggered by chewing and light touch. MRI is unremarkable except for mild compression of the trigeminal nerve (CN V) by a small blood vessel near the pons. Which medication is the MOST appropriate first-line treatment?
A patient exhibits right-sided facial paralysis involving both the upper and lower face, dry eye, and decreased salivation. The patient also reports hyperacusis. Where is the MOST likely location of the lesion affecting the facial nerve (CN VII)?
A patient exhibits right-sided facial paralysis involving both the upper and lower face, dry eye, and decreased salivation. The patient also reports hyperacusis. Where is the MOST likely location of the lesion affecting the facial nerve (CN VII)?
A patient presents with left-sided facial paralysis sparing the forehead. However, they also exhibit weakness of the left arm and leg. Where is the MOST likely location of the lesion?
A patient presents with left-sided facial paralysis sparing the forehead. However, they also exhibit weakness of the left arm and leg. Where is the MOST likely location of the lesion?
A patient undergoes surgical removal of an acoustic neuroma. Postoperatively, the patient exhibits facial paralysis, loss of taste on the anterior two-thirds of the tongue, and decreased tearing from the right eye. Which structure was MOST likely damaged during the procedure?
A patient undergoes surgical removal of an acoustic neuroma. Postoperatively, the patient exhibits facial paralysis, loss of taste on the anterior two-thirds of the tongue, and decreased tearing from the right eye. Which structure was MOST likely damaged during the procedure?
A patient presents with sudden vertigo, nausea and vomiting. Examination reveals horizontal nystagmus beating away from the affected side, and a positive head impulse test. Hearing is intact. Which anatomical structure within the inner ear is MOST likely affected?
A patient presents with sudden vertigo, nausea and vomiting. Examination reveals horizontal nystagmus beating away from the affected side, and a positive head impulse test. Hearing is intact. Which anatomical structure within the inner ear is MOST likely affected?
A patient presents with progressive unilateral sensorineural hearing loss, tinnitus and imbalance. MRI reveals a mass in the cerebellopontine angle. Which cranial nerve is MOST likely affected FIRST by this mass?
A patient presents with progressive unilateral sensorineural hearing loss, tinnitus and imbalance. MRI reveals a mass in the cerebellopontine angle. Which cranial nerve is MOST likely affected FIRST by this mass?
A patient who underwent surgery for the removal of an acoustic neuroma now presents with facial paralysis, but also exhibits altered taste sensation on the anterior two-thirds of the tongue and decreased lacrimation. What specific structure was MOST likely affected during the surgery, leading to these combined deficits?
A patient who underwent surgery for the removal of an acoustic neuroma now presents with facial paralysis, but also exhibits altered taste sensation on the anterior two-thirds of the tongue and decreased lacrimation. What specific structure was MOST likely affected during the surgery, leading to these combined deficits?
During examination of a patient with suspected Bell's palsy, the clinician notes decreased tearing and a subtle change in taste sensation. While facial weakness is prominent, WHICH additional test would BEST help confirm the involvement of the facial nerve proximal to the stylomastoid foramen?
During examination of a patient with suspected Bell's palsy, the clinician notes decreased tearing and a subtle change in taste sensation. While facial weakness is prominent, WHICH additional test would BEST help confirm the involvement of the facial nerve proximal to the stylomastoid foramen?
A patient reports a persistent sore throat, difficulty swallowing, and hoarseness. Examination reveals diminished gag reflex and pooling of saliva in the piriform sinuses. Which cranial nerve is MOST likely affected, and what is the MOST appropriate initial diagnostic test?
A patient reports a persistent sore throat, difficulty swallowing, and hoarseness. Examination reveals diminished gag reflex and pooling of saliva in the piriform sinuses. Which cranial nerve is MOST likely affected, and what is the MOST appropriate initial diagnostic test?
A patient presents with a persistent cough, hoarseness and dysphagia. Examination reveals the palate elevates asymmetrically, and the uvula deviates to the left when the patient says 'Ahh'. The gag reflex is diminished on the right. Where is the lesion MOST likely located?
A patient presents with a persistent cough, hoarseness and dysphagia. Examination reveals the palate elevates asymmetrically, and the uvula deviates to the left when the patient says 'Ahh'. The gag reflex is diminished on the right. Where is the lesion MOST likely located?
A patient develops progressive dysphagia and hoarseness following a surgery to remove a deep mass in the neck. On examination, the right vocal cord is paralyzed in the adducted position. Which specific branch of the vagus nerve (CN X) was MOST likely injured during the procedure?
A patient develops progressive dysphagia and hoarseness following a surgery to remove a deep mass in the neck. On examination, the right vocal cord is paralyzed in the adducted position. Which specific branch of the vagus nerve (CN X) was MOST likely injured during the procedure?
A patient who underwent a radical neck dissection, including removal of the sternocleidomastoid muscle, now exhibits difficulty raising their arm above shoulder level and weakness turning their head to the contralateral side. What rehabilitative strategy would be MOST effective in improving the patient's functional shoulder abduction?
A patient who underwent a radical neck dissection, including removal of the sternocleidomastoid muscle, now exhibits difficulty raising their arm above shoulder level and weakness turning their head to the contralateral side. What rehabilitative strategy would be MOST effective in improving the patient's functional shoulder abduction?
A patient presents with weakness of tongue protrusion and fasciculations. EMG testing confirms denervation of the tongue musculature. Which associated sign would STRONGLY suggest a progressive LOWER motor neuron disease (like ALS) affecting the hypoglossal nerve, rather than a compressive lesion?
A patient presents with weakness of tongue protrusion and fasciculations. EMG testing confirms denervation of the tongue musculature. Which associated sign would STRONGLY suggest a progressive LOWER motor neuron disease (like ALS) affecting the hypoglossal nerve, rather than a compressive lesion?
A patient exhibits atrophy and fasciculations of the tongue. On protrusion, the tongue deviates strongly to the left. Which statement BEST describes the likely location of the lesion and the expected pattern of weakness?
A patient exhibits atrophy and fasciculations of the tongue. On protrusion, the tongue deviates strongly to the left. Which statement BEST describes the likely location of the lesion and the expected pattern of weakness?
A patient presents with a history of progressive difficulty speaking and swallowing. Examination reveals bilateral tongue weakness, fasciculations, and significant atrophy. The MOST likely underlying pathology is affecting which cranial nerve nucleus and in what region of the brainstem?
A patient presents with a history of progressive difficulty speaking and swallowing. Examination reveals bilateral tongue weakness, fasciculations, and significant atrophy. The MOST likely underlying pathology is affecting which cranial nerve nucleus and in what region of the brainstem?
A patient presents with new-onset binocular horizontal diplopia at near with mild blurring of vision. The patient fully recovers after a few hours. The MOST likely cause of these symptoms is:
A patient presents with new-onset binocular horizontal diplopia at near with mild blurring of vision. The patient fully recovers after a few hours. The MOST likely cause of these symptoms is:
A 48-year-old patient notices increasing difficulty discriminating the taste of different foods. All modalities of sensation are intact on exam. Which additional exam finding suggests that the chorda tympani is affected?
A 48-year-old patient notices increasing difficulty discriminating the taste of different foods. All modalities of sensation are intact on exam. Which additional exam finding suggests that the chorda tympani is affected?
A 72-year-old patient presents with diminished visual acuity in the left eye. Visual Acuity and pupillary responses in the right eye are normal. Which of the following indicates the site of the lesion is in the left optic nerve?
A 72-year-old patient presents with diminished visual acuity in the left eye. Visual Acuity and pupillary responses in the right eye are normal. Which of the following indicates the site of the lesion is in the left optic nerve?
A patient presents with difficulty with high-pitched sounds, dizziness and diplopia. Upon exam, the patient is unable to abduct their left eye and is able to shrug their shoulders with resistance. Palatal elevation is normal and symmetrical. Which of the following cranial nerves is the MOST affected?
A patient presents with difficulty with high-pitched sounds, dizziness and diplopia. Upon exam, the patient is unable to abduct their left eye and is able to shrug their shoulders with resistance. Palatal elevation is normal and symmetrical. Which of the following cranial nerves is the MOST affected?
A 39-year-old patient presents with a headache, drooping eyelid and blurry vision. The patient reports a recent history of diplopia that spontaneously resolved a few weeks ago and a history of hypertension. Which of the following is the MOST likely cranial nerve affected?
A 39-year-old patient presents with a headache, drooping eyelid and blurry vision. The patient reports a recent history of diplopia that spontaneously resolved a few weeks ago and a history of hypertension. Which of the following is the MOST likely cranial nerve affected?
An 84-year-old patient presents with deviation of the tongue and reports that their taste has been altered. Strength and sensation to the face is within normal limits. Which of the following cranial nerves is MOST affected?
An 84-year-old patient presents with deviation of the tongue and reports that their taste has been altered. Strength and sensation to the face is within normal limits. Which of the following cranial nerves is MOST affected?
A patient reports with right-sided ptosis, miosis, and anhydrosis. Which lesion is MOST likely responsible for these symptoms?
A patient reports with right-sided ptosis, miosis, and anhydrosis. Which lesion is MOST likely responsible for these symptoms?
A lesion of the optic chiasm would MOST likely cause which visual field defect?
A lesion of the optic chiasm would MOST likely cause which visual field defect?
Which sensory cranial nerves transmit only afferent signals?
Which sensory cranial nerves transmit only afferent signals?
A patient has sensory loss in the face and motor problems chewing. Which nerve is most likely involved?
A patient has sensory loss in the face and motor problems chewing. Which nerve is most likely involved?
Hoarseness, dysphagia and absent gag reflex would most likely indicate damage of what cranial nerve?
Hoarseness, dysphagia and absent gag reflex would most likely indicate damage of what cranial nerve?
What would a positive test for the Weber and Rinne test indicate?
What would a positive test for the Weber and Rinne test indicate?
A patient presents with dysarthria, hoarseness and difficulty swallowing. Which other symptom may likely arise?
A patient presents with dysarthria, hoarseness and difficulty swallowing. Which other symptom may likely arise?
A patient presents with a deviation of the tongue and fasciculations. What other potential sign could be observed under inspection?
A patient presents with a deviation of the tongue and fasciculations. What other potential sign could be observed under inspection?
Under what situation(s) would one have weakness of the upper trapezius and SCM muscles?
Under what situation(s) would one have weakness of the upper trapezius and SCM muscles?
A physical therapist is developing a treatment plan for a patient exhibiting limited sensation on the face. The physical therapist notes chewing is impaired as well. Which of the following interventions is the MOST appropriate for this patient population?
A physical therapist is developing a treatment plan for a patient exhibiting limited sensation on the face. The physical therapist notes chewing is impaired as well. Which of the following interventions is the MOST appropriate for this patient population?
Patient states they have problems with equilibrium. Under what circumstance, is this problem most likely to arise?
Patient states they have problems with equilibrium. Under what circumstance, is this problem most likely to arise?
Following a stroke, a patient presents with upper and lower facial paralysis. The patient also reports dry eyes. What additional sign is MOST associated with facial nerve damage near the internal accoustic meatus?
Following a stroke, a patient presents with upper and lower facial paralysis. The patient also reports dry eyes. What additional sign is MOST associated with facial nerve damage near the internal accoustic meatus?
Lesions in certain cranial nerves can produce specific deficits. If a patient exhibits a combination of difficulty elevating the eyelid, a 'down and out' gaze, and pupillary dilation, but retains full visual acuity, WHICH of the following is the MOST probable mechanism?
Lesions in certain cranial nerves can produce specific deficits. If a patient exhibits a combination of difficulty elevating the eyelid, a 'down and out' gaze, and pupillary dilation, but retains full visual acuity, WHICH of the following is the MOST probable mechanism?
A patient presents with a chief complaint of altered equilibrium. During the assessment, the patient is able to maintain balance with eyes open. However, with eyes closed the patient is unable to maintain their balance. Which of the following is the MOST likely structure affected?
A patient presents with a chief complaint of altered equilibrium. During the assessment, the patient is able to maintain balance with eyes open. However, with eyes closed the patient is unable to maintain their balance. Which of the following is the MOST likely structure affected?
A patient undergoing a neurological examination is noted to have a consistently asymmetric palatal elevation, where the palate elevates higher on one side compared to the other, which MOST strongly suggests a lesion involving WHAT?
A patient undergoing a neurological examination is noted to have a consistently asymmetric palatal elevation, where the palate elevates higher on one side compared to the other, which MOST strongly suggests a lesion involving WHAT?
A patient reports a gradual decline in their sense of smell. To differentiate between age-related olfactory decline AND dysfunction of the olfactory nerve (CN I) itself, WHICH test would be MOST specific?
A patient reports a gradual decline in their sense of smell. To differentiate between age-related olfactory decline AND dysfunction of the olfactory nerve (CN I) itself, WHICH test would be MOST specific?
Consider a patient experiencing hearing loss. If the Weber test lateralizes to the left ear and the Rinne test demonstrates air conduction is greater than bone conduction in the right ear, WHAT type of hearing loss does the patient MOST likely have?
Consider a patient experiencing hearing loss. If the Weber test lateralizes to the left ear and the Rinne test demonstrates air conduction is greater than bone conduction in the right ear, WHAT type of hearing loss does the patient MOST likely have?
A researcher discovers a novel compound that selectively inhibits the function of the chorda tympani nerve. Which specific effect should be expected?
A researcher discovers a novel compound that selectively inhibits the function of the chorda tympani nerve. Which specific effect should be expected?
A patient presents with trigeminal neuralgia. If the patient's pain is primarily located around the forehead and upper eyelid, and the corneal reflex is diminished, WHERE is the MOST likely location of involvement along the trigeminal nerve (CN V)?
A patient presents with trigeminal neuralgia. If the patient's pain is primarily located around the forehead and upper eyelid, and the corneal reflex is diminished, WHERE is the MOST likely location of involvement along the trigeminal nerve (CN V)?
Damage to the lower part of the facial nucleus results in deficits that differ from those caused by damage to the entire facial nucleus. If the entire facial nucleus is damaged, what is the additional function that is lost?
Damage to the lower part of the facial nucleus results in deficits that differ from those caused by damage to the entire facial nucleus. If the entire facial nucleus is damaged, what is the additional function that is lost?
Following a traumatic injury, a patient has difficulty protruding their tongue and exhibits dysarthria. The tongue deviates to the left on attempted protrusion. If MRI reveals a lesion in the right cerebral hemisphere, which additional finding would BEST support the conclusion that the lesion affects the upper motor neuron pathway controlling tongue movement?
Following a traumatic injury, a patient has difficulty protruding their tongue and exhibits dysarthria. The tongue deviates to the left on attempted protrusion. If MRI reveals a lesion in the right cerebral hemisphere, which additional finding would BEST support the conclusion that the lesion affects the upper motor neuron pathway controlling tongue movement?
A patient presents with persistent hoarseness and difficulty swallowing. During examination, the left vocal cord is paralyzed in the adducted position. This symptom suggests dysfunction of WHAT specific branch of the vagus nerve (CN X)?
A patient presents with persistent hoarseness and difficulty swallowing. During examination, the left vocal cord is paralyzed in the adducted position. This symptom suggests dysfunction of WHAT specific branch of the vagus nerve (CN X)?
Flashcards
Olfactory Nerve (I)
Olfactory Nerve (I)
Transmits olfactory (smell) information from the nose.
Optic Nerve (II)
Optic Nerve (II)
Transmits visual information from the eyes.
Oculomotor Nerve (III)
Oculomotor Nerve (III)
Controls eye movement, pupillary constriction, and lens shape.
Trochlear Nerve (IV)
Trochlear Nerve (IV)
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Vestibulocochlear Nerve (VIII)
Vestibulocochlear Nerve (VIII)
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Spinal Accessory Nerve (XI)
Spinal Accessory Nerve (XI)
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Hypoglossal Nerve (XII)
Hypoglossal Nerve (XII)
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Trigeminal Nerve (V)
Trigeminal Nerve (V)
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Facial Nerve (VII)
Facial Nerve (VII)
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Glossopharyngeal Nerve (IX)
Glossopharyngeal Nerve (IX)
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Vagus Nerve (X)
Vagus Nerve (X)
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Abducens Nerve (VI)
Abducens Nerve (VI)
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Olfactory Nerve (I)
Olfactory Nerve (I)
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Optic Nerve (II)
Optic Nerve (II)
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Sensory Cranial Nerves
Sensory Cranial Nerves
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Motor Cranial Nerves
Motor Cranial Nerves
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Mixed Cranial Nerves
Mixed Cranial Nerves
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Oculomotor, Trochlear and Abducent Nerves (III, IV, VI)
Oculomotor, Trochlear and Abducent Nerves (III, IV, VI)
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Diplopia in Abducent Nerve Lesion
Diplopia in Abducent Nerve Lesion
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Lesion of Trigeminal Nerve
Lesion of Trigeminal Nerve
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Testing SCM (Sternocleidomastoid)
Testing SCM (Sternocleidomastoid)
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Lesion of Hypoglossal
Lesion of Hypoglossal
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Function of Facial nerve
Function of Facial nerve
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Study Notes
- Dr. Abeer Elwishy, a Professor of Physical Therapy for Neurology and Neurosurgery at Cairo University, prepared these notes on cranial nerves.
Names 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
Classification of Cranial Nerves
- Sensory cranial nerves contain afferent sensory fibers.
- I: Olfactory nerve
- II: Optic nerve
- VIII: Vestibulocochlear nerve
- Motor cranial nerves contain efferent motor fibers.
- III: Oculomotor nerve
- IV: Trochlear nerve
- VI: Abducent nerve
- XI: Accessory nerve
- XII: Hypoglossal nerve
- Mixed nerves contain both sensory and motor fibers.
- V: Trigeminal nerve
- VII: Facial nerve
- IX: Glossopharyngeal nerve
- X: Vagus nerve
- There are 12 pairs of cranial nerves
- Nuclei are bilaterally supplied by pyramidal tracts, except for the lower part of the facial nucleus and the hypoglossal nucleus.
- Unilateral upper motor neuron lesions typically spare cranial nerves, except in the lower face and tongue involving the facial and hypoglossal nerves.
I: Olfactory Nerve
- Sensory nerve
- Function: Smell
- Tested by using a familiar, non-irritant substance like coffee grounds in each nostril.
- Lesions can cause:
- Anosmia (loss of smell)
- Parsosmia (altered sense of smell)
- Olfactory hallucinations
II: Optic Nerve
- Purely sensory
- Function: Acuity and field of vision
- Testing:
- Acuity of Vision: Uses Snellen's chart or finger counting from 6 meters; reduce distance to 30 cm if needed; test light perception with a torch if hand movements not seen.
- Visual Field (Confrontation Test): Patient sits 60-100 cm apart; one eye is closed; patient looks into the other eye; checks peripheral vision.
- Lesion: decreased acuity of vision.
III, IV, & VI: Oculomotor, Trochlear & Abducent Nerves
- All are purely motor
- Function: Supplies extraocular and intraocular muscles
- Oculomotor innervates: medial, superior, and inferior recti; inferior oblique; and levator palpebrae superioris.
- Trochlear innervates: superior oblique.
- Abducent innervates: lateral rectus.
- Oculomotor Nerve supplies intraocular muscles, the constrictor pupillae of the iris and the ciliary muscle of the lens.
- Extraocular movements test abducent nerve by having the patient look laterally, testing the lateral rectus muscle.
- Extraocular movements test trochlear nerve by having the patient look inwards and downwards, testing the superior oblique muscle.
- Extraocular movements test oculomotor nerve by having the patient look in all other directions
- Tests are done on each eye individually, and with both eyes simultaneously for conjugate movement.
- Ptosis may be due to oculomotor nerve paralysis leading to complete ptosis accompanied by mydriasis and divergent squint.
- Pupillary Examination: Pupils should be equal, round, and reactive to light and accommodation.
- Pupil light reflex tests CN II(afferent) and III(efferent); light exposure should cause constriction in both eyes
- Abnormally, absence of constriction in one eye indicates lesion of occulomotor nerve of this eye; if in both eyes indicate optic nerve lesion;
Accommodation Reflex
- Patient is asked to follow a finger from far to near with both eyes.
- Convergence of the eye: contraction to the medial recti
- Miosis: constriction of the pupils caused from the contraction of the constrictor pupillae muscles
- Accommodation: increased refractive power caused by the contraction of the ciliary muscles
- Lesion of Trochlear Nerve: Diplopia during downward gaze is experienced (e.g., descending stairs or reading); limited movement when looking both downwards and inwards.
- Lesion of the Abducent Nerve: Diplopia may occur when looking toward the paralyzed side; limited movement when looking sideways; convergent squint(eye looks inward).
- Lesion of Occulomotor Nerve includes:
- External ophthalmoplegia: causes ptosis (drooping eyelids) and divergent paralytic squint.
- Internal ophthalmoplegia: causes ipsilateral dilated fixed pupil (mydriasis) as well as loss of direct response to light, but preserves consensual reflex.
V: Trigeminal Nerve
- Mixed nerve
- Function: controls sensation of the face and muscles of mastication
- Sensory part: sensation from face (except angle of mandible); general sensation from the anterior 2/3 tongue, & buccal cavity
- Motor part: supplies muscles of mastication (temporalis, masseter, pterygoids), anterior belly of digastrics, mylohyoid; tensor palate
- Testing Sensory Part - testing for sensations, using both a pin and piece of cotton comparing sensation on both sides of the face and on ophthalmic/maxillary/mandibular divisions
- Corneal & Conjunctival reflexes tests asking patient to look upwards, touching the corneo-conjunctival junction and observing a blink as a result- Absence of blinking denotes facial paralysis
- Testing Motor Part - power of muscles of mastication, pterygoid muscle, temporalis muscle, check jaw reflex checking for absent jaw reflex
VII: Facial Nerve
- Mixed nerve
- Sensory function: receives taste sensations from anterior 2/3 of tongue, buccal cavity.
- Motor function: supplies muscles of facial expression plus posterior belly of digastrics, platysma, stapedius, stylohyoid.
- Autonomic part: supplies lacrimal gland and submaxillary & sublingual salivary glands.
- Sensory Part: (Chorda tympani) taste examination over anterior 2/3 using solutions such as salt, sugar or even bitters
- Glabellar Reflex: tapping the glabella should see cessation after the first 2-3 taps from orbicularis occuli muscles- continual blinking denote Parkinsonism
- Observe the face for any asymmetry as well as involuntary movements as well looking for any forehead wrinkles with the bare teeth
- UMN lesion- Paralysis on opposite sides of the face that spares associative movements; Hypertonia/hyperreflexia; Hemiplegia occur
- LMN lesion- Paralysis affecting associative movements; hypotonia/hyporeflexia; on opposite side of hemiplegia occurs
- UMNL: Obliteration of the naso-labial fold, dropping of the angle of the mouth with saliva. Accumulation behind of cheek and cannot blow check/showing of teeth
- Clinical diagnosis determine side by asking affected side to close- it will occur in UMNL if they can, in LMNL it will not
VIII: Vestibulocochlear Nerve
- Purely sensory.
- Function: Divides into two parts: the Cochlear part and the Vestibular part.
- Cochlear Part: This part carries impulses for hearing therefore if it is damaged, it leads to a decrease acuity of hearing.
- Vestibular Part - it carries impulses for equilibrium and if its damaged, leads to vertigo
- Testing:
- Cochlear Part: Watch/Weber/Rinne test that looks determine acuity of hearing
- Vestibular Part: Test on patients with no prior vertigo using a therapist on seated/supine patients who then stretch out the patient's neck for up to 10 seconds
IX: Glossopharyngeal Nerve
- Mixed nerve.
- Motor fibers innervate the stylopharyngeus and constrictors of the pharynx.
- Sensory fibers carry general sensation from the posterior 1/3 of the tongue, pharynx, and tonsils, as well as taste from the posterior 1/3 of tongue.
- Autonomic fibers provide parasympathetic innervation to the parotid gland.
X: Vagus Nerve
- Mixed nerve.
- Motor Fibres - soft palate supply, as well the pharynx and larynx
- Sensory Fibres - the skin over external auditory and thoracic/abdominal viscera as well
- Autonomic Fibres - innervate the heart (inhibitory), GIT, bronchial tree (secretory/motor)
- Assess Glossopharyngeal & Vagus Nerves through Palatal and Pharyngeal Reflexes along with an open mouth, central uvula and local contractions/gag reflexes
- Lesions of bulbar nerves causes Dysphagia, Dysarthria, Voice Hoarseness and Nasal Regurgitation.
XI: Accessory Nerve
- Purely motor nerve.
- Cranial part shares in the motor innervation of the soft palate and pharynx.
- Spinal part supplies the sternomastoid and trapezius muscles.
- Patient raises his shoulder for testing against resistance is flexion with side bending same plus rotation on the opp side
- Lesion leads to weakness of both Trapezius/SCM Muscle
XII: Hypoglossal Nerve
- Purely motor nerve.
- Function: Supplies intrinsic muscles of tongue
- The test inspects the tongue for fasciculation inside or for deviation; note any deviation that occurs.
- Tests for movement involve moving the tongue to the left/right or asking the patient to push against his cheek
- UMNL: Deviation of the tongue to the opposite side of the lesion and Inability to protrude the tongue can occur
Cranial Nerves for Sensory are: - CN 1 (Olfactory) - CN 2 (Optic) - CN 8 (Vestibulo-cochlear) Cranial Nerves for Parasympathetic actions are - 3 (Oculomotor) motor - 7 (Facial) - 9 (Glossopharyngeal) - 10 (Vagus)
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