Neurology Flashcards
Explain the cause of myotonic dystrophy
Genetic condition with two types depending on gene defect.
Autosomal dominant and shows genetic anticipation
Name three neurological conditions that exhibit genetic anticipation
Myotonic dystrophy
Huntington’s chorea
Friedrich’s ataxia
Name causes of bilateral ptosis
Congenital
Myasthenia gravis
Myotonic dystrophy
Name causes of unilateral ptosis
Third nerve palsy
Horner’s syndrome
Name non-neurological issues associated with myotonic dystrophy
Cataracts
Cardiomyopathy
Arrhythmia
Diabetes
Testicular atrophy
Dysphagia
How is myotonic dystrophy diagnosed?
Genetic testing - DMPK/ZNF9 gene
EMG - dive bomber potentials
Name some causes of unilateral cerebellar syndrome
Demyelination, ie multiple sclerosis
Stroke - posterior infarct or haemorrhagic
Tumour
Multiple system atrophy
Name some causes of bilateral cerebellar syndrome
Demyelination, ie multiple sclerosis
Paraneoplastic syndromes
Bilateral posterior circulation stroke
Tumour
Multiple system atrophy
Drugs eg phenytoin, lithium, carbamazepine
Alcohol
Metabolic conditions eg wilsons, b12 deficiency, hypothyroidism
Infections eg lyme disease, HIV, syphilis
Miller fisher GBS (inflammatory)
Hereditary eg friedrich’s ataxia, ataxic telangiectasia
Neurofibromatosis
Name signs found in cerebellar syndrome
Dysdiadochokinesis
Ataxia
Nystagmus
Intention tremor
Slurred or staccato speech
Hypotonia/hyporeflexia
What is most likely underlying condition if patient has cerebellar signs AND internuclear ophthalmoplegia and spasticity
MS
What is most likely underlying condition if patient has cerebellar signs AND clubbing, tar stained fingers
Bronchial carcinoma
What is most likely underlying condition if patient has cerebellar signs AND stigmata of liver disease?
Alcoholic cerebellar degeneration
What is most likely underlying condition if patient has cerebellar signs AND neuropathy?
Alcoholic cerebellar degeneration
Friedrich’s ataxia
What is most likely underlying condition if patient has cerebellar signs AND gingival hyperplasia?
phenytoin toxicity
How is multiple sclerosis diagnosed?
CNS demyelination disseminated in space and time
MRI - white matter plaques
CSF - oligoclonal IgG bands. Increased protein
Visual evoked potentials - delayed velocity but normal amplitude
What is the sign of internuclear ophthalmoplegia?
eg if lesion on left, on looking to the right right eye has nystagmus and left eye is unable to adduct. both eyes look to left and converge normally.
How is multiple sclerosis managed?
MDT approach
Nurses, physio, OT, social worker, physician
Chronically - interferon beta reduce relapse rate but not progression. Monoclonal antibodies can reduce disease progression. Antispasmodics, carbamazepine for neuropathic pain
Acutely - methylpred to shorten duration
What are the clinical diagnostic criteria for a total anterior circulation stroke?
Unilateral weakness (and/or sensory deficit) of face AND arm AND leg
AND
Homonymous hemianopia
AND
Higher cerebral dysfunction
What are the clinical diagnostic criteria for a total anterior circulation stroke?
Unilateral weakness (and/or sensory deficit) of the face AND arm AND leg
AND
Homonymous hemianopia
AND
Higher cortical dysfunction
What are the clinical diagnostic criteria for a total anterior circulation stroke?
What blood vessel is involved in a total anterior circulation stroke?
middle and anterior cerebral arteries
What are the clinical diagnostic criteria for a partial anterior circulation stroke?
TWO of
Unilateral weakness (and/or sensory deficit) of face AND hand AND leg
Homonymous hemianopia
Higher cortical dysfunction
OR
Higher cortical dysfunction alone
What are the clinical diagnostic criteria for a posterior circulation stroke?
ONE of:
Cranial nerve palsy AND contralateral motor and/or sensory deficit
Homonymous hemianopia
Cerebellar dysfunction
Conjugate eye movement disorder
Bilateral motor or sensory deficit
What are the clinical diagnostic criteria for a lacunar stroke?
ONE of:
Sensory deficit
Motor deficit
Sensori-motor deficit
Ataxic hemiparesis
NO higher cortical dysfunction
What are some acute and subacute complications of stroke?
Acute:
Haemorrhagic transformation
aspiration pneumonia
Subacute:
Pressure sores
DVT
PE
Pneumonia
What is the immediate management of suspected stroke?
CT scan
Depending on results and time since onset:
If ischaemic and
If large vessel occlusion and within 6 hours - discuss with IR re ?thrombectomy
If within 4.5 hours - IV thrombolysis
Admission to hyperacute stroke unit for MDT management
Aspirin and PPI asap if no thrombolysis. Aspirin after 24 hours if thrombolysis for 2 weeks.
If AF start anticoag after 2 weeks, otherwise switch aspirin to clopidogrel
High dose statin after 48 hours
IPCS for thromboprophylaxis
What is the long term management of stroke?
MDT approach
After 2 weeks, switch aspirin to either clopi or anticoagulation
High dose statin
Blood pressure management if appropriate
Physio
SALT input
What are the signs involved in lateral medullary syndrome?
Loss of pain and temperature sensation CONTRALATERAL to the lesion
Cerebellar signs/nystagmus/horner syndrome IPSILATERAL to the lesion
How does lateral medullary syndrome come about?
Occlusion of posterior inferior cerebellar artery or vertebral artery.
Spinothalamic tract decussates below the point of the medulla, hence contralateral symptoms
What are the most common causes of a spastic paraparesis?
Demyelination, ie MS
Cord compression
Trauma
Anterior horn cell disease, ie MND
Cerebral palsy
What would be the common causes of a spastic paraparesis AND a sensory level?
Cord compression, due to trauma, tumour, abscess, haematoma
Cord infarction
Transverse myelitis, due to neuromyelitis optica, infection, autoimmune disease or sarcoid
What would be the suspected causes of spastic paraparesis AND loss of vibration sense and proprioception?
MS
Friedrich’s ataxia
Syphilis
Subacute combined degeneration of the cord
Cervical myelopathy
What would be the suspected causes of spastic paraparesis AND loss of pain and temperature sensation?
Syringomyelia
Anterior spinal artery infarction
What nerve roots control the patellar reflex?
L3/L4
What nerve roots control the ankle jerk reflex?
S1/S2
What nerve roots control hip flexion?
L2/L3
What nerve roots control foot dorsiflexion?
L4/L5
What is the aetiology of Charcot-Marie-Tooth disease?
Group of hereditary neuropathies. Different genetics depending on subtype, most often autosomal dominant or x-linked. CMT 1, 3 and 4 are demyelinating, whereas CMT 2 is an axonal pathology.
What are the presenting features and clinical signs of Charcot-Marie-Tooth disease?
Muscle wasting of small muscles of feet, progresses proximally, in time also affects the upper limbs.
Distal to proximal sensory loss of all modalities, loss of proprioception can lead to sensory ataxia.
Areflexia.
CMT3 usually presents in infancy whereas CMT1 presents by 10 years and CMT2 in the second decade.
What are the differentials for a patient presenting with peripheral neuropathy?
Alcohol excess
Diabetes mellitus
B12 deficiency
Thyroid disease
Infection - HIV, syphilis
Vasculitis
Amyloidosis
Heavy metal poisoning
Drugs eg vincristine
What are the key investigations for peripheral neuropathy?
For underlying condition: check vitamins, thyroid, blood glucose/HbA1c, TFT, LFT, BBV screen, VDRL, serum protein electrophoresis.
Nerve conduction studies
In select cases, may also need:
Nerve biopsy
Imaging of central nervous system
CSF analysis
What are the typical features of Guillain-Barre syndrome?
Progressive weakness of all 4 limbs
Areflexia
Near symmetrical
Mild sensory symptoms, if any
Autonomic dysfunction
Often few weeks after infective illness
High CSF protein
What are the clinical findings in syringomyelia?
At affected levels: -Weakness and wasting of small muscles of the hand
-Loss of upper limb reflexes
-Loss of pain and temperature sensation, preserved proprioception and vibration sense until later stages. Shawl like distribution.
Below affected levels - upper motor neurone signs.
DDX for generalised wasting of hand muscles
Anterior horn cell - MND, syringomyelia, cervical cord comp, polio
Brachial plexus injury
Peripheral nerve - combined median and ulnar entrapment, peripheral neuropathy
Disuse atrophy eg MSK conditions
What is chorea?
Movement disorder causing sudden uncontrollable movements of limbs and facial muscles.
Causes of chorea
Hereditary - Huntingtons, Neuroacanthocytosis, Wilson’s, Benign hereditary chorea
Immune - Sydenham’s chorea, SLE
Drug induced - phenytoin, carbamazepine, valproate, gabapentin, amphetamines, cocaine, methylphenidate, lithium, levodopa, dopamine agonists.
Infection - AIDA, lyme disease
Vascular - post infarct.
Hormonal - hyperthyroidism, hypoparathyroidism, pregnancy
Investigations for chorea
Bloods - FBC, U and E, bone profile, Mg, LFT, TFT
BBV screen, VDRL
Immune - ESR, ANA
Antistreptolysin O titre (if suspected trigger is strep infection)
Caeruloplasmin and 24 hr urine copper
MRI
EEG - if need to differentiate seizures from involuntary movement
Features of Huntington’s
Chorea
Low tone
Personality/mood change
Occulomotor changes, slow saccades
Dysarthria
Ataxia
Progressive
Genetics of Huntington’s
Autosomal dominant
100% penetrance
Usual onset around 40 years
Diagnosed by number of CAG repeats, with >40 being unequivocally abnormal.
What is the pathophysiology of MS?
Acquired immune mediated inflammatory condition causing demyelination throughout CNS.
What are the patterns of MS?
Relapsing-remitting
Secondary progressive
Primary progressive
Investigations for MS
MRI
LP - oligoclonal bands
Visual evoked potentials
Presentation for MS
Can present with pretty much any neurology, commonly:
-Monocular visual loss, painful eye movements (optic neuritis)
-Diplopia
-Sensory disturbance
-Weakness
-Balance issues
-Transverse myelitis
-Autonomic dysfunction
Management of MS
-Flares- methylprednisolone 5/7
-Disease modifying - interferon beta, glatiramer, MAbs
-MDT - PT/OT
-Lifestyle - smoking cessation, inform DVLA
What is the genetic basis of Friedrich’s ataxia?
Autosomal recessive
Mutation of Frataxin gene on chromosome 9; usually a repeat expansion
Decreased frataxin protein results in oxidative damage to cells, primarily CNS and heart
Presentation in Friedrich’s ataxia
Unsteadiness/incoordination is usually the presenting symptom
Cardiomyopathy
Scoliosis, pex cavus
What is the type of ataxia in Friedrich’s ataxia?
Usually afferent, due to degeneration of dorsal root ganglia.
May have dysarthria if CNs involved
Other neurology in Friedrich’s ataxia
Extensor plantars
Areflexia
Pyramidal lower limb weakness
Hearing loss, visual disturbances
Upper limb myotomes
C5 - elbow flexors
C6- wrist extensors
C7 - elbow extensors
C8 - finger flexors
T1 - finger abductors
Polio transmission route
Feco-oral
Polio incubation
2-35 days
What structure is affected by polio?
Predominantly anterior horn.
Also posterior horn, thalamus, hypothalamus, brain stem.
What is post polio syndrome?
new, insidious onset of weakness, fatigue and pain with additional muscle atrophy years after the acute infection
What proportion of those with polio paralysis develop post-polio syndrome?
Over 2/3
What are the symptoms of post-polio syndrome?
Fatigue, myalgia, exercise intolerance, decreased endurance, joint pain
Also cold intolerance and dysphagia
Cerebellar syndrome signs
Arms - dysdiadochokinesia, intention tremor, past pointing (dysmetria)
Legs- ataxic gait, heel shin incoordination
Face - nystagmus (towards lesion), slurring or staccato speech, titubation
Causes of sensory ataxia
Peripheral neuropathy, tabes dorsalis (DCML), Subacute degeneration of the cord, demyelination
