14 - Abnormal gait Flashcards
More Na/Ca/K inside or outside cell? What does this cause?
What happens during depolarisation?
Repolarisation?
Na and Ca outside of the cell, K inside.
The difference between the two leads to a negative charge inside the cell (what is physics?) – roughly -70mV
During depolarisation, Na enters the cell through channels causing the difference to reduce until it reaches 40mV.
K channels open and potassium leaves the cell. Repolarisation.
Na/K channels then restore and maintain the resting potential
Couple ways to try and clinically differentiate ischemic and haemorrhage strokes?
What other thing do you have to exclude that mimics
Trauma, Previous,
often ischemic dont cause headache
HYPOGYCLAEMIA
What is ROSIER for strokes
Recognition of stroke in emergency room
If BM abnormal then correct LoC/Syncope = -1 Seizure = -1 Asymmetric facial weakness = +1 Asymmetric arm weakness = +1 Asymmetric leg weakness = +1 Speech disturbance = +1 Visual field defect = +1 Score greater than 0 = stroke is likely, call stroke team for CT and thrombolysis
Acute stroke Mx
CT ASAP
300mg aspirin daily for 2/52 if ischaemic
Thrombolysis with alteplase if ischaemic
Reverse anticoagulation and refer to neurosurgery for haemorrhagic
Types of stroke syndromes ?
TACI anterior circulation. motor and sensory defects + homonymous hemianopia + higher dysfunction (dysphasis, visuospatial disturbances, altered consciousness)
PACI two of the above.
POCI = posterior circulation. CN palsy + contralateral motor/sensory defect, cerebellar dysfunction, nystagmus, bilateral sensorimotor defects, homonymous hemianopia (isolated)
Lacunar: pure motor or pure sensory.
What is cushings triad in strokes?
Hypertension
bradycardia
irregular respirations
(Raised ICP causes decreased heart rate)
Where is bleeding in SAH
Between arachnoid and pia
Rfs for SAH
Autosomal dominant polycystic kidney disease ADPKD (berry aneurysms)
Any other tings for vascular….
Some features of SAH
Thunderclap headache
reduced GCS, seizures, vomiting, meningism
Subdural caused by what vessel? Time period ? shape on CT
bridging veins
signs of raised ICP / mass effect
Often takes weeks
Crescent
Epidural is where? usual vessel and cause? Common feature ?
shape?
Mx?
Blood between dura mater and skull
Usually caused by acceleration-deceleration injuries meningeal arteries.
Lucid period between injury and LoC
Trauma.
Punched appearance on CT due to arterial pressure
Haematoma evacuated via Burr hole craniotomy
When do you use ABCD2 ? what is it?
For use on pts with suspect TIA with NO NEURO SIGNS
Age 60+ = 1 BP 140/90 = 1 Clinical features: Unilateral weakness (2), Speech disturbance (1) Duration 60mins+ (2), 10-60 mins (1) Diabetes = 1
If you suspected TIA - What to do?
300mg asprin daily
What is CHADVASC for ? what is it? What scoring system do you compare to?
Risk of stroke with AF
CCF Hypertension Age 75+ DM Stroke (2) Vascular Disease Age 65-74 Sex
Compare score with HASBLED to evaluate pros and cons of anticoagulation
HASBLED score for?
What is it?
Major bleeding on anticoagulants
Hypertension Abnormal Liver function Abnormal renal function Stroke Bleeding Labile INRs Elderly Drugs Alcohol
Key CNS parts in voluntary movement
Motor cortex -> basal ganglia ->cerebellum -> brainstem -> corticospinal (pyramidal) tracts -> LMNs
Compare UMN and LMN signs
Reflexes Muscle tone Fasiculation Atrophy Babinski sign
UMN Reflexes - hyper Muscle tone - increased / spastic Fasiculation - No Atrophy - no Babinski sign - positive
LMN Reflexes - hypo Muscle tone - decreased / flaccid Fasiculation - present Atrophy - severe Babinski sign - no
3 main features of parkinsons
resting tremor
bradykinesia
rigidity
Features of parkinsons ? Overlap with side effects of which drugs?
Neurological: Anosmia, postural instability, reduced dexterity, micrographia, decreased arm swing, blank facies, dysphagia, neuropathy,
Autonomic: Constipation, sexual dysfunction, sweating, incontinence, drooling, dizziness,
Psychiatric: depression, insomnia, amnesia, emotional volatility, poverty of thought, visual hallucinations
Antipsychotic
Motor signs in parkinsons …
Symmetric?
most common initial sign?
how does this progress?
Typically asymmetric
resting tremor in an upper extremity
Over time, patients experience progressive bradykinesia, rigidity, and gait difficulty
Axial posture becomes progressively flexed and strides become shorter
Postural instability (balance impairment) is a late phenomenon
What is carbidopa?
peripheral DOPA decarboxylase inhibitor),
.
Prevents peripheral side effects.
Does not cross B-B Barrier
What is COMT
(catechol-o-methyltransferase) inhibitor (Entacapone): reduces peripheral metabolism of levodopa.
What causes normal pressure hydrocephalus?
What can it mimic?
Due to decreased CSF absorption
Usually in elderly
Important reversible cause of dementia.
Due to presentation usually MISDIAGNOSED as Alzheimer’s, CJD, Parkinson’s etc.
What happens in normal pressure hydrocephalus ?
Sx?
Accumulation of CSF in ventricles -> dilation
Usually cerebral aqueduct obstruction
NO sx of raised ICP
Symptoms instead result from distortion of brain structure
3 core features of normal pressure hydrocephalus
GAIT DISTURBANCE
URINARY INCONTINENCE
DEMENTIA
Wet, wobbly and wacky.
Key Sx in MS?
Famous exam signs?
Optic neuritis is hallmark as are paraesthesias, fatigue and weakness
Also: muscle cramps, depression, incontinence, ED, trigeminal neuralgia, pain, diplopia, cognitive deficits
Lhermitte’s sign: electric shock sensation illicted by bending head forward. Also seen in Behcet’s, B12 deficiency, radiation myelopathy and Arnold-Chiari malformation.
Uhthoff’s phenomenon: symptoms become worse in a hot environment such as weather, exercise, saunas/baths etc.
Cell causing damage in MS ?
Common triggers?
Destruction is T-cell mediated. B-B barrier breakdown allows T-cell entry.
Episodes usually preceded by an illness or provoked by a period of stress.
Diagnosis of MS
Via clinical scenario plus imaging
MRI is best. Gadolinium contrast.
You also see oligoclonal banding on LP.
Mx of MS ?
Think of Sx relief too…
Two branches: immunotherapies to treat the underlying disorder and other ancillary therapies which relieve the burden of symptoms.
Immune: prednisolone, plasmapheresis, interferon beta,
Depression: Selective serotonin reuptake inhibitors are preferred
Spasticity: Baclofen is effective in most cases
Pain: Tricyclic antidepressants are first-line drugs for primary pain
Sexual dysfunction: sildenafil
What is acute transverse myelitis? Common DD of which other illness?
How to diagnose?
Mx?
Spinal cord inflammation. Inflammatory attacks damage nerve fibres and myelin, which decreases electric conductivity.
Differential for MS, but also can be caused by it (cervical most common in MS)
Diagnosis - deficit attributable to spinal cord, signs bilaterally; do not have to be symmetrical.
Plasmapheresis - good prognosis
Causes of cerebral palsy ?
Hypoxic, infective, birth trauma, genetic and idiopathic causes
3 types of CP
ataxic, athetoid, spastic
Cerebllar sx?
DDK Ataxia Nystagmus Intention tremor Scanning Dysarthria Heel-Shin test +ve
What is duchenne muscular dystrophy?
Features?
less harmful variant of this disease?
X-linked syndrome of muscle loss (replaced by fat)
Progressive muscle weakness.
Symptoms usually appear at 6.
Survival past early 20s is rare.
Gower’s sign (use hands to walk up body to stand)
Becker is a less harmful variant
How is polio spread?
Sx
fecal oral
weakness + seroconversion illnes
What is guillain barre?
usual preceeding ting? complication?
mx?
Cross-reactive damage to peripheral muscles.
Diarrhoeal (Campylobacter) or URTI
Weakness and pain leading to paralysis
Allegedly from feet up.
Can paralyse respiratory muscles.
Long lasting and requires intense rehab
Treatment is supportive + Ig + plasmapheresis.
