Neuromuscular Disorders Flashcards

Question

Patterns of breathing in neuromuscular disorders

Answer 1

Brain: axial, truncal or generalized hypotonia Cord: paraplegia or tetraplegia Anterior horn cells: proximal > distal, LL > UL Peripheral nerve: distal weakness NMJ: generalized weakness Muscle: proximal weakness

Answer 2

Brain/spinal cord Corticospinal tract disorder Basal ganglia disorders Cerebellar disorders Anterior horn cell Spinal muscular atrophy (SMA) - Congenital Poliomyelitis - Acquired Peripheral nerve Charcot-Marie-Tooth disease (CMT) - Congenital Guillian Barre syndrome (GBS) - Acquired Neuromuscular junction Myasthenia gravis - Congenital/Acquired Botulinum toxicity - Acquired

Answer 3

*Muscle Congenital myopathy Dystrophinopathies (Duchenne/Becker Muscular Dystrophy) Myotonia dystrophies Inflammatory (Dermatomyositis) Metabolic (Pompe disease, mitochondrial myopathies) *Generalized Trisomy 21 Hypothyroidism Prader Willi syndrome

Answer 4

Anterior horn cell disease Autosomal recessive disorder

Answer 5

Deletion in the survival motor neuron 1 (SMN1) Mutation in SMN1 -> degeneration of anterior horn cells -> progressive weakness and wasting of skeletal muscle

Answer 6

The number of copies of SMN2 gene, which produces defective protein.

Answer 7

Classified based on severity Type 1: Werdnig-Hoffman disease (severe type) Type 2: intermediate type SMA Type 3: Kugelberg-Welander disease (mild type) Type 0: Very severe, in utero, results in still birth, or neonatal death Type 4: Adult onset

Answer 8

Type >Age at onset >Development > Prognosis 1 < 6 months> Never sit unsupported >Most die within the first year of life. Usually due to RTI 2> 6-18 months> Sit but never walk unsupported >May grow into late childhood 3> > 18 months> Walk unsupported at some stage> Often grows into adulthood

Answer 9

Alert, normal facial expression (Normal/Superior cognition, no facial weakness) *Symmetrical flaccid paralysis *Pattern of weakness: proximal > distal, legs > arms *Absent deep tendon reflexes *Tongue fasciculations *Intercostal muscle weakness with sparing of the diaphragm - paradoxical/Seesaw breathing *Weakness of the bulbar muscle > weak cry, poor suck and pooling of secretions *Contractures *Survival depends on respiratory and bulbar functions (aspiration risk)

Answer 10

History: decreased fetal movement, floppiness at birth, delayed motor milestones, recurrent aspiration and RTI, Physicals Exam: floppy infant, cognitively bright child, normal facial expression, proximal > distal weakness, tongue fasciculation, bell shaped chest - 'cause of persistent use of diaphragm, paradoxical breathing, contractures

Answer 11

Serum Creatine Kinase: normal or mildly raised (To rule out muscle disease) ECG: may show baseline fibrillations DNA analysis: to test for deletion on SMN1 Muscle biopsy - muscle atrophy Electromyogram

Answer 12

*Supportive Management: Respiratory care Prompt treatment of respiratory infections Chest physiotherapy Physiotherapy Nocturnal BiPAP (Prevents poor oxygenation of brain so no morning headaches) *Definitive treatment Genetic modification drugs(experimental)

Answer 13

Commonly due to acute inflammatory demyelinating polyneuropathy (AIDP) - Affects myelin Less common variants include: Acute axonal neuropathy - Affects axon Chronic inflammatory demyelinating polyradiculoneuropathy CIDP) Miller-fisher syndrome - AIDP + Cranial nerve involvement

Answer 14

Acute (reaches maximum within 48-72 hours, monophasic Demyelinating Peripheral nerves are the target of an abnormal immune response Antecedent viral infection (about half of patients) RTI > GI infections Progressive phase  plateau phase recovery phase

Answer 15

*Progressive motor weakness with areflexia *Ascending or descending (recovery in reverse) *Relatively symmetrical *Weakness progresses rapidly - same as recovery, reaching a nadir by 2-4 weeks *Autonomic dysfunction (arrhythmia, labile BP, GI dysfunction) *Facial weakness (MFS) *Respiratory paralysis *Bulbar dysfunction *Recovery of function within 2-4 weeks

Answer 16

NB. Diagnosis of GBS is clinical: progressive weakness + areflexia Investigations to support diagnosis and rule out differentials include: CSF: Albuminocytologic dissociation after 1st week (↑protein, no/low cells) supports GBS Stool: for polio and non-polio enteroviruses Nerve conduction studies To help differentiate demyelinating type from the axonal type Demyelinating: slow nerve conduction velocity Axonal: decreased amplitude Others Blood: for campylobacter, Coxsackie Serology for mycoplasma, EBV, CMV, VZV, Borrelia MRI of brain and spine - not recommended: the nerve roots lights up on contrast studies in GBS

Answer 17

Poliomyelitis Non-polio enterovirus infections Transverse myelitis Botulinum toxin Tick paralysis Porphyria Diphtheria Spinal cord compression Viral myositis

Answer 18

Any child less than 15 years who has AFP or a person at any age with paralytic illness in whom the clinician suspects Polio Acute: the paralysis is of sudden onset (progresses and reaches maximum level within 72 hours of onset) Flaccid: floppy, not rigid, not stiff Paralysis: loss of muscle strength (weakness, limitation of movement) (For a true AFP, all 3 conditions should be met)

Answer 19

Notify as a case of AFP: disease control officer/public health unit Two (2) stool samples collected 24-48 apart, within 14 days of onset of paralysis in two different specimen containers Place specimen in cold box below 8*C between frozen ice packs Send to WHO-accredited lab within 3 days (If last 2 conditions aren't satisfied sample will be rejected)

Answer 20

Respiratory support: admit to ICU if rapidly progressive Vital capacity < 50% IVIG - Mop up antibodies Plasma exchange - Mop up antibodies NB. Corticosteroids not helpful: may produce some initial improvement but tends to prolong the course Physiotherapy Recovery is usually in reverse order to the progression

Neuromuscular Disorders Flashcards

(45 cards)