neurology Flashcards
What are the roots of the ulnar nerve
C7-T1
Causes of unilateral ptosis
Horners
3rd nerve palsy
Myasthenia
Causes of a proximal weakness
Unable to stand from a chair. Reduced power in shoulder abduction
Neurological - myasthenia, muscular dystrophy, ALS
Muscle disease - myopathy or myositis (Polymyositis and dermatomyositis)
Endo - diabetes, thyrotoxicosis, Cushings
Polymyalgia (apparent weakness due to stiffness and pain, not objectively weak)
Drugs - steroids, alcohol
Electrolyte disturbance
Malignancy
Renal failure
Osteomalacia
Rhabdomyolysis
How to distinguish between cerebellar disease and sensory ataxia
Cerebellar - will have eye signs (nystagmus) and speech change (scanning dysarthria)
Sensory ataxia - sensory change (vibration and joint position sense), pseudoathetosis, able to perform finger-nose testing with eyes open, but not eyes closed
Indications for surgery for carotid artery stenosis
Occlusion between 50-99%
Occlusion >70% according to ESCT criteria (S = seventy)
Occlusion >50% according to NASCET criteria
Inheritance of myotonic dystrophy
Mutation and chromosome
AD with anticipation
Due to trinucletide repeat expansion on chr19 - myotonin protein kinase gene
Jumping vision
Oscillopsia
Cerebellar disease
Friedrich's ataxia Features Inheritance Onset Complications
Features
Cerebellar sx - cerebellar ataxia, scanning dysarthria, nystagmus
Dorsal column loss - Sensory ataxia, upgoing plantars with decreased reflexes, loss of proprioception and vibration sense
UMN signs - Leg wasting & spastic paraparesis
Pes cavus
Inheritance
AR
Onset during teenage years
Prognosis ~20yrs
Complications Cardiac disease - HOCM Optic atrophy (30%) Diabetes mellitus (10%) Sensineural deafness
Holmes Adie pupil
Benign condition
Pupil dilated, but slowly accommodates to light and accommodation
Usually chronic, can be acute with photophobia and blurriness
Syphilis negative (vs Argyll Robertson)
Investigations for peripheral neuropathy
Bloods - FBC (macrocytosis - B12), LFTs for derangement (alcohol)
Immunoglobulins and serum protein electrophoresis (myeloma)
Vitamin deficiencies - B1/6/12
HbA1c
Nerve conduction studies and EMG - determine length-dependent nature and axonal vs demyelinating pattern
Demyelinating pattern and non-length dependence are more in keeping with an underlying inflammatory cause eg CIDP
Ddx of cerebellar gait
S - SOL, stroke, MS
Malignancy related - paraneoplastic
Alcoholic degeneration
Other cerebellar degeneration - Friedrich’s ataxia
What CN are affected in cerebellopontine angle tumours
V, VI, VII, VIII and cerebellum
Causes of sensory ataxia
Central
Friedrich’s ataxia
Spinal Cervical myelopathy (compression at cervical level) Subacute combined degeneration of the cord - B12 deficiency Tabes dorsalis (neurosyphilis) - check for A-R pupil (accommodates but doesn't react to light)
Peripheral neuropathy - Diabetic neuropathy, alcohol
Causes of nystagmus
Cerebellar (ipsilateral lesion)
Vestibular (contralateral lesion)
Peripheral vestibular - Meniere’s, acoustic neuroma, labyrinthitis, vestibular neuritis (vertigo without deafness or tinnitus)
Central vestibular - Stroke/SOL/MS, encephalitis
Investigations for a stroke
CT head for consideration of thrombolysis
ECG for AF (+/- 24hr tape for paroxysmal AF)
Echo for structural heart disease
Carotid doppler for stenosis and consideration of carotid endarterectomy
Contraindications for thrombolysis
Onset of sx >4.5hrs ago (unless also considering thrombectomy)
Seizures at presentation
Ischaemic stroke or head injury in the last 3 months
BP >180/110
Previous intracranial bleed
Active bleeding;
Surgery or major trauma (incl CPR) within last 2wks
Non-compressible arterial puncture within last wk
LP in prev 7/7
Causes of a proximal myopathy
Endocrine - Cushings
Polymyositis / dermatomyositis
Indications for thrombectomy
Thrombectomy with thrombolysis: sx onset of acute ischaemic stroke within past 6hrs and confirmed occlusion of proximal anterior circulation seen in CTA/MRA
Thrombectomy +/- thrombolysis: for people last known to be well within 6-24hrs with sx of acute ischaemic stroke and confirmed occlusion of proximal anterior circulation seen in CTA/MRA AND potential to salvage brain tissue as assessed by MRI DWI or CT
Those with previously good function (pre-stroke functional status of less than 3 on the modified Rankin scale and a score of more than 5 on the National Institutes of Health Stroke Scale (NIHSS))
Indications for a decompressive hemicraniectomy
Within 48hrs of sx onset for people with acute stroke who meet all of the following criteria:
large infarction in MCA territory (>50% on CT)
Score above 15 on the NIHSS
Decreased GCS (score of 1 or more on item 1a of the NIHSS (rousable by minor stimulation, or worse)
What are the features of Friedrich’s ataxia
Cerebellar sx Sensory ataxia Cardiac disease Ophthalmoplegia Nystagmus
Unilateral foot drop
Causes
Other features to look for
Other features:
Pes cavus
Wasting
Areflexia
Levels - spine, sciatic, common peroneal, peripheral neuropathy
Causes:
L4/5 radiculopathy - weakness of inversion and eversion - trauma, disc herniation
Sciatic nerve damage - hip surgery
Common peroneal nerve palsy - trauma, compression, leprosy, polio
Peripheral neuropathy - DM, CIDP, GBS, Charcot Marie Tooth disease
Contraindications for rapid BP lowering in stroke
Underlying structural cause (for example, tumour, arteriovenous malformation or aneurysm)
GCS <6
are going to have early neurosurgery to evacuate the haematoma
have a massive haematoma with a poor expected prognosis
Roots of the median nerve
C6 - T1
Causes of a bilateral foot drop
Causes
Other features to look for
Other features:
Pes cavus
Wasting
Areflexia
Levels - spine, sciatic, common peroneal, peripheral neuropathy
Causes:
1 - peripheral neuropathy - DM, CIDP, Charcot Marie Tooth, leprosy
2 - neuromuscular - inclusion body myositis, MND, myotonic dystrophy - distal weakness
3 - Cauda equina
Mx of myasthenia
ACEi - pyridostigmine
SE - anticholinergic - dry mouth, urinary retention
Steroids followed by steroid sparing agents
Acutely - FVC monitoring with steroids +/- IV Ig
Features of ataxia telangiectasia
Ataxia - cerebellar
Telangiectasia
Delayed motor development
Causes of peripheral neuropathy
Diabetes mellitus
Alcohol
Drugs - nitrofurantoin, amiodarone, isoniazid, vincristine
Vitamin deficiencies - B1/6/12
Immune - CIDP, GBS, ANCA positive vasculitis,
Sarcoidosis
CTD - SLE, Sjogrens, RA
Amyloidosis
Paraneoplastic - either solid tumour or paraproteinaemia related (myeloma)
Hypothyroidism and uraemia
Rare / heritable causes - HSMN
Features of spinocerebellar ataxia
Cerebellar signs
Peripheral neuropathy
UMN signs
Ophthalmoplegia
AD inheritance - CAG trinucleotide repeat expansion
Ddx of chorea like movements
Sydenhams chorea SLE Vasculitis Huntingtons Hyperglycaemia Polycythaemia
Causes of a bilateral LMN VIIth nerve palsy
What else should be checked for
Bilateral Bells GBS Sarcoidosis Myaesthenia gravis MND Lyme disease
GBS What antibody is present Causes Pattern of CF Important ix Mx
Anti-GM1
Post-infection, malignancy, vaccination
Ascending weakness and parasthesiae, autonomic dysfunction
FVC
LP - normal WCC but raised protein
Nerve conduction studies
IVIg / plasma exchange acutely
Supportive mx
Features of Frierich’s ataxia
Sensory loss due to loss of dorsal root ganglion cells and peripheral nerve fibres Motor impairment (loss of motor pathways) - bilateral spastic paraparesis Cerebellar signs (degeneration of spinocerebellar tracts)
Young onset Wasting, deformities - pes cavus Broad gait Cerebellar features UMN signs due to spinal motor degeneration Sensory loss (dorsal columns) Decreased reflexes with upgoing plantars
Other features:
Optic atrophy
HOCM - murmur
Causes of bilateral ptosis
Myasthenia gravis Myotonic dystrophy Oculopharyngeal dystrophy Chronic progressive external ophthalmoplegia (a/w Kearns Sayre) Congenital Bilateral Horners Syringomyelia
What is the distribution of signs in Wallenberg syndrome
Which vessel is affected
Lateral medullary syndrome
Posterior inferior cerebellar artery
Ipsilateral: Horners - SNS loss Facial sensation loss (CN5) Vertigo (CN8) Dysphagia (CN 9 and 10) Ataxia (cerebellum)
Contralateral: ST loss (decussates lower down)
Causes of absent ankle reflex with upgoing plantars
SACD
Hereditary cerebellar ataxia - Friedrich’s
Spinocerebellar ataxias
MND
Taboparesis (neurosyphilis)
Mixed conditions - eg DM with cervical myelopathy
What are the features of myotonic dystrophy
Long drooping face
Unilateral or bilateral ptosis
Frontal balding
Muscle wasting of the face and shoulders.
Cataracts
Slurred speech - dysphagia and dysarthria.
Poor ability to relax post contraction (myotonia)
Hypo-reflexia
Distal muscle weakness (although type II disease presents later with proximal weakness)
Cardiac features - heart block, cardiomyopathy
Diabetes mellitus
Gonadal atrophy with preserved secondary sexual characteristics
Red flags for non-length dependence of peripheral neuropathy
Proximal weakness with preserved distal power
Asymmetry in sensation and motor function
Suggests inflammatory cause (GBS / CIDP) over length dependent processes such as alcohol or diabetes
Causes of predominantly sensory peripheral neuropathy
D - diabetes
D - deficiencies (B vitamins)
D - drugs - linezolid, chemotherapeutics (vincristine)
D - drink (alcohol)
What does weakness with normal reflexes indicate
Lesion at the level of the NMJ or muscle itself
NMJ - myasthenia
Muscle - myopathy
What features can be looked for in the CN exam in support of myasthenia
Bilateral fatiguable ptosis
Complex ophthalmoplegia
Name given to syndrome of ipsilateral CN3 palsy and contralateral hemiparesis
Webers
Mid-brain stroke
Features of pseudo bulbar palsy
Causes
Monotonous slurred speech, dysarthria Dribbles from mouth Cannot protrude tongue Absent palatal movement Emotionally labile Exaggerated jaw jerk
Causes: Bilateral stroke of internal capsule (commonest) MS MND SOL - brainstem tumour Traumatic head injury
Txs for Parkinsons disease
L-dopa in combination with peripheral DOPA decarboxylase inhibitors carbidopa or benserazide
Entacapone (peripheral COMT inhibitor)
DA agonists - ropinerole
MAOi - selegiline
For PD dementia - rivastigmine or amatadine
For tremor predominant PD - add on anticholinergic procyclidine
Causes of chorea (5)
Rheumatic fever - syndenhams chorea (ask about sore throat)
Huntingtons - ask about FHx
Drugs - anti-psychotics
Vascular lesions / SOL in subthalamic nucleus (tends to be unilateral)
SLE
Mx of MND
MDT - PT/OT and neurologist
Communication aids
SALT with assessment for feeding support
Spirometry and early morning ABG for respiratory support
Riluzole is only disease-modifying tx
Causes of a unilateral LMN VIIth nerve palsy
What else should be checked for
Bells palsy Ramsay Hunt syndrome Acoustic neuroma / meningioma (look for involvement of Vth, VIth, VIIth, VIIIth nerves, cerebellar signs and loss of taste on anterior 2/3 of the tongue). Parotid tumour Pontine lesion
Any cause of mono neuritis multiplex - DM, vasculitis, sarcoid
Check ipsilateral ear for signs of Herpes Zoster
Perioral fasciculations are pathognomonic of which condition
Kennedys disease
Hereditary spinomuscular atrophy due to X-linked recessive mutation in androgen receptor gene
LMN affected only - proximal weakness and fasciculation
May be signs of androgen insensitivity - gynaecomastia
Causes of bulbar palsy
LMN lesion
MND Syringobulbia GBS Poliomyelitis SOL - skull base or retropharyngeal
Investigations for myasthenia
Anti-AChR antibodies
If negative, anti-MUSK antibodies
Nerve conduction studies for decremental response
CT chest for thymoma
Causes of wasting of the small muscles of the hands
Other features o/e
Wasting - thenar and hypothenar eminence
Ext at MCP joints, flexion at IP joints
Dorsal guttering
Causes:
Anterior horn cells of C8/T1: cord compression, MND, syringmyelia, CMT disease, old polio
Root lesion at C8/T1: Cervical spondylosis, tumour at C8/T1 (neurofibroma)
Brachial plexus: Cervical rib, Pancoast’s tumour, trauma (Klumpke’s palsy)
Combined ulnar and median nerve lesions
Arthritis causing disuse atrophy (RA)
Cachexia
Features and causes of a spastic paraparesis
Bilateral increased tone and weakness
Hyper-reflexia, upgoing plantars and clonus
Brain
Cerebal palsy, parasaggital meningioma
Spinocerebellar degeneration
Spine MS (and transverse myelitis) Cord compression - SOL, disc B12 deficiency - SACD Trauma MND Hereditary spastic paraparesis Tropical spastic paraparesis (HTLV1)
Causes of mono neuritis multiplex
DM Vasculitis - Churg Strauss, Wegener's Sarcoid Polyarteritis nodosa SLE Amyloidosis
Features of a common peroneal nerve palsy
Inspection
Wasting of anterior and peroneal parts of the leg
Motor
Achilles reflex spared (via S1)
Weak dorsiflexion - ask to walk on heels
Foot eversion lost, foot inversion spared
Weakness of first toe dorsiflexion - extensor hallux longus
Sensory
Anaesthesia over the anterior (dorsal) surface of the leg and foot (deep and superficial peroneal nerves)
Sparing of sensation over the medial side of the foot (saphenous branch of the femoral nerve) and lateral side of the foot (sural branch of the tibial nerve)
Features of Miller Fisher syndrome
Antibody
Ophthalmoplegia
Ataxia (cerebellar)
Areflexia
Anti-GQ1b antibodies
Ddx of isolated LMN signs with normal sensation
Motor neurone disease
Multifocal motor neuropathy (extremities tend to be affected first - anti-GM1 antibodies, treatable with IVIg)
Progressive muscular atrophy (distal weakness before proximal)
Hereditary spinal muscular atrophies
Kennedy disease (rare) - androgen insensitivity
Acute mx of MS
High dose IV steroids
Consider SE - hyperglycaemia, gastric ulcer (give PPI), warn of sleep disturbance
Causes of bulbar speech
MND
Bulbar palsy
Pseudo-bulbar palsy (incl vascular disease and MS)
Brainstem vascular disease and brainstem stroke
Causes of an asymmetric spastic paraparesis
Looks for contralateral sensory change - consider Brown Sequard syndrome
Check for sensory level
Ddx: Compression - disc profusion, tumour MS Vasculitis - SLE, sarcoid Trauma MND Infection - HIV Nutrition - B12, Cu Rare - hereditary spastic paraparesis
What is the most important ddx for MND
Cervical cord compression
What features are suggestive of Progressive Supranuclear Palsy
Axial rigidity and imbalance - falls (without postural hypotension)
Impairment of vertical saccades
Confusion / dementia
Indications for rapid BP control in stroke
Haemorrhagic stroke with sx onset within last 6hrs - lower BP if >150
Haemorrhagic stroke with sx onset beyond last 6hrs
Aim systolic 130-140
Symptoms of thalamic syndrome
What vessel is affected
Vessel: posterior cerebral artery
Signs:
Hemisensory loss of face and body contra laterally - all modalities
Increased pain sensation over the same distribution
What are the causes of cerebellopontine angle syndrome
What is the correct ix
Acoustic neuroma - unilateral tinnitus or deafness
Meningioma
Ix - MRI
Causes of Horners
What else should you examine for
Key ix
Sympathetic trunk damage causing Anhidrosis, ptosis, miosis
Causes:
Central (hypothalamic / brainstem) - stroke (Wallenberg syndrome), SOL, MS, trauma, encephalitis, syringomyelia
Will cause anhidrosis of the face, neck, arm and trunk
Neck (cervical cord and T1; pre-ganglionic) - trauma (to brachial plexus), cervical rib, Pancoast tumour, thyroidectomy
Anhidrosis of face only
Carotid (post-ganglionic) - aneurysm, endarterectomy, dissection, cavernous sinus thrombosis
No anhidrosis
What else to examine for:
Apical chest signs
Neck - scars, aneurysm
Hands - wasting
Key ix: MRI head and arotid
What features in addition to Parkinsonism are suggestive of specific Parkinsons plus syndromes
Gaze paresis - PSP
Autonomic dysfunction and cerebellar signs - MSA
Cognition and visual hallucinations - LBD
Causes of a predominantly sensory peripheral neuropathy
Diabetes
Toxic - alcohol
Drugs - abx, chemotherapy, antiviral
B vitamin deficiencies
Ix to send in suspected myasthenia gravis
Anti-AChR and anti-MUSK antibodies TFT CK to exclude myopathies Spirometry Nerve conduction / EMG Imaging for thymoma
Cervical myelopathy
Compression at cervical cord level causing mixed LMN and UMN in the upper limbs, depending on the level
Causes:
Cervical spondylosis
Spinal cord SOL
Tx of MS
MDT approach
Symptomatic tx Bladder - anticholinergics Spasticity - baclofen Neuropathic pain Depression Fatigue
Disease modifying therapy Beta inferon Glatiramer Fingolimod Natalizmab Cladiribine
Non motor sx of Parkinsons
Anosmia Sleep disturbance and REM sleep disorder Constipation Autonomic symptoms - postural hypotension, erectile dysfunction, urinary incontinence Depression
Features on examination to help diagnose cause of cerebellar ataxia
Associated PN - alcohol or spinocerebellar disease
Upgoing plantars - spinocerebellar disease
Vascular risk factors
Features of malignancy - paraneoplastic syndrome
Medications
FHx
Causes of parkinsonism
Drugs - antipsychotics, antiemetics Idiopathic Parkinson's disease Progressive supra nuclear palsy Multisystem atrophy Lewy body dementia
Features of a syringobulbia
Cerebellar signs - Nystagmus, ataxia
Facial dissociated sensory loss
Bulbar palsy - speech, dysarthria, wasted faciculating tongue, weakness of sternomastoids and trapezius
Causes of a spastic paraparesis and features on examination
Features: Bilateral increased tone Weakness Hyper-reflexic and upgoing plantars Scissoring gait
Causes - brain and spinal cord: Cerebal palsy MS Cord compression - check for sensory level, back pain, no signs above level Cervical spondylosis Trauma MND Disc prolapse
Rarer: Spinal artery thrombosis HTLV - tropical spastic paraparesis Hereditary spastic paraplegia Vasculitis
What are the modes of sensation and what do they sense
Spinothalamic - sharp touch / pain, temperature
Dorsal column - vibration and proprioception, light touch
Completing PD exam
Cerebellar signs
Autonomic signs
Cognition - Lewy body dementia
Assess whether under or over medicated
Causes / associations of carpel tunnel syndrome
Idiopathic Occupational RA and OA Pregnancy Acromegaly Hypo-thyroid and diabetes Trauma
Ix of carpel tunnel
Nerve conduction studies
HbA1c, IGF1, TFT
Causes of a proximal weakness
Polymyositis / dermatomyositis Cushings and steroid use Malignancy associated Alcoholism Diabetic amyotrophy Muscular dystrophy
Multifocal motor neuropathy
Features
Tx
Features:
Progressive LMN signs, starting distally - demyelination
No sensory involvement
Responds to IV Ig and immunosuppression
Kennedy disease
X-linked mutation in androgen receptor causing androgen insensitivity
Features:
LMN signs, classically affecting proximal and bulbar muscles
Perioral fasciculation
Signs of androgen insensitivity - gynaecomastia and testicular atrophy
Primary lateral sclerosis
UMN signs only
Primary muscular atrophy
LMN signs only, typically distally
