Trigeminal afferents and brainstem centers involved in the occurrence of cerebral vasospasm.

Cisternal injections of blood in the rat and squirrel monkey produce an angiographically demonstrable biphasic vasospasm with a maximal late spasm at two days in the rat and six days post-subarachnoid hemorrhage (SAH) in the monkey. The SAH induces a decrease in cerebral blood flow of about 25% and a corresponding increase in glucose uptake of between 30% and 50%. In about half of the animals low-flow areas were noted in the cortex and the basal ganglia with a corresponding marked increase in glucose uptake.

The haemodynamic effect of transcranial Doppler-guided high-dose nimodipine treatment in established vasospasm after subarachnoid haemorrhage.

Eleven patients (7 females) with aneurysmal subarachnoid haemorrhage (SAH) and transcranial Doppler (TCD) signs of vasospasm during prophylactic intravenous nimodipine treatment (2 mg/h) were treated with TCD-guided high-dose (4 mg/h) intravenous nimodipine. The patients were followed clinically and with serial TCD investigations. Increasing nimodipine to high-dose treatment led to a reduction of the abnormally elevated mean flow velocities (FV) in all patients.

Cerebral blood flow and glucose metabolism in the squirrel monkey during the late phase of cerebral vasospasm.

A double-isotope autoradiography technique was used to evaluate cerebral blood flow (CBF) and cerebral glucose metabolism (CMRglu) during the late phase of vasospasm in a squirrel monkey subarachnoid haemorrhage (SAH) model. Cisternal blood injections induced both global and focal changes in CBF and CMRglu six days following SAH, the timepoint of maximal late spasm in this model. There was a global decrease in CBF of about 30% accompanied by an increase in deoxyglucose uptake of about 50%.

Effect of spantide, a substance-P antagonist, on cerebral vasospasm in primates.

Experimental SAH in the squirrel monkey induces an angiographically demonstrable late spasm of about 23% at six days post subarachnoid haemorrhage (SAH). The late spasm is associated with a generalized reduction in cerebral blood flow (CBF) of about 30%. Intracisternal administration of the substance P (SP) antagonist spantide two hours and three days post SAH significantly reduces the degree of late spasm and also decreases the degree of CBF reduction.

Effect of pre- and postganglionic lesioning of the trigeminal nerve on cerebral blood flow and glucose metabolism following a subarachnoid haemorrhage in the squirrel monkey.

Simultaneous cerebral blood flow (CBF) and glucose metabolism (CMRglu) studies with a double isotope autoradiographic technique were applied to squirrel monkeys submitted to a unilateral pre- or postganglionic trigeminal lesion. The CBF values were not affected following a pre- or postganglionic lesion per se. In contrast, there was a global increase in the cerebral glucose uptake of about 50% as compared to controls following both kinds of lesions.