Polyneuropathies Mononeuropathies Motoneuron diseases Zsuzsanna Arányi.

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Transcript of Polyneuropathies Mononeuropathies Motoneuron diseases Zsuzsanna Arányi.

  • Slide 1
  • Polyneuropathies Mononeuropathies Motoneuron diseases Zsuzsanna Arnyi
  • Slide 2
  • Peripheral nerve Motor, sensory and autonomic fibers Fiber types according to diameter: A fibers- 1-17 m in diameter; myelinated motor and sensory fibers B fibers- 1-3 m in diameter; myelinated autonomic fibers C fibers- 0.3-1.3 m in diameter; non-myelinated autonomic and pain fibers
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  • Types of peripheral nerve damage Demyelination Slowed conduction: no symptoms Conduction block: weakness and sensory loss, but no atrophy Axonal damage (axonotmesis) Degeneration of axons distal to the lesion (denervation) Weakness, sensory loss, atrophy Neurotmesis Damage to axons and epineurium Weakness, sensory loss, atrophy No regeneration without nerve suture
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  • Nerve regeneration reinnervation RemyelinationProximo-distal axon regeneration Collateral reinnervation (in case of partial nerve damage) 2-12 weeks1 mm/day Intact basal lamina/endoneurium is needed Starts within 4-6 weeks
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  • Polyneuropathies Generalised disease of the peripheral nervous system (nerve roots and peripheral nerves) Usually the longest nerves are affected first Symptoms start on the toes, feet Usually the symptom of an underlying systemic disease Search for etiology!
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  • Classification of polyneuropathies Clinical presentation Symmetric Asymmetric Time course Acute Chronic Etiology Pathology Axonal Demyelinative Small-fiber
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  • Clinical forms of polyneuropathies Chronic, symmetric, distal and predominantly sensory polyneuropathies Mononeuropathy multiplex Purely motor or sensory polyneuropathies Autonomic polyneuropathies Acute polyneuropathies
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  • Typical symptoms of polyneuropathies Chronic course Symmetric, distal paraesthesia, pain and hypaesthesia in stocking glove distribution; feet are affected first Allodynia Depressed or absent tendon reflexes Distally pronounced muscle weakness, with wasting, fasciculation Gait disorder Sensory ataxia Weakness Autonomic dysfunction (reduced sweating, tachycardia, urinary disturbances, gastroparesis etc.)
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  • Typical complaints of patients with polyneuropathies Tingling, pin-prick, numbness, burning or cold sensation, burning pain (especially during the night) Ants crawling on my legs As if I had tight boots on As if I were walking on a duvet As if I had stockings on when really not As if my skin were thick on my soles Unstable gait, dizziness Loss of dexterity of the hands: I drop objects
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  • Causes of polyneuropathy Metabolic-endocrine disturbances: diabetes mellitus, uremia etc. Vitamin deficiencies: vitamin B 1 -alcoholism, malabsorption, malnutrition, vitamin B 12 Toxic causes: heavy metals, industrial solvents, drugs, alcohol Dysimmune polyneuropathies With manifestation only in the peripheral nervous system: acute inflammatory demyelinative polyneuropathy (Guillain-Barr syndrome), chronic inflammatory demyelinative polyneuropathy (CIDP), multifocal motor neuropathy (MMN) Systemic diseases: vasculitis (polyarteritis nodosa, SLE etc.), paraproteinaemias Paraneoplasia Infectious: lepra, Lyme-disease, HIV Hereditary: Charcot-Marie-Tooth disease etc. Other: critical illness polyneuropathy, small-fiber neuropathy Idiopathic
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  • Investigation of polyneuropathies ENG-EMG Blood tests: We, blood count, glucose, hepatic and renal function Vitamin B 12 Thyroid function Se electrophoresis, autoanti-bodies, cryoglobulin Serological examinations (HIV, Lyme, HCV) Search for tumors CSF Toxicological investigations Sural nerve biopsy Genetic tests
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  • Treatment of polyneuropathies Treat the cause! Immune therapy plasmapheresis: Guillain-Barr syndrome, CIDP immunoglobulins: MMN, Guillain-Barr syndrome, CIDP corticosteroids: CIDP, systemic vasculitis Symptomatic treatment of paraesthesias and neuropathic pain antiepileptic medications (carbamazepine, gabapentin, pregabalin) tricyclic antidepressants (amitriptilin, clomipramin) SNRI antidepressants (duloxetin, venlafaxin) Vitamin B 1 : alcoholism, malabsorption, malnutrition
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  • Polyneuropathies associated with diabetes mellitus Distal symmetric sensory polyneuropathy Mononeuropathies- carpal tunnel syndrome, ulnar nerve lesion Cranial nerve lesions- oculomotor nerve palsy Autonomic neuropathy- sexual and urinary disturbance, gastroparesis and diarrhoea etc. Diabetic amyotrophy- painful, asymmetric, proximal weakness (plexopathy?) Radiculopathy- lumbar, thoraco-abdominal
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  • Diabetic chronic distal symmetric sensory polyneuropathy The most common form of diabetic neuropathy Prevalence among diabetic patients: 20-60% Present at the diagnosis of diabetes in 20% of patients May be the only manifestation of impaired glucose tolerance Severity is usually proportional to the duration and severity of hyperglycemia Prevalence increases with age and duration of diabetes Small fibers (pain, temperature, light touch) are preferentially affected painful diabetic neuropathy in about 20-35% Autonomic dysfunction Trophic alterations diabetic foot
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  • Small fiber neuropathy- skin biopsy Normal Small fiber neuropathy Epidermal nerve fibers (arrow): anti PGP 9.5 antibodies Fibrous tissue and basal lamina: anti collagen IV antibodies
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  • Symptoms of sensory diabetic neuropathy I. Length-dependent: first symptoms on the toes and feet Later stocking-gloves distribution Usually doesnt go above the knees and elbows If symptoms appear on the hands first carpal tunnel syndrome Areflexia Trophic changes
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  • Symptoms of sensory diabetic neuropathy II. Positive sensory symptoms: burning pain (pronounced during the night) hyperesthesia, allodynia paresthesia Negative sensory symptoms: hypesthesia (loss of sensation)
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  • Diabetic foot Related to diabetic sensory neuropathy and peripheral artery disease Diabetic foot ulcers precede 85% of non- traumatic lower limb amputations Life-time prevalence of foot ulcers is 15% in diabetic patients
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  • Guillain-Barr syndrome Acute immunmodulated poly-radiculo-neuro-pathy Pathology: perivascular lymphocyte-macrophage infiltration in the peripheral nervous system leading to macrophage mediated segmental demyelination Incidence: 1.5-2.0/100 000/year In most cases preceded by an infection (upper respiratory tract infection, diarrhoea) Infectious agents associated with Guillain-Barr syndrome: CMV, EBV, HIV, Campylobacter jejuni, Mycoplasma pneumoniae The infectious agent is usually unidentified
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  • Pathomechanism of GBS
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  • Guillain-Barr syndrome- symptoms Acute, symmetric ascending flaccid paralysis Variable severity Respiratory insufficiency Bilateral facial palsy Ascending numbness to a lesser degree Radicular pain Areflexia Autonomic symptoms- tachycardia, cardiovascular instability
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  • Guillain-Barr syndrome- time course Symptoms evolve over 1-2 weeks Plateau is reached within 2-3 weeks Spontaneous recovery within a few months Good prognosis Prognosis is determined mainly by complications of being bed-bound (infection, thrombosis etc.)
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  • Guillain-Barr syndrome- diagnosis Normal neurographySegmental demyelination Conduction blockTemporal dispersion
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  • Guillain-Barr syndrome- diagnosis and treatment Diagnosis Clinical symptoms Electroneurography- confirms segmental demyelination Cerebrospinal fluid examination: elevated protein content with normal cell count (starting from the 2nd week) Treatment Plasmapheresis, immunoglobulin (IVIG) Supportive treatment!
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  • Chronic inflammatory demyelinative polyneuropathy (CIDP) Autoimmune disease Prevalence: 1-2/100 000 Course: chronic monophasic (15%) chronic relapsing-remitting (34%) step-wise progressive (34%) continuously progressive (15%) Symptoms: proximal and distal motor and sensory symptoms, cranial symptoms (not a length-dependent neuropathy) Rarely associated with central nervous system demyelination (3%)
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  • Diagnosis of CIDP ENG/EMG: segmental (non-uniform) demyelination CSF: protein >45 mg/dl, cell count