Glutamate levels in cerebrospinal fluid and triptans overuse in chronic migraine.
OBJECTIVE
Chronic migraine (CM) is a common disorder, affecting 2% to 3% of the general population. Glutamate is implicated in cortical spreading depression, trigeminovascular activation, central sensitization, and may be linked to migraine chronification. Triptans brought a novel option for the acute migraine treatment. As the development of central sensitization impacts upon the effectiveness of triptan therapy, we hypothesized that glutamate might be related to triptan response mechanisms.


METHODS
We studied 19 patients diagnosed with CM according to the International Headache Society (2004) criteria. Patients were divided in those overusing analgesics (NSAIDs); those without overuse, and those overusing triptans.


RESULTS
Cerebrospinal fluid (CSF) glutamate levels were similar in patients overusing acute medications (0.335 +/- 0.225 micromol) compared to those without overuse (0.354 +/- 0.141 micromol), P= NS). In contrast, patients overusing triptans had CSF glutamate levels significantly lower than that observed in nonoverusers (0.175 +/- 0.057 vs 0.354 +/- 0.141 micromol, P= 0.015), and significantly higher than controls (0.175 +/- 0.057 vs 0.109 +/- 0.066 micromol, P= 0.039). In triptan overusers, CSF glutamate levels, although lower, were not significantly different from patients overusing other types of analgesics.


CONCLUSIONS
Our study showed lower glutamate levels in CSF of CM patients overusing triptans. Glutamate may be implicated in triptan response mechanisms, triptans may work in part by reducing extracellular glutamate levels in the brain.
Vieira
Domingos Sávio deSouza
DS
Hospital Israelita Albert Einstein-Instituto Israelita de Ensino e Pesquisa-Instituto do Cérebro, São Paulo, Brazil.
Naffah-Mazzacoratti
Maria da Graça
Mda G
Zukerman
Eliova
E
Senne Soares
Carlos Augusto
CA
Cavalheiro
Esper Abräo
EA
Peres
Mario Fernando Prieto
MF
D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D018698:Glutamic Acid / Q000134:cerebrospinal fluid*; D020773:Headache Disorders / Q000134:cerebrospinal fluid / Q000188:drug therapy; D051271:Headache Disorders, Secondary / Q000134:cerebrospinal fluid / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000134:cerebrospinal fluid* / Q000188:drug therapy*; D010880:Piperidines / Q000008:administration & dosage / Q000009:adverse effects; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage / Q000009:adverse effects*; D014230:Triazoles / Q000008:administration & dosage / Q000009:adverse effects*; D014363:Tryptamines / Q000008:administration & dosage / Q000009:adverse effects*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010880:Piperidines; D017366:Serotonin Receptor Agonists; D014230:Triazoles; D014363:Tryptamines; D018698:Glutamic Acid; C093622:rizatriptan; C106783:naratriptan