The weakness from LEMS typically involves the muscles of the proximal arms and legs (the muscles closer to the trunk). In contrast to myasthenia gravis, the weakness affects the legs more than the arms. This leads to difficulties climbing stairs and rising from a sitting position. Weakness is often relieved temporarily after exertion or physical exercise. High temperatures can worsen the symptoms. Weakness of the bulbar muscles (muscles of the mouth and throat) is occasionally encountered. Weakness of the eye muscles is uncommon. Some may have double vision, drooping of the eyelids and difficulty swallowing, but generally only together with leg weakness; this too distinguishes LEMS from myasthenia gravis, in which eye signs are much more common. In the advanced stages of the disease, weakness of the respiratory muscles may occur. Some may also experience problems with coordination (ataxia). Three-quarters of people with LEMS also have disruption of the autonomic nervous system. This may be experienced as a dry mouth, constipation, blurred vision, impaired sweating, and orthostatic hypotension (falls in blood pressure on standing, potentially leading to blackouts). Some report a metallic taste in the mouth. On neurological examination, the weakness demonstrated with normal testing of power is often less severe than would be expected on the basis of the symptoms. Strength improves further with repeated testing, e.g. improvement of power on repeated hand grip (a phenomenon known as<unk> 's sign"). At rest, reflexes are typically reduced; with muscle use, reflex strength increases. This is a characteristic feature of LEMS. The pupillary light reflex may be sluggish. In LEMS associated with lung cancer, most have no suggestive symptoms of cancer at the time, such as cough, coughing blood, and unintentional weight loss. LEMS associated with lung cancer may be more severe.
Lambert–Eaton myasthenic syndrome
Botulism
Congenital myasthenic syndrome
Guillain–Barré syndrome
Tension myositis syndrome
De Quervain syndrome
Nemaline myopathy
Inclusion body myositis