Neurology

Recommendations for indications for EMG and EEG

The aim of the presented guidelines is to improve clinical practice by reducing unnecessary examinations, thereby reducing waiting times and, ultimately, minimizing unnecessary and often unpleasant or otherwise burdensome tests for patients.

In general, auxiliary examinations are only justified if the results – whether positive or negative – will in some way influence clinical decision-making regarding further management or contribute significantly to establishing a diagnosis.

The most common situations where examinations are unnecessarily indicated include:

·        Repeating examinations recently performed for the same diagnosis – for example, if the examination has already been conducted at another facility; repeated EMG examinations for "monitoring" the progression of chronic axonal polyneuropathy are not justified.

·        Examinations whose results will not affect clinical management – for instance, in cases of painful vertebrogenic syndromes without clear radicular symptoms.

·        Over-investigating – indicating unnecessary examinations when a diagnosis has already been established through other, usually more conclusive, tests.

When indicating electrophysiological examinations, especially EMG, it is essential to clearly define the clinical question on the requisition form. Vague requests such as "EMG DKK," etc., are inadequate. The requisition form should include at least basic medical history and the results of relevant examinations.

If a non-neurologist specialist indicates the examination and there is uncertainty, it is advisable to refer the patient first for neurological assessment, and if needed, the neurologist can then recommend electrophysiological testing.

General terminology:

·        Examination is indicated – only if necessary for establishing a diagnosis and influencing further therapeutic or diagnostic procedures.

·        Examination is not immediately indicated – in situations where spontaneous resolution of symptoms over time is possible (e.g., acutely acquired peripheral nerve palsies, carpal tunnel syndrome in pregnancy, etc.) or when false-negative findings shortly after clinical onset are likely (in case of uncertainty, consultation with a neurologist or electromyographer may be considered).

·        Examination is not indicated – generally applies to cases where test results are often normal or show nonspecific abnormalities and cannot confirm or exclude clinical suspicion (e.g., EEG for headaches, etc.).

Electromyographic Examination (EMG)

Appropriate indications for EMG:

·        Polyneuropathy of unknown origin (examination allows classification into axonal, demyelinating types, thereby refining the etiological diagnosis of neuropathy).

·        Mononeuropathies that cannot be localized by clinical examination or require examination before planned surgery (carpal tunnel syndrome).

·        Mononeuritis multiplex.

·        Disorders of neuromuscular transmission (e.g., myasthenia gravis, etc.).

·        Anterior horn cell disorders (ALS).

·        Muscle weakness with significant elevation of creatine kinase.

Clinical situations where immediate examination is not indicated:

·        Polyneuropathies with known causes (diabetes, alcohol abuse, neurotoxic drugs, vitamin deficiencies, uremia, etc.).

·        Suspected neuropathy of large fibers with normal neurological findings (normal tendon reflexes).

·        Clinically isolated small fiber involvement (EMG is typically normal).

·        Radiculopathy where diagnosis is clear based on clinical and imaging examinations.

·        Suspected hereditary or metabolic myopathy based on clinical examination and positive family history – in these cases, biopsy plus genetic or metabolic testing is more informative.

·        Post-polio syndrome.

·        Chronic fatigue syndrome.

Clinical situations where examination is not indicated:

·        Painful syndromes without neurological symptoms, with negative findings on imaging studies.

·        Myalgia without objective signs of weakness, with minimal or moderate elevation of creatine kinase (up to 2 times the upper limit).

·        Endocrine, metabolic, or steroid myopathy.

·        Polymyalgia rheumatica, fibromyalgia.

EEG

Appropriate indications for EEG:

·        Epileptic seizures – for the diagnosis of epilepsy, to specify the diagnosis of a particular epileptic syndrome.

·        Evaluation of seizure recurrence risk after the first unprovoked seizure.

·        Disorders of consciousness, confusion state – to exclude status epilepticus.

Clinical situations where immediate examination is not indicated:

·        "Screening" examinations in psychiatric patients.

·        Cognitive impairment, dementia in patients over 60 years old.

·        Suspected syncope (based on history) – high risk of false-positive EEG findings!

Clinical situations where examination is not indicated:

·        Headaches, migraines.

·        For "ruling out" the diagnosis of epilepsy.

·        To exclude brain tumors or other expansive processes.

·        Non-specific complaints such as instability, fatigue, etc.

·        ADHD.

Adapted and modified from Guidelines for Clinical Neurophysiology, North Bristol NHS Trust