Role of Electrodiagnostic Tests in Neuromuscular Disease

Transcription

1 Role of Electrodiagnostic Tests in Neuromuscular Disease

2 Electrodiagnostic tests Electroencephalogram (EEG) Electromyography (NCV, EMG) Cerebral evoked potentials (CEP) Motor evoked potentials (MEP) Electronystagmogram (ENG)

3 Clinical applications of EMG Peripheral nerve system Motor neuron disease Peripheral nerve disease NM junction disease Muscle disease

4 Clinical utility of EMG Demonstrate abnormalities of neuromuscular system. Reveal the clinically unsuspected malfunction. Define the anatomic distribution of disease process. Monitor changes objectively over time.

5 Inherent limitations of EMG Kinds of tests and muscles or nerves to be tested must be determined by clinical findings EMG findings must be interpreted in the light of clinical findings

6 Attitude of electromyographer Explain an aim of EMG study Plan the electrophysiologic study Minimize patient s discomfort Supervise technician s practice, such as NCS Perform needle EMG Think about the clinical-electrophysiologic correlation

7 Electrophysiologic studies for NM disorders Nerve conduction studies Long latency responses : F wave, H reflex Needle EMG Repetitive nerve stimulation (Jolly) test Single fiber EMG Blink reflex Autonomic function test MUNE

8 Guidelines for EMG for common NM disorders

9 Guidelines for EMG for common NM disorders

10 Case history, F/45 4 months ago, insidious onset both hand weakness & tingling sensation 3 months ago, lower extremities weakness & tingling sensation Fluctuating course Assessment :polyneuropathy EMG: extensive NCV studies

11 Case history, F/54 7 month ago, both palm tingling sensation & pain Symptoms increased at night Assessment : carpal tunnel syndrome EMG : sensory NCV, terminal latency

12 Case history, M/55 3 months ago, intermittent paresthesia in right upper extremity Radiated downward from the neck to middle fingers Assessment : Rt. C7-radiculopathy EMG : c-paraspinal and upper limb needle EMG

13 Case history, M/26 6 months ago, four extremities weakness Difficulty in climbing stairs Symptoms were gradually worse CK : 1040 Assessment : myopathy EMG : needle EMG

14 Case history, M/55 7 months ago, dysarthria, dysphagia 4 months ago, 4 extremities weakness His weakness was gradually worse Tongue atrophy and fasciculation Assessment : MND EMG : needle EMG

15 Case history, F/25 10 days ago, insidious onset Lt. ptosis Double vision Diurnal variation : pronounced late in the day and relived by rest Assessment : MG EMG : Jolly test

16 Case history, F/17 15 days ago, Lt. facial palsy His symptoms were stationary No sensory change Assessment : Bell s palsy Lt. EMG : Excitability test, Blink test, facial NCV

17 Case history, M/23 Rt. lower extremity hypesthesia after cast for 6 weeks Tendency for the foot to slap Assessment peroneal nerve palsy EMG : Motor NCV and needle EMG

18 Case history, M/60 2 years ago, slowly progressive stiffness, slurring of speech Fatigue, general weakness No family history 9 years ago, impotence, urinary frequency and urgency 4 years ago, constipation Assessment : autonomic dysfunction EMG 1. Valsalva maneuver 2. Sympathetic skin response 3. Quantitative sensory testing

19 Conclusion EMG Minimal discomfort Maximal information patients Best treatment clinicians