American Stroke Association’s 26th International Stroke Conference 2001 Feb
The controversial relations between migraine and vascular headache on one hand, epilepsy on the other hand are once more discussed: survey of the arguments for a more than fortuitous connection, taken from literature and general experience. Critical analysis of the personal case material. Discussion of some specific groups of patients with various combinations of both syndromes: long antecedents of headaches, leading up to sporadic epileptic attacks, focal or generalized; clinical seizures under photic stimulation (10% of the cases with chronic headaches without organic lesions); headaches in the latency period of symptomatic epilepsy; cases of seeming transition between the two syndromes; headaches as a substitute, anaura or as a component of the epileptic seizure, with clearly distinctive features between generalized and focal epilepsy: in patients with bilateral EEG paroxysms, headaches are usually diffuse or bilateral, in those with epileptogenicfoci, headaches, if consistently localized, are always reported to be homolateral to the focus. Considerations concerning pathogenesis include the familiar hypothesis of hypoxic discharges following migrainous vasoconstriction, as well as secondary vascular headaches induced by focal epileptic activity. Headaches caused by excessive discharges in the sensory representation areas (H. Jackson) must be rare. Whether increased neuronal activity in the hypothalamus may be responsible for the migraine syndrome (Herberg), possibly in connection with biogenic amines, remains in open question.
A severe headache can indicate a stroke, but it could signal a lot of other things too. Research presented today at the American Stroke Association’s 26th International Stroke Conference may help doctors tell the difference between a headache or migraine and a rare stroke called cerebral venous thrombosis (CVT). The American Stroke Association is a division of the American Heart Association.
Researchers at the University of San Paulo, Brazil have pinpointed some characteristics of headaches that indicate a CVT – the formation of a blood clot in a vein of the brain. While most clots occur in arteries (which carry blood from the heart to the rest of the body)blood clots in a vein (which carries blood to the heart) is an infrequent condition.
CVT is often difficult to diagnose because individuals may experience a wide range of symptoms including headaches, seizures or visual impairments. Symptoms can occur suddenly or progress for weeks.
“It is particularly important to recognize this condition early before the clot may spread in the cerebral venous system leading to other neurological complications such as – seizures, visual or motor deficits and increase of intracranial pressure,” says lead researcher írica C.S. de Camargo, M.D.
Headache is frequently the first symptom reported by patients arriving in emergency rooms. The Brazilian study aimed to identify the specific characteristics of CVT-related headache to help differentiate CVT from other conditions.
Thirty-nine patients (69 percent female, average age 35 years) were evaluated from March 1996 to June 2000. They were confirmed to have CVT by magnetic resonance imaging and/or angiography. Pertinent headache information such as location, severity and duration was recorded on a standardized form.
Seventy-four percent of patients with headaches also had weakness, sensory deficits, visual impairments or nausea. Most of the headaches were limited to one side of the head (63 percent) and pulsated (49 percent). Pain worsened with head movement (31 percent), physical activity (23 percent) and coughing or sneezing (20 percent).
Headache onset occurred within 48 hours before seeking medical treatment in 26 percent of patients, while 54 percent of patients reported having chronic headaches for more than 30 days.
Headache was the most common symptom (84.6 percent) given for seeking medical care among those studied. But almost half those individuals had experienced headaches before, which may have delayed a correct diagnosis.
Another finding was the presence of “thunderclap” headaches described as very severe and sudden headaches in 11.4 percent of patients and higher cerebrospinal fluid pressures in these patients as compared to those with severe, but not thunderclap, headaches.
The researchers found that in some CVT patients headaches may be sudden and severe mimicking subarachnoid hemorrhage — a type of stroke characterized by a blood vessel bleeding into the small space between the membranes surrounding the brain — or chronic migraine.
In individuals with prior headaches, changes in the characteristics of the headache as well as the presence of neurological signs are important clues to diagnosis, researchers say.
“An accurate diagnosis means patients can receive optimal treatment, including prompt anticoagulant therapy to managethe blood clot, which improves outcomes,” says Camargo.
Camargo acknowledges that the small sample size of this study and lack of a control group make the results less generalizable, but believes CVT is underecognized and should be included inthe diagnosis of headache in the emergency room. A larger ongoing international study is underway.