Neuro 7.5 Flashcards
Causes of raised ICP
Vascular (aneurysm, AV malformation, SDH, IVH, sinus thrombosis)
Infective (abscess, meningitis, encephalitis)
Traumatic
Iatrogenic (some meds, post-surgical)
Idiopathic intracranial HTN
Neoplasia/Tumour
Degenerative
Examples & adverse effect of 5-HT3 antagonists?
- ondansetron & granisetron
- antiemetics usually used in chemo-related nausea
- mainly act in chemoreceptor trigger zone in medulla oblongata
- constipation is common
Features of absence seizures?
EEG?
Rx?
- form of generalised epilepsy mostly seen in childrenm typical onset 3-10yrs girls 2x boys
- absences last a few seconds, ass with a quick recovery
- may be provoked by hyperventilation/stress
- child usually unaware of the seizure, may occur many times/day
EEG: bilateral, symmetrical 3Hz spike & wave pattern
Rx: sodium valproate & ethosuximide 1st line
- good prognosis
Features & Rx of acute confusional state?
- fluctuating
- memory disturbances, loss of short>long term
- disorientation
- agitated/withdrawn
- mood change
- visual hallucinations
- disturbed sleep cycle
- poor attention
Rx underlying cause, modify environment
- 1st line sedative is haloperidol
What is acute disseminated encephalomyelitis?
What are the features
What might MRI show?
Rx?
ADEM: autoimmune demyelinating disease of CNS
- aka post-infectious encephalomyelitis
- e.g. measles, mumps, rubella, varicella, small pox
- acute onset of multifocal neuro Sx with rapid deterioration after a lag time of few days - 2months
- headache, fever, nausea, vomiting
- motor & sensory deficits
- amy also be brainstem involvement inc oculomotor defects
- MRI: may show areas of supra & infra-tentorial demyelination
- Rx: IV glucocorticoids, consider IV Ig when this fails
Genetics of Alzheimer’s disease?
- most sporadic, 5% autosomal dominant
- mutations can occur in the amyloid precursor protein (chr 21), presenilin 1 (chr 14) & presenilin 2 (chr 1) in inherited form
- apoprotein E allele E4 - encodes a cholesterol transport protein
Pathological changes in Alzheimer’s disease:
- macroscopic?
- microscopic?
- biochemical?
Macro: widespread cerebral atrophy esp involving the cortex & hippocampus
Micro: cortical plaques due to deposition of type A-beta-amyloid protein & intraneuronal neurofibrillary tangle caused by abnormal aggregation of the tau protein
Biochemical: Acetylcholine deficit from damage to an ascending forebrain projection
What are neurofibrillary tangles in Alzheimer’s disease?
- paired helical filaments that are partly made from a tau protein - abnormal aggregation of tau protein as they are excessively phosphorylated
Drug Rx in Alzheimer’s disease:
if mild-moderate?
Acetylcholinesterase inhibitors
e.g. donepezil, galantamine, rivastigmine
Drug Rx in Alzheimer’s disease:
2nd line if 1st line intolerant or a C/I or as an add-on if moderate-severe or as mono therapy in severe disease?
NMDA receptor antagonist: Memantine
What is Anti-NMDA receptor encephalitis? How does it present? What tumours are detected in nearly half of female adult patients? What may be shown on MRI? What may be shown in the CSF? How can it be treated?
A paraneoplastic syndrome, presenting as prominent psychiatric features e.g.: agitation, hallucinations, delusions & disordered thinking, seizures, insomnia, dyskinesias & autonomic instability
Ovarian teratomas in females, esp Afro-C
MRI head normal or: abnormalities can be visualised on FLAIR sequences in the deep subcortical limbic structures
CSF: pleiocytosis (high lymphocytes), but can be normal initially
Rx: immunosuppression with IV steroids, Ig, rituximab, cyclophosphamide or plasma exchange
Resection of teratoma can also be therapeutic
Anti-MuSK is an autoAb specific to what?
specific to muscle kinase in myasthenia graves with no evidence of a thymoma and without Ab to acetylcholine receptors
Anti-GM1 is an autoAb specific to what?
AIDP: acute inflammatory demyelinating polyneuropathy, a variant of Guillain-Barre
Embryologically, what does the facial VIIth nerve supply?
efferents?
afferents?
What does it supply?
face ear taste tear
- the structures of the 2nd embryonic branchial arch
- efferent to muscles of facial expression, digastric muscle & also many glandular structures
- contains a few afferent fibres which originate in the cells of its genicular ganglion concerned with taste
face: muscles of facial expression
ear: nerve to stapedius
taste: anterior 2/3 tongue
tear: parasympathetic fibres to lacrimal glands, also salivary glands
Causes of a BL facial nerve palsy?
- Bell’s i.e. idiopathic
- sarcoidosis
- Lyme disease
- Guillain-Barre syndrome
- BL acoustic neuromas (NF type 2)
Causes of a unilateral lower motor neurone facial VIIth nerve palsy?
- Bell’s palsy
- Ramsay-Hunt (herpes zoster)
- acoustic neuroma
- parotic tumours
- HIV
- multiple sclerosis
- diabetes mellitus
What is the pass of the facial VIIth nerve:
Subarachoid origin?
Subarachnoid pathway?
Facial canal path?
What are the 3 branches?
And when it passes through the stylomastoid foramen?
Subarachnoid origin: - motor pons - sensory nervus intermedius Subarachnoid pathway: - through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear VIIIth nerve -> here the motor & sensory component combine to form the facial nerve
Facial canal path:
- the canal passes superior to the vestibule of the inner ear
- at the medial aspect of the middle ear -> becomes wider & contains the geniculate ganglion
Branches:
- greater petrosal nerve
- nerve to stapedius
- chora tympani
Stylomastoid foramen:
- it passes through this foramen (tympanic cavity anterior & mastoid antrum posteriorly)
- posterior auricular nerve & branch to posterior belly of digastric & stylohyoid muscle
Types of 1ry brain injury?
Focal:
- contusion (adjacent to i.e. coup or contralateral i.e. contra-coup to the side of impact)
- or haematoma - extradural/subdural/intracerebral
Diffuse: diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption & tearing of axons
Types of 2ry brain injury?
- i.e. when cerebral oedema, ischaemia, infection, tonsillar or tectorial herniation exacerbates the original injury
- the normal cerebral auto-regulatory processes are disrupted following trauma, rendering the brain more susceptible to blood flow changes & hypoxia
- Cuching’s reflex of hypertension & bradycardia, is late & pre-terminal
Acc-deceleration trauma or blow to head , with features of raised intracranial pressure and sometimes a lucid interval, involves what type of brain injury?
Can often be in the temporal region where a skull fracture can rupture which artery?
Extradural haematoma
- between dura mater & skull
- middle meningeal artery rupture
Brain injury with slower onset of Sx, most commonly occur around the frontal & parietal lobes?
What are the RFs?
Subdural haematoma
- outermost meningeal layer
- old age, alcoholism, anticoagulation
Sudden occipital headache of a brain injury, usually spontaneously in the context of a ruptures cerebral aneurysm or in ass with other injuries?
Subarachnoid haemorrhage
What is myasthenia gravis?
- autoimmune disorder resulting in insufficient functioning acetylecholine receptors
- Ab to Ach Rs seen in 85-90% of cases (less common in disease limited to ocular muscles)
- more common in women 2:1
What are the key features of myasthenia gravis?
What are the 3 associations?
Muscle fatigability - where they get progressively weaker during periods of activity, & slowly improve after periods of rest
- extraocular weakness: diplopia
- proximal weakness: face, neck, limb girdle
- ptosis
- dysphagia
Ass:
- thymomas 15%
- autoimmune disorders: pernicious anaemia, AI thyroid, rheumatoid, SLE
- thymic hyperplasia 50-79%
Ix in myasthenia gravis: what is the most sensitive? what scan is done to exclude a thymoma? which autoAb are present in most, & in the others? what is the Tensilon test?
Single fibre electromyography 92-100% sensitive
CT thorax to exclude thymoma
AutoAb: 85-90% have Ab to acetylcholine receptors - in the rest, 40% are positive for anti-muscle-specific tyrosine kinase Ab
Tensilon test: IV edrophonium reduces muscle weakness temporarily BUT has a risk of cardiac arrhythmia
Management of myasthenia gravis in the long-term (3)?
- Long-acting anticholinesterase e.g. Pyridostigmine
- Immunosuppression - initially pred
- Thymectomy
Rx of a myasthenic crisis?
- plasmapheresis
- IV immunoglobulins
What drugs may exacerbate myasthenia gravis?
- penicillamine
- quinidine, procainamide
- beta-blockers
- lithium
- phenytoin
- Abx: gentamicin, macrolides, quinolones, tetracyclines
When can anti-epileptic drugs be stopped & how?
If seizure-free for >2 years, can be stopped over 2–3months
When to start anti epileptics after the 1st seizure?
- neuro deficit
- structural abnormality on brain imaging
- EEG shows unequivocal epileptic activity
- pt/family/carers consider risk of having a further seizure unacceptable
1st line drug Rx for Focal/partial seizures?
2nd line?
Carbamazepine or Lamotrigine
2nd line: levetiracetam, oxcarbazepine, valproate
1st line drug Rx with generalised seizures?
sodium valproate
2nd line drug Rx in generalised tonic-clonic seizures?
Lamotrigine, Carbamazepine
1st & 2nd line drug Rx in generalised absence seizures?
1st: sodium valproate/ethosuximide
Valproate is particularly effective if co-existent tonic-clonic seizures in 1ry generalised epilepsy
(carbamazepine may actually exacerbate absence seizure)
2nd line drug rx in myoclonic seizures?
clonazepam or lamotrigine
1st line Rx of neuropathic pain?
2nd line what to do?
What can be used as rescue therapy for exacerbations?
What can be used for localised neuropathic pain?
1st: amitriptyline/duloxetine/pregabalin/gabapentin
2nd: try 1 of the other 3
Rescue: Tramadol
Localised: topical capsaicin
What is otosclerosis?
What are the features?
What is the Rx?
- replacement of normal bone by vascular spongy bone
- progressive conductive deafness due to fixation of the stapes at the oval window
- autosomal dominant, typically affecting young adults 20-40yrs onset
- conductive HL
- tinnitus
- normal tympanic membrane +/- flamingo tinge from hyperaemia 10%
- +ve FHx
Rx:
- hearing aid
- stapedectomy
Incongruous visual field defect - where is the lesion?
optic tract
Congruous (symmetrical) visual field defect - where is the lesion?
optic radiation or occipital cortex
Homonymous hemianopia with macular sparing - where is the lesion?
Occipital cortex
Superior homonymous quadrantanopia - where is the lesion?
Temporal lobe
Inferior homonymous quadrantanopia - where is the lesion?
Parietal lobe
Bitemporal hemianopia - where is the lesion?
Optic chiasm
Bitemporal hemianopia: upper quadrant defect > lower quadrant defect - where is the lesion?
Inferior chiasmal compression
= pituitary tumour
Bitemporal hemianopia: lower quadrant defect > upper quadrant defect - where is the lesion?
Superior chiasmal compression
= craniopharyngioma
Headache + fever
CT brain: Petechial haemorrhages in the temporal & inferior frontal lobes. No mass effect. Brain parenchyma otherwise normal
What is the Dx?
Herpes simplex encephalitis
think temporal lobe changes - HSV
Features & pathophysiology of herpes simplex encephalitis?
- fever, headache, psychiatric Sx, seizures, vomiting
- focal e.g. aphasia (temporal lobe features)
- HSV-1 responsible in 95%
- typically affects temporal & inferior frontal lobes
Ix in HSV encephalitis: CSF? confirm HSV? CT? what scan is better? EEG? Rx?
CSF: lymphocytosis, elevated protein
PCR for HSV
CT: medial temporal & inferior frontal changes e.g. petechial haemorrhages (but normal in 1/3)
MRI is better
EEG: lateralised periodic discharges at 2Hz
Rx: IV aciclovir
What is myotonic dystrophy?
What are the genetics?
- inherited myopathy with features developing 20-30yrs old
- affects skeletal, cardiac & smooth muscle
- autosomal dominant
- trinucleotide repeat disorder
2 types DM1 & DM2
Differences between DM1 & DM2 myotonic dystrophy?
DM1:
- CTG repeat at the end of the DMPK (dystrophia myotonic-protein kinase) gene on chromosome 19
- DISTAL weakness is more prominent
DM2:
- repeat expansion of the ZNF9 gene on chromosome 3
- PROXIMAL weakness more prominent
- severe congenital form not seen
General & other features of myotonic dystrophy?
General:
- myotonic facies (long, haggard)
- frontal balding
- BL ptosis
- cataracts
- dysarthria
Other:
- myotonia: tonic spasm of muscle
- weakness of arms & legs (distal initially)
- mild mental impairment
- diabetes mellitus
- testicular atrophy
- cardiac involvement, heart block, cardiomyopathy - prolonged PR interval in 20-40%
- dysphagia
What is ataxic telangiectasia?
What are the features?
- autosomal recessive disorder caused by a defect in the ATM gene encoding DNA repair enzymes
- inherited combined immunodeficiency disorder
- typically presents in early childhood with abnormal movements
Features:
- cerebellar ataxia
- telangiectasia (spider angiomas)
- IgA deficiency -> recurrent chest infections
- 10% risk of developing malignancy, lymphoma or leukaemia, but also non-lymphoid tumours
Drug causes of tinnitus?
Aspirin
Aminoglycosides
Loop diuretics
Quinine
Cause of tinnitus ass with: Associated with hearing loss, vertigo, tinnitus and sensation of fullness or pressure in one or both ears?
Meniere’s disease
Cause of tinnitus ass with: Hearing loss, vertigo, tinnitus?
- Absent corneal reflex is important sign
- Ass with neurofibromatosis type 2
Acoustic neuroma
Features of essential tremor?
Rx?
- autosomal dominant
- postural tremor worse if arms outstreched
- improved by etoh & rest
- most common cause of titibation (head tremor)
Rx Propranolol 1st
- sometimes primidone is used
Head injury criteria for immediate CT head?
- initial GCS < 13
- 2h post injury GCS < 15
- suspected open/depressed skull #
- any sign of a basal skull #
- post-traumatic seizure
- focal neurological deficit
- > 1 episode of vomiting
Head injury criteria for CT head within 8h of injury - for adults with which risk factors who have experinces some loss of consciousness or amnesia since injury?
- age 65+
- any Hx bleeding/clotting disorders
- dangerous mechanism of injury
- > 30mins retrograde amnesia of events immediately prior to injury
If a patient is on warfarin who have sustained a head injury with no other indications for a CT head scan, when should one be done?
Within 8hours
What is the characteristic pathological feature in Lewy body dementia?
Alpha-synuclein cytoplasmic inclusions (Lewy bodies) in the substantia nigra, paralimbic & neocortical areas
- N.b. upto 40% Alzheimer’s pts have lewy bodies
What durgs should be avoided in Lewy body dementia and why?
Neuroleptics e.g. haloeridol
- pts are v sensitive and may develop irreversible parkinsonism
What are the features of Lewy body dementia?
- Progressive cognitive impairment i.e. dementia
- Parkinsonism
- Visual hallucinations (delusions & non-visual hallucinations may also be seen)
Single best Dx Ix for Lewy body dementia?
SPECT/DaT scan
- radioisotope is dopaminergic
- sensitivity 90%, spec 100%
Rx of Lewy body dementia?
- Acetylcholinesterase inhibitors e.g. donepezil, rivastigmine & Memantine can be used as in Alzheimer’s
Wernicke’s aphasia -
what type of aphasia is it?
where is the lesion?
Receptive aphasia
- lesion of superior temporal gyrus
- impaired comprehension, word substitutions, nonsense, neologisms but fluent speech
Broca’s aphasia -
what type of aphasia is it?
where is the lesion?
Expressive aphasia
- lesion of inferior frontal gyrus
- supplied by middle cerebral artery
- normal comprehension but speech is non-fluent, laboured & halting
Conduction aphasia - where is the lesion?
What happens to speech?
- stroke affecting the arcuate fasiculus (connection between Wernicke’s & Broca’s area)
- normal comprehension, fluent speech but repetition is poor, aware of the errors they are making
What happens in global aphasia?
large lesion affecting all 3 areas of: superior temporal gyrus, inferior frontal gyrus & arcuate fasiculus, resulting in severe expressive & receptive aphasia
What is the MoA of triptans?
When should they be taken?
What are the adverse effects?
What are the C/I?
- 5-HT1 agonists
- in acute Rx of migraine: should be taken asap after onset of headache, rather than at onset of aura
- oral, orodispersible, nasal spray & SC injections
- ‘triptan sensations’ - tingling, heat, tightness, heaviness, pressure
- C/I: pts with a Hx/significant RFs for IHD or cerebrovascular disease
Acute Rx of migraine?
if young?
if not effective/not tolerated?
what do you need to be careful with with young people?
1st: combo triptan + nsaid/paracetamol
young 12-17yrs: NASAL triptan in preference
if above not effective/not tolerated offer a non-oral prep of metoclopramide/prochlorperazine & consider adding a non-oral NSAID/triptan
- caution metoclopramide in young people due to acute dystonic reactions
Migraine prophylaxis Rx:
when to give Rx?
what Rx?
if these measures fail?
what may be effective in reducing migraine frequency & intensity for some people?
what is better for women with predictable menstrual migraine for Rx?
- if 2+ attacks/month, effective in 60%
- Topiramate/Propranolol - preferred in women of childbearing age as may be teratogenic & can reduce efficacy of hormonal contraceptives
- if fails: course of acupuncture over 5-8wks or Gabapentin
- Riboflavin 400mg OD may be effective in reducing migraine frequency & intensity for some
- predictable menstrual migraine: Frovatriptan or Zolmitriptan as a mini-prophylaxis
What is pituitary apoplexy?
What are the features?
= sudden enlargement of pituitary tumour 2ry to haemorrhage/infarction
- sudden onset headache similar to SAH
- neck stiffness, vomiting
- visual field defects: classically bitemporal superior quadrantanopia defect
- extraocular nerve palsies
- features of pituitary insufficiency e.g. hypotension 2ry to hypoadrenalism
What features are seen in a parietal lobe lesion?
- sensory inattention
- apraxias
- astereogenesis (tactile agnosia)
- inferior homonymous quadrantanopia
- Gerstmann’s syndrome: alexia, acalculia, finger agnosia & R-L disorientation
Where is the lesion with features of:
- sensory inattention
- apraxias
- astereogenesis (tactile agnosia)
- inferior homonymous quadrantanopia
- Gerstmann’s syndrome: alexia, acalculia, finger agnosia & R-L disorientation??
Parietal lobe
What is Gerstmann’s syndrome?
Lesion of the dominant parietal lobe:
- alexia
- acalculia
- finger agnosia
- R-L disorientation
What are the features in an occipital lobe lesion?
- homonymous hemianopia (with macula sparing)
- cortical blindness
- visual agnosia
Where is the lesion with features of:
- homonymous hemianopia (with macula sparing)
- cortical blindness
- visual agnosia
Occipital lobe
What are the features of a temporal lobe lesion?
- Wernicke’s aphasia (receptive)
- superior homonymous quadrantanopia
- auditory agnosia
- prosopagnosia (difficulty recognising faces)
Where is the lesion with features of:
- Wernicke’s aphasia (expressive)
- superior homonymous quadrantanopia
- auditory agnosia
- prosopagnosia (difficulty recognising faces)
Temporal lobe lesion
What are the features of a frontal lobe lesion?
- Broca’s aphasia (expressive)
- disinhibition
- perseveration
- anosmia
- inability to generate a list
Where is the lesion with features of:
- Broca’s aphasia (expressive)
- disinhibition
- perseveration
- anosmia
- inability to generate a list
Frontal lobe
What are the features of a cerebellum lesion?
Midline lesion: gait & truncal ataxia
Hemisphere lesion: intention tremor, past pointing, dysdiadokinesis, nystagmus
Which area of the brain is associated with Wernicke & Korsakoff syndrome?
Medial thalamus & mammillary bodies of hypothalamus
Which area of the brain is associated with hemiballism?
involuntary, violent, coarse & wide-amplitude movements of the ipsilateral UL & LL
Subthalamic nucleus of the basal ganglia
Which part of the brain is associated with Huntington chorea?
Striatum (caudate nucleus) of the basal ganglia
Which part of the brain is associated with Parkinson’s disease?
Sunstantia nigra of the basal ganglia
Which part of the brain is associated with Kluber-Bucy syndrome: hyper sexuality, hypoerorality, hyperphagia & visual agnosia?
Amygdala
What is the genetics of Friedreich’s ataxia?
- commonest of the early-onset hereditary ataxias
- autosomal recessive, trinucleotide repeat disorder characterised by a GAA repeat in the X25 gene on chr 9 (frataxin)
- does not demonstrate anticipation
What are the most common presenting features of Friedreich’s ataxia?
- gait ataxia & kyphoscoliosis
- usually age 10-15 onset
Neurological features of Friedreich’s ataxia?
What are the other features?
- cerebellar ataxia
- absent ankle jerks/extensor planters
- optic atrophy
- spinocerebellar tract degeneration
- HOCM 90% (commonest cause of death)
- diabetes 10-20%
- high-arched palate/feet
What is neuroleptic malignant syndrome?
- rarely seen in those taking antipsychotics with mortality of 10% with atypicals
- can also occur with dopaminergic drugs e.g. levodopa, usually when suddenly stopped or dose reduced
Features of neuroleptic malignant syndrome?
Rx?
- more common in young males
- onset usually in first 10days of Rx or after increasing dose
- fever, rigidity, tachycardia
- raised CK & leukocytosis may be seen
- reduced reflexes
Rx:
- stop antipsychotic, IV fluids to prevent AKI
- DANTROLENE
- bromocriptine may also be used
Sodium valproate risk in pregnancy
neural tube defects
neurodevelopmental delay
- do not use in pregnancy OR childbearing age women unless clearly necessary
Carbamazepine risk in pregnancy?
least teratogenic of the older anti epileptics
Phenytoin risk in pregnancy
- ass with cleft palate
- give vitamin K in last month of pregnancy to prevent clotting disorders in the newborn
Lamotrigine risk in pregnancy
- dose may need to be increased in pregnancy
- rate of congenital malformations may be low
Anti epileptics when breastfeeding
- safe (except for barbiturates)
When is donepezil contra-indicated for Alzheimer’s?
Cardiac disease inc sick sinus syndrome, supra ventricular conduction abnormalities etc due to increased risk of bradycardia & AV node block
- after initiating, recheck pulse etc
- also C/I if severe hepatic impairment
What is the triad of normal pressure hydrocephalus?
- urinary incontinence
- dementia & bradyphrenia
- gait abnormality (may be similar to PD)
What is the cause of normal pressure hydrocephalus?
What is shown on imaging?
- 2ry to reduced CSF absorption at the arachnoid villi
- changes may be 2ry to head injury, SAH or meningitis
- hydrocephalus with an enlarged IVth ventricle
- also typically an absence of substantial sulcal atrophy
Rx of normal pressure hydrocephalus?
- ventriculoperitoneal shunting
- 10% with shunts experience significant complications e.g. seizures, infection & intracerebral haemorrhages
What is hemiballism?
Which part of the brain is damaged?
What happens during sleep?
Rx?
- involuntary, sudden, jerking movements contralateral to side of the lesion, 1rily affecting proximal limb musculature whilst detail muscles display more choreiform-like movements
- subthalamic mucleus
- Sx decrease whilst asleep
- antidopaminergic agents e.g. haloperidol
What is Erb-Duchenne palsy?
- damage to upper trunk of brachial plexus (C5, C6)
- arm hangs by the side, internally rotated, elbow extended, waiter’s tip
- may be 2ry to shoulder dystocia
What is Klumpke’s injury? (T1, due to traction)
- damage of lower trunk of brachial plexus (C8, T1)
- paralysis of all intrinsic hand muscles
- loss of sensation in medial aspect of hand & forearm
- may be caused by a sudden upward jerk of the hand, or should dystocia
- ass with Horner’s syndrome
What is the motor component of the long thoracic nerve, C5-C7?
What happens when damaged?
- serratus anterior
- winged scapula, e.g. sports injury or mastectomy complication
What is the motor & sensory components of the ulnar nerve C8-T1?
What happens if damaged?
M: all intrinsic hand muscles (except LOAF) & wrist flexion
S: medial 1.5 fingers
- e.g. medial epicondyle fracture leading to a claw hand
What is the motor component of the medial nerve C6, C8 & T1?
Sensory?
Lateral 2 lumbricals
Opponens pollis
Abductor pollis brevis
Flexor pollis brevis
S: palmar aspect of lateral 3.5 fingers
What happens in damage to the median nerve C6, C8, T1?
wrist lesion:
- carpal tunnel syndrome
- paralysis of thinner muscles, opponent pollicis
elbow: loss of pronation of forearm & weak wrist flexion
What is the motor & sensory component of the radial nerve C5-C8?
What happens with injury?
M: extension of forearm, wrist, fingers, thumb
S: small area between dorsal aspect of 1st & 2nd metacarpals
e.g. humeral midshaft fracture causing palsy results in wrist drop
What is the motor & sensory component of the axillary nerve C5-C6?
What happens with injury?
M: shoulder abduction (deltoid)
S: inferior region of deltoid muscle
e.g. humeral neck fracture/dislocation leads to flattened deltoid
What is the motor & sensory component of the musculocutaneous nerve C5-C7?
What happens with injury?
M: elbow flexion (biceps brachii) & supination
S: lateral part of forearm
- isolated injury is rare - usually injured as part of brachial plexus injury
Bitemporal hemianopia with headaches in children - what is commonest cause?
Craniopharyngioma: derived from Rathke’s pouch, often invades the pituitary & hypothalamus (often ventromedial area)
Which part of the hypothalamus is responsible for synthesis of ADH & oxytocin? (which are transported to posterior hypothalamus for storage & release)
supraoptic nucleus & paraventricular nucleus of hypothalamus
Which part of the hypothalamus is responsible for heat generation to maintain core body temperature?
posterior hypothalamus
Which part of the hypothalamus is responsible for heat dissipation to cool down the body to prevent a rise in temp which would be detrimental to body’s internal environment?
Anterior hypothalamus
Which part of the hypothalamus is often invaded by craniopharyngiomas? It also controls satiety centre & removed during the surgery -> leading to uninhibited hunger causing significant weight gain
Ventromedial area of hypothalamus
Dx of multiple sclerosis?
2+ relapses with objective clinical evidence 2+ lesions or 1 lesions with reasonable historical evidence of a previous relapse
i.e. lesions disseminated in time & space
Visual Sx/signs of multiple sclerosis? Motor? Sensory? Cerebellar? Other?
- optic neuritis, optic atrophy
- internuclear ophthalmoplegia
- Uhthoff’s phenomenon (worsening vision after rise in body temp)
- UMN signs: spastic weakness, usually legs
- pins, needles, numbness, trigeminal neuralgia
- Lhermitte’s: paraesthesia in limbs on neck flexion
- cerebellar ataxia (usually seen during acute relapse), tremor
- urinary incontinence
- sexual dysfunction
- intellectual deterioration
What is the eponymous name for when scratching of the inner side of leg leads to extension of the toes = a sign of cerebral irritation
Oppenheim’s sign
What are the RFs for degenerative cervical myelopathy DCM?
- smoking (effects on intervertebral discs)
- genetics
- occupation (exposure to high axial loading)
- Asian populations have a higher rate of ossification of the posterior longitudinal ligament (OPLL), which can result in myelopathy
DCM: degenerative cervical myelopathy
- early Sx often subtle & can vary in severity day to day, making the disease difficult to detect initially (Dx delayed)
- progressive, worsening, deteriorating or new Sx should be a warning sign
- what are the Sx?
- Pain (neck/UL/LL)
- loss of motor function (digital dexterity, gait & imbalance)
- loss of sensory function (numbness)
- loss of autonomic function (urinary/faecal incontinence/impotence - don’t necessarily suggest caudal equina)
Gold standard Ix for (degenerative) cervical myelopathy?
MRI - may reveal disc degeneration & ligament hypertrophy, with accompanying cord signal change
- urgent referral to neurosurgery
- timing of decompressive surgery v important (within 6months has best chance of recovery) - shown to prevent disease progression
What is Meniere’s disease?
What is the natural Hx?
- disorder of inner ear characterised by excessive pressure & progressive dilation of the endolymphatic system
- Sx resolve in majority after 5-10yrs but majority left with a degree of hearing loss
- psychological distress common
What are the features of Meniere’s disease?
Rx?
- recurrent episodes of vertigo, tinnitus & hearing loss (sensorineural) - vertigo is the prominent Sx
- sensation of aural fullness/pressure also common
- +/- nystagmus & +ive Romberg test
- episodes last mins-hours
- typically UL but BL can develop
What is herpes zoster ophthalmicus?
What are the features?
Complications?
- reactivation of the varicella zoster virus in the area supplied by the ophthalmic division of the trigeminal nerve
- 10% of shingles
- vesicular rash around the eye
- Hutchinson’s sign: rash on the tip/side of the nose - indicates nasociliary involvement & is a strong RF for ocular involvement
- ocular: conjunctivitis, keratitis, episcleritis, anterior uveitis
- ptosis
- post-herpetic neuralgia
What is Ramsay Hunt syndrome?
Features?
Rx?
= herpes zoster oticus, caused by the reactivation of the varicella zoster virus in the geniculate ganglion of the VOOth cranial nerve
- auricular pain often 1st
- facial nerve palsy
- vesicular rash around the ear
- vertigo, tinnitus
Rx: oral aciclovir, steroids
What is trigeminal neuralgia?
Pain syndrome of severe UL pain - majority idiopathic but compression of trigeminal roots by tumours/vascular problems may occur
- UL disorder characterised by brief electric shock-like pains, abrupt in onset & termination, limited to 1+ divisions of trigeminal nerve
- commonly evoked by light touch with trigger factors, frequently occurs spontaneously
- small areas in the nasolabial fold/chin q susceptible to triggers
- pain usually remits for variable periods
Rx for trigeminal neuralgia?
Carbamazepine
- refer to neurology if failure to respond to Rx or atypical features e.g. <50y.o.
When you suspect trigeminal neuralgia, what are red flag symptoms that may suggest an underlying cause?
- sensory changes
- deafness/other ear problems
- Hx of skin/oral lesions
- pain only in ophthalmic division of trigeminal, or BL
- optic neuritis
- Fhx of MS
- age onset <40y.o.
Acoustic neuromas = vestibular schwannomas
- what are the features?
- when may it be BL?
- what is the Ix of choice?
- 5% of intracranial tumours, 90% of cerebellopontine angle tumours
CN V: absent corneal reflex
CN VII: facial palsy
CN VIII: hearing loss, vertigo, tinnitus
What is multiple sclerosis?
What are the genetics?
- chronic cell-mediated autoimmune disorder characterised by demyelination in the CNS
- 3x more common in women, most commonly Dx 20-40s, more common at higher latitudes
- monozygotic twin concordance 30%, dizygotic 2%
Commonest form of MS?
relapsing-remitting disease
- acute attacks lasting 1-2months followed by periods of remission
Form of MS with the worst prognosis?
1ry progressive disease
- 10% of pts, progressive deterioration from onset
- more common in older people
What do 65% of pts with relapsing-remitting MS disease go on to develop within 15yrs of Dx?
2ry progressive disease
- when r-r pts deteriorate & have developed neuro signs & Sx between relapses
- gait & bladder disorders generally seen
MRI in MS?
- high signal T2 lesions
- periventricular plaques
- Dawson fingers: often seen on FLAIR images - hyper intense lesions penpendicular to the corpus callosum
CSF in MS?
- oligoclonal bands (and not in serum)
- increased intrathecal synthesis of IgG
Visual evoked potentials in MS?
- delyaed, but well preserved waveform
Good prognostic features in MS?
- female, young 20s/30s
- relapsing-remitting
- sensory Sx only
- long interval between first 2 relapses
- complete recovery between relapses
MS Rs for an acute relapse?
- 5/7 high dose steroids to shorten length of relapse
- but they don’t alter the degree of recovery i.e. if they return to baseline
MS Rx for fatigue?
- trial AMANTADINE after excluding other problems e.g. anaemia, thyroid, depression
- CBT & mindfulness training
MS Rx for spasticity?
- Baclofen/Gabapentin 1st line
- Physio
- other options inc diazepam, dantrolene, tizanidine
MS Rx for oscillopsia: visual fields appear to oscillate?
Gabapentin
MS Rx for bladder dysfunction: urgency, incontinence, overflow etc?
- US/S to assess bladder emptying
- if significant residual volume -> intermittent catheterisation
- if no significant residual volume -> anticholinergics may improve urinary frequency
- anticholinergics may worsen Sx in some pts
DMARD that reduces relapse rate by 30% in MS?
Beta-interferon
- reduces no of relapses & MRI changes but doesn’t reduce overall disability
What are the criteria for using beta-interferon in MS?
- relapsing-remitting disease + 2 relapses in past 2 yrs + able to walk 100m unaided
- 2ry progressive disease + 2 relapses in past 2 yrs + able to walk 10m un/aided
Cause of upbeat nystagmus?
cerebellar vermis lesions
Cause of downbeat nystagmus?
foramen magnum lesions
Arnold-Chiari malformation