Sporadic hemiplegic migraine

Migraine with aura including motor weakness, and no first- or second-degree relative has migraine aura including motor weakness.

Diagnostic criteria:
A. Fulfils criteria for 1.2.3 Hemiplegic migraine
B. No first- or second-degree relative fulfils criteria for 1.2.3 Hemiplegic migraine.

Epidemiological studies have shown that sporadic cases occur with approximately the same prevalence as familial cases.

The attacks in Sporadic hemiplegic migraine have the same clinical characteristics as those in Familial hemiplegic migraine. Some apparently sporadic cases have known FHM mutations, and in some a first- or second-degree relative later develops hemiplegic migraine, thus completing fulfilment of the criteria for Familial hemiplegic migraine and requiring a change of diagnosis.

Sporadic cases usually require neuroimaging and other tests to rule out other causes. A lumbar puncture may be necessary to rule out 7.8 Syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL).