How to approach the patient with muscular symptoms in the general neurological practice?

Muscle symptoms and signs are a frequent reason for general neurological consultations. Weakness is the most reliable clinical indicator of myopathy. Fatigue and exercise intolerance and myalgias frequently occur in non-myopathic conditions. Cramps and myoglobinuria are more often due to systemic factors than being a sign of a metabolic or other myopathy. Contractures and myotonia are rare findings but when present are strong leads towards specific myopathic diagnoses. Serum creatine kinase (CK) is the single most useful screening laboratory study. Creatine kinase increase does not only occur in myopathies, and some myopathies cause no CK increase. Rapid recruitment of short duration, low amplitude motor unit potentials is the most typical hallmark of needle electromyography in myopathies. Critical appreciation of the clinical, laboratory and electromyography findings will help general neurologists select the few patients that need referral for muscle biopsy and genetic studies.