Neurology II Flashcards
A 46-year-old man presents after penetrating injuries to his arm and forearm.
He is unable to extend his fingers. There is no sensory disturbance and there is no vascular injury.
Which nerve has been damaged? Anterior interosseous nerve Median nerve Posterior interosseous nerve Radial nerve Ulna nerve
Posterior interosseous nerve
The posterior interosseus nerve supplies all the extensor muscles except for the brachioradialis, extensor carpi radialis brevis and longus.
It has no cutaneous branch
A 35-year-old man presents to the Emergency department complaining of severe pain in his lower back after lifting a heavy box at work. The pain radiates to his right buttock and thigh. He has had no urinary symptoms.
On examination he can straight leg raise to 90 degrees on the left side but only to 30 degrees on the right. Sciatic stretch test is positive.
He has difficulty plantar flexing his right ankle and has abnormal sensation on the plantar aspect of the foot. His right ankle reflex is absent but all other reflexes are normal. There is no other sensory disturbance.
What is the likely diagnosis?
Cauda equina syndrome L3/L4 disc prolapse L4/L5 disc prolapse L5/S1 disc prolapse Old Sheuermann's disease
An L5/S1 disc prolapse affects the S1 nerve root causing
Sensory loss to the posterior calf and the plantar surface of the foot
Motor loss to gastrocnemius and soleus and
Loss of ankle jerk.
Which is the principal root innervation for the small muscles of the hand?
C5 C6 C7 C8 T1
The small muscles of the hand are innervated principally by T1.
Which of the following is true regarding sensory neural hearing loss?
Approximately 1 per 1000 children will have greater than 40db hearing loss.
The incidence is half as high in babies admitted to neonatal intensive care units compared with the normal population.
The risk is increased in children who have had post-natal rubella.
The risk is increased in Down syndrome.
The risk is increased in Werdig-Hoffman syndrome.
Sensory neural hearing loss is caused by lesions in the cochlea or the auditory nerve or central connections. It may be unilateral or bilateral.
Language acquisition and secondary educational difficulties follow, with social isolation, and an increased risk of mental health problems. The approximate incidence is 1 per 1000 children.
Risk factors include:
NICU admission: low birth weight, less than 32 weeks gestation, prolonged ventilation, prolonged jaundice, ototoxic drugs, hypoxic ischaemic encephalopathy, neonatal meningitis
Congenital infection (rubella, CMV)
Dysmorphic syndromes (affecting head and neck)
Family history of a close relative needing a hearing aid below the age of 5 years
Infections: acute bacterial or TB meningitis, mumps (latter usually unilateral).
If all risk factors are considered only around 50% of cases could be identified by testing between 5 and 10% of all babies.
Conductive hearing loss is related to middle ear pathology. This is commoner in Down syndrome, cleft palate, Turner’s syndrome, and facial malformation syndromes.
Werdig-Hoffman is associated with normal hearing.
A 34-year-old male presents with back pain and weakness.
Which of the following would support a diagnosis of prolapsed intervertebral disc?
Bilateral symmetrical nerve involvement Loss of sensation over the left outer upper thigh No evidence of nerve compression Pain which is unremitting in character Pain which is worse on resting
Prolapsed intervertebral disc is associated with pain and neurological loss in one nerve root.
Frequently roots of the sciatic nerve are affected. Compression of more than one root suggests an alternative diagnosis.
Pain at rest would suggest an alternative diagnosis such as infection, tumour or metabolic disease as would unremitting pain.
A 72-year-old male presents with diplopia.
Which one of the following features would suggest a third nerve palsy?
Constricted pupil Convergent strabismus Enophthalmos Increased lacrimation Unreactive pupil to light
Unreactive pupil to light
In a third nerve palsy there is typically ptosis with a dilated, unreactive pupil and the eyeball is displaced downwards and outwards.
Enophthalmos is seen in Horner’s syndrome. There would be a dilated not constricted pupil and a divergent squint - affected eye deviated ‘down and out’.
Increased lacrimation may be seen in VIIth nerve palsy.
Which of the following anatomical considerations is correct?
Midline cerebellar lesions cause marked horizontal nystagmus
In cortical blindness pupillary reactions are abnormal
Optic chiasm lesions characteristically produce a bitemporal hemianopia
Optic tract lesions produce an ipsilateral homonymous hemianopia
The physiological blind spot is unaffected by papilloedema
The physiological blind spot is enlarged in papilloedema as Peripapillary photoreceptors are displaced.
In cortical blindness, pupillary reflexes, eye movements and fundoscopy are all normal.
Optic tract lesions produce an contralateral homonymous hemianopia.
Horizontal nystagmus occurs in unilateral disease of the cerebral hemisphere, with the fast phase directed to the side of the lesion. Lateral cerebellar lesions classically cause pronounced nystagmus, whereas this is rarer and much more subtle with midline lesions.
Hearing Loss
A mother brings her 7-year-old girl to see you. She has had a moderate hearing loss and has coped well with hearing aids for the last three years, but she has been recently noted by her teacher to be more withdrawn towards her peers in class. In spite of her being teased for being a “teacher’s pet” and now sitting at the front of the classroom constantly, her academic performance has deteriorated.
A Central hearing loss B Conductive hearing loss C High frequency hearing loss D Mild hearing loss E Moderate hearing loss F Noise-induced hearing loss G Ototoxic hearing loss H Profound hearing loss I Severe hearing loss J Sensori-neural hearing loss K Speech discrimination loss
Speech discrimination loss
Hearing loss should be considered in children if there is any suspicion from parents or teachers based on behavioural changes. Accurate electrophysiological testing can be easily and non-invasively carried out in children of any age.
Even in those patients known to have a hearing loss, vigilance is important as progressive changes often occur. A school age child may find increasing difficulty hearing the teacher and need to sit at the front of the room to hear better and lip-read. This indicates a loss of speech discrimination ability.
This loss can also occur in adults with a progressive loss, including those already using hearing aids. Some go on to receive a cochlear implant which can give them the ability to hear speech clearly again.
Hearing Loss
A 22-year-old man comes to see you. He was recently on holiday and learned to waterski. On the day before returning home, he fell while waterskiing at speed and sustained a blow to the right side of his head. On otoscopy you see a small hole in the tympanic membrane. You refer him for audiological assessment. He has a mild hearing loss on the right with normal bone conduction.
A Central hearing loss B Conductive hearing loss C High frequency hearing loss D Mild hearing loss E Moderate hearing loss F Noise-induced hearing loss G Ototoxic hearing loss H Profound hearing loss I Severe hearing loss J Sensori-neural hearing loss K Speech discrimination loss
Conductive hearing loss
Hearing loss is broadly categorised into two aetiological types: conductive and sensorineural.
Conductive losses affect outer and/or middle ear function (for example, tympanic membrane rupture) and will lead to impaired air conduction with normal bone conduction.
Sensorineural losses result from hair-cell losses in the cochlea (inner ear) and both air and bone conduction are affected.
Hearing Loss A Central hearing loss B Conductive hearing loss C High frequency hearing loss D Mild hearing loss E Moderate hearing loss F Noise-induced hearing loss G Ototoxic hearing loss H Profound hearing loss I Severe hearing loss J Sensori-neural hearing loss K Speech discrimination loss
Any patient of any age with a bilateral severe to profound hearing loss should be considered a potential cochlear implant candidate.
The causes of sensorineural hearing losses include otoxicity (due to agents such as gentamicin, cisplatin and other chemotherapeutic agents), bacterial meningitis, skull fracture, noise exposure, presbycusis, genetic syndromes and hereditary deafness and many of the “unknown” causes of hearing loss.
Gentamicin is still used in some countries without the recommended strict monitoring of circulating levels, and hair cell toxicity results.
Hearing Loss
A 65-year-old man comes to see you complaining that he has been misunderstanding some words in conversation - even in quiet environments such as at home with his wife. He has no prior history of hearing loss. You send him for an audiogram which shows a dip in the 6-8 kHz range.
A Central hearing loss B Conductive hearing loss C High frequency hearing loss D Mild hearing loss E Moderate hearing loss F Noise-induced hearing loss G Ototoxic hearing loss H Profound hearing loss I Severe hearing loss J Sensori-neural hearing loss K Speech discrimination loss
High frequency hearing loss is known as the “invisible disability” as its presence is often not obvious from history and basic clinical examination. Early stages of some hearing losses can be as subtle as an adult having trouble understanding a few words of conversation - in age related hearing losses the high frequency sounds of some consonants (for example, “sss” or “fff”) are lost first.
Hearing Loss
A child born in a hospital with a universal neonatal screening programme does not pass the first and second screening procedures and goes on for full diagnostic assessment. The child has a profound bilateral hearing loss. The outcome of the thorough investigations is that the child receives a cochlear implant.
A Central hearing loss B Conductive hearing loss C High frequency hearing loss D Mild hearing loss E Moderate hearing loss F Noise-induced hearing loss G Ototoxic hearing loss H Profound hearing loss I Severe hearing loss J Sensori-neural hearing loss K Speech discrimination loss
Sensori-neural hearing loss
Hearing loss is broadly categorised into two aetiological types: conductive and sensorineural.
Conductive losses affect outer and/or middle ear function (for example, tympanic membrane rupture) and will lead to impaired air conduction with normal bone conduction.
Sensorineural losses result from hair-cell losses in the cochlea (inner ear) and both air and bone conduction are affected.
Hearing loss is also classified according to degree of loss. It is expressed as the number of decibels of hearing loss that is present compared to someone with normal hearing.
Mild 25-40 dB loss
Moderate 40-70 dB loss
Severe 70-90 dB loss
Profound >90 dB loss
Hearing loss
A 70-year-old man presents to clinic complaining of progressive bilateral hearing loss over the last year. He accuses his grandchildren of mumbling. Rinne and Weber tests are both normal. He has a hearing test, which reveals high frequency hearing loss.
A Acoustic neuroma B Acute suppurative otitis media C Barotrauma D Chronic suppurative otitis media E Glue ear F Meniere’s disease G Presbyacusis H Otosclerosis I Vestibular neuronitis
Presbyacusis
This man has presbyacusis or senile deafness. It is caused by a gradual loss of hair cells in the cochlea and a loss of neurones in the cochlear nerve. Usually the high tones go first.
Hearing loss
A 35-year-old woman has developed deafness in her left ear. It became noticeably worse during a recent pregnancy and her mother had premature deafness. On examination both TMs are normal, the Rinne test is negative on the left and the Weber test lateralises to the left side.
A Acoustic neuroma B Acute suppurative otitis media C Barotrauma D Chronic suppurative otitis media E Glue ear F Meniere’s disease G Presbyacusis H Otosclerosis I Vestibular neuronitis
Otosclerosis Conductive deafness(bone better than air) with a normal eardrum, is otosclerosis until proved otherwise. It is more common in women and typically deteriorates in pregnancy.
Causes of facial nerve palsy
A 32-year-old man presents with a one month history of offensive ear discharge from the left ear. Examination reveals a facial nerve palsy and there is an attic perforation of the tympanic membrane.
A Acoustic neuroma B Bell's palsy C Cholesteatoma D Diabetes mellitus E Guillain-Barré syndrome F Motor neurone disease G Otitis externa H Parotid tumour I Ramsay Hunt syndrome J Sarcoidosis
Cholesteatoma
The presence of an attic perforation with ear discharge and facial palsy is indicative of a cholesteatoma.
Causes of facial nerve palsy
An 82-year-old woman presents with a one day history of a severely painful right ear, a right facial palsy and vesicular rash around the right ear.
A Acoustic neuroma B Bell's palsy C Cholesteatoma D Diabetes mellitus E Guillain-Barré syndrome F Motor neurone disease G Otitis externa H Parotid tumour I Ramsay Hunt syndrome J Sarcoidosis
Ramsay Hunt syndrome
In herpes zoster otitis (Ramsay Hunt syndrome), severe pain precedes the emergence of the classical herpes zoster vesicles and facial palsy.
Causes of facial nerve palsy
A 53-year-old woman presents with a history of giddiness, impaired hearing and left facial numbness. Examination reveals left sensorineural deafness, and left trigeminal and facial nerve palsies.
A Acoustic neuroma B Bell's palsy C Cholesteatoma D Diabetes mellitus E Guillain-Barré syndrome F Motor neurone disease G Otitis externa H Parotid tumour I Ramsay Hunt syndrome J Sarcoidosis
Acoustic neuroma
Acoustic neuromas are slow growing neurofibromas, often arising from the acoustic nerve’s vestibular division, giving progressive ipsilateral tinnitus, sensorineural deafness, giddiness and may affect nearby cranial nerves.
Facial nerve palsies may be caused by lesions affecting any part of its course. It arises in the medulla and emerges between pons and medulla, passes through the posterior fossa in close proximity to the middle ear before emerging from the stylomastoid foramen to pass underneath the parotid gland.
Causes can be divided into:
Intracranial - brainstem tumours, stroke, multiple sclerosis, acoustic neuroma
Intratemporal - otitis media, Ramsay Hunt syndrome, cholesteatoma
Infratemporal - parotid tumours, trauma
Others - sarcoid, Guillain-Barré syndrome, diabetes, Bell’s palsy.
Glasgow Coma Scale
An 80-year-old male is admitted after being found collapsed at home. No history is obtainable. On examination he has a pulse of 45 beats per minute, a temperature of 34°C, no eye opening to pressure over the eyebrows and he makes no audible sounds. No movements can be elicited and he has generally brisk reflexes with bilateral extensor plantar responses.
The 80-year-old male with what sounds like raised intracranial pressure has E1, V1, M1 = 3, suggesting a grave prognosis.
Glasgow Coma Scale
A 19-year-old female is brought to the Emergency department following a car accident. On examination she has a head wound, has a pulse of 110 beats per minute, smells of alcohol, is confused. She shouts for her boyfriend while thrashing around on the couch and is difficult to examine. Her eyes are fully open, pupils appear slightly dilated and reflexes appear brisk with down going plantar responses.
In the case of the 19-year-old female she would score E4, V4 (as confused) and M5 (purposeful movements towards changing painful stimuli) = 13.
