Neuropathy Flashcards
What is a Radiculopathy?
Process affecting nerve roots
What is a Neuropathy?
Pathological process affecting a peripheral nerve(s)
What is a Mononeuropathy?
Process affecting a single nerve
What is a Mononeuritis multiplex?
Process affecting several individual nerves
What is a Polyneuropathy/peripheral neuropathy?
Diffuse, symmetrical disease, beginning peripherally
- motor, sensory, autonomic or a combination
- demyelinating/axonal types
- loss of tendon reflexes, ‘glove & stocking’ sensory loss
What are the causes of a polyneuropathy/peripheral neuropathy?
Metabolic Toxic Autoimmune Inflammatory Drugs Infective Vascular Neoplastic Inherited
What are the metabolic causes of a polyneuropathy/peripheral neuropathy?
Diabetes mellitus
B12/folate/thiamine deficiency
Uraemia (CKD)
What are the toxic causes of a polyneuropathy/peripheral neuropathy?
Alcohol
Chronic liver disease
Lead
Radiation
What are the autoimmune causes of a polyneuropathy/peripheral neuropathy?
RA
CTDs
Myxoedema
What are the inflammatory causes of a polyneuropathy/peripheral neuropathy?
Guillain-Barre syndrome
Chronic inflammatory demyelinating polyneuropathy (CIDP)
What are the drug causes of a polyneuropathy/peripheral neuropathy?
Amiodarone Statins Hydralazine Phenytoin Antibiotics
What are the infective causes of a polyneuropathy/peripheral neuropathy?
Syphilis
HIV
What are the vascular causes of a polyneuropathy/peripheral neuropathy?
Vasculitis
What are the neoplastic causes of a polyneuropathy/peripheral neuropathy?
Myeloma
Paraneoplastic syndromes
What are the inherited causes of a polyneuropathy/peripheral neuropathy?
Charcot-Marie-Tooth
-present <20yrs w/ progressive neuropathy
Freidrich’s ataxia
-cerebellar ataxia in 1st decade, UMN limb signs & peripheral neuropathy
What are the most common causes of a polyneuropathy/peripheral neuropathy?
Diabetes mellitus
Carcinomatous neuropathy
B vitamin deficiency
Drugs
What problems can longstanding polyneuropathy/peripheral neuropathy cause?
Claw deformities of foot (pes cavus) Joint arthropathies (charcot foot) Ulceration
What are the two broad pathological types of polyneuropathy/peripheral neuropathy?
Demyelinating
Axonal
What are the features of demyelinating polyneuropathy/peripheral neuropathy?
Damage affects Schwann cells
More common in immune-mediate disease (GBS)
-decreased conduction velocity
-Schwann cells regrow, improves w/ treatment
What are the features of axonal polyneuropathy/peripheral neuropathy?
Nerve cell body damage, degeneration starts at periphery and progresses towards neuronal cell
- reduced amplitude of nerve impulses
- axons cannot regrow, treatment outcomes poor
What other, less common patters of nerve damage are there?
Wallerian degeneration - following nerve section/microinfarction
Compression neuropathy - leads to focal demyelination
Nerve infiltration - malignancy/granulomatous infiltration
At what rate can nerves regenerate?
1mm/day
Requires intact cell bodies
What investigations are appropriate in suspected polyneuropathy/peripheral neuropathy?
Bloods - FBC, U&Es, LFTs, HbA1c, B12/folate, ANCA, VDRL, autoantibodies
Nerve conduction studies (demyelinating/axonal)
LP (raised protein in GBS/CIDP)
Peripheral nn biopsy
What is the underlying pathology of Guillain-Barre syndrome (GBS)?
Most common acute polyneuropathy
Demyelinating
Autoallergic basis, does not recur
How does GBS present?
Paralysis 1-3wks after infection
- ascending paralysis, loss of tendon reflexes
- sensory loss rare
- affects lower limbs initially
- ascends/progresses over several days/weeks
What are the infective causes of severe GBS?
Campylobacter
CMV
What are the common complications of GBS?
Venous thrombo embolism
Autonomic involvement
-BP lability
-arrhythmias
What is required for a diagnosis of GBS?
Clinical
Nerve conduction studies (slowed conduction)
CSF (protein raised)
What is the management of GBS?
Severe cases progress rapidly over hrs/days
Admit to HDY (prevent sores, chest infections, DVTs etc.)
-s.c. heparin + TED stockings
High dose IVIG w/i 2wks
-reduce duration/severity
What is the prognosis of GBS?
Mild - little disability before spontaneous recovery
Complete recovery over months in 80-90%
May be left w/ residual weakness
Mortality high in acute phase (10%
What features suggest a poor prognosis of GBS?
Older age
Rapid onset of sx
Axonal patterns of damage
What is Shingles?
Reactivation of VZV infection w/i dorsal root ganglia
How does Shingles present?
Occurs in lower thoracic dermatomes Pain/paraesthesia for several days Erythema/dermatomal eruption of vesicles -become pustular 2-3/7 later -may separate 3wks later
What is Ophthalmic herpes?
Infection of 1st division of CN5
Can lead to uveitis, corneal scarring, 2o panopthalmitis
What is Ramsey-hunt syndrome?
Infection of geniculate ganglion Facial palsy (often severe/irreversible) Facial/ear pain Vesicles in ear canal/pinna/soft palate Sensorineural deafness Vertigo Neuropathy of CN 5/9/10
What is the management of Shingles?
5-7 days Acyclovir PO
Paracetamol + Amitryptyline for pain
What is Post-herpetic neuralgia?
Common complication of shingles (10%)
Pain in prev shingles zone
-burning, continuous pain
-responds poorly to anaesthesia
How is Post-herpetic neuralgia managed?
Amitryptyline
Topical capsaicin
Recover over 2yrs
