Neurology Flashcards
Glascow coma score
Eyes 4 - spontaneous opening 3 - opens on command 2 - opens in response to pain 1 - no opening
Verbal 5 - normal speech 4 - confused 3 - incoherent speech 2 - incomprehensible sounds 1 - no sounds
Motor 6 - norma movement 5 - localisation towards pain 4 - withdrawal from pain 3 - flexor response to pain 2 - extensor reponse to pain 1 - no movement
LMN lesion
Tone - flaccid Involuntary movement - fasciculations Reflexes - decreased Platar reflex - downgoing Weakness - present
UMN lesion
Tone - spastic Involuntary movement - none Reflexes - increased Platar reflex - up-going Weakness - present
Extrapyramidal lesion
Tone - rigid Involuntary movement - tremor Reflexes - normal Platar reflex - down going Weakness - absent
Muscle strength grading
5 - full power 4 - submaximal power against resistance 3 - full ROM against gravity withou resistance 2 - full ROM without gravity 1 - muscle flicker 0 - no muscle contraction
Neuromuscular disease overview
Motor neuron disease Weakness - segmental and asymetrical, distal->proximal Fasciculations - yes Reflexes - increased Sensory - no Autonomic - no EMG - denervation and reinervation NCS - normal Muscle enzyme - normal
Peripheral neuropathy Weakness - distal (except GBS) but may be assymetrical Fasciculations - yes Reflexes - decreased/absent Sensory - yes Autonomic - yes EMG - signsof demyelination+ axonal loss NCS - abnormal Muscle enzyme - normal
Neuromuscular junction Weakness - proximal and fatiguable Fasciculations - no Reflexes - normal Sensory - no Autonomic -no EMG - decremental response in MG, jitter on single fibre EMG NCS - normal Muscle enzyme - normal
Myopathy Weakness - proximal Fasciculations - no Reflexes - normal Sensory - no Autonomic -no EMG - small, short motor potentials NCS - normal Muscle enzyme - increased
Lumbar puncture
Samples Tube #1 cell count and differential Tube #2 chemistry: glucose and protein Tube #3 microbiology: gram stain + culture Tube #4 cytology Tube #5 cel count: compare to tube #1
Normal
- clear
- protein <0.45g/L
- glucose 60% of serum glucose, >3.0mmol/L
- 0-5 WBC, 0RBC, 0 neutrophil
Viral infections
- normal or slightly increased proteins <1g
- normal glucose
- <1000x10^6/L cells, lymphocytes mostly
Bacterial infections
- opalescent yellow
- increased protein >1g
- decreased glucose
- > 1000x10^6/L cells, mainly PMN
Granuomatous infections
- clear or opalescent
- increased protein but <5g/L
- decreased glucose
- <1000x10^6/L cells, mainly lymphocytes
Olfactory nerve deficits
Absence of smell
DDx:
- nasal obstructions
- olfactory neuroepithelial: destruction by viral infections
- central: Kallman’s syndrome, head injury, cranial surgery
- endocrine/metabolic: DM, adrenal dysfunction, vitamin deficiency
Optic nerve deficits
Acute visual loss
DDx
- Opthalmologic: acute angle closure glaucoma, vitreous hemorrhage, retinal detachment, uveitis, trauma
- Infection/inflammation: endophthalmitis
- Optic nerve; optic neuritis, anterior ischemic neuropathy, compression
- Vascular: TIA/amaurosis fugax, central retinal artery or vein occlusion, carotid-cavernous sinus fistula
- CNS: stroke, optic tract/chiasm lesion, migraine
Oculomotor nerve deficits
Ptosis, resing position depressed and abducted, dilated pupil. Vertical and horizontal diplopia
DDx
- Midbrain: complete unilateral 3rd nerve palsy, weakness of superior rectus and ptosis, contralateral pyramidal/cerebellar signs
- Posterior communicating artery aneurysm: early dilation of pupil, then CNIII palsy
- Cavernous sinus: associated with CN II, IV, VI, V1 and V2 deficits. Internal carotid aneurysm, meningioma, sinus thrombosis.
- Ischemia of CNIII: pupil sparing CN III palsy. DM, temporal arteritis, HTN.
Trochlear nerve deficits
Binocular vertical and torsional diplopia, downward and inward gaze. Difficulty going down stairs or reading.
DDx
- Common: ischemic, idiopathic, trauma, congenital
- Others: cavernous sinus, superior orbital fissure
Trigeminal nerve deficits
Ipsilateral facial numbness, weakness of muscle of mastication with pterygoid deviation towards the lesion.
DDx
- Brainstem: ischemia, syringobulbia, demyelination
- Peripheral: tumour, aneurysm, metastatic infiltration
- Trigeminal ganglion: acoustic neuroma, meningioma, fracure o middle fossa
- Cavernous sinus
- Trauma
- Others: trigeminal neuralgia, herpes zoster
Abducens nerve deficits
Inward deviation, inability to abduct on affected side.
DDx:
- Pons: facial weakness and contralaeral pyramidal signs
- Tentorial orifice: alse localising sign of increased ICP
- Cavernous sinus
- Vascular
- Congenital: Duane’s syndrome
Facial nerve deficit
LMN lesion: ipsilaeral facial weakness demonstrated by facial droop, flatened forehead, inability to close eyes, flattened nasolabial fold.
UMN lesion: contralateral facial weakness with forehead sparing
impaired lacrimation, decreased salviation, numbness behind auricle, hyperacusis, taste dysfunction of anterior 2/3
DDx
- Idiopathic: Bell’s palsy
- Others: temporal bone fracture, EBV, Ramsey-Hunt, otitis media/mastoiditis, sarcoidosis, DM, paotid gland disease
Glossopharyngeal nerve deficit
Taste dysfunction in posterior 1/3 tongue. Absent gag reflex and dysphagia. Glossopharyngeal neuralgia, sharp pain of posterior pharynx radiaing to ear, triggered by swallowing.
Vagus nerve deficit
oropharyngeal dysphagia, dysarthria. Uvula and palateal deviation away from lesion.
Accessory nerve deficit
LMN lesion: paralysis of ipsilateral trapezius and sternocleidomastoid.
UMN lesion: paralysis o ipsilateral sternocleidomastoid and contralateral trapezius
Accessory nerve deficit
LMN lesion: paralysis of ipsilateral trapezius and sternocleidomastoid.
UMN lesion: paralysis o ipsilateral sternocleidomastoid and contralateral trapezius
Hypoglossal nerve deficit
LMN lesion: tongue deviation toward side of lesion, ipsilateral tongue atrophy, fasiculations
UMN lesion: absence of atrophy and fasiculations
Seizure
Terminology
- Provoked: fever, trauma, metabolic, neoplasm
- Unprovoked: no structrural or metabolic cause
Generalised seizures
- involves the entire brain, can be convulsive or non-convulsive (absence)
- Tonic-clonic: prodrome of unease or irritability hours before attack, tonic phase (muscle contraction, trunk hyperextension, cry from respiratory muscle spasm, last 30secs) followed clonic phase (violent jerking, tongue biting, frothing, incontinence), typically followed by several mins of deep unconsciousness and post-ictal confusion, headache.
- Absence: usually only in children, un-responsive or 5-10secs with arrest in activity, no post-ictal confusion
- Tonic: decreased LOC, muscle contraction, drop attacke
- Clonic: decreased LOC with repetitive jerks
- Myoclonic: brief contractions localised to muscle groups of one or more extremeties
- Atonic: loss of posture, dop attack
Partial seizure
- simple (no change in LOC) or complex (alteration of mood, memory, perception)
- Motor: jerking or sustained spasm of localised muscles
- Sensory: numbness, tingling
- Autonomic: epigastric discomfort, pallor, sweatin, piloerection
- Psychiatric: more commonly complex
Investigations
- FBC, glucose, U&E, LFTs, CRP, calcium, magnesium
Treatment
- Avoid precipitating facors
- Medical therapy if 2 or more unprovoked seizures in last 6 months, known organic brain disease, EEG wih epileptiform activity, first episode of status epilepticus
- General seizures: lamotrigine, valproate, topiramate
- Partial seizures: carbamazepine, gabapentin, phenytoin, tiagabine
- Absent seizures: ethosuximide
- Stop driving until seizure free for 12 months
Status epilepticus
Sustained seizure activity >30mins can result in brain damage.
Management
1. ABCs
2. Vital signs + blood glucose finger prick
3. Lab investigations: U&E, Ca, Mg, PO4, glucose, FBC, toxicology, anticonvulsant levels, lumbar puncture
4. 50% glucose 50mL + thiamine 100mg
5. Lorazepam 1mg/kg at 2mg/min
If not controlled:
- Phenytoin 20mg/kg IV at max rate of 50mg/min
- Phenobarbital 1000-1500 mg IV slowly
Delirium
Acute onset, disorientation, marked variability, fluctuating level of consciousness, poor attention, and marked psychomotor change.
Etiology
- Vascular: subarachnoid haemorrhage, stroke/TIA
- Infections: meningitis, encephalitis, abcess
- Traumatic: diffuse axonal shear, epidural hematoma, subdural hematoma
- Autoimmune: acute CNS vasculitis, SLE
- Neoplastic: mass effect/edema, hemorrhage, seizure
- Seizure: status epilepticus
- Primary psychiatric: psychotic disorder, mood disorder, anxiety disroder
Dementia
Acquired generalised and progressive impairment of cognitive function associated with impairment in usual activities of daily living. 15% of those >65 have dementia, 60-80% AD, 10-20% vascular dementia.
Etiology
- Alzheimer’s disease: memory imparment, asphasia, apraxia, agnosia
- Lewy body dementia: visual hallucinations, parkinsonism, fluctuating cognition
- Frontotemporal dementia: behavioural presentation (disinhibition, decreased social awareness, mental rigidity, memory spared), language presentation (progressive non-fluent aphasia, semantic dementia)
- Parkinsonism
- Huntington’s: chorea
- Multi-infarct dementia: stepwise or progressive deterioration
- CNS vasculitis: systemic signs of vasculitis
- Chronic meningitis
- Chronic encephalitis
- Chronic abscess
- HIV
- Creutsfelt-Jacob disease
- Syphilis
- Diffuse axonal shear, epidural hematoma, subdural hematoma
- SLE
- Neoplastic/paraneoplastic
Reversible causes:
- Alcohol intoxication, withdrawal, Wernicke’s encephalopathy
- Medication: benzodiazepines, anticholinergics
- Heavy metals
- Hepatic or renal failure
- Wilson’s disease
- B12 deficiency
- Hypo/hyperglycaemia
- Hypo/hypercortisol
- Thyroid dysfunction
- normal pressure hydrocephalus
- Depression
- Brain tumour
- Subdural hematoma
History
- geriatric giants: confusion, incontinence, falls, polypharmacy, memory, safety, pyschiatric
- ADLs and IADLs
- alcohol, smoking
- OTC, medications, compliance
- vascular diase and head trauma hx
- collateral Hx
Issues to consider
- failure to cope
- fitness to drive
- caregiver education and stress, respite services
- power of attorney
- wills
- advance directives
Alzheimer’s disease
Progressive cognitive decline interfering with social and occupational functioning characterised by :
1) anterograde amnesia - inability to learn new information
2) one of the following cognitive disturbance:
- asphasia: language disturbance
- apraxia: impaired ability to carry out motor activities
- agnosia: failure to recognise or identify new objects
- disturbance in executive functions
Pathophysiology
- genetic: minority <7% of AD cases are autosomal dominant inheritence
- pathology: diffuse cortical atrophy, senile plaques, neurofibrillary tangles
Risk factors:
- age
- family Hx of AD
- head injury
- low education level
- smoking
- Down’s syndrome
Features:
- cognitive impairment
- psychiatric manifestations: major depressive disorder, psychosis, apathy
- motor manifestation late in disease
Mean duration of disease 10yrs
Lewy body dementia
Progressive cognitive decline interfering with social or occupational function, memory loss not usually an early feature. 15-25% of all dementias. One or two of the following features:
- fluctuating cognition with pronounced variation in attention and alertness
- recurrent visual hallucinations
- parkinonism
Etiology
- Lewy bodies found in both cortical and subcortical structures
- mixed DLB and AD pathology common
Treatment
- acetylcholinesterase inhibitors
Typical survival 3-6yrs
Frontotemporal dementia
Third most common cause of cortical dementia. Behavioural variant is more common and presents with social conduct disorder. Language variant presents with disorder of expressive language.
Features:
Core features:
1) Insidious onset and gradual progression
2) Early decline in social interpersonal conduct
3) Early impairment in regulation of personal conduct
4) Early emotional blunting
5) Early loss of insight
Supportive features:
1) Behavioural
2) Speech and language
3) Physical signs
Imaging shows predominantly frontal and/or anterior temporal lobe atrophy
Creutsfeldt-Jakob disease
Rare degenerative fatal brain disorder. Prion proteins causing alterations in the brain such as spongiform changes, astrocytosis and neuronal loss.
No known treatment
Aphasia
An acquired disturbance of language characterised by errors in speech production, writing, comprehension or reading.
- Broca’s area (posterior inferior frontal lobe): involved in speech production
- Wernicke’s area (posterior superior temporal lobe): involved with comprehension of language
- Angular gyrus is responsible for relaying written visual stimuli to Wernicke’s
- Arcuate fasciculu association bundle connects Wernicke’s to Broca’s
- Opposite side of hand dominance
Apraxia
Inability to perform skilled voluntary motor sequences that cannot be accounted for by weakness, ataxia, sensory loss, impaired comprehension or inattention
Agnosia
Disorder in the recognition of the significance of sensory stimuli in the presence of intact sensation and naming
Mild traumatic brain injury
Traumatic induced alteration in mental status that may involve loss of conciousness. Typically confusion and amnesia which may occur immediately after the trauma, LOC must be less than 30min and initial GCS must be 13-15.
Treatment
- early rehabilitation to maximise outcomes: OT, PT, SLP
- pharmacological managment of headaches, pain, depression
- CBT, relaxation therapy
- rest with adequate time before return to play sports
Paraneoplastic syndromes
Uncommon complication of cancer, may be presenting complaint, can be neurological, endocrine, hematological or other
Associated neoplasma
- small cell lung cancer: cerebellar degeneration, encephalitis, retinopathy, neuropathy, LEMS
- breast: cerebellar degeneration, encephalomyelitis, opsoclonus-myoclonus
- ovarian: cerebellar degeneration
- thyoma: myasthenia gravis
- other syndromes: necrotising myelopathy, motor neuron syndrome, neuropathies, mononeuritis multiplex, polymyositis, dermatomyositis, encephailtis
Investigations
- antibodies
Treatment
- often palliative
- consider steroids, IVIg, plasmapheresis, treatmentof malignancy
Movement disorders
Tremor
1) Postural:
- upper limbs, head, voice, fine tremor worse on outstretched arms, associated with family hx.
- physiologic, benign essential, drugs hyperthyroid, hyperglycemic
- Rx: propanolol, anticonvulsants, primidone, alcohol (for essential)
2) Intention:
- any location, coarse tremor, worse with finger to nose with cerebellar findings.
- cerebellar lesion, alcohol, MS, Wilson’s
- Rx: treat underlying cause
3) Resting:
- distal upper limbs, pill rolling, worse with rest while concetrating, associated with “TRAP”
- PD, Parkinsonism, Wilson’s disease
- Rx: l-dopa/carbidopa, anticholinergics, surgery, DBS
Chorea
- jerky involuntary movements affecting shoulder, hips, face
- PD therapy, Hungtinton’s
Dystonia
- abnormal muscle tone resulting in muscular spasm and abnormal posture
- primary dystone: familial, sporadic
- dystonia-plus syndromes
- secondary dystonia: thalamotomy, stroke, CNS tumour
- heterodegenerative dystonias: Parkinsonian disorders, Wilson’s disease, Huntington’s disease
Tics
- habitual spasmodic contraction of the muscles, most often in the face
- primary tic disorders: transient tic disorder, chronic tic disorder, Gilles de la Tourette
- secondary tic disorder: encephalitis, CJD, Syndenham’s chorea, head trauma, mental retardation
- association with OCD and ADHD
Parkinson’s disease
Loss of dopaminergic neurons in pars compacta of substantia nigra, thus reduced dopamine in striatum leading to disinhibiton of the indirect pathway and decreased activation of the direct pathway, causing increased inhibiton of the cortical motor areas.
Etiology
- Sporadic
- Familial 20%
- mean onset 60 yrs
Features
- tremor: pill rolling, resting
- rigidity, lead-pipe with superimposed cogwheeling due to tremor
- bradykinesia: slow small amplitude movements, difficulty initiating movement
- postural instability: late findings of falls, accerleration of steps
- masked facies, hypophonia, dyarthria, micrographia, shuffling git
- freezing: occurs iwth walking and triggered by initiating stride, lasts seconds
- cognition: slow thinking, dementia late finding
- behavioural: personality changes, decreased spontaneous speech, depression, sleep disturbances
- autonomic: later findings of constipation, urinary retention, sexual dysfuction
Treatment
- l-dopa and carbidopa is mainstay, complication of dyskinesia
- for early PD treatment: dopamine agonists, amantadine, MAOI
- adjuncts: dopamine agonists, MAOI, anticholinergics, COMT inhibitors
- surgical thalamotomy, deep brain stimulation
Parkinsonian disorders
Parkinsonism
- akinesia often accompanied by rigidity
Lewy body dementia
- flunctuating cognition, recurrent visual hallucinations, parkinsonism
Progressive supranuclear palsy
- limited vertical gaze
- early falls, axial rigidity, akinesia, dysarthria, dysphagia
Multiple system atrophy
Vascular parkinsonism
- multi-infarct presentation with lower body parkinsonism
Huntington’s disease
AD CAG repeats in Huntingtin gene on chromosome 4. Global cerebral atrophy, especially affecting the striatum leading to increased acitivty of the direct pathway and decreased activity of the indirect pathway. Mean onset 35-44 but varies with degree of anticipation.
Features
- insidious onset with clumsiness, fidgetiness, irritability, progressing over 15 yrs to dementia, psychosis and chorea
- chorea: begins in face, shrugging of shoulders, parakinesia (pseudopurposeful movement)
- dementia
- mood changes: irritability, depression, anhedonia, impulsivity, bouts of violence
- psychosis
MRI: enlarged ventricles, atrophy of cerebral cortex and caudate nucleus
Genetic testing
No disease altering treatment
- psychiatric symptoms: antidepressants and antipsychotics
- chorea: neuoleptics and benzodiazepines
- dystonia: botulinum toxin
Tourette’s syndrome
Presence of motor and vocal tics at some point during illness.
Multiple tics a day nearly everyday
Onset prior to 18yrs
Treatment
- clonidine, clonazepam
Prognosis
- begins at 5yrs of age, progressively increasing until 10yrs, improves in adolescence
- 50% tic free by 18yrs
Restless leg syndrome
Disorder characterised by an urge to move legs to relieve unpleasant sesations
- worse at night and with prolonged immobility
- described as crawling, aching, tingling sensation, lasting for 1 hr or longer
Investigations
- rule out iron deficiency anemia
- rule out venous insufficiency
Treatment
- warm baths, gentle stretching and massage, aimed at reducing stress and relaxing muscles
- if symptoms are unmanageable, medications such as low dose gabapentin may be used
Wernicke-Korsakoff syndrome
Deficiency of thiamine due to alcohol abuse
- acute: apathy, confusion, impaired EOM, ataxia
Gait disturbance
Disorders of balance:
- Cerebellar ataxia: wide-based without high stepping, veers to side of cerebellar lesion
- Sensory ataxia: wide-based with high stepping posture and positive Rhomberg (closing eyes while standing)
Disorders of locomotion
- Parkinsonian: small paces, stooped posture, reduced armswing
- Spastic: scissoring of legs, toe walking with bilateral circumduction
- Slapping: high stepping due to foot drop
- Apraxic: feet barely leave the ground, frontal lobe pathology
- Waddling gait: rotation of pelvis due to proximal muscle weakness
- Antalgic gait: asymmetric due to pain from MSK problem
Cerebellar ataxis
Etiology
- Congenital
- Hereditary
- Acquired
- neurodegenerative
- systemic: alcohol, celiac sprue, hypothroidism, thiamine deficiency
- toxins: CO, heavy metals, lithium, anticonvulsants
- vascular: infarct, bleed, basilar migraine
- auroimmune: MS
- children: tumours, post-viral
Motor neuron disease
Progressive neurodegenerative disease that causes UMN and LMN symptoms and is ultimately fatal. Occurs between 40-60yrs
Etiology
- genetis 5-10%, viral, autoimmune, paraneoplastic, idiopathic
Pathology
- degeneration and loss of motor neurons with astrocytic gliosis
- disorder of anterior horn cells of spinal cord, cranial nerve nuclei, and corticospinal tract
Features
- limb motor symptoms: segmental and asymmetrical UMN and LNM symptoms
- bulbar findings: dysarthria, dysphagia, tongue atrophy, and fasciculations
- pseudobulbar affect or emotional lability
- sparing of occular muscles and of sphincters
Investigations:
- EMG: devervation, reinnervation, fasiculations
- muscle biopsy: small angulated fibers (denervation) , fiber-type grouping
- rule out cord compression with CT and MRI
Management
- disease specific: riluzole - reduces damage to motor neurons by decreaseg release of glutamate
- muscle stiffness: baclofen, tizanidine
- sialorrhea: TCA, anticholinergics
- pseudobulbar affect: TCA, SSRIs
- non-pharmcological: ventilatory support, early nutritional support, rehabilitation, psychosocial support
Motor neuron disease
Progressive neurodegenerative disease that causes UMN and LMN symptoms and is ultimately fatal. Occurs between 40-60yrs
Etiology
- genetis 5-10%, viral, autoimmune, paraneoplastic, idiopathic
Pathology
- degeneration and loss of motor neurons with astrocytic gliosis
- disorder of anterior horn cells of spinal cord, cranial nerve nuclei, and corticospinal tract
Features
- limb motor symptoms: segmental and asymmetrical UMN and LNM symptoms
- bulbar findings: dysarthria, dysphagia, tongue atrophy, and fasciculations
- pseudobulbar affect or emotional lability
- sparing of occular muscles and of sphincters
Investigations:
- EMG: devervation, reinnervation, fasiculations
- muscle biopsy: small angulated fibers (denervation) , fiber-type grouping
- rule out cord compression with CT and MRI
Management
- disease specific: riluzole - reduces damage to motor neurons by decreaseg release of glutamate
- muscle stiffness: baclofen, tizanidine
- sialorrhea: TCA, anticholinergics
- pseudobulbar affect: TCA, SSRIs
- non-pharmcological: ventilatory support, early nutritional support, rehabilitation, psychosocial support
Peripheral neuropathies
Radiculopathy: dermatomal deficit from nerve root lesion
Neuropathy: peripheral nerve deficits
Diagnostic approach
1) Differentiate: motor, sensory, autonomic or mixed
2) Pattern of deficit: symmetry, focal vs diffuse, upper vs lower limbs, cranial nerve involvement
3) Temporal pattern: acute vs chronic, relapsing remitting vs constant vs progressive
4) History: PMH, detailed FHx, exposures, systemic symptoms
5) Detailed peripheral neuro exam: LMN findings, differentiate between root and peripheral nerves, cranial nerves, respiratory status
Etiology
- Vascular: PAN, SLE, RA,
- Infectious: HIV, leprosy, Lyme
- Immune: GBS, CIDP
- Hereditary:HMSN
- Neoplastic: paraneoplastic, myeloma, lymphoma, monoclonal gammopathy
- Toxin, alcohol, heavy metals, medications
- Metabolic: diabetes, hypothyroidism, renal failure
- Nutritional: B12 deficiency
- Other: porphyria, amyloid
Guillain-Barre syndrome
Acute rapidly elvolving polyneuropathy that often starts in the distal limbs and ascends. Viral/bacterial infections and vaccinations have been shown to predispose to GBS
Features:
- sensory: distal and symmetric parethesia, loss of proprioception and vibration sense, pain
- motor: weakness starting distally in legs, areflexia
- autonomic: blood pressure dysregulation, arrhythmias, bladder dysfunction
Investigations
- CSF: high protein, normal WBC
- EMG: conduction block, motor slowing
Treatment
- IVIg or plasmapheresis
- supportive management
Prognosis
- symptoms peaks at 2-3 wks, resolution at 4-6wks
- 5% mortality with 15% permenant substantial deficits
Myasthenia gravis
Damage and blockage of post-synaptic ACh receptors by specific antibodies. 15% have associated thymic neoplasia, 85% have thymic hyperplasia. Autoimmune disorder due to auto-antibodies. Onset women in 20’s, men in 60’s
Features:
- fatiguability and weakness of skeletal muscles without reflex, sensory or coordination abnormalities
- typically occular (diplopia, ptosis), bulbar (dysarthria/dysphagia), neck flexor/extensor weaknes, proximal limb weakness
- respiratory muscle weakness may lead to respiratory failure
Investigations
- EMG: decremental response to repetitive stimulation
- endrophonium test: can cause respiratory distress
- spirometry: forced vital capacity needs to be monitored
- anti-acetylcholine recptor antibody assay
- CT/MRI to screen for thyoma/thymic hyperplasia
Managment
- thymectomy 85% show improvement
- pyridostigmine (ACh inhibitors) for symptomatic relief
- immunosuppression: steroids, azathioprine, cyclophosphamide
- IVIg and plasmapheresis for crises
Lambert-Eaton myasthenic syndrome
Down-regulation of presynaptic voltage-gated Ca channels secondary to specific channel binding antibody, decreases amount of ACh released into synaptic cleft. 50-66% are associated with small cell carcinoma.
Features:
- weakness of skeletal muscles without sensory or coordination abnormalities
- reflexes diminished or absent, increase with repetitive muscle contraction
- bulbar and occular muscles affected in 25%
- prominent anticholinergic symptoms: dry mouth, impotence, constipation, blurred vision
Investigations
- no response to edrophonium test
- EMG: incremental reponse to repetitive stimulus
- screen for malignancy
Management
- tumour removal
- ACh modulation with pyridostigmine
- immunomodulation with steroids, plasmapheresis, IVIg
Botulism
Caused by toxin produced by spores of Clostridium botulimum bacteria.
Features:
- occur 6-48hr after ingestion
- difficulty with convergence, ptosis, paralysis of extraoccular muscles
- dilated poorly reactive pupils
- jaw weakness, dysarthria, dysphagia
- spreads to trunks and limbs, abdominal cramps with N+V, symmetric weakness with paralysis and absent/decreased tendon reflexes, anticholinergic symptoms
- rarely respiratory distress
Investigations
- blood test for toxin
- stool culture
Treatment
- botulinum anti-toxin
- supportive therapy
Myotonic dystrophy
Unstable CTG repeat in DMK gene, number of repeats correlates with severity of symptoms. AD inheritance, most common adult muscular dystrophy.
Features
- ptosis, bifacial weakness, frontal baldness, triangular face
- distal weaker than proxima, steppage gait
- delayed relaxation of muscles after exertion 9elicit by tapping thenar muscles with hammer)
- cardiac: 90% have conduction defects, heart block
- respiratory: hypoventilation secondary to muscle weakness
- ocular: subcapsula cataracts, retinal degeneration, decreased intraocular pressure
EMG: long runs with declining frequency and amplitude
Management
- no cure, progressive and death around 50yrs
- phenytoin used for management
Pain management
Non-pharmacological
- physical: PT, accupuncture, chiropracter, manipulation, massage
- psychoeducation: CBT, family therapy, education, psychotherapy
Medical
- primary analgesics: paracetamol, NSAIDs, opiates
- adjuvants: antidepressants (TCA, SSRIs), anticonvulsants (gabapentin, carbamazepine), baclofen, sympatholytics, a2-adrenergic agonists (clonidine, pregabalin)
Surgical
- direct delivery: implantable morphine pump
- central ablation: stereotactic thalamotomy, spinal tractotomy or dorsal root entry lesion
- peripheral ablation: nerve blocks, facet joint denervation
- DBS or dorsal column stimulation
Neuropathic pain
Pain resulting from a disturbance of the central or peripheral nervous system.
Features:
- hyperalgesia/allodynia
- burning, pricking, electric shock, numbness
- can be spontaneous or evoked
- distribution may not fall along classical neuro-anatomical lines
Associated issues:
- sleep difficulty
- anxiety, stress, mood alteration
- sexual dysfunction
Causes:
- Sympathetic: complex regional pain syndrome
- Central: phantom limb, post spinal cord injury, post stroke, MS
- Non-sympathetic: damage to peripheral nerves
Treatmetn
- treat underlying cause
- Pharmacotherapy: TCA, SNRI, anticonvulsant, long acting opiate, topical lidocaine,
- Surgical therapies: dorsal column stimulation, DBS
- Others: CBT, PT, acupuncture, meditation, massage
Trigeminal neuralgia
Recurrent episodes of sudden onset, excruciating unilateral parosxysmal shooting pain in the trigeminal root teritory V3>V2»V1
Etiology
- classic: idiopathic, compression by tortuous blood vessel
- secondary: cerebellopontine angle tumour, MS
- F>M, usually middle age to elderly
Management
- First line: carbamazepine
- Second line: lamotrigine
- Surgical treatment if medical treatment fails
Postherpetic neuralgia
Pain persisting beyound 4 months in the region of a cutaneous outbreak of herpes zoster. Destruction of sensory ganglion neurons secondary to herpes reactivation.
Features:
- Constant deep ache, burning, intermittent spontaneous lancinating/jabbing pain, allodynia
- Thoracic, trigeminal, cervical > lumbar > sacral
- Associated impaired sleep, decreased appetite, decreased libido.
- risk increases with age
Prevention
- varicella zoster vaccine reduces incidence of herpes zoster
- early treatment of acute herpes with acyclovir
- early treatment of herpes zoster with pain meds for 90d: amitryptiline, gabapentin
Treatment
- medical: TCA, gabapentin, opiate, lidocaine patch
- surgical: spinal tractomy, dorsal root entry zone lesion
Painful diabetic neuropathy
Determine if pain is neuropathic or vascular. Neuropathic pain affects the feet, is sharp/tingling, pain present at rest and improves with walking.
Treatment
- pregabalin
- amitryptyline, gabapentin, valproate, tramadol
Complex regional pain syndromes
Definition:
1) presence of an initiating noxious event
2) continuing pain, allodynia, or hyperalgesia with pain disproportionate to inciting event
3) evidence during the course of symptoms of edema, changes in skin blood flow or abnormal vasamotor activity
4) absence of conditions that would otherwise account for degree of pain and dysfunction.
Prevention
- early mobilisation after injury/infarction
Treatment
- goal of treatment: to allow active participation in rehabilitation
- conservative treatment: education, support groups, PT/OT, smoking cessation
- medical: topical capsaicin, TCA, NSAID
- referral to pain team
Tension headaches
Features:
- Prevelance: 70%
- Onset: 15-40yrs
- Sex bias: F>M
- Family hx: none
- Location: bilateral frontal, nuchal-occipital
- Duration: mins-days
- Course: gradual, worse in evening
- Quality: band-like, constant
- Severity: mild-mod
Triggers:
- depression, anxiety
- noise
- hunger, sleep deprivation
Palliating:
- rest
Associated Sx:
- none
Managment:
- non-pharmacological: counselling, heat, massage
- pharmacological: simple analgesics, TCA
Migraines
- Prevelance: 12%
- Onset: 10-30
- Sex bias: F>M
- Family hx: +++
- Location: unilateral>bilateral, frontotemporal
- Duration: hours-days
- Course: gradual, worse in evening
- Quality: throbbing
- Severity: mod-severe
Triggers:
- noise/light
- caffeine/alcohol
- hunger, stress, sleep deprivation
Palliating:
- rest
Associated Sx:
- nausea/vomiting
- photo/phonophobia
- aura
Management:
- acute: NSAIDs, triptans, ergotamine
- prophylaxis: TCA, anticonvulsants, propanolol, verapamil
Cluster headaches
- Prevelance: <1%
- Onset: 20-40
- Sex bias: M>F
- Family hx: +
- Location: retroorbital
- Duration: 10min-2h
- Course: daily attacks for weeks to months, more common early morning or late evening
- Quality: constant, aching, stabbing
- Severity: severe, wakes from sleep
Triggers:
- light
- alcohol
Palliating:
- walking around
Associated Sx:
- red watery eye
- nasal congestion
- unilateral Horner’s
Managment:
- acute: oxygen, sumatriptan
- prophylaxis: verapamil, lithium, prednisolone
Drugs affecting sleep
Antihistamines: increased sleepiness
Srimulants: increased arousal
Caffeine: increased wakefuness
Benzodiazepines: reduced slow wave sleep
Antidepressants: reduce REM, prolong REM latency
Alcohol: hastens cleep onset but associated with increased arousals
Sleep history
Initiation of sleep - events prior to sleep - lights - latency - restless legs - hallucinations Maintaining sleep - number of wakeups/night - sleep walking/talking - snoring/gasping - dreams/nightmares Consequence of sleep - restorative - morning headache - hypersomelence
Stroke pathophysiology
Ischemic
- Arterial: thrombus formation
= large vessel: typically involves stenosis or occlusion of internal carotid artery, or vertebral and intracranial arteries
= small vessel: chronic hypertension stimulates cerebral blood vessel wall thickening, affects small penetrating arteries and leads to lacunar infarcts in basal ganglia, internal capsule, and thalamus
- Cardioembolic: blockage from cardiac emboli, AF, rheumatic valve disease, prosthetic heart valves, recent MI, infectious IE
- Systemic hypoperfusion: inadequate blood flow, most commonly associated with pump failure. Leads to ischemia in watershed areas between major cerebral arterial territories.
Hemorrhagic:
- Intracerebral: most commonly involves rupture of Charcot-Bouchard aneurysms in putamen, thalamus, cerebellum, pons
- Subarachnoid: sudden thunderclap headache with meningism, cause by rupture of aneurysms in circle of Willis
Vascular territories
- ACA: contralateral leg paresis and sensory loss
- MCA: contralateral weakness and sensory loss of face and arm, cortical sensory loss, contralateral homonymous hemianopia/quadrantopia, aphasia (left hemisphere), neglect (right hemisphere)
- PCA: contralateral hemianopia/quadrantopia, alexia (left hemisphere), CN II and IV palsy, sensory loss, amnesia, decreased LOC, cortical blindness
- Basilar (locked in syndrome): quadriparesis or quadriplegia, anarthria, impaired horizontal eye movements, spared vertical eye movement
- PICA (lateral medullary syndrome): ipsilateral ataxia, ipsilateral Horner’s, ipsilateral facial sensory loss, contralateral limb impairment of pain and temperature sensation, nystagmus, vertigo, dysarthria
- Anterior spinal artery (medial medullary syndrome): contralateral hemiparesis (facial sparing), contralateral impaired proprioception and vibration sensation, ipsilateral tongue weakness
- Lacunar infarcts (deep hemispheric white matter, brainstem, internal capsule): pure motor hemiparesis, pure sensory loss, ataxic hemiparesis (ipslateral ataxia and leg paresis), dyarthria-clumsy hand syndrome
Ischemic stroke assessment and management
Initial assessment:
1) Has the patient had a stroke?
2) Is the patient a candidate for rtPA?
- onset: time last known symptom free
- mimics to rule out: seizure, hypoglycemia, migraine
- identify symptoms/deficits
Assessment
- CT signs: hypodensity of parenchyma, loss of cortical white-grey differentiation
- can appear normal on CT during first several hours, may require perfusion CT or CT angiography
Thrombolysis
- rtPA can be given within <6hrs of stroke onset provided there is no hemorrhage on CT
Antiplatelet therapy
- given at presentation for those with TIA or not eligible for rtPA, recommend aspirin or clopidogrel
Blood pressure control
- do not lower BP unless severe hypertension, withhold antihypertensive medication for at least 5 days after stroke
- administer if sBP >220mmHg or dBP >120mmHg in non-rtPA patients
- administer if sBP >185mmHg or dBP >110mmHg in rt-PA patients
- IV labetalol or IV nicardipine are first line
Other managment:
- avoid hyperglycemia
- lower temperature if febrile
- prevent complications: NPO, DVT prophylaxis, early rehabilitiation
Stroke prevention
Primary stroke prevention
- Hypertension: target BP <140/90, ACEi for first-line
- Cigarette smoking: smoking cessation
- Diabetes: HbA1c <50, fasting blood glucose 4-7
- Hypercholestrolemia: statins to reduce stroke risk with CAD or high risk of cardiovascular events
- Atrial fibrillation: CHADS2-VASc score >1 requires anticoagulation therapy, dabigatran, warfarin
- Exercise: regular physical activity
Secondary stroke prevention
- Antiplatelet therapy: ASA or clopidogrel
- Carotid stenting: carotid endarterectomy for those with >70% stenosis, 2wks post stroke
- Stoke rehabilitation
- everything in primary prevention
Cerebral hemorrhage
CT assessment: hyperdense areas.
Further investigations:
- lumbar puncture: if subarachnoid
- cerebral angiogram: if suspect aneurysm
- repeat CT head in 4-6wks after hemorrhage has resolved to rule out underlying lesion
Management
- Medical: antihypertensives, ICP lower managment if necressary
- Surgical
Multiple sclerosis
Chronic inflammatory disease of the CNS characterised by relapsing remitting or progressive neurologic symptoms due to inflammation, demyelination and axonal degeneration
Features:
- relapsing remitting 85%
- primary progressive 10%
- progressive relapsing 5%
- secondary progressive (most RRMS become SPMS)
MS variant’s
