Cortical spreading depression aggravates early brain injury in a mouse model of subarachnoid hemorrhage

Intra-arterial lidocaine administration of lidocaine in middle meningeal artery for short-term treatment of subarachnoid hemorrhage-related headaches

BACKGROUND AND PURPOSE

We report short- and intermediate-term effects on headaches with intra-arterial injection of lidocaine in the middle meningeal artery in patients with severe headaches associated with subarachnoid hemorrhage.

METHODS

We treated seven patients with intra-arterial lidocaine in doses up to 50 mg in each middle meningeal artery via a microcatheter bilaterally (except in one patient). We recorded the maximum intensity of headache (graded by 11-point numeric rating scale) prior to procedure and every day for the next 10 days or discharge, whichever came first. We identified changes in the middle meningeal artery pre- and post-intra-arterial lidocaine administration and quantified from Grade 0 (no change) to Grade 5 (severe narrowing or near occlusion of anterior and posterior dural branches or proximal middle meningeal artery that precludes adequate imaging of distal branches).

RESULTS

We observed improvement in severity of headaches of headache in all seven subarachnoid hemorrhage patients. The resolution of headache was immediate and complete in four patients, unilateral immediate resolution in one patient, and delayed complete resolution in patient. Two patients met the definition of severe headache (defined as 2 or more days with maximum pain scores of 8 or greater or need for 3 or more different analgesics for 2 or more days) post-lidocaine treatment. One of these patients had are lapse in headache with the severity matching pretreatment severity and required a second treatment. On analysis of angiographic data, there was consistent narrowing of middle meningeal arteries after administration of intra-arterial lidocaine and was graded as 5 in 2 arteries, 4 in 10 arteries, and 3 in 2 arteries.

CONCLUSIONS

We found that intra-arterial injection of lidocaine can result in consistent amelioration of headache in patients with subarachnoid hemorrhage. The therapeutic benefit may be related to vasoconstriction (reversal of vasodilation) in the middle meningeal arteries after administration of lidocaine.

Understanding Headaches Attributed to Cranial and/or Cervical Vascular Disorders: Insights and Challenges for Neurologists

In recent decades, cranial and cervical vascular disorders have become major global health concerns, significantly impacting patients, families, and societies. Headache is a prevalent symptom of these vascular diseases and can often be the initial, primary, or sole manifestation. The intricate relationship between headaches and cranial/cervical vascular disorders poses a diagnostic and therapeutic challenge, with the underlying mechanisms remaining largely elusive. Understanding this association is crucial for the early diagnosis, prevention, and intervention of such conditions. This review aims to provide a comprehensive overview of the clinical features and potential pathogenesis of headaches attributed to cranial and cervical vascular disorders and provide a reference for disease management and a basis for potential pathological mechanisms.

Cortical Spreading Depolarization and Delayed Cerebral Ischemia; Rethinking Secondary Neurological Injury in Subarachnoid Hemorrhage

Poor outcomes in Subarachnoid Hemorrhage (SAH) are in part due to a unique form of secondary neurological injury known as Delayed Cerebral Ischemia (DCI). DCI is characterized by new neurological insults that continue to occur beyond 72 h after the onset of the hemorrhage. Historically, it was thought to be a consequence of hypoperfusion in the setting of vasospasm. However, DCI was found to occur even in the absence of radiographic evidence of vasospasm. More recent evidence indicates that catastrophic ionic disruptions known as Cortical Spreading Depolarizations (CSD) may be the culprits of DCI. CSDs occur in otherwise healthy brain tissue even without demonstrable vasospasm. Furthermore, CSDs often trigger a complex interplay of neuroinflammation, microthrombi formation, and vasoconstriction. CSDs may therefore represent measurable and modifiable prognostic factors in the prevention and treatment of DCI. Although Ketamine and Nimodipine have shown promise in the treatment and prevention of CSDs in SAH, further research is needed to determine the therapeutic potential of these as well as other agents.

Dynamic Measurements of Cerebral Blood Flow Responses to Cortical Spreading Depolarization in the Murine Endovascular Perforation Subarachnoid Hemorrhage Model

Delayed cerebral ischemia (DCI) is the most severe complication after subarachnoid hemorrhage (SAH), and cortical spreading depolarization (CSD) is believed to play a vital role in it. However, the dynamic changes in cerebral blood flow (CBF) in response to CSD in typical SAH models have not been well investigated. Here, SAH was established in mice with endovascular perforation. Subsequently, the spontaneous CBF dropped instantly and then returned to baseline rapidly. After KCl application to the cortex, subsequent hypoperfusion waves occurred across the groups, while a lower average perfusion level was found in the SAH groups (days 1-7). Moreover, in the SAH groups, the number of CSD decreased within day 7, and the duration and spreading velocity of the CSD increased within day 3 and day 14, respectively. Next, we continuously monitored the local field potential (LFP) in the prefrontal cortex. The results showed that the decrease in the percentage of gamma oscillations lasted throughout the whole process in the SAH group. In the chronic phase after SAH, we found that the mice still had cognitive deficits but experienced no obvious tissue damage. In summary, SAH negatively affects the CBF responses to CSD and the spontaneous LFP activity and causes long-term cognitive deficits in mice. Based on these findings, in the specific phase after SAH, DCI is induced or exacerbated more easily by potential causers of CSD in clinical practice (edema, erythrocytolysis, inflammation), which may lead to neurological deterioration.