Neurology Flashcards
Drug side effects:
Peripheral neuropathy
amiodarone phenytoin metronidazole nitrofurantoin isoniazid
Drug side effects:
thrombocytopenia
sodium valproate
heparin
Mechanism of action:
Phenytoin
binds to sodium channels increasing their refractory period
P450 inducer
Phenytoin
Adverse effects
Acute
initially: dizziness, diplopia, nystagmus, slurred speech, ataxia
later: confusion, seizures
Phenytoin
Adverse effects
Chronic
gingival hyperplasia (secondary to increased expression of platelet derived growth factor, PDGF), hirsutism, coarsening of facial features, drowsiness
megaloblastic anaemia (secondary to altered folate metabolism)
peripheral neuropathy
enhanced vitamin D metabolism causing osteomalacia
lymphadenopathy
dyskinesia
Phenytoin
Adverse effects
Idiosyncratic
fever rashes, including severe reactions such as toxic epidermal necrolysis hepatitis Dupuytren's contracture* aplastic anaemia drug-induced lupus
Phenytoin monitoring
Phenytoin levels do not need to be monitored routinely but trough levels, immediately before dose should be checked if:
adjustment of phenytoin dose
suspected toxicity
detection of non-adherence to the prescribed medication
Brain lesions
Gross anatomy
Parietal lobe lesions
sensory inattention apraxias astereognosis (tactile agnosia) inferior homonymous quadrantanopia Gerstmann's syndrome (lesion of dominant parietal): alexia, acalculia, finger agnosia and right-left disorientation
Brain lesions
Gross anatomy
Occipital lobe lesions
homonymous hemianopia (with macula sparing)
cortical blindness
visual agnosia
Brain lesions
Gross anatomy
Temporal lobe lesions
Wernicke’s aphasia: this area ‘forms’ the speech before ‘sending it’ to Brocas area. Lesions result in word substituion, neologisms but speech remains fluent
superior homonymous quadrantanopia
auditory agnosia
prosopagnosia (difficulty recognising faces)
Brain lesions
Gross anatomy
Frontal lobe lesions
expressive (Broca's) aphasia: located on the posterior aspect of the frontal lobe, in the inferior frontal gyrus. Speech is non-fluent, laboured, and halting disinhibition perseveration anosmia inability to generate a list
Brain lesions
Gross anatomy
Cerebellar lesions
midline lesions: gait and truncal ataxia
hemisphere lesions: intention tremor, past pointing, dysdiadokinesis, nystagmus
Brain lesions
Medial thalamus and mammillary bodies of the hypothalamus
Wernicke’s and Korsakoff’s
Brain lesions
Subthalamic nucleus of the basal ganglia
Hemiballism (coarse, violent, wide amplitude movements, ipsilateral arm and leg).
Brain lesions
Striatum (caudate nucleus) of the basal ganglia
Huntington’s Chorea
Brain Lesions
Substantia nigra of the basal ganglia
Parkinson’s disease
Brain lesions
Amygdala
Kluver-Bucy syndrome (hypersexuality, hyperorality, hyperphagia, visual agnosia
What is Friedreich’s ataxia?
Friedreich’s ataxia is the most common of the early-onset hereditary ataxias. It is an autosomal recessive, trinucleotide repeat disorder characterised by a GAA repeat in the X25 gene on chromosome 9 (frataxin). Friedreich’s ataxia is unusual amongst trinucleotide repeat disorders in not demonstrating the phenomenon of anticipation.
The typical age of onset is 10-15 years old. Gait ataxia and kyphoscoliosis are the most common presenting features.
Neurological features of Friedreich’s ataxia
absent ankle jerks/extensor plantars
cerebellar ataxia
optic atrophy
spinocerebellar tract degeneration
Other features of Friedreich’s ataxia
hypertrophic obstructive cardiomyopathy (90%, most common cause of death) diabetes mellitus (10-20%) high-arched palate
uses of carbamazepine
focal seizures - epilepsy
trigeminal neuralgia
bipolar disordre
Mechanism of action - carbamazepine
binds to sodium channels to increase their refractory period
Side effects of carbamazepine
P450 enzyme inducer dizziness and ataxia drowsiness headache visual disturbances (especially diplopia) Steven-Johnson syndrome leucopenia and agranulocytosis hyponatraemia secondary to syndrome of inappropriate ADH secretion
Carbamazepine is known to exhibit autoinduction, hence when patients start carbamazepine they may see a return of seizures after 3-4 weeks of treatment.
Stroke symptoms
anterior cerebral artery
Contralateral hemiparesis and sensory loss, lower extremity > upper
Stroke symptoms
middle cerebral artery
Contralateral hemiparesis and sensory loss, upper extremity > lower
Contralateral homonymous hemianopia
Aphasia
Stroke symptoms
posterior cerebral artery
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
Stroke symptoms
Weber’s syndrome (branches of the posterior cerebral artery that supply the midbrain)
Ipsilateral CN III palsy
Contralateral weakness of upper and lower extremity
Stroke Symptoms
Posterior inferior cerebellar artery (lateral medullary syndrome, Wallenberg syndrome)
Ipsilateral: facial pain and temperature loss
Contralateral: limb/torso pain and temperature loss
Ataxia, nystagmus
Stroke Symptoms
Anterior inferior cerebellar artery (lateral pontine syndrome)
Symptoms are similar to Wallenberg’s (see above), but:
Ipsilateral: facial paralysis and deafness
Stroke symptoms
retinal/ ophthalmic artery
amaurosis fugax
Stroke symptoms
Basilar artery
Locked in syndrome
Stroke symptoms
Lacunar infarcts
present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia
strong association with hypertension
common sites include the basal ganglia, thalamus and internal capsule
Tuberous sclerosis
Autosomal dominant
Like neurofibromatosis, the majority of features seen in TS are neurocutaneous
Cutaneous features of tuberous sclerosis
depigmented ‘ash-leaf’ spots which fluoresce under UV light
roughened patches of skin over lumbar spine (Shagreen patches)
adenoma sebaceum (angiofibromas): butterfly distribution over nose
fibromata beneath nails (subungual fibromata)
café-au-lait spots* may be seen
Neurological features of tuberous sclerosis
developmental delay
epilepsy (infantile spasms or partial)
intellectual impairment
Other features of tuberous sclerosis
retinal hamartomas: dense white areas on retina (phakomata)
rhabdomyomas of the heart
gliomatous changes can occur in the brain lesions
polycystic kidneys, renal angiomyolipomata
lymphangioleiomyomatosis: multiple lung cysts
Sensory lesions of the spinal cord
Neurosyphilis
affects the dorsal columns
loss of vibration and proprioception
Motor lesions of the spinal cord
ALS/MND
affects both upper (corticospinal tracts) and lower motor neurons
results in a combination of upper and lower motor neuron signs
Motor lesions of the spinal cord
Polio
affects anterior horns resulting in lower motor neuron signs
Combined motor and sensory lesions of the spinal cord
Brown-Sequard syndrome (spinal cord hemisection)
Which tracts
- Lateral corticospinal tract
- Dorsal columns
- Lateral spinothalamic tract
Combined motor and sensory lesions of the spinal cord
Brown-Sequard syndrome (spinal cord hemisection)
Clinical notes
- Ipsilateral spastic paresis below lesion
- Ipsilateral loss of proprioception and vibration sensation
- Contralateral loss of pain and temperature sensation
Combined motor and sensory lesions of the spinal cord
Subacute combined degeneration of the spinal cord (vitamin B12 & E deficiency)
Which tracts
- Lateral corticospinal tracts
- Dorsal columns
- Spinocerebellar tracts
Combined motor and sensory lesions of the spinal cord
Subacute combined degeneration of the spinal cord (vitamin B12 & E deficiency)
Clinical notes
- Bilateral spastic paresis
- Bilateral loss of proprioception and vibration sensation
- Bilateral limb ataxia
Combined motor and sensory lesions of the spinal cord
Friedreichs ataxia
Which tracts
- Lateral corticospinal tracts
- Dorsal columns
- Spinocerebellar tracts
Combined motor and sensory lesions of the spinal cord
Friedreichs ataxia
Clinical notes
- Bilateral spastic paresis
- Bilateral loss of proprioception and vibration sensation
- Bilateral limb ataxia
In addition cerebellar ataxia → other features e.g. intention tremor
Combined motor and sensory lesions of the spinal cord
Anterior spinal artery occlusion
which tracts
- Lateral corticospinal tracts
2. Lateral spinothalamic tracts
Combined motor and sensory lesions of the spinal cord
Anterior spinal artery occlusion
Clinical notes
- Bilateral spastic paresis
2. Bilateral loss of pain and temperature sensation
Combined motor and sensory lesions of the spinal cord
Syringomelia
Which tracts
- Ventral horns
2. Lateral spinothalamic tract
Combined motor and sensory lesions of the spinal cord
Syringomelia
Clinical notes
- Flacid paresis (typically affecting the intrinsic hand muscles)
- Loss of pain and temperature sensation
Combined motor and sensory lesions of the spinal tract
MS
Which tracts
Asymmetrical, varying spinal tracts involved
Combined motor and sensory lesions of the spinal tract
MS
Clinical notes
Combination of motor, sensory and ataxia symptoms
Motor and descending tracts
pyrimadal tracts
Lateral corticospinal tracts
anterior corticospinal tracts
Motor and descending tracts
Extrapyrimidal tracts
rubrospinal tracts
reticulospinal tracts
olivospinal tracts
vestibular spinal tracts
Sensory and ascending tracts
Dorsal column medial lemniscus system
Grascile fasciculus
Cuneate fasciculus
Sensory and ascending tracts
Spinocerebellar tracts
posterior spinocerebellar tracts
anterior spinocerebellar tracts
Sensory and ascending tracts
Anterolateral tracts
anterior spinothalamic tracts
lateral spinothalamic tracts
spino-oliviary tract
Bitemporal hemianopia
lesion of optic chiasm
upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour
lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma
Homonymous quadrantanopias
superior: lesion of the inferior optic radiations in the temporal lobe (Meyer’s loop)
inferior: lesion of the superior optic radiations in the parietal lobe
mnemonic = PITS (Parietal-Inferior, Temporal-Superior)
homonymous hemianopia
incongruous defects: lesion of optic tract
congruous defects: lesion of optic radiation or occipital cortex
macula sparing: lesion of occipital cortex
what are congruent visual defects
A congruous defect simply means complete or symmetrical visual field loss and conversely an incongruous defect is incomplete or asymmetric.
incongruous defects = optic tract lesion;
congruous defects = optic radiation lesion or occipital cortex
Key features of myasthenia gravis
The key feature is muscle fatigability - muscles become progressively weaker during periods of activity and slowly improve after periods of rest:
extraocular muscle weakness: diplopia
proximal muscle weakness: face, neck, limb girdle
ptosis
dysphagia
Associations with myasthenia gravis
thymomas in 15%
autoimmune disorders: pernicious anaemia, autoimmune thyroid disorders, rheumatoid, SLE
thymic hyperplasia in 50-70%
Investigations of myasthenia gravis
single fibre electromyography: high sensitivity (92-100%)
CT thorax to exclude thymoma
CK normal
autoantibodies: around 85-90% of patients have antibodies to acetylcholine receptors. In the remaining patients, about about 40% are positive for anti-muscle-specific tyrosine kinase antibodies
Tensilon test: IV edrophonium reduces muscle weakness temporarily - not commonly used any more due to the risk of cardiac arrhythmia
Management of myasthenia gravis
long-acting acetylcholinesterase inhibitors
pyridostigmine is first-line
immunosuppression:
prednisolone initially
azathioprine, cyclosporine, mycophenolate mofetil may also be used
thymectomy
Management of myasthenic crisis
plasmapheresis
intravenous immunoglobulins
Pharmacology of triptans
Triptans are specific 5-HT1B and 5-HT1D agonists used in the acute treatment of migraine. They are generally used first-line in combination therapy with an NSAID or paracetamol.
_ take after the onset of headache, not aura
adverse effects of triptans
‘triptan sensations’ - tingling, heat, tightness (e.g. throat and chest), heaviness, pressure
triptan contraindications
patients with a history of, or significant risk factors for, ischaemic heart disease or cerebrovascular disease
What is restless leg syndrome
Restless legs syndrome (RLS) is a syndrome of spontaneous, continuous lower limb movements that may be associated with paraesthesia. It is extremely common, affecting between 2-10% of the general population. Males and females are equally affected and a family history may be present
Features of restless leg syndrome
uncontrollable urge to move legs (akathisia). Symptoms initially occur at night but as condition progresses may occur during the day. Symptoms are worse at rest
paraesthesias e.g. ‘crawling’ or ‘throbbing’ sensations
movements during sleep may be noted by the partner - periodic limb movements of sleeps (PLMS)
Causes and associations of restless leg syndrome
there is a positive family history in 50% of patients with idiopathic RLS iron deficiency anaemia uraemia diabetes mellitus pregnancy
Management of restless leg syndrome
there is a positive family history in 50% of patients with idiopathic RLS iron deficiency anaemia uraemia diabetes mellitus pregnancy
Features of von-Hippel Lindau
cerebellar haemangiomas: these can cause subarachnoid haemorrhages
retinal haemangiomas: vitreous haemorrhage
renal cysts (premalignant)
phaeochromocytoma
extra-renal cysts: epididymal, pancreatic, hepatic
endolymphatic sac tumours
clear-cell renal cell carcinoma
Vestibular neuritis
a 30-year-old woman who is recovering from an upper respiratory tract infections presents with recurrent attacks of vertigo associated with nausea and vomiting. There is no hearing loss or tinnitus
Viral labyrinthitis
e.g. Hx
a 30-year-old woman who has recently developed an upper respiratory tract infection presents with vertigo and vomiting. Her hearing is also affected. The symptoms came on suddenly this morning
Viral labyrinthitis
Recent viral infection
Sudden onset
Nausea and vomiting
Hearing may be affected
Vestibular neuritis
Recent viral infection
Recurrent vertigo attacks lasting hours or days
No hearing loss
Acoustic neuroma
Hearing loss, vertigo, tinnitus
Absent corneal reflex is important sign
Associated with neurofibromatosis type 2
Vertebrobasilar ischaemia
Elderly patient
Dizziness on extension of neck
Meniere’s disease
Associated with hearing loss, tinnitus and sensation of fullness or pressure in one or both ears
Benign paroxysmal positional vertigo
Gradual onset
Triggered by change in head position
Each episode lasts 10-20 seconds
becker muscular dystrophy
develops after the age of 10 years
intellectual impairment much less common
non-frameshift insertion in the dystrophin gene resulting in both binding sites being preserved leading to a milder form
Duchene muscular dystrophy
progressive proximal muscle weakness from 5 years
calf pseudohypertrophy
Gower’s sign: child uses arms to stand up from a squatted position
30% of patients have intellectual impairment
there is a frameshift mutation resulting in one or both of the binding sites are lost leading to a severe form
Dystrophinopathies
X-linked recessive
due to mutation in the gene encoding dystrophin, dystrophin gene on Xp21
dystrophin is part of a large membrane associated protein in muscle which connects the muscle membrane to actin, part of the muscle cytoskeleto
Stereotypical history of Becker’s dystrophy
onset > 10 years old, pseudohypertrophy of calf muscles, trouble standing from sitting, no learning disability
Presenting features of Freidreich’s ataxia
typical age of onset is 10-15 years old. Gait ataxia and kyphoscoliosis are the most common presenting features.
History of posterior cerebral artery stroke eye symptoms
contralateral homonymous hemianopia with macular sparing and visual agnosia
History of middle cerebral artery stroke
contralateral hemiparesis and sensory loss with the upper extremity being more affected than the lower, contralateral homonymous hemianopia and aphasia
Von Hipple lindau chromosome
Chromosome 3
Typical history of MS
conjugate horizonal gaze palsy, nystagmus in abducting eye
lethargy, optic neuritis, paraesthesia, spastic weakness
Examples of 5-HT3 antagonists
ondansetron
granisetron
What are 5-HT3 antagonists
5-HT3 antagonists are antiemetics used mainly in the management of chemotherapy-related nausea. They mainly act in the chemoreceptor trigger zone area of the medulla oblongata.
Side effects of 5-HT3 antagonists
Constipation
QT prolongation
Non-neurological associations with Friedreich’s ataxia
hypertrophic obstructive cardiomyopathy (90%, most common cause of death) diabetes mellitus (10-20%) high-arched palate
Kluver-Bucy syndrome: stereotypical history
a man who has recently been treated for herpes simplex encephalitis presents with a sudden increase in appetite and sexual desire
Edrophonium
readily reversible acetylcholinesterase inhibitor. It prevents breakdown of the neurotransmitter acetylcholine and acts by competitively inhibiting the enzyme acetylcholinesterase, mainly at the neuromuscular junction
What is ataxic telangiectasia
Ataxia telangiectasia is an autosomal recessive disorder caused by a defect in the ATM gene which encodes for DNA repair enzymes. It is one of the inherited combined immunodeficiency disorders. It typically presents in early childhood with abnormal movements.
Features of ataxic telangiectasia
cerebellar ataxia
telangiectasia (spider angiomas)
IgA deficiency resulting in recurrent chest infections
10% risk of developing malignancy, lymphoma or leukaemia, but also non-lymphoid tumours
Stereotypical history of Branchial cyst
a 20-year-old presents with a painless swelling on the lateral aspect of the neck. On examination it is smooth, non-tender and fluctuant
What is a branchial cyst
An oval, mobile cystic mass that develops between the sternocleidomastoid muscle and the pharynx
Develop due to failure of obliteration of the second branchial cleft in embryonic development
Usually present in early adulthood
What is a cervical rib
More common in adult females
Around 10% develop thoracic outlet syndrome
Cystic hygroma
A congenital lymphatic lesion (lymphangioma) typically found in the neck, classically on the left side
Most are evident at birth, around 90% present before 2 years of age
Pharyngeal pouch
More common in older men
Represents a posteromedial herniation between thyropharyngeus and cricopharyngeus muscles
Usually not seen but if large then a midline lump in the neck that gurgles on palpation
Typical symptoms are dysphagia, regurgitation, aspiration and chronic cough
Thyroglossal cyst
More common in patients < 20 years old
Usually midline, between the isthmus of the thyroid and the hyoid bone
Moves upwards with protrusion of the tongue
May be painful if infected
Idiosyncratic side effects of phenytoin
fever rashes, including severe reactions such as toxic epidermal necrolysis hepatitis Dupuytren's contracture* aplastic anaemia drug-induced lupus
Acute side effects of phenytoin
initially: dizziness, diplopia, nystagmus, slurred speech, ataxia
later: confusion, seizures
Chronic side effects of phenytoin
common: gingival hyperplasia (secondary to increased expression of platelet derived growth factor, PDGF), hirsutism, coarsening of facial features, drowsiness
megaloblastic anaemia (secondary to altered folate metabolism)
peripheral neuropathy
enhanced vitamin D metabolism causing osteomalacia
lymphadenopathy
dyskinesia
Ethosuximide
Ethosuximide is an antiepileptic that is particularly indicated in patients with absence seizures
blocks T-type calcium channels in thalamic neurons
Riluzole- used in management of Amyotrophic lateral scelosis
prevents stimulation of glutamate receptors
used mainly in amyotrophic lateral sclerosis
prolongs life by about 3 months
BIPAP at night - prolongs life by approx 7 months
Side effects of lamotrigine
Stevens-Johnston syndrome
Stereotypical history of mytonic dystrophy
a 25-year-old man with muscle weakness is reviewed in clinic. On shaking his hand he has difficultly loosening his grip. On examination he has frontal balding, bilateral ptosis and cataracts
What is myotonic dystrophy
Myotonic dystrophy (also called dystrophia myotonica) is an inherited myopathy with features developing at around 20-30 years old. It affects skeletal, cardiac and smooth muscle. There are two main types of myotonic dystrophy, DM1 and DM2.
Genetics of myotonic dystrophy
autosomal dominant
a trinucleotide repeat disorder
DM1 is caused by a CTG repeat at the end of the DMPK (Dystrophia Myotonica-Protein Kinase) gene on chromosome 19
DM2 is caused by a repeat expansion of the ZNF9 gene on chromosome 3
Myotonic dystrophy DM 2
- ZNF9 gene on chromosome 3
- Proximal weakness more prominent
- Severe congenital form not seen
Myotonic dystrophy DM1
DM1 DM2
- DMPK gene on chromosome 19
- Distal weakness more prominent
General features of myotonic dystrophy
myotonic facies (long, 'haggard' appearance) frontal balding bilateral ptosis cataracts dysarthria
Other features of myotonic dystrophy
myotonia (tonic spasm of muscle)
weakness of arms and legs (distal initially)
mild mental impairment
diabetes mellitus
testicular atrophy
cardiac involvement: heart block, cardiomyopathy
dysphagia
Treatment of SAH
- coil aneurysms
- strict bed rest and BP control
- Vasospasm is prevented using a 21-day course of nimodipine (a calcium channel inhibitor targeting the brain vasculature) and treated with hypervolaemia, induced-hypertension and haemodilution**
Complications of SAH
Re-bleeding
Vasospasm (also termed delayed cerebral ischaemia), typically 7-14 days after onset
Hyponatraemia (most typically due to syndrome inappropriate anti-diuretic hormone (SIADH))
Seizures
Hydrocephalus
Death
Chromosome for neurofibromatosis type 1
Chromosome 17
Chromosome for neurofibromatosis type 2
Chromosome 22
Conductive hearing loss
Rinne’s test Bone conduction > air conduction in affected ear
Air conduction > bone conduction in unaffected ear Webber’s- Lateralises to affected ear
Sensorineural hearing loss
Rinne’s test- Air conduction > bone conduction bilaterally
Webber’s test - Lateralises to unaffected ear
Stereotypical history of cavernous sinus thrombus
a young man presents with an acute headache associated with unilateral periorbital edema. On examination there is a lateral gaze palsy
Features of cavernous sinus thrombus
headache (may be sudden onset)
nausea & vomiting,
cavernous sinus syndrome: local infection (e.g. sinusitis), neoplasia, trauma
periorbital oedema
ophthalmoplegia: 6th nerve damage typically occurs before 3rd & 4th
trigeminal nerve involvement may lead to hyperaesthesia of upper face and eye pain
central retinal vein thrombosis
Features of sagittal sinus thrombus
headache, vomiting
seizures and hemiplegia
parasagittal biparietal or bifrontal haemorrhagic infarctions are sometimes seen
lateral sinus thrombus features
6th and 7th cranial nerve palsies
benzhexol
antiparkinsonian agent of the antimuscarinic class
Stereotypical history of syringomelia
a 30-year-old man presents with progressive weakness of his hands. On examination you notice wasting of the small muscles of the hand. Also pain and temperature sensation is reduced but light touch is preserved.
What is syringomelia
a collection of cerebrospinal fluid within the spinal cord.
Syringobulbia
similar phenomenon to syringomyelia which there is a fluid-filled cavity within the medulla of the brainstem. This is often an extension of the syringomyelia but in rare cases can be an isolated finding.
Presentation of syringomelia
‘cape-like’ (neck and arms) loss of sensation to temperature but preservation of light touch, proprioception and vibration. spastic weakness (predominantly of the upper limbs), paraesthesia, neuropathic pain, upgoing plantars and bowel and bladder dysfunction. Scoliosis in long term
selegiline
MOAB used to treat parkinsons
Stereotypical history of normal pressure hydrocephalus
an elderly man presents with gradual worsening dementia and bradyphrenia associated with a slow, shuffling gait. He has also recently suffered with urinary incontinence
Stereotypical history of multisystem atrophy
an elderly man presents with parkinsonism atonic bladder, postural hypotension and cerebellar signs
Stereotypical history of conduction aphasia
a patient is noted to speak fluently but have difficulty repeating phrases. He is aware of the errors he is making and comprehension remains normal
Stereotypical history of Wernicke’s aphasia
a patient is noted to speak fluently but makes little sense with mulitple word substitutions and neologisms. He also has difficulty understanding what people are saying to him
Features of parietal lobe lesions
sensory inattention apraxias astereognosis (tactile agnosia) inferior homonymous quadrantanopia Gerstmann's syndrome (lesion of dominant parietal): alexia, acalculia, finger agnosia and right-left disorientation
stereotypical history of posterior inferior cerebellar artery stroke
sudden onset vertigo and vomiting, dysphagia, ipsilateral facial pain and temperature loss, contralateral limb pain and temperature loss and ataxia
Stereotypical history of anterior inferior cerebellar artery stroke
sudden onset vertigo and vomiting, ipsilateral facial paralysis and deafness
Features of neuroleptic malignant syndrome
pyrexia muscle rigidity autonomic lability: typical features include hypertension, tachycardia and tachypnoea agitated delirium with confusion AKI secondary to raised CK
Management of neuroleptic malignant syndrome
stop antipsychotic patients should be transferred to a medical ward if they are on a psychiatric ward and often they are nursed in intensive care units IV fluids to prevent renal failure dantrolene bromocriptine
Features of Meniere’s disease
recurrent episodes of vertigo, tinnitus and hearing loss (sensorineural). Vertigo is usually the prominent symptom
a sensation of aural fullness or pressure is now recognised as being common
other features include nystagmus and a positive Romberg test
episodes last minutes to hours
typically symptoms are unilateral but bilateral symptoms may develop after a number of years
Natural history of Meniere’s disease
symptoms resolve in the majority of patients after 5-10 years
the majority of patients will be left with a degree of hearing loss
psychological distress is common
Investigation of Meniere’s disease
ENT assessment is required to confirm the diagnosis
patients should inform the DVLA. The current advice is to cease driving until satisfactory control of symptoms is achieved
acute attacks: buccal or intramuscular prochlorperazine. Admission is sometimes required
prevention: betahistine and vestibular rehabilitation exercises may be of benefit
Features of CJD
dementia (rapid onset)
myoclonus
Investigations of CJD
CSF is usually normal
EEG: biphasic, high amplitude sharp waves (only in sporadic CJD)
MRI: hyperintense signals in the basal ganglia and thalamus
Sporadic CJD
accounts for 85% of cases
10-15% of cases are familial
mean age of onset is 65 years
New variant CJD
younger patients (average age of onset = 25 years)
psychological symptoms such as anxiety, withdrawal and dysphonia are the most common presenting features
the ‘prion protein’ is encoded on chromosome 20 - it’s role is not yet understood
methionine homozygosity at codon 129 of the prion protein is a risk factor for developing CJD - all patients who have so far died have had this
median survival = 13 months
Reye’s syndrome
Reye’s syndrome is a severe, progressive encephalopathy affecting children that is accompanied by fatty infiltration of the liver, kidneys and pancreas. The aetiology of Reye’s syndrome is not fully understood although there is a known association with aspirin use and a viral cause has been postulated
Features of Reye’s syndrome
The peak incidence is 2 years of age, features include:
there may be a history of preceding viral illness
encephalopathy: confusion, seizures, cerebral oedema, coma
fatty infiltration of the liver, kidneys and pancreas
hypoglycaemia
Stereotypical history of cluster headaches
a male smoker presents with recurrent episodes of severe pain around one eye which typical lasts around 1 hour. These episodes have occured daily for the past 6 weeks and are associated with ocular erythema and lacrimatio
Features of cluster headaches
pain typical occurs once or twice a day, each episode lasting 15 mins - 2 hours
clusters typically last 4-12 weeks
intense sharp, stabbing pain around one eye (recurrent attacks ‘always’ affect same side)
patient is restless and agitated during an attack
accompanied by redness, lacrimation, lid swelling
nasal stuffiness
miosis and ptosis in a minority
Management of cluster headaches
acute: 100% oxygen (80% response rate within 15 minutes), subcutaneous triptan (75% response rate within 15 minutes)
prophylaxis: verapamil is the drug of choice. There is also some evidence to support a tapering dose of prednisolone
stereotypical history of freidreich’s ataxia
a teenage boy presents with clumsy walking. On examination he has gait ataxia, an intention tremor and loss of lower limb reflexes
Pathophysiology of Lambert-Eaton syndrome
Lambert-Eaton myasthenic syndrome is seen in association with small cell lung cancer and to a lesser extent breast and ovarian cancer. It may also occur independently as an autoimmune disorder. Lambert-Eaton myasthenic syndrome is caused by an antibody directed against presynaptic voltage-gated calcium channel in the peripheral nervous system.
Features of Lambert-Eaton Syndrome
repeated muscle contractions lead to increased muscle strength (in contrast to myasthenia gravis)
in reality, this is seen in only 50% of patients and following prolonged muscle use muscle strength will eventually decrease
limb-girdle weakness (affects lower limbs first)
hyporeflexia
autonomic symptoms: dry mouth, impotence, difficulty micturating
ophthalmoplegia and ptosis not commonly a feature (unlike in myasthenia gravis)
Kluver-Bucy syndrome
hypersexuality, hyperorality, hyperphagia, visual agnosia
disease of the amygdala
Features of Ramsay Hunt syndrome
auricular pain is often the first feature
facial nerve palsy
vesicular rash around the ear
other features include vertigo and tinnitus
What is Ramsay Hunt syndrome
Ramsay Hunt syndrome (herpes zoster oticus) is caused by the reactivation of the varicella zoster virus in the geniculate ganglion of the seventh cranial nerve.
Management of Ramsay Hunt Syndrome
oral aciclovir and corticosteroids are usually given
Stereotypical history of BPPV
a 55-year-old woman presents with recurrent episodes of vertigo that are often triggered by a change in head position. Each episode lasts around 10-20 seconds and is associated with nausea
sub acute combined degeneration of the spinal cord
due to vitamin B12 deficiency
dorsal columns + lateral corticospinal tracts are affected
joint position and vibration sense lost first then distal paraesthesia
upper motor neuron signs typically develop in the legs, classically extensor plantars, brisk knee reflexes, absent ankle jerks
if untreated stiffness and weakness persist
Complications of SAH (aneurysmal)
Re-bleeding Vasospasm (also termed delayed cerebral ischaemia), typically 7-14 days after onset Hyponatraemia (SIADH) Seizures Hydrocephalus Death
Klumpke’s palsy (claw hand)
traction or tear of the lower trunk of the brachial plexus (C8 to T1)
wasting of intrinsic hand muscles and flexion deformities of the proximal interphalangeal (PIP) & distal interphalangeal (DIP) joints.
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL)
rare cause of multi-infarct dementia
patients often present with migraine
Causes of gingival hyperplasia
phenytoin
ciclosporin
calcium channel blockers (especially nifedipine)
Normal pressure hydrocephalus
urinary incontinence
dementia and bradyphrenia
gait abnormality (may be similar to Parkinson’s disease)
Lambert-Eaton myasthenic syndrome
associated with small cell lung cancer (also breast and ovarian)
antibody directed against pre-synaptic voltage gated calcium channel in the peripheral nervous system
can also occur independently as autoimmune disorde
Lambert-Eaton myasthenic syndrome
associated with small cell lung cancer (also breast and ovarian)
antibody directed against pre-synaptic voltage gated calcium channel in the peripheral nervous system
can also occur independently as autoimmune disorder
Anti-Hu
associated with small cell lung carcinoma and neuroblastomas
sensory neuropathy - may be painful
cerebellar syndrome
encephalomyelitis
Anti-Yo
associated with ovarian and breast cancer
cerebellar syndrome
Anti-GAD antibody
associated with breast, colorectal and small cell lung carcinoma
stiff person’s syndrome or diffuse hypertonia
Anti- Ri
associated with breast and small cell lung carcinoma
ocular opsoclonus-myoclonus
Purkinje cell antibody
peripheral neuropathy in breast cancer
hemiballismus
type of chorea which is caused by a decreased activity in the subthalamic nucleus of the basal ganglia in most case
Wernicke’s area
Brodmann area 22 in the superior temporal gyrus
