Neuropathies Flashcards
Upper vs lower motor neuron
Tone
-upper: spasticity
-lower: normal or reduced
Power
-upper: lower limb flexor, upper limb extensor and suppinator weakness
Reflexes
-Hyperreflexia = CNS
-Hyporeflexia = probably PNS
Sensation
-Nerve or root territory = PNS
-Positional = PNS
Coordination
-In absence of weakness/sensory loss = CNS
Location
-One sided symptoms = CNS
-Symptoms in single limb = PNS
-Bilateral symptoms = either
Time course
-Acute without abnormal positioning = CNS
-Acute with abnormal positioning = PNS
Pain
-Usually peripheral
Atrophy and fasiculations in PNS
GBS overview
Epidemiology
-occurs in all ages, but more common with age
Pathophys
-Antibody cross reactivity
-Antibodies to Schwann cells, myelin or axons
Trigger
-Antecedant trigger in month prior for 75%
-Infection: C jejuni (most common), respiratory viruses, HIV, ?COVID
-Vaccinations: very rare
-Systemic stressor: surgery, trauma, illness
Time course
-Onset over days to a week
-Progression over 2-4 weeks
-CIDP after 8 weeks
Weakness
-Flaccid weakness or paralysis
-Symmetric, proximal and distal
-Legs and arms most common
-CN and bulbar common
Deep tendon reflexes
-Decreased or absent
Sensory
-Paraesthesia in hands and feet common
-Back and limb pain common
-Only mild sensory loss
Autonomic system
-Hyper/hypotension
-Brady/tachycardia
-Fever
-Urinary retention
-Ileus
LP
-Raised protein but not WCC classic
-Normal protein common if early
-Mild pleocytosis sometimes
Needle EMG
-decreased recruitment
Nerve conduction studies
-demyelination (majority) or axonal type
Treatment
-IVIg
-PLEX
-ICU for respiratory failure
MS overview
Epidemiology
-Female:male is 2:1
-Usually in 15-50 yrs
Pathophys
-Inflammatory autoimmune disorder
-Autoreactive lymphocytes
-Demyelination and axonal degeneration
Most common features
-Onset over hours to days. Lasts for weeks
-Mono or multi focal
-Sensory (positive and negative, any modality, hemi or bilateral signs)
-Motor (spasticity, paraparesis/plegia, cerrebellar)
-Reflexes (asymmetric hyperreflexia, clonus, babinski)
-Bowel, bladder, sexual dysfunction
-Optic neuritis (painful monocular visual impairment, worse with eye movements, afferent pupil defect)
-Eye movement abnormalities
-Pain (headache, back, spasms, neuropathic)
-Fatigue
-Lhermitte sign (electric shock sensation down back/limbs with neck flexion)
-Uhthoff phenomenon (heat sensitivity)
MRI Brain and spine
-White matter areas
-Hyperintense T2, hypointense T1
-Gad enhancing T1 with active plaques
LP
-If unable to meet criteria without it
-Oligoclonal IgG bands not found in serum
-Mild pleocytosis sometimes
-Normal protein and pressure
Evoked potential test
-subclinical lesions
Antibody testing
-atypical presentation, possible differentials
-AQP4 and MoG IgG
McDonald criteria
-Objective evidence of dissemination in time and space
Treatment
-High dose steroids for acute exacerbation
-PLEX if steroids ineffective
-Disease modifying therapy (monoclonal antibodies, oral therapies, injectables)
Neuropathy, myopathy or NMJ disease
Motor
-Proxima symmetric weakness supports myopathy
-Nerve, root or plexus distribution supports neuropathy
Sensory
-Significant loss supports neuropathy
Reflexes
-Normal in myopathy
-Variable in NMJ
-Loss supports neuropathy
Bulbar
-Neuropathy or NMJ
Symmetric proximal and distal weakness
Symmetric proximal and distal weakness
-with sensory loss: GBS
-without sensory loss: rare stuff
Asymmetric distal weakness
With sensory loss:
-mononeuritis multiplex
-mononeuropathy
-radiculopathy
Without sensory loss:
-MND
Symmetric distal sensory loss, with or without weakness
Metabolic (diabetes)
Drugs
Toxins
Hereditary
Subacute combined degeneration
Upper or upper and lower limbs
Painless
Symmetric sensory loss
Distal areflexia
Upper motor neuron signs
Autonomic nervous system involvement differentials
Diabetes
Amyloid
GBS
HIV
Drugs
Hereditary
MND overview
Epidemiology
-almost always sporadic
-increases with age
Pathophys
-Gene and environmental
-Degeneration and gliosis cortical and spinal motor neurons
Clinical features
-upper and motor neuron signs is classic. Can begin or stay as either
-limbs, neck or bulbar
-asymmetric distal onset most common
-UMN and LMN usually in same area
-weakness
-atrophy (split hand syndrome)
-relentless progression and spread
-frontotemporal dementia
Negatives
-no sensory loss
-no bowel or bladder dysfunction
-no ocular palsy
Treatment
-mostly supportive
-improved survival and slowed progression with riluzole and edaravone
