Pastest Flashcards
Which part of the brain degenerates in Huntington’s disease?
The caudate nucleus
“A 45 year old man has significant tics but his language, memory and insight are only mildly to moderately impaired. He also has prominent depression and a butterfly pattern in the caudate nucleus on CT scan. Which is the most likely form of dementia in this person?”
Huntington’s disease
This presents with bradykinesia, rigidity, cogwheeling and shuffling gait?
Parkinson’s disease
Triad of normal pressure hydrocephalus
- Dementia
- Shuffling gait
- Incontinence
Dementia
Shuffling gait
Incontinence
Normal pressure hydrocephalus
On CT or MRI scan, the patient will have expanded ventricles that compress the cerebral cortex
Normal pressure hydrocephalus
How does L-dopa work?
Passes through the BBB and is metabolized to dopamine
How many layers in the dura mater?
- 2 layers
- the two layers separate to enclose the venous sinuses
The dura mater is richly innervated and therefore, stretch causes pain. Give an example of pain associated with this
- Headahce of meningitis (caused by inflammation of the meninges)
- Postdural headache (after lumbar puncture or spinal anaesthetic) - headache results from the stimulation of sensory nerve endings due to stretch of the dura after removal of the CSF
This type of haematoma is commonly associated with trauma. Name the type of haematoma and the artery commonly involved
- Extradural haematoma
- Middle meningeal artery
This type of haematoma often occurs in elderly or demented people or in people with alcohol problems (bc shrinkage of the brain occurs)
-Subdural haematoma (venous bleeding between the dura mater and the arachnoid mater)
The bridging veins that run across the surface of the brain makes them vulnerable to bleeding).
As the bleed is venous rather than arterial, lower pressures result in a more gradual accumulation of blood than an arterial bleed. The result is a gradual deterioration in cognitive function and patients often present with confusion (chronic subdural haematoma).
This type of haematoma usually follows the rupture of a berry aneurysm in the region of the circle of Willis/
Subarachnoid haemorrhage
-This causes blood to contaminate the CSF (detected on lumbar puncture)
This type of bleed occurs within the brain parenchyma itself
Intracerebral bleed
Carries secretomotor fibres to the lacrimal gland through the greater petrosal nerve
Facial nerve
Secretomotor to the submandibular and sublingual glands
Facial nerve
Is the buccinator a muscle of mastication?
No, it keeps food pushed into the mouth during chewing so it only AID mastication
(therefore buccinator is supplied by CNVII, the muscles of mastication are supplied by the mandibular division of CNV)
Why do people with Bell’s palsy suffer from hyperacusis (sensitivity to sounds)
-Denervation of the stapedius muscle (normally serves to dampen down sounds in the middle ear).
Also suffer:
- loss of sensation to anterior 2/3rds of tongue
- dry eyes (loss of secretomotor supply to lacrimal gland) - this means you need to protect the eye to prevent keratitis and corneal ulceration in a facial nerve palsy. This is exacerbated by denervation of orbicularis oculi, which normally functions to spread the tear film over the surface of the cornea with the blinking reflex.
“A 42 year old lady attends a neurological outpatient clinic as an urgent referral, with a short but progressive history of double vision. It is noted by her husband that her speech would be worse last thing in the evening. She is a non-smoker and drinks 18 units a week of alcohol.”
- Myasthenia gravis (lol)
- You should carry out nerve conduction studies with repetitive nerve stimulation
Which type of skull fracture leads to “panda eyes”
Base of skull fracture (panda eyes = bruising around both eyes, not extending beyond the orbital margin)
What weird CSF stuff could you see in a base of skull fracture?
CSF Rhinorrhoea - can present like a nosebleed, following trauma.
Diagnose with blotting paper, if it is CSF rhinorrhoea, then it there will be a central blood clot surrounded by a stain of strw-coloured fluid (the CSF)
Base of skull fracture and x-ray findings
X-ray may not show the fracture BUT look for the sign of a fluid level in the sphenoidal sinus on the lateral x-ray
A CT scan shows a crescent shaped haematoma
(acute) subdural haematoma
A CT scan shows a lens-shaped (biconvex) haematoma
Extra-dural haematoma
A CT scan shows frontal contusions and a large amount of blood in the basal cisterns
Subarachnoid haemorrhage !! (Blood in the basal cisterns - around brainstem and midbrain) indicates subarachnoid haemorrhage !!
Supplies parasympathetic fibres to the submandibular and aublingual salivary glands
Facial nerve
An uncal herniation could damage which cranial nerve?
CNIII (occulomotor)
This type of herniation could also damage (compress) the posterior cerebral artery
See “friday night football” saved image on mac
Gottron papules and hleiotrope rash?
Dermatomyositis
Malar rash, discoid rash and photosensitivity?
SLE
“A middle aged lady presents with pain in the muscles around her shoulders. On examination, she is obese and has difficulty standing from a chair without using her hands. There are discrete, erythematous, scaly papules over her knuckles bilaterally.
Dermatomyositis
the papules are gottrons papules
This is the major descending motor tract in humans
The corticospinal tract
This tract connects the primary motor cortex with the alpha motor neurons in the ventral horn of the spinal cord
The corticospinal tract
Spasticity
UMN
Hyperreflexia
UMN
Pyramidal weakness
UMN (flexors stronger than extensors in arms and vice versa in legs)
Babinski sign
UMN
Clasp knife rigidity
UMN
Extensor plantar responses
UMN
A plexiform neuroma will cause UMN or LMN symptoms?
LMN (because its in the nerve plexus duh)
Mononeuritis multiplex will cause UMN or LMN signs?
LMN
LMN weakness is distal/segmental
Palsy of this nerve will result in palatal weakness (causing “nasal speech”)
Vagus nerve
Palsy of this nerve will result in loss of reflex contraction of the palate in the gag reflex
Vagus nerve
Palsy of this nerve will result in hoarseness of the voice (in a unilateral laryngeal nerve lesion)
Vagus nerve
Palsy of this nerve will result in a bovine cough (with a bilateral recurrent nerve lesion)
Vagus nerve
Autosomal dominant triplet disease affecting chromosome 4
Huntingtons
How many CAG repeats present in huntingtons when disease becomes fully penetrant
When CAG repeats reach 41 or more, the disease is fully penetrant
How does tetrabenazone help in huntingtons?
Helps with the movement disturbances
Which type of tumour found in the brain (and occasionally spinal cord) is associated with NF 1?
Astrocytoma
Transient, bilateral facial palsies associated with fever, uveitis and parotitis
Heerfordt’s syndrome - an acute syndrome seen in sarcoidosis
A 26 year old woman presents to her GP with a left sided facial palsy. Several days previously, she had woken with a right sided facial weakness but this had resolved over 2-3 days. She has also developed pain and welling in her parotid glands associated with fever and painful ‘red eyes’. Subsequent investigation confirm bilateral hilar lymphadenopathy on CXR and hypercalcemia
Heerfordt’s syndrome
Three conditions which can cause bilateral facial palsies
- Heerfordt’s syndtome (seen in sarcoidosis)
- Lyme disease
- Myasthenia gravis
A 24 year old woman presents to her GP with a 2 month history of pain and blurring of her vision now associated with a right sided facial palsy and facial spasm. Subsequent investigations reveal delayed visual evoked potentials
Pontine demyelination
-This woman has features suggestive of optic neuritis and pontine demyelination due to MS
(the facial palsy, similar in onset and character to a Bell’s palsy may be associated with facial spasm and myokymic twitching ( a diffuse rippling of the muscles)
A 61 year old man with known type II diabetes mellitus presents in the outpatient clinic for his annual review. In the last few months he has developed parasthesiae and numbness in his right ring and little fingers, a right sided foot drop and a left sided facial weakness
Mononeuritis multiplex
(numerous causes: diabetes, rheumatoid arthritis, SLE, polyarteritis nodosa, granulomatosis with polyangitis, sarcoidosis, carcinoma and amyloidosis)
Why is it not possible to replace dopamine directly in parkinson’s disease?
It doesn’t cross the blood brain barrier
so you give L-dopa which is the amino acid precursor of dopamine
Why might you use benzatropine in Parkinson’s disease?
Benzatropine is particularly useful when resting tremor is the predominant symptom (its a muscarinic antagonist)
When are MAO-B inhibitors good in parkinsons?
Good early and late in the disease
-have the advantage of once daily dosing regime
(e.g. selegiline)
However, selegiline metabolises to amphetamine and so can cause cognitive side effects
A disease that affects the anterior horn cells and leads to only motor deficits
Motor neuron disease
This occurs as a result of degeneration of the anterior horn cells of the spinal cord and upper motor neurons in the motor cortex
Amyotrophic lateral sclerosis (ALS)
A 32 year old patient presents with progressive weakness of the arms and legs over 1 week. Three weeks earlier she had an episode of diarrhoea lasting 5 days. Examination confirms distal weakness and ‘glove and stocking’ sensory loss
Guillain-Barre
How does phenytoin toxicity present?
As cerebella syndrome
A 24 year old epileptic patient complains of a 4 day history of unsteadiness and altered vision. Colleagues have commented that he appears drunk whilst at work. he attended neurology outpatients 3 weeks previously. On examination today: wide based gait, past pointing and intention tremor. Which of his medications is most likely to have caused this?
Phenytoin
Usual complication following a subdural haematoma
Recurrent haemorrhage
(there is breakdown and organisation of the haematoma. Organised haematomas are attached to the inner surface of the dura and not adherent to the underlying arachnoid. The lesion can retract as granulation tissue matures until there is only a thin layer of reactive connective tissue (subdural membranes). The bleeding will occur from the thin walled vessels of the granulation tissue
A 20 year old student presents to her GP because of a tremor she has noticed in her left hand over the past few months. On examination, she has subtle dysarthria and a wide based gait. When the doctor passively moves her left elbow, he notices hypertonia which is independent of whether he moves her elbows slowly or briskly. She carries a diagnosis of bipolar disorder and was started on a medication by her psychiatrist two weeks ago. Which test is most appropriate to confirm diagnosis?
This patient has Wilson’s disease. Confirmation of diagnosis is by 24 hour urine collection (look at how much copper has been excreted, more than 0.64 micromoles in 24 hours is suggestive of Wilson’s disease)
What does a dat scan measure?
Striatal dopamine transport - useful test for parkinsons
What does an EEG/electroencephalogram look for?
Looks for evidence of seizure activity or to look for areas of cortical hyperexcitability that might predispose to future seizures
Triad of Wernicle’s encephalopathy
- Gait ataxia
- Occulomotor dysfunction
- Encephalopathy
Due to vitamin B1 deficiency. Typically occurs in those who are chronically vitamin deficient e.g. alcoholics.
Can also occur in anorexia nervosa, hyperemesis gravidarum and in those on total parenteral nutrition without proper vitamin supplementation.
Normal intracranial pressure
Medication given IV to help decrease intracranial pressure
Mannitol
Is intracranial pressure lower in adults or children?
Lower in children
Which nerve is affected in Bell’s palsy?
Cranial nerve VII (causes a lower motor neurone lesion with involvement of an entire side of the face - as opposed to an upper motor neuron VIIth nerve lesion, which spares the forehead)
One sided face droop and inability to close eye
Bells palsy
When might carpal tunnel symptoms be worse?
At night
Where is the nerve compressed in radial neuropathy?
Spiral groove of the humers
Symptoms of radial neuropathy
- Weakness of wrist extension, finger extension and elbow flexion (due to involvement of brachioradialis muscle)
- there is also a varying degree of sensory loss on the dorsum of the hand
Which nerve supplies the interosseous muscles of the hand?
The ulnar nerve
Symptoms of musculocutaneous nerve palsy?
Weakness of elbow flexion and sensory loss over the lateral forearm
A sentinel headache precedes a ____?
A sentinel headache precedes a subarachnoid haemorrhage
Can epidural haematomas cross the suture lines of the skull?
no
Following cardiac catheterisation through the right femoral artery, 1 57 year old man develops pain and numbness over the anteromedial side of the knee, leg and medial malleolus. There is no motor or any other sensory deficit. Which nerve is most likely to have been injured during the procedure?
Saphenous nerve (have a look at this nerve supply) BUT ALSO, this nerve can be injured in procedures such as femoral artery catheterisation for angiography, saphenous vein harvest for coronary artery bypass grafting or long saphenous vein stripping for varicose veins
Path of the spinal accessory nerve?
- Exits the spinal cord at C1-C5
- Ascends through the foramen magnum
- Exits the skull through the jugular foramen
Which muscles does the spinal accessory nerve innervate?
- Sternocleidomastoid
- Trapezius
This muscle is the most important muscle supporting the scapula and clavicle and is responsible for elevation of the shoulders
Trapezius
Nerve supply to the levator scapulae
Dorsal scapular nerve
Nerve supply to the rhomboid muscles
Dorsal scapular nerve
Nerve supply to the supraspinatous muscle?
Suprascapular nerve
The axillary nerve has an anterior and a posterior branch, what do they supply?
Anterior branch - innervates the deltoid
Posterior branch - innervates the deltoid and the skin over the deltoid
Symptoms of myasthenia gravis usually occur at which age?
Symptoms start around age 20 (F:M 3:1)
-in general symptoms appear initially in the upper parts of the body
Commonly presents with diplopia, drooping eyelids, dysphagia, dysarthria, but with normal pupils, normal reflexes and normal sensation
Myasthenia Gravis
What will electromyography show in myasthenia gravis?
Decreased muscle contraction upon repetitive stimulation
Treatment of choice for myasthenia gravis
Neostigmine or pyridostigmine
Difference between having an abnormal dystrophin gene and not having dystrophin gene at all?
Abnormal dystrophin gene - Becker muscular dystrophy
Missing dystrophin gene - Duchenne muscular dystrophy
Autonomic features of lambert eaton syndrome?
Dry mouth and constipation
Which muscle is involved in blowing out cheeks?
Buccinator muscle (CNVII)
Corneal reflex- which nerves?
Afferent limb - CNV
Efferent limb - CNVII
Which nerve supplies general somatic sensation to the anterior 2/3rds of the tongue?
Mandibular division of the trigeminal nerve
Which level does the spinal cord terminate?
Around L1/L2
Proteinaceous beta-sheets
Creutzfeldt-Jakob disease
In giant cell arteritis, what would a biopsy of the temporal artery show?
It would show a granulomatous vasculitis in the walls of the artery (in some cases so severe as to cause obliteration of the arterial lumen)
Another name for wrist drop?
Radial nerve palsy
-Patients with wrist drop are unable to extend their wrist. It can occur in patients with stab wounds in the chest and fractures of the humerus
