1. By Dr R. C. Ibekwe

2.  Neuromuscular diseases are disorders caused by abnormality of any component of the lower motor neuron system: anterior horn cell, peripheral nerve, neuromuscular junction, or muscle.  Common symptoms of neuromuscular disease may include infantile floppiness or hypotonia, delay in motor milestones, feeding and respiratory difficulties, abnormal gait characteristics, frequent falls, difficulty with stairs or arising from the floor, and muscle cramps or stiffness  These neuromuscular diseases may be genetically determined, congenital or acquired, acute or chronic, and progressive or static.

3.  Spinal cord 1. Poliomyelitis 2. Spinal cord tumor 3. Spinal muscle atrophy  Peripheral nerves 1. Polyneuropathy  Guillan barre syndrome  Diphtheria  Leprosy  Diabetis mellitus  Thiamine deficiency  Vitamine B12 deficiency  Lead and mercury poisoning

4. 1. Mononeuropathy  Bell’s palsy  Erb’s palsy  Peroneal nerve palsy  Sciatic nerve palsy Disease of neuromuscular junction  Myasthenia gravis  Botulism Diseases of muscles 1. Muscular dystrophies 2. Polymyositis 3. Corticosteroid myopathy 4. Hyperthyroid myopathy 5. Hypothyroid myopathy

5.  The muscular dystrophies are an inherited group of progressive disorders resulting from defects in a number of genes required for normal striated muscle function  Duchenne muscular dystrophy is the most common hereditary neuromuscular disease affecting all races and ethnic groups. The incidence is 1 : 3,600 live born infant boys.  This disease is inherited as an X-linked recessive trait.

6.  Duchenne muscular dystrophy is caused by a defective gene located on the X chromosome that is responsible for the production of dystrophin  Absence of dystrophin allows influx of calcium which activates the proteases that causes muscle degeneration

7.  Clinical onset of weakness usually occurs between two and three years of age  Weakness — Weakness selectively affects the proximal before the distal limb muscles, and the lower before the upper extremities.  Gowers' sign—results from proximal weakness of the pelvic girdle muscles. It is not specific to any one neuromuscular disease

8.  Pseudohypertrophy due to Increased gastrocnemius calf circumference caused by increase in fat and connective tissue, not true muscle  Trendelenburg gait/waddling gait—weakness of hip abductors produces tendency toward lateral pelvic tilt and pelvic drop of swing phase side.

9. Gower’s sign

10. Pseudohypertrophy of the gatronemuis

11.  Patients are usually wheelchair bound by the age of twelve.  Contractures most often involve the ankles, knees, hips, and elbows. Scoliosis is common. The thoracic deformity further compromises pulmonary capacity and compresses the heart  Cardiomyopathy Heart failure and arrhythmias can be the immediate cause of death  Intellectual impairment occurs in all patients, although only 20–30% have an IQ <70. atric population.

12.  Becker muscular dystrophy  Limb-Girdle Muscular dystrophy  Fascioscapulohumeral muscular dystrophy

13.  Creatine kinase — Serum creatine kinase (CK) concentrations are elevated in all patients and is usually 10 to 20 times the upper limit of normal and may be higher.  Electrocardiogram — Electrocardiographic abnormalities are frequent among patients with DMD.  Electromyography — The EMG reveals myopathic changes, usually consisting of small polyphasic potentials. This is a non specific finding.

14.  Muscle biopsy — Muscle biopsy demonstrates degeneration, regeneration, isolated "opaque" hypertrophic fibers, and significant replacement of muscle by fat and connective tissue.  Blood polymerase chain reaction (PCR) for the dystrophin gene mutation is the primary test

15.  Counselling:- explain the mode of disease inheritance, the possibility of prenatal diagnosis, the child’s capability, disease progression and life expectancy  Nutrition:- avoid obesity and encourage calcium and vitamin D intake  Immunizations — The 2004 American Thoracic Society guidelines recommend that all patients with DMD should receive the pneumococcal vaccine and annual influenza vaccine  Treat complications:- pneumonia and cardiac failure

16.  Drugs:- steriods have been tried and is said to improve strength of muscle and lung function  Physiotherapy:- aim to try and avoid contractures  Surgery and occupational therapists may elongate period of ambulation  Prognosis is poor most are wheel chair bound by 12 yrs and die before their 20 th birthday

17.  This is a disease of the neuromuscular junction and mainly an autoimmune disease that releases anti ACH receptor antibodies  It is caused by the destruction and reduction in acetylcholine receptors in the presence of normal release of presynaptic acetylcholine.  Hallmark is easy fatigability and weakness of skeletal muscles

18.  The earliest and the most constant manifestation is ptosis and affectation of extraocular muscles. The patient can not sustain upward gaze for 30 – 90 seconds  There is also a progressive weakness on muscle activity. Symptoms worsen later in the day and when tired  Weakness if untreated can progress to involve respiratory muscles leading to respiratory arrest and aspiration.

19.  Juvenile myasthenia gravis:- this is 8 times more common in females. Onset around age 8 yrs  Transient neonatal type:- this is due to transient transfer of maternal antibodies and abates by 2 -4 weeks  Persistent neonatal type:- this an inherited disease from an unaffected mother

20.  Tensolin test:- this a clinical therapeutic trial. Myasthenia gravis shows a rapid reversal of symptoms to IV edrophonium 0.2mg/kg or IM neostigmine 0.04mg/kg  Electromyogram:- this shows a decremental response to muscle potential  Anti-Ach antibody:- this demonstrates the autoimmune origin  Chest X-ray/CT scan to look out for co-existing thymoma  Creatnine kinase/nerve conduction test are all normal

21.  Anticholinesterase drugs:- this provides symptomatic relief without influencing the course of the underlying disease. Neostigmine or pyridostigmine can be used  Thymectomy:- this can lead to symptomatic relief and its mechanism of achieving this unclear  Corticosteroids:- this can be used as an adjunct  Azathioprine:- can be used in severe and progressing disease with poor response to the above 3  Plasmapheresis:- this can be used for temporary relief

22.  They are a group of inherited diseases that causes degeneration and atrophy of the anterior horn cells and the motor nuclei in the brain stem  The diseases can be classified into types depending on clinical severity ( Types 1,2 and 3)  Type 1 is the infantile type and also called werdnig-hoffman is the most common and most severe  Most of them including Werdnig hoffman is autosomal recessively transmitted.

23.  Onset of symptoms in the first 6 months of life, may manifest with poor fetal movt in utero  Hypotonia of proximal, distal, intercostal and bulbar muscles  They are floppy and lie in frog position with hips abducted and knees flexed. When held in ventral position they form an inverted U.

24.  Weak intercostal muscles leads to paradoxical respiration and bulbar palsy causes difficulty in sucking and swallowing  Extra ocular muscles are unaffected and intelligence is normal  muscle wasting and fibrillation more marked in tongue

25.  Diagnosis is mainly clinical but can be confirmed by Molecular genetic testing  Creatinine kinase, EMG and motor nerve conduction are not diagnostic  Treatment is supportive, ventilator support and feeding gastrotomy  Prognosis is poor, most die by their 2 nd birthday of respiratory failure and pneumonia

26. Thank you