What does diagnosis of myoclonus entail?

The diagnosis of myoclonus involves a multi-step process combining various approaches:

1. Medical History and Symptoms:

- The doctor begins by understanding the patient's symptoms, including the frequency, duration, intensity, and any specific patterns of the myoclonus.

2. Physical Examination:

- A thorough neurological exam is performed, including observation of the patient's motor functions, such as gait, posture, balance, and coordination. The doctor also checks for any physical signs of underlying conditions.

3. Imaging Tests:

- Imaging studies, such as MRI or CT scans of the brain and spinal cord, may be ordered to assess for any structural abnormalities or lesions.

4. Electrophysiological Studies:

- Electromyography (EMG) and electroencephalography (EEG) may be recommended. EMG records muscle activity, while EEG records brain activity. These tests help identify the type and origin of myoclonus.

5. Laboratory Tests:

- Blood tests, including complete blood count, electrolyte levels, thyroid function, liver function, and metabolic panels, may be performed to check for any underlying medical conditions.

6. Genetic Testing:

- If there is a suspicion of a genetic cause, specific genetic tests may be ordered based on the suspected condition or family history.

7. Diagnostic Criteria:

- Depending on the specific clinical features and test results, the doctor may categorize myoclonus based on its clinical characteristics, such as:

- Essential myoclonus: Idiopathic, no underlying cause

- Symptomatic myoclonus: Caused by an underlying condition

- Cortical myoclonus: Originates in the cerebral cortex

- Subcortical myoclonus: Originates in subcortical structures

- Primitive myoclonus: Also known as physiological myoclonus, considered a normal occurrence

8. Differential Diagnosis:

- Myoclonus can be mistaken for other conditions such as tremors, tics, or seizures. Therefore, careful evaluation is crucial to distinguish myoclonus from these other movement disorders.

9. Collaborative Approach:

- In complex cases, a collaborative effort among specialists such as neurologists, movement disorder specialists, geneticists, and other healthcare professionals may be necessary to reach a comprehensive diagnosis.

10. Treatment Plan:

- Once a diagnosis is established, the appropriate treatment can be recommended based on the specific cause and characteristics of the myoclonus.