Seizures, often complex partial, may be the first symptom of a brain tumor. Although seizure type does not reliably distinguish seizures caused by a tumor from those with other etiologies,32,36,44,45 clinical ictal characteristics, such as focal clonic activity, may suggest that seizure onset is occurring in a focal region and an associated lesion must be excluded.
Clinical seizure semiology provides clues for the region of ictal onset and its potentially associated focal lesion. The International League against Epilepsy has described seizure syndromes according to anatomic location:46
|Anatomic location||General characteristics of seizures|
|Frontal lobe||Usually occur several times per day, short in duration, during sleep. Complex gestural automatisms common at onset. Tonic/postural manifestations prominent.|
|Occipital lobe||Usually simple partial and secondarily generalized seizures. Initial signs can include tonic/clonic contraversion of eyes, head, or both; palpebral jerks; and forced closure of eyelids.Most commonly, but not always, include visual symptoms that are contralateral to cortex: Positive visual manifestations include sparks, flashes, and phosphenes (more common). Negative visual manifestations include scotoma, hemianopsia, and amaurosis.|
|Parietal lobe||Most are simple partial but can secondarily generalize.In the dominant parietal lobe, language is often involved. Most frequently involve hand, arm, and face with predominantly sensory features:Positive symptoms include tingling and electric feeling. Negative symptoms include numbness, absent body part, and asomatognosia.|
|Temporal lobe||Simple partial seizures: autonomic/psychic symptoms and sensory phenomena: olfactory, auditory, and (most commonly) rising epigastric sensation. Complex partial seizures: alteration in consciousness with behavioral arrest, often followed by oroalimentary or hand automatisms. Postictal confusion is usually followed by amnesia of the event.|
For example, very brief seizures with abundant posturing activity at onset and quick termination suggest a frontal lobe origin. Psychical symptoms with automatisms suggest temporal lobe origin. Seizure localization is complicated, however, by the difficulty of distinguishing seizure onset from manifestations of seizure spread.
Reviews of detailed seizure classification and ictal semiology are available.46–48
Reviewed and revised March 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.
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