General neurology [29/10/20] Flashcards
4 key features of Parkinson’s disease
Bradykinesia, rigidity, postural instability, tremor
Parkinsonism cauases
- idiopathic PD
- vascular Parkinsonism
- normal pressure hydrocephalus
- Parkinson’s plus syndrome [PPS]
- iatrogenic
Typical preparation of L-dopa for PD
- Co-careldopa/ co-beneldopa [L-dopa given with a dopa-decarboxylase]
- CR prep
- dispersable prep [rescue/morn.]
- can have Statevo which is co-careldopa plus etacapone [etacapone helps stop breakdfown of L-dopa and is a COMT inhibitor]
Dopamine agonists available, and their advantage over L-dopa
- non-ergot [Ropinirole, Pramiexole, Rotigotine]
- ergot [Bromotcriptine etc.]
- adv: less dyskinesia, longer acting
- dis: higher risk hallucinations, compulsive behaviour, postural hypotension, daytime sleepiness, specific ergot SE like fibrosis lungs/chest so need constant monitoring ECG/CT
Examples of MAOI and cautions related to them
- Selegiline, Rasagiline.
- Serotonin syndrome: pyrexia, agitation, sweating, diarrhoea
- Tramadol, Dethidine, MTX are CI
When to start drug treatment for PD?
No disadvantage starting early, generally for Sx control [esp. L-dopa best for that]
Non-motor Sx of PD
Mood, sleep [esp. REM sleep], cognitive, impulse control disorder, autonomic dysfunction, anosmia [pts can have Sx for 20y without Dx]
REM sleep disorder: pts acting out their dreams.
Insomnia due to stiffness/restlessness
Psychotic PD Tx
- assess provoking factors [could be illness, metabolic, infection]
- refer to neuro
- disconintue meds like MAOI
- intitiate clozapine, quitiepine [consider acetylcholine esterase inhibitors]
Autonomic Sx PD
orthostatic hypotnesion, N and vomiting, hypersalivation, nocturia, sweating etc.
When can DBS be used for PD and what is the benefit?
used in the subthalamic nucleus, lowers requirement for L-dopa [by about half its dose]
- only for pts with motor fluctutations
Sx of a third nerve palsy
Parasympethic fibres
Apex petrous part temporal bone
Fixed dilated pupil
Sx of cerebellar syndrome
Ataxia, nystagmus
ipsilateral
Midraib, pons, medulla
What is above and below the brain stem?
Above: thalamus, internal capsule
Below: spinal cord
Describe the reticulating activating system and its function
Peri-aqueductal grey matter/ floor of the 4th ventricle
->
alertness, sleep/awake, REM/nonREM sleep, resp control, CV drive
Disorders affecting the brainstem
Tumour [meningioma, schwanomma, mets etc,], inflammation [MS], metabolic, trauma, Haemorrhage [AVM, aneurysm], infarct [vertebral artery infarct], infection [cerebellar in ear]
What is compensated type 2 respiratory failure?
High CO2, normal or low O2, high bicarb [to compensate]
Mx of acute neuromuscular respiratory weakness
- ABCD
- ABG
- ECG
- supportive Mx respiratory and autonomic instability
- early anaesthetic call
- consider infection
- Tx underlying condition
How to investigate MG?
- consider culprit [drugs like Mebeverine]
- bloods for ACh receptor antibodies [MuSK]: 85% positive [though takes 3w]
- thyroid function [autoimmune coexistence]
- CT chest [possible thymoma]
- if antibodies there: simple fibre EMG [NM] dysfunction
Mx of generalised MG
- assess severity
- caution Rx [stop Mebeverine]
- Pyridostigmine 30mg qid inc. to 60 qid and higher [max 450mg per day]
- steroids 10mg al days increasing by 10mg after 3rd dose aiming for 100mg alt days [quicker if IP, beware dips]
- bone protection, PPI
- IVIg
- Tx infections early, aggressively and care with antibiotics
- LARGE list of drugs CI in MG patients
What is a typical pyramidal [or UMN] pattern of weakness?
- Flexors > extensors in UL
- Extensors > flexors in LL
- consequently, pt circumducts leg to walk as cannot flex hip properly to take step
Ix for pt with back pain, difficulty walking, pyramidal weakness
- MRI cervical spine [possible compression], LP, admit and observe = DONE IMMEDIATELY
- [NCS, anti-glioside antibodies, infection serology for cause]
Mx of GBS
IVIg, monitor pulse and BP, monitor FVC
Autonomic instability Mx for GBS
- tachycardia: drugs/DC cardioversion
- bradycardia: drugs/pacing
- HTN: labetolol
- hypotension: fluids, inotropics
Mx of respiratory failure in MND
Care with O2, consider infection, NIV on ward, ITU usually not appropriate
Origin and function of the pyramidal and extrapyramidal tracts
Pyramidal
- origin: cerebral cortex
- function: voluntary control of muscles and face
Extrapyramidal
- origin: brainstem
- function: involuntary and autonomic control muscles such as tone, balance, posture, locomotion
Functionally, how are pyramidal tracts split?
- Corticospinal tracts: lateral [90%, decussate medulla and terminate ventral horn] and anterior [ipsilateral then decussates cervical and thoracic segmental levels]
- Corticobulbar
Functionally, how are the extrapyramidal tracts split?
Originate brainstem, motor fibres spinal cord
Four tracts:
- vestibulospinal and reitculospinal do not decussaate, ipsilateral innervation
- rubrospinal and tectospinal contralteral
How many somatic pairs of nerve in the NS?
31 pairs
UMN vs LMN features
UMN
- bulk: normal, tone: increased, strength: decreased, fasciculations: absent, reflexes: increased
LMN
- bulk: reduced [wasting], tone: normal or decreased, strength: decreased, fasciculations: may be present, reflexes: decreased or absent
Causes of weakness
Neuropathies - peripheral neuropathy - GBS - MEI - MND Myopathies
Compare three main types peripheral nerve damage
Polyneuropathy [peripheral neuropathy]
Mononeuropathy multiplex [at least 2 neurones]
Mononeuropathy
Predominantly motor loss peripheral neuropathy
- GBS
- chronic inflammatory demyleinating polymuerhpathy [CIDP] i.e. chronic GBS
- hereditary sensorimotor neuroapthies [HSMN] e.g. Charcot Marie Tooth Disease
- DIptheria
- Pomphoria? or something
Predominantly sensory loss peripheral neuropathy
- deficiency states [B12/folate]
- DM
- alcohol/toxins/drugs
- metabolic abn. e.g. uraemia
- leprosy
- amyloidosis
Define mononeuritis multiplex
- Painful, asymmetrical sensory and motor neuropathy
Features and causes of mononeuritis multiplex
- Subacute presentation
- Inflammatory/immune mediated
- Causes: vasculitides e.g. Churg-Strauss, CT disorders [like sarcoid]
Mononeuropathy exmaples
Median nerve [Carpal Tunnel]
Ulnar elbow
Radial axilla
Common peroneal nerve leg
Neuropathy Ix
history and exam - neurpathy screen vasculitic screen - EMG/NCS -CSF study - imaging/nerve biopsty
[all after Hx optional]
neuropathy Tx
20% idiopathic with no Tx [just give analgesic]
treat underlying cause [e.g. deficiency/DM]
inflammatory like CIDP then prrednisolone with steroids sparing agents like azathioprine
vasculitic neurpathy give prednisolone with immunosuppreant like cyclophosphamide
Features of GBS [incl. on LP]
AI response causing demyelination Post infectious e.g. resp or GI Subacute [<6w] ascending paralysis/numbness/areflexia NCS: demyleinating LP: raised CSF protein
Tx for GBS
IVIg or plasmapharesis, support, monoitor, FVC, ITU review
How long recorvry GBS?
Weeks to years
Features of MG
AID; antibodies against nicotinic acetylchline receptors
Common, potentially fatal
Thymus dysfunction common [hyperplasia, thymoma]
Generalised weakness:
- proximal limbs
- neck and face [head drop, ptosis]
- extraocular [complex diplopia]
bublar Sx [speech and swallow] pareticularly in elderly
ocular in 10-25% pts
risk other AID like thyroid, PA
Ix for MG
Tensilon test [allow accumulation of ACh in the NMJ]
- AChR antibodies
- EMG [look at NMJ]
- CT thorax
Tx for MG
- acetylcholine esterase inhibitors [Pyridostigmine]: in symptomatic
- immunosuppresants [steroids start slwoly, azathioprine/MTX/mycophenolate]
- thymomectomy
What is a myasthenic crisis?
- Severe weakness incl. respiraotry muscles
- High risk of death
- Cause: infection, natural disease cycel, under/overdosing
Mx for myasthenic crisis?
Take change in myasthenic condition seriously
urgent revierw neurologist
Think about breathing and monitor
Anaesthetic review
Simple definition of MND
Slelective degeneration of motor neurones in the motor cortex and anterior horn of the spinal cord [also CN]. presents with LMN and UMN signs.
Ix for MND
LP, NCS/EMG, MRI [to r/o]
Clinical features of MND
No sensory, visual, or B/B involvement
Asymmetrical weakness
Bulbar and limb onset
Survival typically 2-5y
Common muscle disorders
- steroid myopathy
- statin myopathy
- metabolic and endocrine myopathies
- myotonic dystrophy
List some uncommon muscle disorders
Most muscular dystrophies - Duchenne, FSHD Inflammatory muscle disorders - polymyositis, dermatomyositis Mitochondrial disorders
Features of muscle disroders
Stairs, chair, hair
wasting is common
Facial weakness occurs in some [FSMD]
Neck weakness and contractures can occur
Scoliosis often feature especially in Duchenne
Eye movements disorders are rare [seen in mitochrondrial]
Muscle Ix
CK, EMG, ESR/CRP,
+/- genetics [like DMD], biopsy
General rule, nerve compared to muscle disease?
Nerve = distal weakness Muscle = proximal weakness
Aetiology of MND
Sporadic [unknown], or familial [SODL, C9ORF2]
Types of MND
- ALS [50]: LMN and UMN. Worse bulbar onset.
- PLS: motor cortex only, so UMN
- PMA: LMN, best prognosis
- PBP: CNs 9 to 12, palsy tongue, chewing and swallowing. Worse prognosis.
Features of MND
Sx: weakness, bublar Sx [dysarthria, dysphagia, siarrlorrhoea]
Sx: assymetrical pattern weakness, ALS both UMn and LMN signs
Ix: no Dx test, neurophysioogy/EMG may detect denervation, MEI helps excl, LP to r/o
Mx for MND
Riluzole, NIV, gastrostomy
What are PD associated with?
Lewy bodies [tangles alpha-synuclein and ibiquitin]
Ix for PD
usually clincial Dx, MRi and CT to r/o, PET and SPECt scans [alsdo DaTSCAn]
Define Huntington’s Disease
Inherited neurodegenerative disease characterised by chorea, dystonia, incoordination, cognitive decline and benhioural difficulties
Aetiology of HD
AD [complete penetrance], gene chromosoem 4 encodes for Huntingtin, degneration of cholinergic and GABAnergic neurones. CAG nucleotides need over 35 repeats.
Features of HD
after 35 y.o, chorea, personality changes, intellectual impairment, dystonia, saccadic eyes, rigidity, dementia, bulbar Sx, sleep problems
Ix for HD [incl. part of brain looked at]
genetic testing, CT/MRI can show atrophy of caudate nucleus
Mx and prognosis for HD
No DMT, 15-20 years life
Define dementia
Syndrome deteriorating memory, thinking, behaivour, and ability for ADLs
Types of dementia
AD [50%], vascular [25%], LBD [15%], FTD [5%], mixed dementia, PD+ genetic causes dementia
Also, potentially Tx causes dementia
potentially Tx causes of dementia
Substance abuse, hypothyroidism, SOL, NPH, syhpilis, vit. B12 defi, pellagra
Dx of dementia
histor yna dexam, screen impairment with e.g, MMSE
Ix for dementia
dementia screem, r/o other causes confusion like FBC, LFTs, U and E, EST, TFT, syphilis, cvortisol, glucose, CT head, EEG, LP [CJD]
Mx of dementia
acetyolcholinesterase inhibotres [e.g. donepezil] for mild to mod AD
NMDA [memantine] for 2nd line where ACHe doesn;t work
What is PSP?
Supranuclear palsy or Parkinson plus syndrome;
impairments vertical gaze [hard stairs], parkinsons, falls, speech, cognitive impairment
Mx of PSP
poor repsonse to L-dopa
What is TGA~?
Loss transient memory
anxious and repeat questions
no recall events
Chorea cause
daamge basal ganglia
- HD, RFs, drugs [l-dopa antipsychotics], thyrotoxicoiss, PRV, poison, ataxis trelangactasia etc.
Lewy body dementia Sx
Progressive cognitive decline: - attention and EF decline first compared to memory loss cognitive fluctutating - usually CD before Parkinsons - visual hallucinations
Cx of stroke
raised ICP [cerebral oedema, haemorrhage, [signs HTN, new neurology, GCS] - aspiration pressure sores depression cognitiv e impariemtn othert medical problems]
