Neurology Flashcards
What are the clinical signs of dystrophia myotonica?
Face: long thin expressionless face; wasting of facial muscles; bilateral ptosis; frontal balding; dysarthria
Hands: myotonia; wasting and weakness; percussion myotonia
Cataracts
Cardiomyopathy, arrhythmia (look for PPM)
Diabetes
Dysphagia
Explain the genetics of dystonia myotonica
DM1: expansion of CTG trinucleotide repeat sequence in DMPK gene on chromosome 19
DM2: expansion of CCTG tetranucleotide repeat sequence within ZNF9 gene on chromosome 3
Shows genetic anticipation
Both are autosomal dominant
How is dystonia myotonica diagnosed?
Clinical features
EEG: dive-bomber potentials
Genetic testing
How is dystrophia myotonica managed?
Patients die prematurely of cardiac and respiratory complications
Weakness is a major problem
Phenytoin may help myotonia
Advise against general anaesthetic (high risk cardiac/respiratory complications)
What are the common causes of unilateral ptosis?
Third nerve palsy
Horner’s syndrome
What are the clinical signs of cerebellar syndrome?
DANISH
Dysdiadochokinesis Ataxia Nystagmus Intention tremor Scanning dysarthria Hypotonia/hyporeflexia
What are the causes of cerebellar syndrome?
PASTRIES
Paraneoplastic cerebellar syndrome Alcoholic cerebellar degeneration Sclerosis (MS) Tumour (posterior fossa) Rare (Friedrich’s ataxia) Iatrogenic (phenytoin toxicity) Endocrine (hypothyroidism) Stroke (brain stem)
What are the clinical signs of multiple sclerosis?
Internuclear ophthalmoplegia, optic atrophy, reduced visual acuity, any cranial nerve palsy
Upper motor neurone spastictiy, weakness, brisk reflexes, altered sensation
Cerebellar syndrome (DANiSH)
What are the diagnostic criteria for multiple sclerosis?
Central nervous system demyelination causing neurological impairment that is disseminated in both space and time
What is the cause of multiple sclerosis?
Unknown
But, both genetic and environmental factors appear to play a role
Environmental- increasing latitude, epstein-barr infection
Genetic - HLA-DR2, interlukin 2 and 7
How would you investigate a patient with suspected multiple sclerosis?
CSF: oligoclonal IgG bands
MRI: peri ventricular white matter plaques
Visual evoked potentials: delayed velocity but normal amplitude, suggests previous optic neuritis
What are the other (non-neurological) clinical features of multiple sclerosis?
Depression Urinary retention or incontinence Impotence Bowel problems Uthoff’s phenomenon - symptoms worse after a hot bath or exercise
How is MS treated?
Multidisciplinary team involvement
Disease-modifying treatments -
Interferon beta and glatiramer reduce relapse rate but don’t affect progression
Monoclonal antibody therapy use may be limited by toxicity
Symptomatic treatments - methylprednisolone during acute relapse may shorten duration, anti-spasmodics, carbamazepine, laxatives
What is the definition of a stroke and a transient ischaemic attack?
Stroke - rapid onset, focal neurological deficit due to a vascular lesion lasting more than 24 hours
TIA - focal neurological deficit lasting less than 24 hours
What is the Bamford classification of stroke?
Total anterior circulation stroke (hemiplegia, homonomous hemianopia, dysphasia, dyspraxia, neglect)
Partial anterior circulation (2/3 of TACS symptoms)
Lacunar (pure hemi- motor or sensory loss)
What is lateral medullary syndrome?
Most common brainstem vascular syndrome
Due to occlusion of the posterior inferior cerebellar artery
Variable in it’s presentation
How does lateral medullary syndrome present?
Ipsilateral: cerebellar signs, nystagmus, horner’s syndrome, palatal paralysis, loss of trigeminal pain and temperature sensation
Contralateral: loss of pain and temperature sensation
What are the causes of lower limb spasticity?
Spinal cord lesions i.e myelopathy
Hyperacute - likely spinal cord infarct/ischaemia, trauma
acute - disc bulge, metastatic cord compression
Sub-acute - MS
Chronic - b12 deficiency, genetic causes (hereditary spastic paraparesis)
What are the clinical signs of syringomyelia?
Weakness and wasting of the small muscles of the hands
Loss of reflexes in the upper limbs
Loss of pain and temperature sensation with preservation of joint position and vibration sense
Charcot joints
Pyramidal weakness in legs with upgoing plantars
Kyphoscoliosis
Horner’s syndrome
What is syringomyelia?
Caused by a progressively expanding fluid filled cavity within the spinal cord, typically spanning several levels
What are the most important causes of a Charcot joint?
Tabes dorsalis (hip and knee)
Diabetes (foot and ankle)
Syringomyelia (shoulder and elbow)
What are the clinical signs of motor neurone disease?
Wasting and fasiculation
Usually spastic but may be flaccid
Weakness
Reflexes may be absent or brisk, upgoing plantars
Normal sensory examination
Speech may be bulbar (palatal weakness) or pseudo-bulbar (spastic tongue)
What is the pathophysiology of motor neurone disease?
Progressive disease of unknown aetiology
Axonal degeneration of upper and lower motor neurones
What are the types of motor neurone disease?
Amyotrophic lateral sclerosis: affects cortico-spinal tracts and predominantly produces spastic parapesis and tetraparesis
Progressive muscular atrophy: affects anterior horn cells, predominantly producing wasting, fasciculation and weakness, has the best prognosis
Progressive bulbar palsy: affecting lower cranial nerves and suprabulbar nuclei producing speech and swallow problems, has the worst prognosis
How would you investigate a patient with suspected motor neurone disease?
Clinical diagnosis
EMG: fasiculation
MRI: excludes cord compression and brain stem lesions
What is the management of motor neurone disease?
Multidisciplinary approach (including communication aids, PT, OT, SALT, dietetics)
Measure FVC and consider ABG as patients may require NIV
Riluzole slows disease progression but does not improve function or quality of life
What is the prognosis of motor neurone disease?
Most die within 3 years of diagnosis from pneumonia and respiratory failure
Worse if elderly at onset, female and with bulbar involvement
What are the causes of wasting of the hand muscles?
Motor neurone disease Syringomyelia Cervical cord compression Polio Pancoast’s tumour Trauma Peripheral neuropathy Disuse atrophy
What are the lumbosacral root levels and corresponding movements?
L2/3 - hip flexion L3/4 - knee extension, knee jerk L4/5 - ankle dorsiflexion L5/S1 - knee flexion, hip extension S1/2 - foot plantarflexion, ankle jerk
What are the cervical roots and corresponding movements?
C5/6 - elbow flexion and supination, biceps and supinator jerks
C7/8 - elbow extension, triceps jerk
C8/T1 - finger adduction
What are the clinical signs of Parkinsonism?
Expressionless face Coarse, pill-rolling tremor (usually asymmetrical) Bradykinesia Cog-wheel rigidity Shuffling gait with absent arm swing Slow, faint and monotonous speech
How would you distinguish Parkinson’s disease from multi-system atrophy?
Parkinsonism with postural hypotension, cerebellar and pyramidal signs
What are the causes of Parkinsonism?
Parkinson’s disease Parkinson’s plus syndromes Drug-induced (phenothiazines) Anoxic brain injury Post-encephalitis MPTP toxicity
What are the Parkinson’s plus syndromes?
Multi-system atrophy
Progressive supranuclear palsy
Corticobasal degeneration (unilateral Parkinsonian signs)
What is the pathology of Parkinsonism?
Degeneration of the dopaminergic neurones between the substantia nigra and the basal ganglia
What is the treatment of Parkinson’s?
L-Dopa (issues are nausea, dyskinesia, effects of treatment wearing off)
Dopamine agonists (bromocriptine - less side effects and delay need to start l-dopa)
MAOB inhibitors
Anticholinergics (useful in drug induced tremor)
Surgery such as deep brain stimulation may be useful in some cases
What are the causes of tremor?
Resting - Parkinsonism
Postural - benign essential tremor, anxiety, thyrotoxicosis, CO2, hepatic encephalopathy, alcohol
Intention - cerebellar disease
What are the clinical signs of hereditary sensory motor neuropathy?
Wasting of distal lower limb muscles with preservation of thigh muscles (inverted champagne bottle)
Pes cavus Weakness of ankle dorsiflexion and toe extension Stocking sensory loss High stepping gait (foot drop) Stamping (absent proprioception) Wasting of hand muscles
What are the types of hereditary sensory motor neuropathy?
Also known as Charcot-Marie-Tooth disease
HSMN 1 (demyelinating) HSMN 2 (axonal)
Autosomal dominant inheritance
What is the management of hereditary sensory motor neuropathy?
No disease modifying treatments available Multi-disciplinary team approach Orthotics Occupational therapy Analgesia
What are the causes of pes cavus?
Unilateral: burns, previous compartment syndrome, poliomyelitis, spinal trauma, spinal cord tumours
Bilateral: Friedrich’s ataxia, muscular dystrophy, cerebral palsy, syringomyelia, hereditary spastic paraparesis, hereditary sensory motor neuropathy
What are the causes of a predominantly sensory peripheral neuropathy?
Metabolic: Diabetes, vitamin deficiencies
Toxic: Alcohol, medications (isoniazid), chemotherapy
Auto-immune: rheumatoid arthritis, Hypothyroidism, vasculitis, GBS, SLE
Infective: herpes zoster, HIV
Haematological: MGUS, myeloma, lymphoma
Genetic: Charcot-Marie-Tooth disease
What are the causes of a predominantly motor peripheral neuropathy?
Acute: Gullian-Barre, botulism
Lead toxicity
Porphyria
HSMN
What are the clinical signs of Friedrich’s ataxia?
Young adult with an ataxic gait
Pes cavus
Bilateral cerebellar ataxia
Leg wasting with absent reflexes and bilateral upgoing plantars
Posterior column signs (loss of vibration and proprioception)
Others: high arched palate, kyphoscoliosis, HOCM, diabetes (check urine glucose)
What do you know about Friedrich’s ataxia?
Inheritance is usually autosomal recessive
Onset is during teenage years
Survival rarely exceeds 20 years from diagnosis
Association with HOCM and a mild dementia
What are the causes of extensor plantars with absent knee jerks?
Friedrich’s ataxia
Subacute combined degeneration of the cord
Motor neurone disease
What are the clinical signs of a facial nerve palsy?
Unilateral facial droop
Absent nasolabial fold
Absent forehead crease
Inability to raise eyebrows, screw eyes up or smile
How can you localise the lesion causing facial nerve palsy?
Pons (MS, stroke) - VI palsy and long tract signs
Cerebellar-pontine angle (Acoustic neuroma) - V, VI and VIII and cerebellar signs
Auditory/facial canal (Cholesteatoma, abscess) - VIII
What are the causes of a unilateral facial palsy?
Bell’s palsy is the commonest Herpes-zoster (ramsay hunt syndrome) Mononeuropathy (diabetes, sarcoid, Lyme) Tumour MS/stroke
What are the causes of a bilateral facial palsy?
Guillian Barre Myasthenia gravis Sarcoidosis Bilateral Bell’s palsy Lyme disease
What is Bell’s palsy?
Rapid onset facial nerve palsy
HSV-1 implicated
Swelling and compression of the nerve within the facial canal
Treatment: prednisolone, aciclovir, eye protection
Prognosis: 70-80% make a full recovery, more common and may have poorer outcomes in pregnancy
What are the clinical signs of myasthenia gravis?
Bilateral ptosis Complicated bilateral extra-ocular muscle palsies Myasthenic snarl Nasal speech Proximal muscle weakness in upper limbs with fatiguability Normal reflexes Sternotomy scars (thymectomy) Assess FVC
What other conditions may be associated with myasthenia gravis?
Diabetes Rheumatoid arthritis Thyrotoxicosis SLE Thymomas
What is the cause of myasthenia gravis?
Anti-nicotinic acetylcholine receptor antibodies affect motor end plate neurotransmission
How would you investigate a patient with suspected myasthenia gravis?
Anti acetlycholine receptor antibodies present in 90%
Anti-MuSK often positive if above negative
EMG - decreased response to titanic train of impulses
Tensilon test
CT (thymoma), thyroid function
How would you treat a patient with myasthenia gravis?
IV immunoglobulin or plasmapharesis in acute setting
Acetylcholine esterase inhibitor (pyridostigmine)
Immunosuppression (steroids, azathioprine)
Thymectomy usually beneficial even if patient does not have a thymoma
What is Lamber-Eaton myasthenic syndrome?
Diminished reflexes that improve after exercise
Lower limb girdle weakness
Associated with malignancy
Antibodies block presynaptic calcium channels
“Second wind” on EMG
What are the causes of bilateral extra ocular palsies?
Myasthenia gravis
Graves disease
Miller-Fischer syndrome
Cavernous sinus pathology
What are the causes of a bilateral ptosis?
Congenital Senile Myasthenia gravis Myotonic dystrophy Bilateral Horner’s syndrome
What are the clinical signs of tuberous sclerosis?
Butterfly rash, periingual fibromas, Shagreen patch, Ash leaf macules Cystic lung disease Polycystic kidneys Evidence dialysis or renal transplant White patches on retina Seizures Signs of epileptic treatment
What is tuberous sclerosis?
Autosomal dominant condition with variable penetrance
80% have epilepsy
Cognitive defects in 50%
How would you investigate a patient with suspected tuberous sclerosis?
Skull xray - railroad calcifications
CT/MRI head - tuberous mass in cerebral cortex
Echo
Abdominal USS - renal cysts
What are the clinical signs of neurofibromatosis?
Cutaneous neurofibromas Cafe au lait patches >15 Axillary freckling Lisch nodules in the iris Hypertension (renal artery stenosis, phaeochromocytoma) Fibrosis Neuropathy with large palpable nerves Reduced visual acuity
What is the inheritance of neurofibromatosis?
Autosomal dominant Type 1 (chromosome 17) is classical peripheral form Type 2 (chromosome 22) is central and presents with bilateral acoustic neuromas and deafness
What conditions is neurofibromatosis associated with?
Phaeochromocytoma
Renal artery stenosis
What are the complications of neurofibromatosis?
Epilepsy
Sarcomatous change
Scoliosis
Mental retardation
What is a Horner’s pupil?
Ptosis
Sunken eye
Anhydrosis
What are the causes of a Horner’s pupil?
MS, Stroke (Brain stem)
Syrinx (Spinal cord)
Aneurysm, trauma, Pancoast tumour (neck)
What is a Holmes-Adie pupil?
Moderately dilated pupil with a poor response to light and sluggish accommodation
May have absent ankle and knee jerks
A benign condition that is more common in females
What is an Argyll Robertson pupil?
Small, irregular pupil which accommodates but does not react to light
Atrophied and depigmented iris
Look for sensory ataxia
Usually a manifestation of quaternary syphyllis, but may be related to diabetes
What are the clinical signs of an oculomotor nerve palsy?
Complete ptosis
Dilated pupil
Eye points down and out
What are the causes of an oculomotor nerve palsy?
Medical: mononeuritis multiplex, midbrain stroke, MS, migraine
Surgical: posterior communicating artery aneurysm, cavernous sinus pathology, cerebral uncus herniation
What are the clinical signs of optic atrophy?
Relative afferent pupillary defect
Disc pallor
What are the causes of optic atrophy?
Glaucoma, tumour, Paget’s and MS most common
Retinitis pigmentosa
Central retinal artery occlusion
Friedrich’s ataxia
Tertiary syphyllis
What are the clinical signs of age related macular degeneration?
Drusen
Fibrosis
Neovascularisation
What are the causes of age related macular degeneration?
Risk factors: age, white race, family history, smoking
Associated with coronary artery disease and stroke
What are the causes of retinitis pigmentosa?
Friedrich’s ataxia
Kearns-Sayre syndrome
Congenital: usually autosomal recessive
Acquired: post-inflammatory retinitis
No treatment although vitamin A may slow progression
What are the clinical signs of retinal artery occlusion?
Pale fundus with thread like arterioles
Cherry red macula
May have signs AF or a carotid bruit
What are the causes of retinal artery occlusion?
Embolic (carotid plaque rupture) - treat with aspirin, anticoagulation and endarterectomy
Giant cell arteritis - high dose steroids
What are the clinical signs of retinal vein occlusion?
Flame haemorrhages
Swollen optic disc
Cotton wool spots
Tortuous veins
May have visual field defect or signs hypertension and diabetes
What are the causes of retinal vein occlusion?
Hypertension
Hyperglycemia
Hyperviscocity (myeloma)
High intraocular pressure (glaucoma)
How would you differentiate cerebellar ataxia from sensory ataxia on examination?
Cerebellar ataxia usually has associated nystagmus and dysarthria
Sensory ataxia usually has sensory impairment, particularly joint position sense and vibration sense.
In sensory ataxia, finger-nose test may be normal with eyes open, but impaired with eyes closed
How would you investigate a patient with cerebellar ataxia?
MRI is far superior to CT for looking at brainstem lesions
However, CT important in the acute setting to rule out haemorrhage
Investigate the cause- LP if ?MS, thyroid function tests
What are the causes of sensory ataxia?
Central: spinal cord pathology (dorsal column damage) - cervical myelopathy
Peripheral neuropathy - alcohol, diabetes, b12 deficiency, platinum chemotherapies, HIV, Sjorgren’s syndrome, paraneoplastic syndrome
Combined peripheral and central: B12 deficiency
How would you investigate a patient with peripheral neuropathy?
Look for the cause
Urine dip, fundoscopy, blood glucose
Bloods: FBC, haemantinics, HbA1c, auto-immune screen, vasculitis screen, HIV tests, paraproteins
Nerve conduction studies to distinguish between axonal and demyelinating conditions
Full history including social and family history
