M1.4 — 5 congenital peripheral and early neuropathies Flashcards
(22 cards)
what conditions is neonatal hypotonia “floppy baby” seen in?
- neuromuscular disorders (congenital myopathies, congenital myasthenia gravies, severe spinal muscular atrophy)
- disorder of CNS
What is Dejerine-Sottas Disease?
a hereditary motor and sensory neuropathy
- severe demyelinating polyneuropathy = very slow nerve conduction
- presents in infancy with delayed motor developement
- elevated CSF protein
what is Congenital Hypomyelination?
a hereditary motor and sensory neuropathy
- severe neuropathy with absence of myelin
- diffuse hypotonia, generalized weakness
- delayed motor milestones
- high survival rate
What is Gillian-Barre syndrome?
- immunologically mediated neuropathy - may be triggered by acute bacterial or viral infection
- acute inflammatory demyelinating polyneuropathy causing ascending paralysis
- immune system targets peripheral nerves, spinal sensory and motor nerves root - occasionally cranial nerves
- varies from mild to ventilation required
- evolves rapidly peaking from hours - 4 weeks (average is 2 weeks), plateaus then recovery in weeks-months (most recover in 6-12 months)
what are symptoms of Guillan-Barre syndrome? what are the most common and most prominent early symptoms?
- weakness *most common - progresses rapidly over a few days followed by prolonged periods of stabilization then gradual recovery
- pain *most prominent early symptoms (low back and legs)
- may mimic meningitis with severe head and paraspinal pain
- diminished reflexes
- ataxia
- paresthesia
- cranial neuropathy
- dysautonomia
who most commonly gets Guillan-Barre syndrome?
mean age 7 yo but affects all age groups
M:F 1.5:1
what is the most common cause of acute flaccid paralysis in children?
Guillain-Barré syndrome
What is Acute Motor-axonal Neuropathy?
- an immunologically mediated neuropathy
- presents with acute paralytic illness similar to GBS- outcome more severe
- distinguishing characteristic is the motor axon targeted while sensory neuron spared
- predominantly affects children
How does diabetes mellitus present peripheral neuropathy?
- systemic disorder
- bilateral symmetrical involvement of the distal portion of the long nerves
- weakness of small muscles of the feet
- reduced achilles reflex
- stocking type sensory loss in feet with fading border
How does systemic Lupus Erythematosus present peripheral neuropathy?
- symmetrical distal sensorimotor neuropathy
- progressive multi focal neuropathy
- acute, predominantly motor polyneuropathy
How does celiac disease present peripheral neuropathy?
- sudden refusal to walk
- absence of DTR in both lower limbs
- preceded by GI symptoms
- resolution of neurological symptoms with gluten free diet
What can cause toxic peripheral neuropathy? what can it target?
- chemotherapy
- antibacterial, antiviral drugs
- organic solvents
- intesticides, rodent poison, heavy metals
- post-vaccination
- small and large sensory fibers
- motor and autonomic fibers
What are different types of juvenile myasthenia gravis in children?
- transient neonatal myasthenia gravis
- congenital myasthenias gravis (genetic)
- autoimmune myasthenia gravis (juvenile) (rare)
What does juvenile myasthenia gravis target?
- post-synaptic neuromuscular junction in skeletal muscle
- results in muscle weakness, neuromuscular fatigue
- thymic hyperplasia
what are the clinical features of juvenile myesthenia gravis? what is the hallmark and most common sign
- fluctuating fatigue and weakness *(hallmark) - least in the morning and progressive through day - proximal most common
- weakness most frequently manifested in extraocular muscles (Ptosis* [most common sign], strabismus and diplopia affect 90%)
- eye lid twitch sign
- ocular migraine (more common in female children, male adults)
- bulbar weakness in 50% after 2 years and 75% in 4 years (slow chewing and swallowing, drooling, weak or nasal voice, poor pronunciation)
what are common features of congenital myopathies?
- generalized weakness, hypotonia
- hyporeflexia
- dysmorphic features secondary (pectus excavatum, scoliosis, foot deformities, high arched palate, elongated facies)
what are 4 types of classic congenital myopathies?
- nemaline myopathy
- central core disease
- myotubular myopathy
- myofibular myopathies
What are clinical features of nemaline myopathy?
- rod shaped structure in muscle fibers
- weakness, hypotonia, weak DTR
- weakness most severe in face, neck flexors and proximal limb muscles (elongated and expressionless face, mouth tent shaped, high arch palate)
- waddling gate
- hyperlordosis, often rigid spine
- slow gross motor skills
- serum CK elevated
what are the clinical features of central core disease?
- centrally placed cores of disorganized myofibrils
- weakness and hypotonia in infancy - more severe in lower limbs
- delayed motor milestones
- msk deformities (kyphoscoliosis, hip dysplasia, pes cavus/planus)
what are clinical features of myotubular myopathy?
- centrally placed nuclei in extra full muscle fibers
- extremely rare
- polyhydraminos and reduced fetal movements
- males present with severe floppiness and weakness
- difficulty with respiration and feeding
- extremely poor prognosis
What is muscular dystrophy? what are signs and the pathological hallmark?
- primary, genetic disease of muscle
- muscle weakness and hypotonia at birth or shortly after
- multiple contractures
- dystrophic pattern in muscle biopsy *(pathological hallmark)
- serum CK elevated in early stages
- condition is static, may slowly progress
What are clinical features of myofibrillar myopathies?
- onset early childhood to middle age
- myofibrils selectively degraded
- weakness commonly distal
- cardiac symptoms may dominate
- accumulation of electron dense granular material
