Neurology Flashcards
Parkinson’s disease definition
Neurodegenerative disease caused by the disruption of dopaminergic neurotransmission in the basal ganglia. Histological loss of melanin containing dopaminergic neurones in the substantia nigra and cytoplasmic inclusions known as lewy bodiers in surviving neurones. 60-80% neurone loss before clinical symptoms.
Dementia in parkinsons disease
Late, 15-30% patients. Earlier occurance of cognitive symptoms (i.e. within 1 year of motor symptoms may suggest lewy body dementia)
Parkinson’s vs Parkinsonism
Parkinson’s asymmetrical distribution of signs, good reponse to levodopa, absent parkinsonian plus signs, progressive progression.
Parkinsonism more symmetrical, poor response to levodopa, may have addditional signs to suggest PP syndromes
Parkinsonian plus syndromes
MSA
PSP
CBD
MSA
Parkinsonism, autonomic failure, cerebellar dysfunction and pyramidal signs.
Progressive loss of neuronal/oligodendronal cells at numerous sites in CNS, with relative sparing of globus pallidus, caudate nucleus, CST and anterior horn cells.
PSP
Most common PP+. Multiple neurotransmitter pathways (cholinergic, adrenergic, dopaminergic).
Abnormal vertical then horizontal saccades. Difficulty opening eyes, early and prominent falls, speach/swallow, frontal symptoms of depression, apathy, cognitive impairment.
Symmetrical parkinsonian features.
CBD
Frontoparietal cortical atrophy + extrapyramidal degeneration. Limb aprexia (&alien limb syndrome) + cortical sensory loss.
What is parkinsonism?
Movement disorder characterised by bradykinesia and at least one of rigidity, tremor or postural instability
Carpel tunnel syndrome
Look for: weakness of flexion, abduction and opposition of thumb. Decreased sensation over lateral three and a half fingers. Tinel’s sign (tingling in median nerve distribution on percussion of median nerve). Phalen’s sign (hyperextension of wrist for 1 minute reproduces symptoms. Look for a scar of previous median nerve decompression.
Associations: Acromegaly, myxoedema, rheumatoid arthritis, occupational trauma, pregnancy.
Chorea
Sydenham’s chorea, Huntington’s disease, polycythemia vera, chorea gravidarum, drug induced, systemic disease (SLE, thyrotoxicosis, etc). If hemichorea, consider infarction or tumour.
Ankylosing spondylitis
Features shown: ‘Question mark’ posture due to loss of lumbar lordosis, fixed kyphoscoliosis of thoracic spine and hyperextension at cervical spine and some protuberance of the abdomen.
Look for: whole body turning when patient tries to rotate neck, inability of the occiput to make contact with the wall when the heels and back are against the wall (occiput-to-wall distance), limited spinal movement (increased finger floor distance and Schober’s test), reduced chest expansion, eyes (iritis and anterior uveitis), aortic regurgitation and apical lung fibrosis.
Homonymous hemianopia
Lesion behind the optic chiasm.
Bitemporal hemianopia
Lesion at the optic chiasm
DDx pituitary tumour, craniopharyngioma, suprasellar meningioma, glioma, metastasis
Pituitary tumours compress from below (upper temporal first), craniopharyngiomas compress from above (lowe temporal field first)
Look for: acromegaly, cushings, hypopituitarism, gynaecomastia, sarcoid, tuberculosis, malignancy
Homonymous upper quadrantopia
Temporal cortex
Homonymous lower quadranopia
Parietal cortex
PITS
What do you understand by homonymous
Identical pattern of visual field defects in each eye
Kennedy-Foster syndrome
Ipsilateral optic atrophy 2* to compression of optic nerve
Contralateral paplilloedema secondary to raised ICP
Myotonic Dystrophy Examination
Face - myopathic pacies, thin expressionless, wasting of facial and SCN muscles, bilateral ptosis, frontal balding, dysarthria from myotonia of tongue and pharynx
Hands - myotonia (grip my hand, not let go), wasting and weakness distally with areflexia
Percussion myotonia - percus thenar eminence and watch for involuntary thumb movement
Additional - catracts, CM, PPM from brady/tachy arrythmias, diabetes, testicular atrophy, dysphagea
Myotonic dystrophy genetics
AD, with genetic anticipation
DM1 - CTG trinucleotide repeat DMPK gene Chr19
DM2 - CCTG trinucleotide repeat within ZNF9 gene on chr 3
DM1 in 20s and 30s, DM2 later (but variable)
Diagnosing myotonic dystrophy
Clinical examination
EMG - dive bomber potentials
Genetic testing
Management of myotonic dystrophy
Respiratory and cardiac complications leading causes of mortality
Weakness - no treatment
Phenytoin may help myotonia
High risk of complications from anaesthesia
DDx ptosis
Bilateral - MG, myotonic dystrophy, congenital
Unilateral - 3rd nerve palsy, horners syndrome
Interpreting cerebellar lesion
Ipsilateral cerebellar signs in the limbs
Nystagmus - maximal fast paced direction towards (when looking at) the lesions
But** in vestibular/VIII lesions maximum away from the lesion
Causes of cerebellar syndrome
PASTRIES Paraneoplastic Alcoholic Sclerosis (MS) Tumour Rare (Freidrich, ataxia telangectasia) Iatrogenic (phenytoin) Endocrine (hypothyroidism) Stroke
Investigating MS
GCS - oligoclonal bands
MRI - periventricular white matter changes
Visual Evoked Potentials - dleayed velocity but normal amplitude to suggest optic neuritis
MS treatment
MDT - nurses, PT, OT, social worker, physician
Treatments:
INF-b reduces relapse rate but does not affect progression.
mAb - natalizumab (anti a4 integrin, blocks T cell trafficking) and alemtuzumab (anti-CD-52, lymphocyte depletion)
Symptomatic - methylprednisolone will shorten duration of attack
Anti-spasmodics like baclofen
Neuropathic pain - carbamazepine
Bladder and bowel regimes
Pyramidal weakness
Extensors weaker than flexors in upper limbs
Flexors weaker than extensore in lower limbs
Define stroke and TIA
Stroke - rapid onset focal neurological deficit secondary to vascular lesion lasting >24 hours
TIA - rapid onset focal neurological deficit secondary to vascular lesion lasting <24 hours
Bamford classification of stroke
TACS - HHH (hemianopia, higher dysfunction, hemiplegia)
PACS - 2/3 TACS
LACS - pure hemi motor or sensory loss, ataxic hemiplegia
POCS -
Cranial nerve palsy and a contralateral motor/sensory deficit
Bilateral motor/sensory deficit
Conjugate eye movement disorder (e.g. horizontal gaze palsy)
Cerebellar dysfunction (e.g. vertigo, nystagmus, ataxia)
Isolated homonymous hemianopia
Lateral Medullary Syndrome (Wallenberg)
PICA occlusion
Ipsilateral cerebellar, horner, palatal paralysis, loss of V sensation
Contralateral loss of pain and temperature sensation
Subacute combined degeneration of the cord
Absent reflexes with upgoing plantars
Spastic legs - examination
Observation - wheelchair, sticks, disuse atrophy and contractures
Increased tone, ankle clonus
Weakness
Hyperreflexia and extensor plantats
Scissoring gait
Other - look at back for surgical scars, syringomyelia (upper limb signs), anterior spinal artery thrombosis, hereditary spastic parapalegia (+ve FH), SCDC, Friedrich ataxia, cord compression
Cord compression
Disc prolapse above L2/L1 Malignancy Traumatic Infection - abscess of TB investigation - spinal MRI Management - surgical decompression, streroids / Rx for malignant choice
Examining syringomyelia
Weakness/wasting small musles of hand, areflexia, dissociated sensory loss in upper limbs and chest, loss of pain (STT) but preserved vibration and proprioception (dorsal column)
Scars from burns
Charcot joints
Pyramidal weakness in lower limbs with upgoing plantars
Kyphscoliosis and horners
If syrinx extends into brainstem (syringobulbia) may be cerebellar and lower cranial signs
What is syringomyelia
Progressively expanding fluid filled cavity (syrinx) within cervical cord, typically spanning several levels
Expands ventrally:
1. STT = pain and loss of temp at level of syrinx
2. Anterior horn cells = segmental LMN weakness at level
3. CST = UMN weakenss below level of syrinx
4. Dorsal columns spared (intact proprioception and vibration sense)
Signs may be asymmetrical
MRI scan
What are charcot joints
Painless deformity and destruction of a joint with new bone formation following repeated minor trauma secondary to loss of pain sensation Tabes dorsalis - hip and knee Diabetes - foot and ankle Syringomyelia - elbow and shoulder Bisphosphonates can help
MND on examination
Inspection: Wasting and fascilculations Tone: spastic / flaccid Power: reduced Reflexes: absent or brisk Sensory: normal Speech: dysarthria (bulbar - donald duck, nasal, palatal weakness); or pseudobulbar (hot potato, spastic tongue) Tongue: wasting and fasciculations No sensory, extra-ocular, cerebellar, or extramyramidal involement
MND definition and investigation
Progressive neurodgenerative disease of unknown aetiology resulting in axonal degeneration of upper and lower motor neurones. 3 main subtypes:
- Amyotrophic Lateral Sclerosis (50%, ALS) - CST predominant = spastic paraparesis or tetraparesis
- Progressive muscular atrophy (25%) = Anterior horn cells prdominantly = wasting fasciculations and weakness, best prognosis
- Progressive bulbar palsy (25%) = lower cranial nerves and suprabulbar nuclei, speech and swallow problems, worst prognosis
MND investigation treatment and prognosticaiton
Clinical diagnosis, EMG, MRI brain/spine to r/u cervical cord compression, myelopathy and brainstam lesions
Supportive: PEG feeding and NIPPV
MDT
Rilozule - slow disease progression 3/12 but not affecting function or QoL
Most die within 3 years, usually resp complications
Wost if elderly, female and bulbar onser
DDx wasting of hand muscles
Anterior horn cell - MND, syringomyelia, cervical cord compression, polio
Brachial plexus - cervical rib, pancoast tumour, trauma
Peripheral nerve - combined medial & ulnar lesions
Muscle - disure atrophy (e.g. RA)
What is a fasciculation?
Visible muscle twitching at rest
Due to axonal loss results in surviving neurones recruiting and innervaintg more myofibrils than ususal resulting in large motor units
Commonly in MND or syringomyelia
Treating parkinsons disease
levodopa with peripheral dopa-decarboxylase inhibitor (co-careldopa, co-beneldopa). SE of nausea nad dyskinesia. Effects wear off after few years so best to pick moment. on/off motor fluctuations can be decreases by MR preperations
Dopamine agonists - younger patients, less SE, saves L dopa until necessary. Apomorphine also agonist which can be used as S/C or infusion for pts with severe off periods
MAO-B inhibitors (selegiline) inhibit breakdown of dopamine
Anticholiergics - reduced tremor
COMT inhibitors (e.g. entercapone) - inhibit peripheral breakdown of L dopa thus reducing motor flucutations
Amantadine - increases dopamine release
Surgery / DBS
Causes of tremor
Resting - PD
Postural - benign essential (50% familial, improves with etoh)
Anxiety, thyrotoxicosis, CO2 and HE, alcohli
intention - cerebellar disease
Hereditary sensory motor neuropathy - examination
Charcot-Marie-Tooth disease
Wasting distal lower limb muscle with preservation of thigh bulk (inverted champagne appearance), pes cavus, weakness ankle dorsiflexion and toe extension
Variable degree stocking distribution of sensory loss (usuallly mild)
High stepping gait (foot drop) + stamping (loss of proprioception)
Wasting hand muscles
Palpable lateral popliteal nerve
Genetics of CMT
Hereditary sensory motor neuropathy I (demyelinating) II (axonal) AD - PMP 22 in type 1 Also known as peroneal muscular atrophy
Causes of peripheral neuropathy
Sensory –> DM, Alcohol, Drugs (isoniazid, vincristine), Vitamin B1 b12
Motor –> Guillain Barre, lead, porphyria, HSMN
Mononeuritis multiplex –> DM, CTD (SLE, RA), vasculitis (PAN, CS), malignancy
Friedrich Ataxia - examination
Young Adult, wheelchair
Pes cavus
Bilateral cerebellar ataxia
Leg wasting with absent reflexes and bilateral upgoing plantars
Posterior column signs (loss of vibration and propriocepiton)
Kyphosclolisos Optic atrophy High arched palate SN deafness HOCM DM
Friedrich ataxia - genetics
AR
ONset teenage
Survival 20 years from diagnosis
Association with HOCM and DM
Extensor plantars + absent knee jerks
Friedrich ataxia SCDC MND Taboparesis Conus medullaris lesion Combined lower and upper pathology (e.g. cervical spondylosis with peripheral neuropahy
Facial nerve palsy
U/L facial droop, involvement of forehead
VI+VII palsy - pons (MS/Stroke)
V+VI+VIII+cerebellar - cerebropontine lesion
VII + VIII - auditory/facial canal
Scars/parotic mass - tumour / trauma
Commonest VII palsy
Bells - LMN
Rapid onset 1-2 days, HSV implicated
Swelling and compression within facial canal causes demyelination and temporary condution block
Prednisolone if started within 72h improves outcomes, acyclovir
EYE proteciton (tape, viscotears)
70-80% full recovery, remainder varying degrees of weakenss
More common in pregnancy
Other - VZV (ramsay hunt), mononeuropathy (DM, sarcoid, lyme), tumour/trauma, MS
Bilateral facial palsy
Guillain barre Sarcoidosis Lyme disease MG B/L bells palsy
Examining myaesthenia gravis
Bilateral ptosis worse on sustained upwards gaze
Complex bilateral extraocular palsies
Myaesthenic snarl
Bulbar - nasal speech, palatal weakness, poor swallow
Fatiguability
Sternotomy (thymectomy)
FVC
Investigating myaesthenia gravis
Anti-AChR +ve in 90%
Anti-MuSK (muscle specific kinase) if Anti-AChr -ve
EMG - decremented response
Tensilon tests - an acetylcholine esterase inhibitor increases ACH at motor endplate to improve weakness (risks heart block or asystole)
CT - thymoma
TFTs (graves in 5%
Treating myaesthenia gravis
Acute - IVIg or plasmapheresis is severe
Chronic - acetylcholine esterase inhibitors (pyridostigmine)
Immunusupression - steroids, azathiopine
Thymectomy - beneficial even if no thymoma
LEMS - diminished reflexes become brisker after exercise, lower limb girdle weakenss, SCLC association, Ab block voltage gated calcium channels, EMG
Causes of bilateral extra-ocular palsies
MG Graves disease Mitochondrial disease (e.g. Kearns-Sayre) Miller Fisher Cavernous sinus pathology
Cause of bilateral ptosis
Congenital Senile MG Myotonic Dystrophy Bilateral Horners
Horners syndrome
Ptosis, miosis, anhydrosis, enothalmos
Look ipsilateral side of neck for scars - trauma, central lines, carotid endarterectomy, aneurysms, pancoast tumour
Brainstem - MS, stroke
Spinal cord - syrinx
Neck - aneurysm, Pancoast tumour
Holmes Adie pupil
Myotonic pupil
Moderately dilated pupil with poor light response and a sluggish reaction to accomodation
Absent or diminished ankle and knee jerks
Benign condition
III palsy
Down and out
Ptosis (usually complete)
Pilated pupil
Medical - pupil normal
- Mononeutritis multiplex (DM), midbrain infarct (webers) or demyelination, migraine)
Surgical - pupil blown
- posterior communicating artery aneurysm, cavernous sinus thrombosis, tumour or fistula, cerebral uncal herniation
Compression of the cord
Myelopathy
Compression of the nerve roots
Radiculopathy
Ddx myelopathy
Sudden - vascular (spinal infarcts), disc prolapse
Inflammatory - MS, transverse myelitis
Transverse myelitis
Immune - MS, post infectious, paraneoplastic
Viral - VZV, EBV, CMV, HSV
Bacterial - TB
Assessing double vision
Does the double vision disappear when covering either eye = biocular diplopia
Is the double vision horizontal or vertical? Horizontal diplopia: lateral / medial rectus (unilateral / bilateral VI or INO) Vertical diplopia: superior / inferior rectus, superior / inferior oblique (III or IV)
Is the double vision worse on looking in any particular direction?
Diplopia is maximal in the direction of action of the paretic muscle
Surgical Sieve
INVITED MD
Infection Neoplasia Vascular Inflammatory/autoimmune Trauma Endocrine Degenerative Metabolic Drugs Congenital
Sturge Weber Syndrome
Port wine stain - classically V1 and v2 facial distribution
Leptomeningioma
Seizures
Glaucoma
