Myopathy power point presentationnn.pptx

Myopathy power point presentationnn.pptxMyopathy power point presentationnn.pptxMyopathy power point presentationnn.pptxMyopathy power point presentationnn.pptxMyopathy power point presentationnn.pptxMyopathy power point presentationnn.pptxMyopathy power point presentationnn.pptx

1. Myopathy Ardit Tela, April 2024

2. Definition and clinical Myopathies present as pure motor syndromes without any disturbance of sensory or autonomic function Tend to be bilateral and affect proximal muscles preferentially Sometimes asymmetric (IBM or FSH muscular dystrophy) Sometimes distal (myotonic dystrophy, IBM or hereditary myopathies)

3. Classification of muscle disorders Muscular dystrophies Inflammatory myopathies Necrotizing autoimmune myopathies (NAM) Endocrine associated myopathies Drug induced and toxic myopathies Metabolic myopathies Myopathy associated with periodic paralysis

4. Muscular dystrophies inherited muscle disorders characterized by a progressive course and often an early onset, usually with a specific clinical and muscle biopsy pattern Myotonic dystrophy Duchenne muscular dystrophy Becker muscular dystrophy Emery- Dreifuss muscular dystrophy Facioscapulohumeral muscular dystrophy Oculopharyngeal muscular dystrophy The limb girdle muscular dystrophies.

5. Inflammatory myopathies associated most commonly with a presumed immunologic attack polymyositis (PM) dermatomyositis (DM) IBM

6. Necrotizing autoimmune myopathies rare but increasingly recognized as an etiology of muscle weakness Similar to the common inflammatory myopathies with proximal weakness and elevated creatine kinase (CK) levels. But, on muscle biopsy, there are many necrotic fibers with little or no inflammation Risk factor is statin use

7. Endocrine myopathies often seen in disorders of the thyroid and adrenal glands can accompany some cases of acromegaly and parathyroid disease

8. Drug induced and toxic myopathies include those caused by steroids, alcohol, colchicine, azidothymidine, clofibrate, and as a direct toxic effect of many of the cholesterol-lowering agents

9. Metabolic myopathies resulting from inherited enzyme deficiencies important in intracellular energy production May present: as cramps and myoglobinuria The most common of these are caused by a deficiency of carnitine palmitoyl- transferase (CPT) along the lipid pathway and myophos-phorylase (McArdle’s disease) along the glycogen pathway. as part of a more diffuse neurologic syndrome, often involving the central nervous system as a typical clinical proximal myopathy

10. Congenital myopathies a group of myopathies in which each disorder has a fairly specific muscle biopsy finding on histochemical staining Genetic testing or muscle biopsy usually is needed for definitive diagnosis, unless there is a known confirmed diagnosis in the family

11. Myopathy associated with period paralysis occurs in the setting of hypokalemic and hyperkalemic periodic paralysis Patients develop proximal weakness in the fifth or sixth decade

12. The role of EDX in myopathy molecular genetics has supplanted the need for electrodiagnostic (EDX) studies or muscle biopsy in many patients with inherited conditions in patients with suspected myopathy and no evidence of an inherited condition, a muscle biopsy ultimately will be required for definitive diagnosis, regardless of the findings on EDX studies EMG can often confirm the presence of a myopathy, as well as add diagnostic information if certain types of spontaneous activity are present fibrillation potentials and positive sharp waves in a myopathy suggest the possibility of inflammation or necrosis myotonic discharges suggest one of the myotonic muscle or periodic paralysis disorders

13. Nerve conduction studies Mostly to exclude other motor disorders that may mimic myopathy Sensory and motor nerve conduction studies are always normal, unless there is a coexistent neuropathy If the myopathy is severe enough to affect distal and proximal muscles or is one of the rare myopathies that preferentially affects distal muscles, motor studies may show decreased compound muscle action potential (CMAP) amplitudes with normal latencies and conduction velocities can easily differentiate demyelinating polyneuropathy from myopathy by the presence of conduction block or temporal dispersion, marked slowing of distal latencies and conduction velocity, or a combination of these findings

14. Needle EMG More information then NCS must be individualized based on the distribution of the patient’s symptoms the yield of finding abnormalities increases as progressively more proximal muscles are sampled

15. Introduction to needle EMG First, MUAPs are typically small, short and polyphasic A similar pattern can occur in weak muscles with NMJ disorders, as well as with early reinnervation after severe denervation (i.e., nascent motor units) Second, some myopathies may display minimal, equivocal, or no changes most commonly seen in steroid myopathy and some metabolic and mitochondrial myopathies Third, measuring the serum CK immediately after the EMG examination probably is not wise The CK level may rise slightly as a consequence of the EMG examination (typically 1.5× normal)

16. MUAPs analysis

17. MUAPs features MUAP duration is the most important parameter to measure in myopathy reflects the total number of muscle fibers in a motor unit Characteristically decreases In mild or equivocal cases, quantitative EMG of 10–20 MUAPs should be performed MUAP amplitude commonly is decreased, but it can also be normal or increased if the needle electrode is placed near split or reinnervated fibers MUAP phases often are increased Early recruitment One of the most important findings in a myopathy is the presence of an early recruitment pattern inappropriate firing of many MUAPs to generate a small amountof force

18. Clinical case