These neuromyotonic discharges can cause bursts of spontaneous motor activity that present either continuously or in recurring, decrementing clusters.

[3] The symptoms (especially the stiffness and fasciculations) are most prominent in the calves, legs, trunk, and sometimes the face and neck, but can also affect other body parts.

[3] Diagnosis is clinical and initially consists of ruling out more common conditions, disorders, and diseases, and usually begins at the general practitioner level.

The neurologist or specialist may run a series of more specialized tests, including needle electromyography EMG/ and nerve conduction studies (NCS) (these are the most important tests), chest CT (to rule out paraneoplastic) and specific blood work looking for voltage-gated potassium channel antibodies, acetylcholine receptor antibody, and serum immunofixation, TSH, ANA ESR, EEG etc.

Neuromyotonia is characterized electromyographically by doublet, triplet or multiplet single unit discharges that have a high, irregular intraburst frequency.

Some doctors will only give the diagnosis of peripheral nerve hyperexcitability as the differences between the three are largely a matter of the severity of the symptoms and can be subjective.

Moreover, the generic use of the term peripheral nerve hyperexcitability syndromes to describe the aforementioned conditions is recommended and endorsed by several prominent researchers and practitioners in the field.

Anticonvulsants, including phenytoin and carbamazepine, usually provide significant relief from the stiffness, muscle spasms, and pain associated with neuromyotonia.

[5] It is speculated that the plasma exchange causes an interference with the function of the voltage-dependent potassium channels, one of the underlying issues of hyper-excitability in autoimmune neuromyotonia.

However, in recent years increased understanding of the basic mechanisms of NMT and autoimmunity has led to the development of novel treatment strategies.

A very small proportion of cases with NMT may develop central nervous system findings in their clinical course, causing a disorder called Morvan's syndrome, and they may also have antibodies against potassium channels in their serum samples.

Sleep disorder is only one of a variety of clinical conditions observed in Morvan's syndrome cases ranging from confusion and memory loss to hallucinations and delusions.